use axum::http::{HeaderValue, StatusCode};
use platform_auth::{AuthPlatformErrorKind, WechatProviderError};
use platform_llm::{LlmError, LlmErrorKind};
use platform_oss::{OssError, OssErrorKind};
use serde_json::json;

use crate::http_error::AppError;

// API 层统一消费 platform 的稳定错误分类，避免各 route 重复 match 具体 provider 分支。
pub fn map_llm_error(error: LlmError) -> AppError {
    let message = llm_error_message(&error);
    let status = match error.kind() {
        LlmErrorKind::InvalidRequest => StatusCode::BAD_REQUEST,
        LlmErrorKind::InvalidConfig => StatusCode::SERVICE_UNAVAILABLE,
        LlmErrorKind::Upstream
            if matches!(
                error,
                LlmError::Upstream {
                    status_code: 429,
                    ..
                }
            ) =>
        {
            StatusCode::TOO_MANY_REQUESTS
        }
        LlmErrorKind::Timeout
        | LlmErrorKind::Connectivity
        | LlmErrorKind::Upstream
        | LlmErrorKind::StreamUnavailable
        | LlmErrorKind::EmptyResponse
        | LlmErrorKind::Transport
        | LlmErrorKind::Deserialize => StatusCode::BAD_GATEWAY,
    };

    AppError::from_status(status).with_message(message)
}

pub fn map_oss_error(error: OssError, provider: &'static str) -> AppError {
    let status = oss_error_status(error.kind());
    AppError::from_status(status).with_details(json!({
        "provider": provider,
        "message": error.to_string(),
    }))
}

pub fn map_phone_auth_platform_store_error(message: String) -> AppError {
    AppError::from_status(StatusCode::INTERNAL_SERVER_ERROR).with_message(message)
}

pub fn map_wechat_provider_error(error: WechatProviderError) -> AppError {
    let status = match error.kind() {
        AuthPlatformErrorKind::Disabled
        | AuthPlatformErrorKind::MissingCode
        | AuthPlatformErrorKind::InvalidCallback => StatusCode::BAD_REQUEST,
        AuthPlatformErrorKind::InvalidConfig => StatusCode::SERVICE_UNAVAILABLE,
        AuthPlatformErrorKind::RequestFailed
        | AuthPlatformErrorKind::DeserializeFailed
        | AuthPlatformErrorKind::MissingProfile
        | AuthPlatformErrorKind::Upstream => StatusCode::BAD_GATEWAY,
        AuthPlatformErrorKind::InvalidClaims
        | AuthPlatformErrorKind::SignFailed
        | AuthPlatformErrorKind::VerifyFailed
        | AuthPlatformErrorKind::CookieConfig
        | AuthPlatformErrorKind::HashFailed
        | AuthPlatformErrorKind::InvalidVerifyCode => StatusCode::INTERNAL_SERVER_ERROR,
    };

    AppError::from_status(status).with_message(error.to_string())
}

pub fn attach_retry_after(error: AppError, retry_after_seconds: u64) -> AppError {
    match HeaderValue::from_str(&retry_after_seconds.to_string()) {
        Ok(value) => error.with_header("retry-after", value),
        Err(_) => error,
    }
}

fn oss_error_status(kind: OssErrorKind) -> StatusCode {
    match kind {
        OssErrorKind::InvalidConfig | OssErrorKind::InvalidRequest => StatusCode::BAD_REQUEST,
        OssErrorKind::ObjectNotFound => StatusCode::NOT_FOUND,
        OssErrorKind::Request | OssErrorKind::SerializePolicy | OssErrorKind::Sign => {
            StatusCode::BAD_GATEWAY
        }
    }
}

fn llm_error_message(error: &LlmError) -> String {
    match error {
        LlmError::InvalidConfig(message)
        | LlmError::InvalidRequest(message)
        | LlmError::Transport(message)
        | LlmError::Deserialize(message) => message.clone(),
        LlmError::Timeout { .. }
        | LlmError::Connectivity { .. }
        | LlmError::Upstream { .. }
        | LlmError::StreamUnavailable
        | LlmError::EmptyResponse => error.to_string(),
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn map_oss_error_uses_stable_kind_for_not_found() {
        let error = map_oss_error(
            OssError::ObjectNotFound("missing object".to_string()),
            "oss",
        );

        assert_eq!(error.status_code(), StatusCode::NOT_FOUND);
    }

    #[test]
    fn map_llm_error_preserves_upstream_rate_limit() {
        let error = map_llm_error(LlmError::Upstream {
            status_code: 429,
            message: "too many requests".to_string(),
        });

        assert_eq!(error.status_code(), StatusCode::TOO_MANY_REQUESTS);
    }

    #[test]
    fn map_wechat_provider_error_keeps_provider_boundary() {
        let error = map_wechat_provider_error(WechatProviderError::MissingCode);

        assert_eq!(error.status_code(), StatusCode::BAD_REQUEST);
        assert_eq!(error.message(), "缺少微信授权 code");
    }
}