use std::{fs, path::Path, sync::Arc};

use aes::Aes256;
use axum::{
    Json,
    extract::{Query, State},
    http::{HeaderMap, HeaderValue, StatusCode, header::CONTENT_TYPE},
    response::{IntoResponse, Response},
};
use base64::{
    Engine as _, alphabet,
    engine::general_purpose::{GeneralPurpose, GeneralPurposeConfig, STANDARD as BASE64_STANDARD},
};
use bytes::Bytes;
use cbc::cipher::{BlockDecryptMut, KeyIvInit, block_padding::NoPadding};
use ring::{
    aead,
    rand::{SecureRandom, SystemRandom},
    signature,
};
use serde::{Deserialize, Serialize};
use serde_json::{Value, json};
use sha1::Sha1;
use sha2::{Digest, Sha256};
use shared_contracts::runtime::{
    WechatH5PaymentResponse, WechatMiniProgramPayParamsResponse, WechatNativePaymentResponse,
};
use shared_kernel::offset_datetime_to_unix_micros;
use std::convert::TryInto;
use time::OffsetDateTime;
use tracing::{info, warn};
use url::Url;

use crate::{http_error::AppError, state::AppState};

const WECHAT_PAY_PROVIDER_MOCK: &str = "mock";
const WECHAT_PAY_PROVIDER_REAL: &str = "real";
const WECHAT_PAY_BODY_SIGNATURE_METHOD: &str = "WECHATPAY2-SHA256-RSA2048";
const WECHAT_PAY_PAY_SIGN_TYPE: &str = "RSA";
const WECHAT_PAY_ACCEPT_HEADER: &str = "application/json";
const WECHAT_PAY_CONTENT_TYPE_HEADER: &str = "application/json";
const WECHAT_PAY_USER_AGENT: &str = "Genarrative-WechatPay/1.0";
const WECHAT_PAY_SERIAL_HEADER: &str = "Wechatpay-Serial";
const WECHAT_PAY_SIGNATURE_TEST_PREFIX: &str = "WECHATPAY/SIGNTEST/";
const WECHAT_PAY_APP_ID_MAX_CHARS: usize = 32;
const WECHAT_PAY_MCH_ID_MAX_CHARS: usize = 32;
const WECHAT_PAY_DESCRIPTION_MAX_CHARS: usize = 127;
const WECHAT_PAY_OUT_TRADE_NO_MAX_CHARS: usize = 32;
const WECHAT_PAY_NOTIFY_URL_MAX_CHARS: usize = 255;
const WECHAT_PAY_OPENID_MAX_CHARS: usize = 128;
const WECHAT_PAY_CLIENT_IP_MAX_CHARS: usize = 45;
const WECHAT_PAY_JSAPI_PATH: &str = "/v3/pay/transactions/jsapi";
const WECHAT_PAY_H5_PATH: &str = "/v3/pay/transactions/h5";
const WECHAT_PAY_NATIVE_PATH: &str = "/v3/pay/transactions/native";
const WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY_BYTES: usize = 43;
const WECHAT_MINIPROGRAM_MESSAGE_AES_KEY_BYTES: usize = 32;
const WECHAT_MINIPROGRAM_MESSAGE_RANDOM_BYTES: usize = 16;
const WECHAT_MINIPROGRAM_MESSAGE_LENGTH_BYTES: usize = 4;
const WECHAT_MINIPROGRAM_MESSAGE_AES_KEY_BASE64: GeneralPurpose = GeneralPurpose::new(
    &alphabet::STANDARD,
    GeneralPurposeConfig::new().with_decode_allow_trailing_bits(true),
);

#[derive(Clone, Debug)]
pub enum WechatPayClient {
    Disabled,
    Mock,
    Real(Arc<RealWechatPayClient>),
}

#[derive(Clone, Debug)]
pub struct RealWechatPayClient {
    client: reqwest::Client,
    app_id: String,
    mch_id: String,
    merchant_serial_no: String,
    private_key: Arc<signature::RsaKeyPair>,
    platform_public_key_der: Vec<u8>,
    platform_serial_no: String,
    api_v3_key: String,
    notify_url: String,
    jsapi_endpoint: String,
    h5_endpoint: String,
    native_endpoint: String,
    query_order_endpoint_base: String,
}

#[derive(Clone, Debug)]
pub struct WechatMiniProgramOrderRequest {
    pub order_id: String,
    pub description: String,
    pub amount_cents: u64,
    pub payer_openid: String,
}

#[derive(Clone, Debug)]
pub struct WechatWebOrderRequest {
    pub order_id: String,
    pub description: String,
    pub amount_cents: u64,
    pub payer_client_ip: String,
}

#[derive(Clone, Debug)]
pub struct WechatPayNotifyOrder {
    pub out_trade_no: String,
    pub transaction_id: Option<String>,
    pub trade_state: String,
    pub success_time: Option<String>,
}

#[derive(Clone, Debug, PartialEq, Eq)]
struct WechatVirtualPaymentNotifyOrder {
    out_trade_no: String,
    transaction_id: Option<String>,
    paid_at_micros: Option<i64>,
    event: String,
}

#[derive(Serialize)]
pub struct WechatVirtualPaymentNotifyResponse {
    #[serde(rename = "ErrCode")]
    err_code: i32,
    #[serde(rename = "ErrMsg")]
    err_msg: String,
}

#[derive(Debug)]
pub enum WechatPayError {
    Disabled,
    InvalidConfig(String),
    InvalidRequest(String),
    RequestFailed(String),
    Upstream(String),
    Deserialize(String),
    Crypto(String),
    InvalidSignature(String),
}

#[derive(Serialize)]
struct WechatJsapiOrderRequest<'a> {
    appid: &'a str,
    mchid: &'a str,
    description: &'a str,
    out_trade_no: &'a str,
    notify_url: &'a str,
    amount: WechatJsapiAmount,
    payer: WechatJsapiPayer<'a>,
}

#[derive(Serialize)]
struct WechatJsapiAmount {
    total: i64,
    currency: &'static str,
}

#[derive(Serialize)]
struct WechatJsapiPayer<'a> {
    openid: &'a str,
}

#[derive(Serialize)]
struct WechatH5OrderRequest<'a> {
    appid: &'a str,
    mchid: &'a str,
    description: &'a str,
    out_trade_no: &'a str,
    notify_url: &'a str,
    amount: WechatJsapiAmount,
    scene_info: WechatH5SceneInfo<'a>,
}

#[derive(Serialize)]
struct WechatH5SceneInfo<'a> {
    payer_client_ip: &'a str,
    h5_info: WechatH5Info,
}

#[derive(Serialize)]
struct WechatH5Info {
    #[serde(rename = "type")]
    kind: &'static str,
}

#[derive(Serialize)]
struct WechatNativeOrderRequest<'a> {
    appid: &'a str,
    mchid: &'a str,
    description: &'a str,
    out_trade_no: &'a str,
    notify_url: &'a str,
    amount: WechatJsapiAmount,
    scene_info: WechatNativeSceneInfo<'a>,
}

#[derive(Serialize)]
struct WechatNativeSceneInfo<'a> {
    payer_client_ip: &'a str,
}

#[derive(Deserialize)]
struct WechatJsapiOrderResponse {
    prepay_id: Option<String>,
    code: Option<String>,
    message: Option<String>,
}

#[derive(Deserialize)]
struct WechatH5OrderResponse {
    h5_url: Option<String>,
    code: Option<String>,
    message: Option<String>,
}

#[derive(Deserialize)]
struct WechatNativeOrderResponse {
    code_url: Option<String>,
    code: Option<String>,
    message: Option<String>,
}

#[derive(Deserialize)]
struct WechatPayNotifyBody {
    #[serde(default)]
    resource: Option<WechatPayNotifyResource>,
}

#[derive(Deserialize)]
struct WechatPayNotifyResource {
    ciphertext: String,
    nonce: String,
    #[serde(default)]
    associated_data: Option<String>,
}

#[derive(Deserialize)]
struct WechatPayTransactionResource {
    out_trade_no: String,
    #[serde(default)]
    transaction_id: Option<String>,
    trade_state: String,
    #[serde(default)]
    success_time: Option<String>,
}

#[derive(Deserialize)]
struct WechatPayQueryOrderResponse {
    out_trade_no: String,
    #[serde(default)]
    transaction_id: Option<String>,
    trade_state: String,
    #[serde(default)]
    success_time: Option<String>,
}

#[derive(Deserialize)]
struct WechatVirtualPaymentNotifyBody {
    #[serde(rename = "Event", alias = "event")]
    event: String,
    #[serde(rename = "OutTradeNo", alias = "out_trade_no", default)]
    out_trade_no: Option<String>,
    #[serde(rename = "MchOrderId", alias = "mch_order_id", default)]
    mch_order_id: Option<String>,
    #[serde(rename = "WeChatPayInfo", alias = "wechat_pay_info", default)]
    wechat_pay_info: Option<WechatVirtualPaymentNotifyPayInfo>,
}

#[derive(Deserialize)]
struct WechatVirtualPaymentNotifyPayInfo {
    #[serde(rename = "MchOrderNo", alias = "mch_order_no", default)]
    mch_order_no: Option<String>,
    #[serde(rename = "TransactionId", alias = "transaction_id", default)]
    transaction_id: Option<String>,
    #[serde(rename = "PaidTime", alias = "paid_time", default)]
    paid_time: Option<i64>,
}

#[derive(Debug, Deserialize)]
pub(crate) struct WechatMiniProgramMessagePushQuery {
    signature: Option<String>,
    timestamp: Option<String>,
    nonce: Option<String>,
    echostr: Option<String>,
    msg_signature: Option<String>,
}

#[derive(Debug, Deserialize)]
struct WechatMiniProgramEncryptedMessage {
    #[serde(rename = "ToUserName", alias = "to_user_name", default)]
    to_user_name: Option<String>,
    #[serde(rename = "Encrypt", alias = "encrypt")]
    encrypt: String,
}

impl WechatPayClient {
    pub fn from_config(config: &crate::config::AppConfig) -> Result<Self, WechatPayError> {
        if !config.wechat_pay_enabled {
            return Ok(Self::Disabled);
        }

        if config
            .wechat_pay_provider
            .trim()
            .eq_ignore_ascii_case(WECHAT_PAY_PROVIDER_MOCK)
        {
            return Ok(Self::Mock);
        }

        if !config
            .wechat_pay_provider
            .trim()
            .eq_ignore_ascii_case(WECHAT_PAY_PROVIDER_REAL)
        {
            return Err(WechatPayError::InvalidConfig(
                "WECHAT_PAY_PROVIDER 仅支持 mock 或 real".to_string(),
            ));
        }

        let app_id = config
            .wechat_mini_program_app_id
            .as_ref()
            .or(config.wechat_app_id.as_ref())
            .map(|value| value.trim())
            .filter(|value| !value.is_empty())
            .ok_or_else(|| WechatPayError::InvalidConfig("微信支付缺少小程序 AppID".to_string()))?
            .to_string();
        let mch_id = required_config(config.wechat_pay_mch_id.as_deref(), "WECHAT_PAY_MCH_ID")?;
        let merchant_serial_no = required_config(
            config.wechat_pay_merchant_serial_no.as_deref(),
            "WECHAT_PAY_MERCHANT_SERIAL_NO",
        )?;
        let private_key_pem = read_private_key_pem(
            config.wechat_pay_private_key_pem.as_deref(),
            config.wechat_pay_private_key_path.as_deref(),
        )?;
        let private_key = Arc::new(parse_rsa_private_key(&private_key_pem)?);
        let platform_public_key_pem = read_pem(
            config.wechat_pay_platform_public_key_pem.as_deref(),
            config.wechat_pay_platform_public_key_path.as_deref(),
            "WECHAT_PAY_PLATFORM_PUBLIC_KEY_PEM 或 WECHAT_PAY_PLATFORM_PUBLIC_KEY_PATH 未配置",
            "读取微信支付平台公钥失败",
        )?;
        let platform_public_key_der = parse_public_key_pem(&platform_public_key_pem)?;
        let platform_serial_no = required_config(
            config.wechat_pay_platform_serial_no.as_deref(),
            "WECHAT_PAY_PLATFORM_SERIAL_NO",
        )?;
        let api_v3_key = required_config(
            config.wechat_pay_api_v3_key.as_deref(),
            "WECHAT_PAY_API_V3_KEY",
        )?;
        if api_v3_key.as_bytes().len() != 32 {
            return Err(WechatPayError::InvalidConfig(
                "WECHAT_PAY_API_V3_KEY 必须是 32 字节字符串".to_string(),
            ));
        }
        let notify_url = required_config(
            config.wechat_pay_notify_url.as_deref(),
            "WECHAT_PAY_NOTIFY_URL",
        )?;
        validate_notify_url(&notify_url, "WECHAT_PAY_NOTIFY_URL")?;
        let jsapi_endpoint = normalize_required_url(
            &config.wechat_pay_jsapi_endpoint,
            "WECHAT_PAY_JSAPI_ENDPOINT",
        )?;
        let h5_endpoint =
            resolve_wechat_pay_transaction_endpoint(&jsapi_endpoint, WECHAT_PAY_H5_PATH)?;
        let native_endpoint =
            resolve_wechat_pay_transaction_endpoint(&jsapi_endpoint, WECHAT_PAY_NATIVE_PATH)?;
        let query_order_endpoint_base = resolve_query_order_endpoint_base(&jsapi_endpoint)?;

        Ok(Self::Real(Arc::new(RealWechatPayClient {
            client: reqwest::Client::new(),
            app_id,
            mch_id,
            merchant_serial_no,
            private_key,
            platform_public_key_der,
            platform_serial_no,
            api_v3_key,
            notify_url,
            jsapi_endpoint,
            h5_endpoint,
            native_endpoint,
            query_order_endpoint_base,
        })))
    }

    pub async fn create_mini_program_order(
        &self,
        request: WechatMiniProgramOrderRequest,
    ) -> Result<WechatMiniProgramPayParamsResponse, WechatPayError> {
        match self {
            Self::Disabled => Err(WechatPayError::Disabled),
            Self::Mock => Ok(build_mock_pay_params(&request.order_id)),
            Self::Real(client) => client.create_mini_program_order(request).await,
        }
    }

    pub async fn create_h5_order(
        &self,
        request: WechatWebOrderRequest,
    ) -> Result<WechatH5PaymentResponse, WechatPayError> {
        match self {
            Self::Disabled => Err(WechatPayError::Disabled),
            Self::Mock => Ok(build_mock_h5_payment(&request.order_id)),
            Self::Real(client) => client.create_h5_order(request).await,
        }
    }

    pub async fn create_native_order(
        &self,
        request: WechatWebOrderRequest,
    ) -> Result<WechatNativePaymentResponse, WechatPayError> {
        match self {
            Self::Disabled => Err(WechatPayError::Disabled),
            Self::Mock => Ok(build_mock_native_payment(&request.order_id)),
            Self::Real(client) => client.create_native_order(request).await,
        }
    }

    pub fn parse_notify(
        &self,
        headers: &HeaderMap,
        body: &[u8],
    ) -> Result<WechatPayNotifyOrder, WechatPayError> {
        match self {
            Self::Disabled => Err(WechatPayError::Disabled),
            Self::Mock => parse_mock_notify(body),
            Self::Real(client) => client.parse_notify(headers, body),
        }
    }

    pub async fn query_order_by_out_trade_no(
        &self,
        order_id: &str,
    ) -> Result<WechatPayNotifyOrder, WechatPayError> {
        match self {
            Self::Disabled => Err(WechatPayError::Disabled),
            Self::Mock => Ok(WechatPayNotifyOrder {
                out_trade_no: normalize_out_trade_no(order_id)?,
                transaction_id: Some(format!("mock-{order_id}")),
                trade_state: "SUCCESS".to_string(),
                success_time: Some(OffsetDateTime::now_utc().to_string()),
            }),
            Self::Real(client) => client.query_order_by_out_trade_no(order_id).await,
        }
    }
}

impl RealWechatPayClient {
    async fn create_mini_program_order(
        &self,
        request: WechatMiniProgramOrderRequest,
    ) -> Result<WechatMiniProgramPayParamsResponse, WechatPayError> {
        validate_jsapi_order_request(self, &request)?;
        let amount_total = i64::try_from(request.amount_cents)
            .map_err(|_| WechatPayError::InvalidRequest("微信支付金额超出 i64 范围".to_string()))?;
        let body = serde_json::to_string(&WechatJsapiOrderRequest {
            appid: &self.app_id,
            mchid: &self.mch_id,
            description: &request.description,
            out_trade_no: &request.order_id,
            notify_url: &self.notify_url,
            amount: WechatJsapiAmount {
                total: amount_total,
                currency: "CNY",
            },
            payer: WechatJsapiPayer {
                openid: &request.payer_openid,
            },
        })
        .map_err(|error| WechatPayError::Deserialize(format!("微信支付请求序列化失败：{error}")))?;
        let timestamp = OffsetDateTime::now_utc().unix_timestamp().to_string();
        let nonce = create_nonce()?;
        let authorization =
            self.build_authorization("POST", WECHAT_PAY_JSAPI_PATH, &timestamp, &nonce, &body)?;
        let response = with_wechat_pay_jsapi_headers(
            self.client
                .post(&self.jsapi_endpoint)
                .header("Authorization", authorization),
            &self.platform_serial_no,
        )
        .body(body)
        .send()
        .await
        .map_err(|error| {
            WechatPayError::RequestFailed(format!("微信支付 JSAPI 下单请求失败：{error}"))
        })?;
        let status = response.status();
        let response_text = response.text().await.map_err(|error| {
            WechatPayError::Deserialize(format!("微信支付 JSAPI 下单响应读取失败：{error}"))
        })?;
        let payload =
            serde_json::from_str::<WechatJsapiOrderResponse>(&response_text).map_err(|error| {
                WechatPayError::Deserialize(format!("微信支付 JSAPI 下单响应解析失败：{error}"))
            })?;

        if !status.is_success() {
            return Err(WechatPayError::Upstream(format!(
                "微信支付 JSAPI 下单失败：{}",
                payload
                    .message
                    .or(payload.code)
                    .unwrap_or_else(|| format!("HTTP {status}"))
            )));
        }

        let prepay_id = payload
            .prepay_id
            .map(|value| value.trim().to_string())
            .filter(|value| !value.is_empty())
            .ok_or_else(|| WechatPayError::Upstream("微信支付未返回 prepay_id".to_string()))?;
        self.build_pay_params(&prepay_id)
    }

    async fn create_h5_order(
        &self,
        request: WechatWebOrderRequest,
    ) -> Result<WechatH5PaymentResponse, WechatPayError> {
        validate_web_order_request(self, &request)?;
        let amount_total = i64::try_from(request.amount_cents)
            .map_err(|_| WechatPayError::InvalidRequest("微信支付金额超出 i64 范围".to_string()))?;
        let body = serde_json::to_string(&WechatH5OrderRequest {
            appid: &self.app_id,
            mchid: &self.mch_id,
            description: &request.description,
            out_trade_no: &request.order_id,
            notify_url: &self.notify_url,
            amount: WechatJsapiAmount {
                total: amount_total,
                currency: "CNY",
            },
            scene_info: WechatH5SceneInfo {
                payer_client_ip: &request.payer_client_ip,
                h5_info: WechatH5Info { kind: "Wap" },
            },
        })
        .map_err(|error| {
            WechatPayError::Deserialize(format!("微信支付 H5 请求序列化失败：{error}"))
        })?;
        let response_text = self
            .post_wechat_json(
                &self.h5_endpoint,
                WECHAT_PAY_H5_PATH,
                body,
                "微信支付 H5 下单请求失败",
            )
            .await?;
        let payload =
            serde_json::from_str::<WechatH5OrderResponse>(&response_text).map_err(|error| {
                WechatPayError::Deserialize(format!("微信支付 H5 下单响应解析失败：{error}"))
            })?;
        let h5_url = payload
            .h5_url
            .map(|value| value.trim().to_string())
            .filter(|value| !value.is_empty())
            .ok_or_else(|| {
                WechatPayError::Upstream(
                    payload
                        .message
                        .or(payload.code)
                        .unwrap_or_else(|| "微信支付未返回 h5_url".to_string()),
                )
            })?;

        Ok(WechatH5PaymentResponse { h5_url })
    }

    async fn create_native_order(
        &self,
        request: WechatWebOrderRequest,
    ) -> Result<WechatNativePaymentResponse, WechatPayError> {
        validate_web_order_request(self, &request)?;
        let amount_total = i64::try_from(request.amount_cents)
            .map_err(|_| WechatPayError::InvalidRequest("微信支付金额超出 i64 范围".to_string()))?;
        let body = serde_json::to_string(&WechatNativeOrderRequest {
            appid: &self.app_id,
            mchid: &self.mch_id,
            description: &request.description,
            out_trade_no: &request.order_id,
            notify_url: &self.notify_url,
            amount: WechatJsapiAmount {
                total: amount_total,
                currency: "CNY",
            },
            scene_info: WechatNativeSceneInfo {
                payer_client_ip: &request.payer_client_ip,
            },
        })
        .map_err(|error| {
            WechatPayError::Deserialize(format!("微信支付 Native 请求序列化失败：{error}"))
        })?;
        let response_text = self
            .post_wechat_json(
                &self.native_endpoint,
                WECHAT_PAY_NATIVE_PATH,
                body,
                "微信支付 Native 下单请求失败",
            )
            .await?;
        let payload =
            serde_json::from_str::<WechatNativeOrderResponse>(&response_text).map_err(|error| {
                WechatPayError::Deserialize(format!("微信支付 Native 下单响应解析失败：{error}"))
            })?;
        let code_url = payload
            .code_url
            .map(|value| value.trim().to_string())
            .filter(|value| !value.is_empty())
            .ok_or_else(|| {
                WechatPayError::Upstream(
                    payload
                        .message
                        .or(payload.code)
                        .unwrap_or_else(|| "微信支付未返回 code_url".to_string()),
                )
            })?;

        Ok(WechatNativePaymentResponse { code_url })
    }

    async fn post_wechat_json(
        &self,
        endpoint: &str,
        canonical_path: &str,
        body: String,
        request_error_prefix: &str,
    ) -> Result<String, WechatPayError> {
        let timestamp = OffsetDateTime::now_utc().unix_timestamp().to_string();
        let nonce = create_nonce()?;
        let authorization =
            self.build_authorization("POST", canonical_path, &timestamp, &nonce, &body)?;
        let response = with_wechat_pay_json_headers(
            self.client
                .post(endpoint)
                .header("Authorization", authorization),
            &self.platform_serial_no,
        )
        .body(body)
        .send()
        .await
        .map_err(|error| {
            WechatPayError::RequestFailed(format!("{request_error_prefix}：{error}"))
        })?;
        let status = response.status();
        let response_text = response.text().await.map_err(|error| {
            WechatPayError::Deserialize(format!("微信支付响应读取失败：{error}"))
        })?;
        if !status.is_success() {
            return Err(WechatPayError::Upstream(format!(
                "微信支付下单失败：HTTP {status}，{response_text}"
            )));
        }

        Ok(response_text)
    }

    fn build_authorization(
        &self,
        method: &str,
        canonical_url: &str,
        timestamp: &str,
        nonce: &str,
        body: &str,
    ) -> Result<String, WechatPayError> {
        let message = format!("{method}\n{canonical_url}\n{timestamp}\n{nonce}\n{body}\n");
        let signature = self.sign_message(&message)?;
        Ok(format!(
            "{WECHAT_PAY_BODY_SIGNATURE_METHOD} mchid=\"{}\",nonce_str=\"{}\",timestamp=\"{}\",serial_no=\"{}\",signature=\"{}\"",
            self.mch_id, nonce, timestamp, self.merchant_serial_no, signature
        ))
    }

    fn build_pay_params(
        &self,
        prepay_id: &str,
    ) -> Result<WechatMiniProgramPayParamsResponse, WechatPayError> {
        let time_stamp = OffsetDateTime::now_utc().unix_timestamp().to_string();
        let nonce_str = create_nonce()?;
        let package = format!("prepay_id={prepay_id}");
        let message = format!(
            "{}\n{}\n{}\n{}\n",
            self.app_id, time_stamp, nonce_str, package
        );
        let pay_sign = self.sign_message(&message)?;

        Ok(WechatMiniProgramPayParamsResponse {
            time_stamp,
            nonce_str,
            package,
            sign_type: WECHAT_PAY_PAY_SIGN_TYPE.to_string(),
            pay_sign,
        })
    }

    fn parse_notify(
        &self,
        headers: &HeaderMap,
        body: &[u8],
    ) -> Result<WechatPayNotifyOrder, WechatPayError> {
        self.verify_notify_signature(headers, body)?;
        let notify = serde_json::from_slice::<WechatPayNotifyBody>(body).map_err(|error| {
            WechatPayError::Deserialize(format!("微信支付通知解析失败：{error}"))
        })?;
        let resource = notify.resource.ok_or_else(|| {
            WechatPayError::InvalidRequest("微信支付通知缺少 resource".to_string())
        })?;
        let plain_text = decrypt_aes_256_gcm(
            self.api_v3_key.as_bytes(),
            resource.nonce.as_bytes(),
            resource.associated_data.as_deref().unwrap_or("").as_bytes(),
            resource.ciphertext.as_str(),
        )?;
        let transaction = serde_json::from_slice::<WechatPayTransactionResource>(&plain_text)
            .map_err(|error| {
                WechatPayError::Deserialize(format!("微信支付通知资源解析失败：{error}"))
            })?;

        Ok(WechatPayNotifyOrder {
            out_trade_no: transaction.out_trade_no,
            transaction_id: transaction
                .transaction_id
                .map(|value| value.trim().to_string())
                .filter(|value| !value.is_empty()),
            trade_state: transaction.trade_state,
            success_time: transaction.success_time,
        })
    }

    async fn query_order_by_out_trade_no(
        &self,
        order_id: &str,
    ) -> Result<WechatPayNotifyOrder, WechatPayError> {
        let order_id = normalize_out_trade_no(order_id)?;
        let path = format!(
            "/v3/pay/transactions/out-trade-no/{}?mchid={}",
            urlencoding::encode(&order_id),
            urlencoding::encode(&self.mch_id),
        );
        let request_url = format!(
            "{}/{}?mchid={}",
            self.query_order_endpoint_base.trim_end_matches('/'),
            urlencoding::encode(&order_id),
            urlencoding::encode(&self.mch_id),
        );
        let timestamp = OffsetDateTime::now_utc().unix_timestamp().to_string();
        let nonce = create_nonce()?;
        let authorization = self.build_authorization("GET", &path, &timestamp, &nonce, "")?;
        let response = with_wechat_pay_json_headers(
            self.client
                .get(request_url)
                .header("Authorization", authorization),
            &self.platform_serial_no,
        )
        .send()
        .await
        .map_err(|error| WechatPayError::RequestFailed(format!("微信支付查单请求失败：{error}")))?;
        let status = response.status();
        let response_text = response.text().await.map_err(|error| {
            WechatPayError::Deserialize(format!("微信支付查单响应读取失败：{error}"))
        })?;
        if !status.is_success() {
            return Err(WechatPayError::Upstream(format!(
                "微信支付查单失败：HTTP {status}，{response_text}"
            )));
        }
        let payload = serde_json::from_str::<WechatPayQueryOrderResponse>(&response_text).map_err(
            |error| WechatPayError::Deserialize(format!("微信支付查单响应解析失败：{error}")),
        )?;

        Ok(WechatPayNotifyOrder {
            out_trade_no: payload.out_trade_no,
            transaction_id: payload
                .transaction_id
                .map(|value| value.trim().to_string())
                .filter(|value| !value.is_empty()),
            trade_state: payload.trade_state,
            success_time: payload.success_time,
        })
    }

    fn verify_notify_signature(
        &self,
        headers: &HeaderMap,
        body: &[u8],
    ) -> Result<(), WechatPayError> {
        let timestamp = read_required_header(headers, "Wechatpay-Timestamp")?;
        let nonce = read_required_header(headers, "Wechatpay-Nonce")?;
        let signature = read_required_header(headers, "Wechatpay-Signature")?;
        let serial = read_required_header(headers, "Wechatpay-Serial")?;
        if serial != self.platform_serial_no {
            warn!(
                received_serial = serial,
                configured_serial = self.platform_serial_no.as_str(),
                "微信支付通知平台公钥序列号不匹配"
            );
            return Err(WechatPayError::InvalidSignature(format!(
                "微信支付通知平台公钥序列号不匹配：received={serial}"
            )));
        }
        if signature.starts_with(WECHAT_PAY_SIGNATURE_TEST_PREFIX) {
            warn!("收到微信支付签名探测通知");
            return Err(WechatPayError::InvalidSignature(
                "微信支付签名探测通知".to_string(),
            ));
        }

        let message = build_notify_signature_message(timestamp.as_bytes(), nonce.as_bytes(), body);
        let signature_bytes = BASE64_STANDARD.decode(signature).map_err(|_| {
            WechatPayError::InvalidSignature("微信支付通知签名 base64 无效".to_string())
        })?;
        let public_key = signature::UnparsedPublicKey::new(
            &signature::RSA_PKCS1_2048_8192_SHA256,
            &self.platform_public_key_der,
        );
        public_key
            .verify(&message, &signature_bytes)
            .map_err(|_| WechatPayError::InvalidSignature("微信支付通知签名验签失败".to_string()))
    }

    fn sign_message(&self, message: &str) -> Result<String, WechatPayError> {
        let rng = SystemRandom::new();
        let mut signature = vec![0_u8; self.private_key.public().modulus_len()];
        self.private_key
            .sign(
                &signature::RSA_PKCS1_SHA256,
                &rng,
                message.as_bytes(),
                &mut signature,
            )
            .map_err(|_| WechatPayError::Crypto("微信支付签名失败".to_string()))?;
        Ok(BASE64_STANDARD.encode(signature))
    }
}

pub async fn handle_wechat_pay_notify(
    State(state): State<AppState>,
    headers: HeaderMap,
    body: Bytes,
) -> Result<StatusCode, AppError> {
    let notify = state
        .wechat_pay_client()
        .parse_notify(&headers, &body)
        .map_err(map_wechat_pay_notify_error)?;
    if notify.trade_state != "SUCCESS" {
        info!(
            order_id = notify.out_trade_no.as_str(),
            trade_state = notify.trade_state.as_str(),
            "收到非成功微信支付通知"
        );
        return Ok(StatusCode::NO_CONTENT);
    }

    let paid_at_micros = notify
        .success_time
        .as_deref()
        .and_then(|value| shared_kernel::parse_rfc3339(value).ok())
        .map(offset_datetime_to_unix_micros)
        .unwrap_or_else(current_unix_micros);

    state
        .spacetime_client()
        .mark_profile_recharge_order_paid(
            notify.out_trade_no.clone(),
            paid_at_micros,
            notify.transaction_id.clone(),
        )
        .await
        .map_err(|error| {
            AppError::from_status(StatusCode::BAD_GATEWAY)
                .with_message(format!("确认微信支付订单失败：{error}"))
        })?;
    info!(
        order_id = notify.out_trade_no.as_str(),
        "微信支付通知已确认订单入账"
    );

    Ok(StatusCode::NO_CONTENT)
}

pub async fn handle_wechat_virtual_payment_message_push_verify(
    State(state): State<AppState>,
    Query(query): Query<WechatMiniProgramMessagePushQuery>,
) -> Response {
    let token = match read_wechat_message_push_config(
        state.config.wechat_mini_program_message_token.as_deref(),
        "WECHAT_MINIPROGRAM_MESSAGE_TOKEN",
    ) {
        Ok(token) => token,
        Err(error) => return build_wechat_message_push_verify_error_response(error),
    };
    let aes_key = match read_wechat_message_push_config(
        state
            .config
            .wechat_mini_program_message_encoding_aes_key
            .as_deref(),
        "WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY",
    ) {
        Ok(value) => value,
        Err(error) => return build_wechat_message_push_verify_error_response(error),
    };
    match resolve_wechat_message_push_verify_response(
        token,
        aes_key,
        state
            .config
            .wechat_mini_program_app_id
            .as_deref()
            .or(state.config.wechat_app_id.as_deref()),
        &query,
    ) {
        Ok(plaintext) => (StatusCode::OK, plaintext).into_response(),
        Err(error) => build_wechat_message_push_verify_error_response(error),
    }
}

pub async fn handle_wechat_virtual_payment_notify(
    State(state): State<AppState>,
    headers: HeaderMap,
    Query(query): Query<WechatMiniProgramMessagePushQuery>,
    body: Bytes,
) -> Response {
    let response_format = detect_virtual_payment_notify_response_format(&headers, &body);
    let encrypted_payload = match parse_wechat_mini_program_message_push_payload(&body) {
        Ok(payload) => payload,
        Err(error) => return build_virtual_payment_notify_error_response(error, response_format),
    };
    let token = match read_wechat_message_push_config(
        state.config.wechat_mini_program_message_token.as_deref(),
        "WECHAT_MINIPROGRAM_MESSAGE_TOKEN",
    ) {
        Ok(token) => token,
        Err(error) => return build_virtual_payment_notify_error_response(error, response_format),
    };
    let aes_key = match read_wechat_message_push_config(
        state
            .config
            .wechat_mini_program_message_encoding_aes_key
            .as_deref(),
        "WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY",
    ) {
        Ok(value) => value,
        Err(error) => return build_virtual_payment_notify_error_response(error, response_format),
    };
    let signature = query
        .msg_signature
        .as_deref()
        .or(query.signature.as_deref())
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .unwrap_or("");
    let timestamp = query.timestamp.as_deref().map(str::trim).unwrap_or("");
    let nonce = query.nonce.as_deref().map(str::trim).unwrap_or("");
    if signature.is_empty() || timestamp.is_empty() || nonce.is_empty() {
        return build_virtual_payment_notify_error_response(
            WechatPayError::InvalidRequest("微信消息推送加密参数不完整".to_string()),
            response_format,
        );
    }
    if !verify_wechat_message_push_signature(
        token,
        timestamp,
        nonce,
        encrypted_payload.encrypt.as_str(),
        signature,
    ) {
        return build_virtual_payment_notify_error_response(
            WechatPayError::InvalidSignature("微信消息推送 msg_signature 无效".to_string()),
            response_format,
        );
    }
    let notify_body = match decrypt_wechat_message_push_ciphertext(
        aes_key,
        encrypted_payload.encrypt.as_str(),
        state
            .config
            .wechat_mini_program_app_id
            .as_deref()
            .or(state.config.wechat_app_id.as_deref()),
    ) {
        Ok(body) => body,
        Err(error) => return build_virtual_payment_notify_error_response(error, response_format),
    };
    let notify = match parse_virtual_payment_notify(notify_body.as_bytes()) {
        Ok(notify) => notify,
        Err(error) => return build_virtual_payment_notify_error_response(error, response_format),
    };
    if notify.event != "xpay_goods_deliver_notify" && notify.event != "xpay_coin_pay_notify" {
        info!(
            event = notify.event.as_str(),
            order_id = notify.out_trade_no.as_str(),
            "收到非订单入账虚拟支付推送"
        );
        return build_virtual_payment_notify_success_response(response_format);
    }

    let paid_at_micros = notify.paid_at_micros.unwrap_or_else(current_unix_micros);
    if state
        .spacetime_client()
        .mark_profile_recharge_order_paid(
            notify.out_trade_no.clone(),
            paid_at_micros,
            notify.transaction_id.clone(),
        )
        .await
        .is_err()
    {
        warn!(
            order_id = notify.out_trade_no.as_str(),
            "确认微信虚拟支付订单失败"
        );
        return build_virtual_payment_notify_error_response(
            WechatPayError::Upstream("确认微信虚拟支付订单失败".to_string()),
            response_format,
        );
    }

    state.publish_profile_recharge_order_update(notify.out_trade_no.clone());

    info!(
        event = notify.event.as_str(),
        order_id = notify.out_trade_no.as_str(),
        "微信虚拟支付推送已确认订单入账"
    );

    build_virtual_payment_notify_success_response(response_format)
}

pub fn map_wechat_pay_error(error: WechatPayError) -> AppError {
    match error {
        WechatPayError::Disabled => AppError::from_status(StatusCode::BAD_REQUEST)
            .with_message("微信支付暂未启用")
            .with_details(json!({ "provider": "wechat_pay" })),
        WechatPayError::InvalidConfig(message) => {
            AppError::from_status(StatusCode::SERVICE_UNAVAILABLE)
                .with_message(message)
                .with_details(json!({ "provider": "wechat_pay" }))
        }
        WechatPayError::InvalidRequest(message) => AppError::from_status(StatusCode::BAD_REQUEST)
            .with_message(message)
            .with_details(json!({ "provider": "wechat_pay" })),
        WechatPayError::RequestFailed(message)
        | WechatPayError::Upstream(message)
        | WechatPayError::Deserialize(message)
        | WechatPayError::Crypto(message) => AppError::from_status(StatusCode::BAD_GATEWAY)
            .with_message(message)
            .with_details(json!({ "provider": "wechat_pay" })),
        WechatPayError::InvalidSignature(message) => {
            AppError::from_status(StatusCode::UNAUTHORIZED)
                .with_message("微信支付通知签名无效")
                .with_details(json!({ "provider": "wechat_pay", "reason": message }))
        }
    }
}

pub fn map_wechat_pay_init_error(error: WechatPayError) -> crate::state::AppStateInitError {
    crate::state::AppStateInitError::WechatPay(error.to_string())
}

pub fn build_wechat_payment_request(
    order_id: String,
    product_title: String,
    amount_cents: u64,
    payer_openid: String,
) -> WechatMiniProgramOrderRequest {
    WechatMiniProgramOrderRequest {
        order_id,
        description: format!("陶泥儿 - {product_title}"),
        amount_cents,
        payer_openid,
    }
}

pub fn build_wechat_web_payment_request(
    order_id: String,
    product_title: String,
    amount_cents: u64,
    payer_client_ip: String,
) -> WechatWebOrderRequest {
    WechatWebOrderRequest {
        order_id,
        description: format!("陶泥儿 - {product_title}"),
        amount_cents,
        payer_client_ip,
    }
}

pub fn current_unix_micros() -> i64 {
    let value = OffsetDateTime::now_utc().unix_timestamp_nanos() / 1_000;
    i64::try_from(value).unwrap_or(i64::MAX)
}

fn map_wechat_pay_notify_error(error: WechatPayError) -> AppError {
    warn!(error = %error, "微信支付通知处理失败");
    map_wechat_pay_error(error)
}

fn read_wechat_message_push_config<'a>(
    value: Option<&'a str>,
    key: &str,
) -> Result<&'a str, WechatPayError> {
    value
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .ok_or_else(|| WechatPayError::InvalidConfig(format!("{key} 未配置")))
}

fn build_wechat_message_push_verify_error_response(error: WechatPayError) -> Response {
    let message = match error {
        WechatPayError::Disabled => "微信消息推送暂未启用".to_string(),
        WechatPayError::InvalidConfig(message)
        | WechatPayError::InvalidRequest(message)
        | WechatPayError::RequestFailed(message)
        | WechatPayError::Upstream(message)
        | WechatPayError::Deserialize(message)
        | WechatPayError::Crypto(message)
        | WechatPayError::InvalidSignature(message) => message,
    };
    (StatusCode::BAD_REQUEST, message).into_response()
}

fn resolve_wechat_message_push_verify_response(
    token: &str,
    aes_key: &str,
    expected_app_id: Option<&str>,
    query: &WechatMiniProgramMessagePushQuery,
) -> Result<String, WechatPayError> {
    let timestamp = query.timestamp.as_deref().map(str::trim).unwrap_or("");
    let nonce = query.nonce.as_deref().map(str::trim).unwrap_or("");
    let echostr = query.echostr.as_deref().map(str::trim).unwrap_or("");
    if timestamp.is_empty() || nonce.is_empty() || echostr.is_empty() {
        return Err(WechatPayError::InvalidRequest(
            "微信消息推送校验参数不完整".to_string(),
        ));
    }
    let msg_signature = query
        .msg_signature
        .as_deref()
        .map(str::trim)
        .filter(|value| !value.is_empty());
    if let Some(signature) = msg_signature {
        if !verify_wechat_message_push_signature(token, timestamp, nonce, echostr, signature) {
            return Err(WechatPayError::InvalidSignature(
                "微信消息推送 msg_signature 无效".to_string(),
            ));
        }
        return decrypt_wechat_message_push_ciphertext(aes_key, echostr, expected_app_id);
    }

    let signature = query
        .signature
        .as_deref()
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .ok_or_else(|| WechatPayError::InvalidRequest("微信消息推送校验参数不完整".to_string()))?;
    if !verify_wechat_message_push_signature(token, timestamp, nonce, "", signature) {
        return Err(WechatPayError::InvalidSignature(
            "微信消息推送校验签名无效".to_string(),
        ));
    }
    Ok(echostr.to_string())
}

fn parse_wechat_mini_program_message_push_payload(
    body: &[u8],
) -> Result<WechatMiniProgramEncryptedMessage, WechatPayError> {
    serde_json::from_slice(body).map_err(|error| {
        WechatPayError::Deserialize(format!("微信消息推送 JSON 解析失败：{error}"))
    })
}

fn verify_wechat_message_push_signature(
    token: &str,
    timestamp: &str,
    nonce: &str,
    value: &str,
    signature: &str,
) -> bool {
    let mut parts = [token, timestamp, nonce, value];
    parts.sort_unstable();
    let mut hasher = Sha1::new();
    hasher.update(parts.join("").as_bytes());
    let expected = hex::encode(hasher.finalize());
    expected.eq_ignore_ascii_case(signature)
}

fn decrypt_wechat_message_push_ciphertext(
    encoding_aes_key: &str,
    ciphertext: &str,
    expected_app_id: Option<&str>,
) -> Result<String, WechatPayError> {
    let key = decode_wechat_message_push_encoding_aes_key(encoding_aes_key)?;
    let ciphertext = BASE64_STANDARD
        .decode(ciphertext.as_bytes())
        .map_err(|error| {
            WechatPayError::Crypto(format!("微信消息推送密文 Base64 解码失败：{error}"))
        })?;
    let iv = &key[..WECHAT_MINIPROGRAM_MESSAGE_RANDOM_BYTES];
    let cipher = cbc::Decryptor::<Aes256>::new_from_slices(&key, iv)
        .map_err(|error| WechatPayError::Crypto(format!("微信消息推送 AES 初始化失败：{error}")))?;
    let decrypted = cipher
        .decrypt_padded_vec_mut::<NoPadding>(&ciphertext)
        .map_err(|error| WechatPayError::Crypto(format!("微信消息推送密文解密失败：{error}")))?;
    let plaintext = remove_wechat_message_push_pkcs7_padding(&decrypted)?;
    let payload = parse_wechat_message_push_plaintext(&plaintext)?;
    if let Some(app_id) = expected_app_id
        .map(str::trim)
        .filter(|value| !value.is_empty())
        && payload.app_id != app_id
    {
        return Err(WechatPayError::InvalidSignature(
            "微信消息推送明文 appid 校验失败".to_string(),
        ));
    }
    Ok(payload.message)
}

fn decode_wechat_message_push_encoding_aes_key(
    encoding_aes_key: &str,
) -> Result<Vec<u8>, WechatPayError> {
    if encoding_aes_key.chars().count() != WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY_BYTES {
        return Err(WechatPayError::InvalidConfig(format!(
            "WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY 必须是 {WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY_BYTES} 位"
        )));
    }
    let padded_key = format!("{encoding_aes_key}=");
    let key = WECHAT_MINIPROGRAM_MESSAGE_AES_KEY_BASE64
        .decode(padded_key.as_bytes())
        .map_err(|error| {
            WechatPayError::InvalidConfig(format!(
                "WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY Base64 解析失败：{error}"
            ))
        })?;
    if key.len() != WECHAT_MINIPROGRAM_MESSAGE_AES_KEY_BYTES {
        return Err(WechatPayError::InvalidConfig(
            "WECHAT_MINIPROGRAM_MESSAGE_ENCODING_AES_KEY 解码后长度必须为 32 字节".to_string(),
        ));
    }
    Ok(key)
}

fn remove_wechat_message_push_pkcs7_padding(plaintext: &[u8]) -> Result<Vec<u8>, WechatPayError> {
    let Some(&pad_len) = plaintext.last() else {
        return Err(WechatPayError::Deserialize(
            "微信消息推送明文为空".to_string(),
        ));
    };
    let pad_len = pad_len as usize;
    if pad_len == 0 || pad_len > 32 || pad_len > plaintext.len() {
        return Err(WechatPayError::Deserialize(
            "微信消息推送 PKCS7 填充无效".to_string(),
        ));
    }
    if plaintext[plaintext.len() - pad_len..]
        .iter()
        .any(|byte| *byte as usize != pad_len)
    {
        return Err(WechatPayError::Deserialize(
            "微信消息推送 PKCS7 填充校验失败".to_string(),
        ));
    }
    Ok(plaintext[..plaintext.len() - pad_len].to_vec())
}

struct WechatMessagePushPlaintext {
    message: String,
    app_id: String,
}

fn parse_wechat_message_push_plaintext(
    plaintext: &[u8],
) -> Result<WechatMessagePushPlaintext, WechatPayError> {
    if plaintext.len()
        < WECHAT_MINIPROGRAM_MESSAGE_LENGTH_BYTES + WECHAT_MINIPROGRAM_MESSAGE_RANDOM_BYTES + 1
    {
        return Err(WechatPayError::Deserialize(
            "微信消息推送明文长度不足".to_string(),
        ));
    }
    let len_offset = WECHAT_MINIPROGRAM_MESSAGE_RANDOM_BYTES;
    let length_bytes: [u8; WECHAT_MINIPROGRAM_MESSAGE_LENGTH_BYTES] = plaintext
        [len_offset..len_offset + WECHAT_MINIPROGRAM_MESSAGE_LENGTH_BYTES]
        .try_into()
        .map_err(|_| WechatPayError::Deserialize("微信消息推送长度字段解析失败".to_string()))?;
    let message_len = u32::from_be_bytes(length_bytes) as usize;
    let message_start = len_offset + WECHAT_MINIPROGRAM_MESSAGE_LENGTH_BYTES;
    let message_end = message_start + message_len;
    if plaintext.len() <= message_end {
        return Err(WechatPayError::Deserialize(
            "微信消息推送明文长度与内容不匹配".to_string(),
        ));
    }
    let app_id_start = message_end;
    let message =
        String::from_utf8(plaintext[message_start..message_end].to_vec()).map_err(|error| {
            WechatPayError::Deserialize(format!("微信消息推送明文不是合法 UTF-8：{error}"))
        })?;
    let app_id =
        String::from_utf8(plaintext[app_id_start..plaintext.len()].to_vec()).map_err(|error| {
            WechatPayError::Deserialize(format!("微信消息推送 appid 不是合法 UTF-8：{error}"))
        })?;
    Ok(WechatMessagePushPlaintext { message, app_id })
}

fn parse_virtual_payment_notify(
    body: &[u8],
) -> Result<WechatVirtualPaymentNotifyOrder, WechatPayError> {
    if let Ok(notify) = serde_json::from_slice::<WechatVirtualPaymentNotifyBody>(body) {
        return build_virtual_payment_notify_order(
            notify.event,
            notify.out_trade_no,
            notify.mch_order_id,
            notify.wechat_pay_info,
        );
    }

    let text = std::str::from_utf8(body).map_err(|error| {
        WechatPayError::Deserialize(format!("微信虚拟支付推送不是合法 UTF-8：{error}"))
    })?;
    let event = extract_virtual_payment_text_value(text, "Event")
        .ok_or_else(|| WechatPayError::InvalidRequest("微信虚拟支付推送缺少 Event".to_string()))?;
    let out_trade_no = extract_virtual_payment_text_value(text, "OutTradeNo");
    let mch_order_id = extract_virtual_payment_text_value(text, "MchOrderId");
    let wechat_pay_info = extract_virtual_payment_block(text, "WeChatPayInfo").map(|inner| {
        WechatVirtualPaymentNotifyPayInfo {
            mch_order_no: extract_virtual_payment_text_value(&inner, "MchOrderNo"),
            transaction_id: extract_virtual_payment_text_value(&inner, "TransactionId"),
            paid_time: extract_virtual_payment_text_value(&inner, "PaidTime")
                .and_then(|value| value.parse::<i64>().ok()),
        }
    });

    build_virtual_payment_notify_order(event, out_trade_no, mch_order_id, wechat_pay_info)
}

fn build_virtual_payment_notify_order(
    event: String,
    out_trade_no: Option<String>,
    mch_order_id: Option<String>,
    wechat_pay_info: Option<WechatVirtualPaymentNotifyPayInfo>,
) -> Result<WechatVirtualPaymentNotifyOrder, WechatPayError> {
    let event = event.trim().to_string();
    if event.is_empty() {
        return Err(WechatPayError::InvalidRequest(
            "微信虚拟支付推送缺少 Event".to_string(),
        ));
    }
    let out_trade_no = out_trade_no
        .or(mch_order_id)
        .or_else(|| {
            wechat_pay_info
                .as_ref()
                .and_then(|info| info.mch_order_no.clone())
        })
        .map(|value| value.trim().to_string())
        .filter(|value| !value.is_empty())
        .ok_or_else(|| {
            WechatPayError::InvalidRequest("微信虚拟支付推送缺少 OutTradeNo".to_string())
        })?;
    let transaction_id = wechat_pay_info
        .as_ref()
        .and_then(|info| info.transaction_id.clone())
        .map(|value| value.trim().to_string())
        .filter(|value| !value.is_empty());
    let paid_at_micros = wechat_pay_info
        .and_then(|info| info.paid_time)
        .map(|paid_time| paid_time.saturating_mul(1_000_000));

    Ok(WechatVirtualPaymentNotifyOrder {
        out_trade_no,
        transaction_id,
        paid_at_micros,
        event,
    })
}

fn extract_virtual_payment_text_value(text: &str, tag: &str) -> Option<String> {
    let open = format!("<{tag}>");
    let close = format!("</{tag}>");
    let start = text.find(&open)? + open.len();
    let end = text[start..].find(&close)? + start;
    let raw = &text[start..end];
    Some(trim_virtual_payment_text_value(raw))
}

fn extract_virtual_payment_block(text: &str, tag: &str) -> Option<String> {
    let open = format!("<{tag}>");
    let close = format!("</{tag}>");
    let start = text.find(&open)? + open.len();
    let end = text[start..].find(&close)? + start;
    Some(text[start..end].to_string())
}

fn trim_virtual_payment_text_value(value: &str) -> String {
    let trimmed = value.trim();
    if let Some(inner) = trimmed
        .strip_prefix("<![CDATA[")
        .and_then(|value| value.strip_suffix("]]>"))
    {
        return inner.trim().to_string();
    }
    trimmed.to_string()
}

fn build_virtual_payment_notify_error_response(
    error: WechatPayError,
    response_format: VirtualPaymentNotifyResponseFormat,
) -> Response {
    warn!(error = %error, "微信虚拟支付通知处理失败");
    let message = match error {
        WechatPayError::Disabled => "微信虚拟支付暂未启用".to_string(),
        WechatPayError::InvalidConfig(message)
        | WechatPayError::InvalidRequest(message)
        | WechatPayError::RequestFailed(message)
        | WechatPayError::Upstream(message)
        | WechatPayError::Deserialize(message)
        | WechatPayError::Crypto(message)
        | WechatPayError::InvalidSignature(message) => message,
    };
    build_virtual_payment_notify_response(response_format, 1, message)
}

fn build_virtual_payment_notify_success_response(
    response_format: VirtualPaymentNotifyResponseFormat,
) -> Response {
    build_virtual_payment_notify_response(response_format, 0, "success")
}

fn build_virtual_payment_notify_response(
    response_format: VirtualPaymentNotifyResponseFormat,
    err_code: i32,
    err_msg: impl Into<String>,
) -> Response {
    let err_msg = err_msg.into();
    match response_format {
        VirtualPaymentNotifyResponseFormat::Json => Json(
            build_wechat_virtual_payment_notify_response(err_code, err_msg),
        )
        .into_response(),
        VirtualPaymentNotifyResponseFormat::Xml => {
            let body = format!(
                "<xml><ErrCode>{err_code}</ErrCode><ErrMsg><![CDATA[{err_msg}]]></ErrMsg></xml>"
            );
            let mut response = (StatusCode::OK, body).into_response();
            response.headers_mut().insert(
                CONTENT_TYPE,
                HeaderValue::from_static("application/xml; charset=utf-8"),
            );
            response
        }
    }
}

fn with_wechat_pay_json_headers(
    builder: reqwest::RequestBuilder,
    platform_serial_no: &str,
) -> reqwest::RequestBuilder {
    builder
        .header(reqwest::header::ACCEPT, WECHAT_PAY_ACCEPT_HEADER)
        .header(
            reqwest::header::CONTENT_TYPE,
            WECHAT_PAY_CONTENT_TYPE_HEADER,
        )
        .header(reqwest::header::USER_AGENT, WECHAT_PAY_USER_AGENT)
        .header(WECHAT_PAY_SERIAL_HEADER, platform_serial_no)
}

fn with_wechat_pay_jsapi_headers(
    builder: reqwest::RequestBuilder,
    platform_serial_no: &str,
) -> reqwest::RequestBuilder {
    with_wechat_pay_json_headers(builder, platform_serial_no)
}

fn build_mock_pay_params(order_id: &str) -> WechatMiniProgramPayParamsResponse {
    let time_stamp = OffsetDateTime::now_utc().unix_timestamp().to_string();
    let nonce_str = "mock-nonce".to_string();
    let package = format!("prepay_id=mock-{order_id}");
    let pay_sign = hex_sha256(format!("{time_stamp}\n{nonce_str}\n{package}\n").as_bytes());

    WechatMiniProgramPayParamsResponse {
        time_stamp,
        nonce_str,
        package,
        sign_type: WECHAT_PAY_PAY_SIGN_TYPE.to_string(),
        pay_sign,
    }
}

fn build_mock_h5_payment(order_id: &str) -> WechatH5PaymentResponse {
    WechatH5PaymentResponse {
        h5_url: format!(
            "https://mock.wechat-pay.local/h5?out_trade_no={}",
            urlencoding::encode(order_id)
        ),
    }
}

fn build_mock_native_payment(order_id: &str) -> WechatNativePaymentResponse {
    WechatNativePaymentResponse {
        code_url: format!(
            "weixin://pay.weixin.qq.com/bizpayurl/up?pr=mock-{}",
            hex_sha256(order_id.as_bytes())
        ),
    }
}

fn parse_mock_notify(body: &[u8]) -> Result<WechatPayNotifyOrder, WechatPayError> {
    let value = serde_json::from_slice::<Value>(body).map_err(|error| {
        WechatPayError::Deserialize(format!("mock 微信支付通知解析失败：{error}"))
    })?;
    Ok(WechatPayNotifyOrder {
        out_trade_no: value
            .get("outTradeNo")
            .or_else(|| value.get("out_trade_no"))
            .and_then(Value::as_str)
            .map(str::trim)
            .filter(|value| !value.is_empty())
            .ok_or_else(|| {
                WechatPayError::InvalidRequest("mock 微信支付通知缺少 outTradeNo".to_string())
            })?
            .to_string(),
        transaction_id: value
            .get("transactionId")
            .or_else(|| value.get("transaction_id"))
            .and_then(Value::as_str)
            .map(str::trim)
            .filter(|value| !value.is_empty())
            .map(ToOwned::to_owned),
        trade_state: value
            .get("tradeState")
            .or_else(|| value.get("trade_state"))
            .and_then(Value::as_str)
            .unwrap_or("SUCCESS")
            .to_string(),
        success_time: value
            .get("successTime")
            .or_else(|| value.get("success_time"))
            .and_then(Value::as_str)
            .map(ToOwned::to_owned),
    })
}

fn build_wechat_virtual_payment_notify_response(
    err_code: i32,
    err_msg: impl Into<String>,
) -> WechatVirtualPaymentNotifyResponse {
    WechatVirtualPaymentNotifyResponse {
        err_code,
        err_msg: err_msg.into(),
    }
}

#[derive(Clone, Copy)]
enum VirtualPaymentNotifyResponseFormat {
    Json,
    Xml,
}

fn detect_virtual_payment_notify_response_format(
    headers: &HeaderMap,
    body: &[u8],
) -> VirtualPaymentNotifyResponseFormat {
    let content_type = headers
        .get(CONTENT_TYPE)
        .and_then(|value| value.to_str().ok())
        .unwrap_or("")
        .to_ascii_lowercase();
    if content_type.contains("xml") {
        return VirtualPaymentNotifyResponseFormat::Xml;
    }
    let body_trimmed = body
        .iter()
        .copied()
        .skip_while(|byte| byte.is_ascii_whitespace())
        .next();
    match body_trimmed {
        Some(b'<') => VirtualPaymentNotifyResponseFormat::Xml,
        _ => VirtualPaymentNotifyResponseFormat::Json,
    }
}

fn required_config(value: Option<&str>, key: &str) -> Result<String, WechatPayError> {
    value
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .map(ToOwned::to_owned)
        .ok_or_else(|| WechatPayError::InvalidConfig(format!("{key} 未配置")))
}

fn normalize_required_url(value: &str, key: &str) -> Result<String, WechatPayError> {
    let value = value.trim();
    if value.starts_with("https://") {
        return Ok(value.to_string());
    }

    Err(WechatPayError::InvalidConfig(format!(
        "{key} 必须是 https 地址"
    )))
}

fn validate_notify_url(value: &str, key: &str) -> Result<(), WechatPayError> {
    if value.chars().count() > WECHAT_PAY_NOTIFY_URL_MAX_CHARS {
        return Err(WechatPayError::InvalidConfig(format!(
            "{key} 不能超过 {WECHAT_PAY_NOTIFY_URL_MAX_CHARS} 字符"
        )));
    }
    if value.contains('?') || value.contains('#') {
        return Err(WechatPayError::InvalidConfig(format!(
            "{key} 不能包含 query 或 fragment"
        )));
    }
    Ok(())
}

fn resolve_query_order_endpoint_base(jsapi_endpoint: &str) -> Result<String, WechatPayError> {
    let url = Url::parse(jsapi_endpoint)
        .map_err(|_| WechatPayError::InvalidConfig("WECHAT_PAY_JSAPI_ENDPOINT 无效".to_string()))?;
    let origin = url
        .origin()
        .ascii_serialization()
        .trim_end_matches('/')
        .to_string();
    Ok(format!("{origin}/v3/pay/transactions/out-trade-no"))
}

fn resolve_wechat_pay_transaction_endpoint(
    jsapi_endpoint: &str,
    transaction_path: &str,
) -> Result<String, WechatPayError> {
    let url = Url::parse(jsapi_endpoint)
        .map_err(|_| WechatPayError::InvalidConfig("WECHAT_PAY_JSAPI_ENDPOINT 无效".to_string()))?;
    let origin = url
        .origin()
        .ascii_serialization()
        .trim_end_matches('/')
        .to_string();
    Ok(format!("{origin}{transaction_path}"))
}

fn normalize_out_trade_no(value: &str) -> Result<String, WechatPayError> {
    let value = value.trim();
    validate_out_trade_no(value)?;
    Ok(value.to_string())
}

fn validate_jsapi_order_request(
    client: &RealWechatPayClient,
    request: &WechatMiniProgramOrderRequest,
) -> Result<(), WechatPayError> {
    validate_non_empty_max_chars(
        &client.app_id,
        WECHAT_PAY_APP_ID_MAX_CHARS,
        "微信支付 appid",
    )?;
    if !client.app_id.starts_with("wx") {
        return Err(WechatPayError::InvalidConfig(
            "微信支付 appid 必须使用小程序 AppID".to_string(),
        ));
    }
    validate_non_empty_max_chars(
        &client.mch_id,
        WECHAT_PAY_MCH_ID_MAX_CHARS,
        "微信支付 mchid",
    )?;
    if !client.mch_id.chars().all(|ch| ch.is_ascii_digit()) {
        return Err(WechatPayError::InvalidConfig(
            "微信支付 mchid 必须是数字字符串".to_string(),
        ));
    }

    validate_non_empty_max_chars(
        &request.description,
        WECHAT_PAY_DESCRIPTION_MAX_CHARS,
        "微信支付商品描述",
    )?;
    validate_out_trade_no(&request.order_id)?;
    if request.amount_cents == 0 {
        return Err(WechatPayError::InvalidRequest(
            "微信支付金额必须大于 0 分".to_string(),
        ));
    }
    validate_non_empty_max_chars(
        &request.payer_openid,
        WECHAT_PAY_OPENID_MAX_CHARS,
        "微信支付 payer.openid",
    )?;
    Ok(())
}

fn validate_web_order_request(
    client: &RealWechatPayClient,
    request: &WechatWebOrderRequest,
) -> Result<(), WechatPayError> {
    validate_non_empty_max_chars(
        &client.app_id,
        WECHAT_PAY_APP_ID_MAX_CHARS,
        "微信支付 appid",
    )?;
    if !client.app_id.starts_with("wx") {
        return Err(WechatPayError::InvalidConfig(
            "微信支付 appid 必须使用已绑定的微信 AppID".to_string(),
        ));
    }
    validate_non_empty_max_chars(
        &client.mch_id,
        WECHAT_PAY_MCH_ID_MAX_CHARS,
        "微信支付 mchid",
    )?;
    if !client.mch_id.chars().all(|ch| ch.is_ascii_digit()) {
        return Err(WechatPayError::InvalidConfig(
            "微信支付 mchid 必须是数字字符串".to_string(),
        ));
    }
    validate_non_empty_max_chars(
        &request.description,
        WECHAT_PAY_DESCRIPTION_MAX_CHARS,
        "微信支付商品描述",
    )?;
    validate_out_trade_no(&request.order_id)?;
    if request.amount_cents == 0 {
        return Err(WechatPayError::InvalidRequest(
            "微信支付金额必须大于 0 分".to_string(),
        ));
    }
    validate_non_empty_max_chars(
        &request.payer_client_ip,
        WECHAT_PAY_CLIENT_IP_MAX_CHARS,
        "微信支付 payer_client_ip",
    )?;
    Ok(())
}

fn validate_non_empty_max_chars(
    value: &str,
    max_chars: usize,
    field_name: &str,
) -> Result<(), WechatPayError> {
    let value = value.trim();
    if value.is_empty() {
        return Err(WechatPayError::InvalidRequest(format!(
            "{field_name} 不能为空"
        )));
    }
    if value.chars().count() > max_chars {
        return Err(WechatPayError::InvalidRequest(format!(
            "{field_name} 不能超过 {max_chars} 字符"
        )));
    }
    Ok(())
}

fn validate_out_trade_no(value: &str) -> Result<(), WechatPayError> {
    validate_non_empty_max_chars(
        value,
        WECHAT_PAY_OUT_TRADE_NO_MAX_CHARS,
        "微信支付 out_trade_no",
    )?;
    if value.chars().count() < 6 {
        return Err(WechatPayError::InvalidRequest(
            "微信支付 out_trade_no 不能少于 6 字符".to_string(),
        ));
    }
    if !value
        .chars()
        .all(|ch| ch.is_ascii_alphanumeric() || matches!(ch, '_' | '-' | '|' | '*'))
    {
        return Err(WechatPayError::InvalidRequest(
            "微信支付 out_trade_no 只能包含数字、大小写字母、_、-、|、*".to_string(),
        ));
    }
    Ok(())
}

fn read_private_key_pem(
    inline_pem: Option<&str>,
    path: Option<&Path>,
) -> Result<String, WechatPayError> {
    read_pem(
        inline_pem,
        path,
        "WECHAT_PAY_PRIVATE_KEY_PEM 或 WECHAT_PAY_PRIVATE_KEY_PATH 未配置",
        "读取微信支付私钥失败",
    )
}

fn read_pem(
    inline_pem: Option<&str>,
    path: Option<&Path>,
    missing_message: &str,
    read_error_prefix: &str,
) -> Result<String, WechatPayError> {
    if let Some(value) = inline_pem.map(str::trim).filter(|value| !value.is_empty()) {
        return Ok(value.replace("\\n", "\n"));
    }
    let Some(path) = path else {
        return Err(WechatPayError::InvalidConfig(missing_message.to_string()));
    };
    fs::read_to_string(path).map_err(|error| {
        WechatPayError::InvalidConfig(format!("{read_error_prefix}：{}：{error}", path.display()))
    })
}

fn parse_rsa_private_key(pem: &str) -> Result<signature::RsaKeyPair, WechatPayError> {
    let (label, der) = parse_single_pem_block(pem)?;
    match label.as_str() {
        "PRIVATE KEY" => signature::RsaKeyPair::from_pkcs8(&der),
        "RSA PRIVATE KEY" => signature::RsaKeyPair::from_der(&der),
        _ => {
            return Err(WechatPayError::InvalidConfig(
                "微信支付私钥必须是 PRIVATE KEY 或 RSA PRIVATE KEY PEM".to_string(),
            ));
        }
    }
    .map_err(|error| WechatPayError::InvalidConfig(format!("微信支付私钥解析失败：{error}")))
}

fn parse_public_key_pem(pem: &str) -> Result<Vec<u8>, WechatPayError> {
    let (label, der) = parse_single_pem_block(pem)?;
    if label != "PUBLIC KEY" {
        return Err(WechatPayError::InvalidConfig(
            "微信支付平台公钥必须是 PUBLIC KEY PEM".to_string(),
        ));
    }
    Ok(der)
}

fn parse_single_pem_block(pem: &str) -> Result<(String, Vec<u8>), WechatPayError> {
    let mut label: Option<String> = None;
    let mut content = String::new();
    for line in pem.lines().map(str::trim).filter(|line| !line.is_empty()) {
        if let Some(raw_label) = line
            .strip_prefix("-----BEGIN ")
            .and_then(|value| value.strip_suffix("-----"))
        {
            label = Some(raw_label.trim().to_string());
            continue;
        }
        if line.starts_with("-----END ") {
            break;
        }
        if label.is_some() {
            content.push_str(line);
        }
    }
    let label = label
        .ok_or_else(|| WechatPayError::InvalidConfig("微信支付 PEM 缺少 BEGIN 标记".to_string()))?;
    let der = BASE64_STANDARD
        .decode(content)
        .map_err(|_| WechatPayError::InvalidConfig("微信支付 PEM base64 无效".to_string()))?;
    if der.is_empty() {
        return Err(WechatPayError::InvalidConfig(
            "微信支付 PEM 内容为空".to_string(),
        ));
    }
    Ok((label, der))
}

fn create_nonce() -> Result<String, WechatPayError> {
    let mut bytes = [0_u8; 16];
    SystemRandom::new()
        .fill(&mut bytes)
        .map_err(|_| WechatPayError::Crypto("生成微信支付 nonce 失败".to_string()))?;
    Ok(hex_encode(&bytes))
}

fn decrypt_aes_256_gcm(
    key: &[u8],
    nonce: &[u8],
    associated_data: &[u8],
    ciphertext_base64: &str,
) -> Result<Vec<u8>, WechatPayError> {
    let mut ciphertext = BASE64_STANDARD
        .decode(ciphertext_base64)
        .map_err(|_| WechatPayError::Crypto("微信支付通知密文 base64 无效".to_string()))?;
    if ciphertext.len() < aead::AES_256_GCM.tag_len() {
        return Err(WechatPayError::Crypto(
            "微信支付通知密文长度无效".to_string(),
        ));
    }
    let nonce = aead::Nonce::try_assume_unique_for_key(nonce)
        .map_err(|_| WechatPayError::Crypto("微信支付通知 nonce 长度无效".to_string()))?;
    let key = aead::UnboundKey::new(&aead::AES_256_GCM, key)
        .map_err(|_| WechatPayError::Crypto("微信支付通知解密 key 无效".to_string()))?;
    let plain_text = aead::LessSafeKey::new(key)
        .open_in_place(
            nonce,
            aead::Aad::from(associated_data),
            ciphertext.as_mut_slice(),
        )
        .map_err(|_| WechatPayError::Crypto("微信支付通知认证或解密失败".to_string()))?;
    Ok(plain_text.to_vec())
}

fn read_required_header<'a>(
    headers: &'a HeaderMap,
    name: &'static str,
) -> Result<&'a str, WechatPayError> {
    headers
        .get(name)
        .and_then(|value| value.to_str().ok())
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .ok_or_else(|| WechatPayError::InvalidSignature(format!("微信支付通知缺少 {name} 请求头")))
}

fn build_notify_signature_message(timestamp: &[u8], nonce: &[u8], body: &[u8]) -> Vec<u8> {
    let mut message = Vec::with_capacity(timestamp.len() + nonce.len() + body.len() + 3);
    message.extend_from_slice(timestamp);
    message.push(b'\n');
    message.extend_from_slice(nonce);
    message.push(b'\n');
    message.extend_from_slice(body);
    message.push(b'\n');
    message
}

fn hex_sha256(content: &[u8]) -> String {
    let mut hasher = Sha256::new();
    hasher.update(content);
    hex_encode(&hasher.finalize())
}

fn hex_encode(bytes: &[u8]) -> String {
    bytes.iter().map(|byte| format!("{byte:02x}")).collect()
}

impl std::fmt::Display for WechatPayError {
    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::Disabled => formatter.write_str("微信支付暂未启用"),
            Self::InvalidConfig(message)
            | Self::InvalidRequest(message)
            | Self::RequestFailed(message)
            | Self::Upstream(message)
            | Self::Deserialize(message)
            | Self::Crypto(message) => formatter.write_str(message),
            Self::InvalidSignature(message) => formatter.write_str(message),
        }
    }
}

impl std::error::Error for WechatPayError {}

#[cfg(test)]
mod tests {
    use super::*;
    use cbc::cipher::{BlockEncryptMut, block_padding::NoPadding};

    #[test]
    fn mock_pay_params_use_request_payment_shape() {
        let params = build_mock_pay_params("recharge:user:1:points_60");

        assert!(!params.time_stamp.is_empty());
        assert_eq!(params.sign_type, "RSA");
        assert!(params.package.starts_with("prepay_id=mock-"));
        assert!(!params.pay_sign.is_empty());
    }

    #[test]
    fn jsapi_order_request_uses_wechat_v3_snake_case_fields() {
        let body = serde_json::to_value(WechatJsapiOrderRequest {
            appid: "wx-test-app",
            mchid: "1900000001",
            description: "陶泥儿 - 60泥点",
            out_trade_no: "rcgtest001",
            notify_url: "https://api.example.com/api/profile/recharge/wechat/notify",
            amount: WechatJsapiAmount {
                total: 600,
                currency: "CNY",
            },
            payer: WechatJsapiPayer {
                openid: "openid-test",
            },
        })
        .expect("JSAPI order request should serialize");

        assert_eq!(body["out_trade_no"], "rcgtest001");
        assert_eq!(
            body["notify_url"],
            "https://api.example.com/api/profile/recharge/wechat/notify"
        );
        assert!(body.get("outTradeNo").is_none());
        assert!(body.get("notifyUrl").is_none());
    }

    #[test]
    fn h5_order_request_uses_wechat_required_scene_info() {
        let body = serde_json::to_value(WechatH5OrderRequest {
            appid: "wx-test-app",
            mchid: "1900000001",
            description: "陶泥儿 - 60泥点",
            out_trade_no: "rcgtest001",
            notify_url: "https://api.example.com/api/profile/recharge/wechat/notify",
            amount: WechatJsapiAmount {
                total: 600,
                currency: "CNY",
            },
            scene_info: WechatH5SceneInfo {
                payer_client_ip: "203.0.113.10",
                h5_info: WechatH5Info { kind: "Wap" },
            },
        })
        .expect("H5 order request should serialize");

        assert_eq!(body["scene_info"]["payer_client_ip"], "203.0.113.10");
        assert_eq!(body["scene_info"]["h5_info"]["type"], "Wap");
        assert_eq!(body["amount"]["currency"], "CNY");
        assert!(body.get("sceneInfo").is_none());
        assert!(body["scene_info"].get("payerClientIp").is_none());
    }

    #[test]
    fn native_order_request_uses_code_url_response_shape() {
        let body = serde_json::to_value(WechatNativeOrderRequest {
            appid: "wx-test-app",
            mchid: "1900000001",
            description: "陶泥儿 - 60泥点",
            out_trade_no: "rcgtest001",
            notify_url: "https://api.example.com/api/profile/recharge/wechat/notify",
            amount: WechatJsapiAmount {
                total: 600,
                currency: "CNY",
            },
            scene_info: WechatNativeSceneInfo {
                payer_client_ip: "203.0.113.10",
            },
        })
        .expect("Native order request should serialize");
        let response = serde_json::from_value::<WechatNativeOrderResponse>(json!({
            "code_url": "weixin://pay.weixin.qq.com/bizpayurl/up?pr=test"
        }))
        .expect("Native order response should deserialize");

        assert_eq!(body["scene_info"]["payer_client_ip"], "203.0.113.10");
        assert_eq!(
            response.code_url.as_deref(),
            Some("weixin://pay.weixin.qq.com/bizpayurl/up?pr=test")
        );
    }

    #[test]
    fn transaction_endpoints_reuse_configured_wechat_pay_origin() {
        let h5_endpoint = resolve_wechat_pay_transaction_endpoint(
            "https://pay-gateway.example.com/v3/pay/transactions/jsapi",
            WECHAT_PAY_H5_PATH,
        )
        .expect("H5 endpoint should resolve");
        let native_endpoint = resolve_wechat_pay_transaction_endpoint(
            "https://pay-gateway.example.com/v3/pay/transactions/jsapi",
            WECHAT_PAY_NATIVE_PATH,
        )
        .expect("Native endpoint should resolve");

        assert_eq!(
            h5_endpoint,
            "https://pay-gateway.example.com/v3/pay/transactions/h5"
        );
        assert_eq!(
            native_endpoint,
            "https://pay-gateway.example.com/v3/pay/transactions/native"
        );
    }

    #[test]
    fn jsapi_order_request_rejects_provider_field_limit_violations() {
        assert!(validate_out_trade_no("abc12").is_err());
        assert!(validate_out_trade_no("abc123").is_ok());
        assert!(validate_out_trade_no("abc123_-|*").is_ok());
        assert!(validate_out_trade_no("abc123中文").is_err());
        assert!(validate_out_trade_no("a".repeat(33).as_str()).is_err());

        assert!(validate_notify_url("https://api.example.com/pay/notify", "notify").is_ok());
        assert!(validate_notify_url("https://api.example.com/pay/notify?x=1", "notify").is_err());
        assert!(validate_notify_url(&format!("https://{}", "a".repeat(248)), "notify").is_err());

        validate_non_empty_max_chars("陶泥儿 - 60泥点", WECHAT_PAY_DESCRIPTION_MAX_CHARS, "描述")
            .expect("short description should pass");
        assert!(
            validate_non_empty_max_chars(
                &"泥".repeat(128),
                WECHAT_PAY_DESCRIPTION_MAX_CHARS,
                "描述"
            )
            .is_err()
        );
        validate_non_empty_max_chars("openid-test", WECHAT_PAY_OPENID_MAX_CHARS, "openid")
            .expect("short openid should pass");
        assert!(
            validate_non_empty_max_chars(&"o".repeat(129), WECHAT_PAY_OPENID_MAX_CHARS, "openid")
                .is_err()
        );
        validate_non_empty_max_chars(
            "203.0.113.10",
            WECHAT_PAY_CLIENT_IP_MAX_CHARS,
            "payer_client_ip",
        )
        .expect("short client ip should pass");
        assert!(
            validate_non_empty_max_chars(
                &"1".repeat(46),
                WECHAT_PAY_CLIENT_IP_MAX_CHARS,
                "payer_client_ip",
            )
            .is_err()
        );
    }

    #[test]
    fn jsapi_order_request_sets_wechat_required_http_headers() {
        let request = with_wechat_pay_jsapi_headers(
            reqwest::Client::new()
                .post("https://api.mch.weixin.qq.com/v3/pay/transactions/jsapi")
                .header(
                    "Authorization",
                    "WECHATPAY2-SHA256-RSA2048 mchid=\"1900000001\"",
                ),
            "PUB_KEY_ID_0119000000012026051400000000000001",
        )
        .build()
        .expect("request should build");

        let headers = request.headers();
        assert_eq!(
            headers
                .get(reqwest::header::ACCEPT)
                .and_then(|value| value.to_str().ok()),
            Some(WECHAT_PAY_ACCEPT_HEADER)
        );
        assert_eq!(
            headers
                .get(reqwest::header::CONTENT_TYPE)
                .and_then(|value| value.to_str().ok()),
            Some(WECHAT_PAY_CONTENT_TYPE_HEADER)
        );
        assert_eq!(
            headers
                .get(reqwest::header::USER_AGENT)
                .and_then(|value| value.to_str().ok()),
            Some(WECHAT_PAY_USER_AGENT)
        );
        assert_eq!(
            headers
                .get(WECHAT_PAY_SERIAL_HEADER)
                .and_then(|value| value.to_str().ok()),
            Some("PUB_KEY_ID_0119000000012026051400000000000001")
        );
    }

    #[test]
    fn notify_signature_message_preserves_raw_body_bytes() {
        let body = b"{\"message\":\"hello\\r\\nworld\"}\r\n";
        let message = build_notify_signature_message(b"1778759600", b"nonce-1", body);

        assert_eq!(
            message,
            b"1778759600\nnonce-1\n{\"message\":\"hello\\r\\nworld\"}\r\n\n".to_vec()
        );
    }

    #[test]
    fn parse_mock_notify_defaults_success_state() {
        let notify =
            parse_mock_notify(br#"{"outTradeNo":"order-1"}"#).expect("mock notify should parse");

        assert_eq!(notify.out_trade_no, "order-1");
        assert_eq!(notify.transaction_id, None);
        assert_eq!(notify.trade_state, "SUCCESS");
    }

    #[test]
    fn parse_virtual_payment_notify_supports_goods_event_json() {
        let notify = parse_virtual_payment_notify(
            br#"{"Event":"xpay_goods_deliver_notify","OutTradeNo":"order-1","WeChatPayInfo":{"TransactionId":"wx-1","PaidTime":1710000000}}"#,
        )
        .expect("virtual payment notify should parse");

        assert_eq!(notify.event, "xpay_goods_deliver_notify");
        assert_eq!(notify.out_trade_no, "order-1");
        assert_eq!(notify.transaction_id.as_deref(), Some("wx-1"));
        assert_eq!(notify.paid_at_micros, Some(1_710_000_000_000_000));
    }

    #[test]
    fn parse_virtual_payment_notify_supports_coin_event_xml() {
        let notify = parse_virtual_payment_notify(
            br#"<xml><Event><![CDATA[xpay_coin_pay_notify]]></Event><OutTradeNo><![CDATA[order-2]]></OutTradeNo><WeChatPayInfo><TransactionId><![CDATA[wx-2]]></TransactionId><PaidTime>1710000001</PaidTime></WeChatPayInfo></xml>"#,
        )
        .expect("virtual payment xml notify should parse");

        assert_eq!(notify.event, "xpay_coin_pay_notify");
        assert_eq!(notify.out_trade_no, "order-2");
        assert_eq!(notify.transaction_id.as_deref(), Some("wx-2"));
        assert_eq!(notify.paid_at_micros, Some(1_710_000_001_000_000));
    }

    #[test]
    fn parse_virtual_payment_notify_rejects_missing_order_no() {
        let error = parse_virtual_payment_notify(br#"{"Event":"xpay_goods_deliver_notify"}"#)
            .expect_err("missing order id should fail");

        match error {
            WechatPayError::InvalidRequest(message) => {
                assert!(message.contains("OutTradeNo"));
            }
            other => panic!("unexpected error: {other:?}"),
        }
    }

    #[test]
    fn decode_wechat_message_push_encoding_aes_key_allows_trailing_bits() {
        let canonical_key = BASE64_STANDARD.encode([0u8; 32]);
        let mut encoding_aes_key = canonical_key.trim_end_matches('=').to_string();
        encoding_aes_key.replace_range(encoding_aes_key.len() - 1.., "B");

        let decoded = decode_wechat_message_push_encoding_aes_key(&encoding_aes_key)
            .expect("wechat aes key with trailing bits should decode");

        assert_eq!(decoded, vec![0u8; WECHAT_MINIPROGRAM_MESSAGE_AES_KEY_BYTES]);
    }

    #[test]
    fn wechat_message_push_signature_uses_sorted_sha1_parts() {
        let token = "token-1";
        let timestamp = "1710000000";
        let nonce = "nonce-1";
        let encrypt = "encrypted-payload";
        let signature = build_wechat_message_push_test_signature(token, timestamp, nonce, encrypt);

        assert!(verify_wechat_message_push_signature(
            token, timestamp, nonce, encrypt, &signature
        ));
        assert!(!verify_wechat_message_push_signature(
            token,
            timestamp,
            nonce,
            "tampered-payload",
            &signature
        ));
    }

    #[test]
    fn wechat_message_push_plain_get_verify_returns_echostr() {
        let token = "AAAAA";
        let timestamp = "1714036504";
        let nonce = "1514711492";
        let echostr = "4375120948345356249";
        let signature = "f464b24fc39322e44b38aa78f5edd27bd1441696";

        let plaintext = resolve_wechat_message_push_verify_response(
            token,
            "unused-aes-key",
            Some("wx-test-app"),
            &WechatMiniProgramMessagePushQuery {
                signature: Some(signature.to_string()),
                timestamp: Some(timestamp.to_string()),
                nonce: Some(nonce.to_string()),
                echostr: Some(echostr.to_string()),
                msg_signature: None,
            },
        )
        .expect("plain url verification should return echostr");

        assert_eq!(plaintext, echostr);
    }

    #[test]
    fn wechat_message_push_decrypts_safe_mode_ciphertext() {
        let app_id = "wx-test-app";
        let message = r#"{"Event":"xpay_coin_pay_notify","OutTradeNo":"order-1"}"#;
        let encoding_aes_key = build_wechat_message_push_test_encoding_aes_key();
        let encrypted =
            encrypt_wechat_message_push_test_ciphertext(&encoding_aes_key, message, app_id);

        let decrypted =
            decrypt_wechat_message_push_ciphertext(&encoding_aes_key, &encrypted, Some(app_id))
                .expect("encrypted message should decrypt");

        assert_eq!(decrypted, message);
    }

    #[test]
    fn wechat_message_push_rejects_mismatched_app_id() {
        let encoding_aes_key = build_wechat_message_push_test_encoding_aes_key();
        let encrypted = encrypt_wechat_message_push_test_ciphertext(
            &encoding_aes_key,
            r#"{"Event":"xpay_coin_pay_notify","OutTradeNo":"order-1"}"#,
            "wx-real-app",
        );

        let error =
            decrypt_wechat_message_push_ciphertext(&encoding_aes_key, &encrypted, Some("wx-other"))
                .expect_err("mismatched app id should fail");

        match error {
            WechatPayError::InvalidSignature(message) => {
                assert!(message.contains("appid"));
            }
            other => panic!("unexpected error: {other:?}"),
        }
    }

    fn build_wechat_message_push_test_signature(
        token: &str,
        timestamp: &str,
        nonce: &str,
        value: &str,
    ) -> String {
        let mut parts = [token, timestamp, nonce, value];
        parts.sort_unstable();
        let mut hasher = Sha1::new();
        hasher.update(parts.join("").as_bytes());
        hex::encode(hasher.finalize())
    }

    fn build_wechat_message_push_test_encoding_aes_key() -> String {
        let raw_key = std::array::from_fn::<_, 32, _>(|index| index as u8);
        BASE64_STANDARD
            .encode(raw_key)
            .trim_end_matches('=')
            .to_string()
    }

    fn encrypt_wechat_message_push_test_ciphertext(
        encoding_aes_key: &str,
        message: &str,
        app_id: &str,
    ) -> String {
        let key = decode_wechat_message_push_encoding_aes_key(encoding_aes_key)
            .expect("test aes key should decode");
        let mut plaintext = Vec::new();
        plaintext.extend_from_slice(b"0123456789abcdef");
        plaintext.extend_from_slice(&(message.as_bytes().len() as u32).to_be_bytes());
        plaintext.extend_from_slice(message.as_bytes());
        plaintext.extend_from_slice(app_id.as_bytes());
        let pad_len = 32 - (plaintext.len() % 32);
        plaintext.extend(std::iter::repeat(pad_len as u8).take(pad_len));
        let iv = &key[..WECHAT_MINIPROGRAM_MESSAGE_RANDOM_BYTES];
        let cipher = cbc::Encryptor::<Aes256>::new_from_slices(&key, iv)
            .expect("test aes cipher should init");
        let encrypted = cipher.encrypt_padded_vec_mut::<NoPadding>(&plaintext);
        BASE64_STANDARD.encode(encrypted)
    }
}