use std::time::Instant;

#[cfg(test)]
use axum::http::StatusCode;
use module_runtime::RuntimeTrackingScopeKind;
use platform_image::PlatformImageFailureAudit;
use serde_json::{Value, json};
use time::OffsetDateTime;
use uuid::Uuid;

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

pub(crate) const EXTERNAL_API_FAILURE_EVENT_KEY: &str = "external_api_call_failure";
pub(crate) const EXTERNAL_API_AUDIT_MODULE_KEY: &str = "external-api";

#[derive(Clone, Debug)]
pub(crate) struct ExternalApiFailureDraft {
    pub(crate) provider: &'static str,
    pub(crate) endpoint: String,
    pub(crate) operation: String,
    pub(crate) failure_stage: &'static str,
    pub(crate) status_code: Option<u16>,
    pub(crate) status_class: Option<&'static str>,
    pub(crate) timeout: bool,
    pub(crate) retryable: bool,
    pub(crate) error_message: String,
    pub(crate) error_source: Option<String>,
    pub(crate) raw_excerpt: Option<String>,
    pub(crate) latency_ms: Option<u64>,
    pub(crate) prompt_chars: Option<usize>,
    pub(crate) reference_image_count: Option<usize>,
    pub(crate) image_model: Option<&'static str>,
    pub(crate) user_id: Option<String>,
    pub(crate) profile_id: Option<String>,
    pub(crate) request_id: Option<String>,
}

impl ExternalApiFailureDraft {
    pub(crate) fn new(
        provider: &'static str,
        endpoint: impl Into<String>,
        operation: impl Into<String>,
        failure_stage: &'static str,
        error_message: impl Into<String>,
    ) -> Self {
        Self {
            provider,
            endpoint: endpoint.into(),
            operation: operation.into(),
            failure_stage,
            status_code: None,
            status_class: None,
            timeout: false,
            retryable: false,
            error_message: error_message.into(),
            error_source: None,
            raw_excerpt: None,
            latency_ms: None,
            prompt_chars: None,
            reference_image_count: None,
            image_model: None,
            user_id: None,
            profile_id: None,
            request_id: None,
        }
    }

    pub(crate) fn with_status_code(mut self, status_code: Option<u16>) -> Self {
        self.status_code = status_code;
        self
    }

    pub(crate) fn with_optional_status_class(mut self, status_class: Option<&'static str>) -> Self {
        self.status_class = status_class;
        self
    }

    pub(crate) fn with_timeout(mut self, timeout: bool) -> Self {
        self.timeout = timeout;
        self
    }

    pub(crate) fn with_retryable(mut self, retryable: bool) -> Self {
        self.retryable = retryable;
        self
    }

    pub(crate) fn with_error_source(mut self, error_source: Option<String>) -> Self {
        self.error_source = error_source;
        self
    }

    pub(crate) fn with_raw_excerpt(mut self, raw_excerpt: Option<String>) -> Self {
        self.raw_excerpt = raw_excerpt;
        self
    }

    pub(crate) fn with_latency_ms(mut self, latency_ms: Option<u64>) -> Self {
        self.latency_ms = latency_ms;
        self
    }

    pub(crate) fn with_prompt_chars(mut self, prompt_chars: Option<usize>) -> Self {
        self.prompt_chars = prompt_chars;
        self
    }

    pub(crate) fn with_reference_image_count(
        mut self,
        reference_image_count: Option<usize>,
    ) -> Self {
        self.reference_image_count = reference_image_count;
        self
    }

    pub(crate) fn with_image_model(mut self, image_model: Option<&'static str>) -> Self {
        self.image_model = image_model;
        self
    }

    pub(crate) fn with_user_id(mut self, user_id: Option<String>) -> Self {
        self.user_id = user_id;
        self
    }

    pub(crate) fn with_profile_id(mut self, profile_id: Option<String>) -> Self {
        self.profile_id = profile_id;
        self
    }

    pub(crate) fn with_request_id(mut self, request_id: Option<String>) -> Self {
        self.request_id = request_id;
        self
    }

    pub(crate) fn with_audit_context(mut self, context: &ExternalApiAuditContext) -> Self {
        self.user_id = context.user_id.clone();
        self.profile_id = context.profile_id.clone();
        self.request_id = context.request_id.clone();
        self
    }
}

/// 外部 API 失败审计的调用方上下文（用户 / 档案 / 请求 id）。
#[derive(Clone, Debug, Default)]
pub(crate) struct ExternalApiAuditContext {
    pub(crate) user_id: Option<String>,
    pub(crate) profile_id: Option<String>,
    pub(crate) request_id: Option<String>,
    /// 父流程允许外部调用占用到的绝对时刻。该字段只在进程内用于预算截断，
    /// 不写入 tracking metadata，也不会通过内部协议传递绝对时间。
    pub(crate) external_call_deadline: Option<Instant>,
}

/// 抠图供应商（BgFilter / 阿里云通用抠图）调用失败的统一失败审计入口。
/// 即使随后兜底成功，供应商故障也必须进入 OTLP + tracking_event，不能只 warn! 后静默。
#[allow(clippy::too_many_arguments)]
pub(crate) async fn record_matting_external_api_failure(
    state: &AppState,
    context: &ExternalApiAuditContext,
    provider: &'static str,
    endpoint: String,
    operation: &'static str,
    failure_stage: &'static str,
    status_code: Option<u16>,
    timeout: bool,
    transport: bool,
    latency_ms: Option<u64>,
    error_message: String,
    raw_excerpt: Option<String>,
) {
    let draft = build_matting_external_api_failure_draft(
        provider,
        endpoint,
        operation,
        failure_stage,
        status_code,
        timeout,
        transport,
        latency_ms,
        error_message,
        raw_excerpt,
        context,
    );
    record_external_api_failure(state, draft).await;
}

/// BgFilter worker 专用入口：保留同一份 OTLP / tracking draft，但只允许写入本进程
/// 独立 outbox。outbox 缺失、满载或写盘失败时丢弃，禁止在受限 worker 中逐条同步
/// 直写 SpacetimeDB。
#[allow(clippy::too_many_arguments)]
pub(crate) async fn record_matting_external_api_failure_outbox_only(
    state: &AppState,
    context: &ExternalApiAuditContext,
    provider: &'static str,
    endpoint: String,
    operation: &'static str,
    failure_stage: &'static str,
    status_code: Option<u16>,
    timeout: bool,
    transport: bool,
    latency_ms: Option<u64>,
    error_message: String,
    raw_excerpt: Option<String>,
) {
    let draft = build_matting_external_api_failure_draft(
        provider,
        endpoint,
        operation,
        failure_stage,
        status_code,
        timeout,
        transport,
        latency_ms,
        error_message,
        raw_excerpt,
        context,
    );
    record_external_api_failure_with_policy(
        state,
        draft,
        ExternalApiAuditPersistencePolicy::RequireOutboxDropOnFailure,
    )
    .await;
}

/// 构建抠图失败审计 draft。`transport` 必须由调用方从错误结构化字段读取，
/// 不能用 `status_code.is_none()` 反推——本地处理失败同样没有上游 HTTP 状态。
#[allow(clippy::too_many_arguments)]
pub(crate) fn build_matting_external_api_failure_draft(
    provider: &'static str,
    endpoint: String,
    operation: &'static str,
    failure_stage: &'static str,
    status_code: Option<u16>,
    timeout: bool,
    transport: bool,
    latency_ms: Option<u64>,
    error_message: String,
    raw_excerpt: Option<String>,
    context: &ExternalApiAuditContext,
) -> ExternalApiFailureDraft {
    // 传输层：无上游 HTTP 状态 + timeout/transport 标记 → statusClass=transport、retryable=true。
    // 本地处理：无上游 HTTP 状态且非 transport → statusClass=local、retryable=false。
    // 不得把「status_code=None」一律当成 transport，否则 LocalProcessing 会污染可重试 5xx 分析。
    let is_transport_failure = timeout || transport;
    let resolved_status_class = if is_transport_failure && status_code.is_none() {
        "transport"
    } else if status_code.is_none() {
        "local"
    } else {
        status_class(status_code)
    };
    ExternalApiFailureDraft::new(provider, endpoint, operation, failure_stage, error_message)
        .with_status_code(status_code)
        .with_optional_status_class(Some(resolved_status_class))
        .with_timeout(timeout)
        .with_retryable(is_retryable_external_api_failure(
            status_code,
            timeout,
            is_transport_failure,
        ))
        .with_latency_ms(latency_ms)
        .with_raw_excerpt(raw_excerpt)
        .with_audit_context(context)
}

pub(crate) fn matting_failure_audit_status_code(error: &AppError) -> Option<u16> {
    // 真实上游 HTTP 状态优先；本地处理 / 传输层都没有可写的上游 status。
    if let Some(status) = error
        .details()
        .and_then(|details| details.get("upstreamStatus"))
        .and_then(Value::as_u64)
        .and_then(|value| u16::try_from(value).ok())
    {
        return Some(status);
    }
    if matting_failure_audit_is_local_processing(error) || matting_failure_audit_is_transport(error)
    {
        return None;
    }
    Some(error.status_code().as_u16())
}

pub(crate) fn matting_failure_audit_is_local_processing(error: &AppError) -> bool {
    error
        .details()
        .and_then(|details| details.get("localProcessing"))
        .and_then(Value::as_bool)
        .unwrap_or(false)
}

pub(crate) fn matting_failure_audit_is_transport(error: &AppError) -> bool {
    matting_failure_audit_timeout(error)
        || error
            .details()
            .and_then(|details| details.get("transport"))
            .and_then(Value::as_bool)
            .unwrap_or(false)
}

pub(crate) fn matting_failure_audit_timeout(error: &AppError) -> bool {
    error
        .details()
        .and_then(|details| details.get("timeout"))
        .and_then(Value::as_bool)
        .unwrap_or(false)
}

pub(crate) fn matting_failure_audit_latency_ms(error: &AppError) -> Option<u64> {
    error
        .details()
        .and_then(|details| details.get("latencyMs"))
        .and_then(Value::as_u64)
}

pub(crate) fn matting_failure_external_call_attempted(error: &AppError) -> bool {
    error
        .details()
        .and_then(|details| details.get("externalCallAttempted"))
        .and_then(Value::as_bool)
        .unwrap_or(true)
}

pub(crate) fn matting_failure_audit_failure_stage(
    error: &AppError,
    fallback: &'static str,
) -> &'static str {
    let stage = error
        .details()
        .and_then(|details| details.get("failureStage"))
        .and_then(Value::as_str);
    match stage {
        Some("preflight") => "preflight",
        Some("source_download") => "source_download",
        Some("source_decode") => "source_decode",
        Some("source_validate") => "source_validate",
        Some("source_normalize") => "source_normalize",
        Some("temp_upload") => "temp_upload",
        Some("aliyun_segment") => "aliyun_segment",
        Some("result_download") => "result_download",
        Some("result_decode") => "result_decode",
        Some("result_validate") => "result_validate",
        Some("result_encode") => "result_encode",
        _ => fallback,
    }
}

pub(crate) fn matting_failure_audit_raw_excerpt(error: &AppError) -> Option<String> {
    error
        .details()
        .and_then(|details| {
            details
                .get("upstreamMessage")
                .or_else(|| details.get("rawExcerpt"))
        })
        .and_then(Value::as_str)
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .map(|value| value.chars().take(800).collect())
}

pub(crate) fn build_external_api_failure_draft_from_platform_image_audit(
    audit: &PlatformImageFailureAudit,
) -> ExternalApiFailureDraft {
    ExternalApiFailureDraft::new(
        audit.provider,
        audit.endpoint.clone(),
        audit.operation.clone(),
        audit.failure_stage,
        audit.error_message.clone(),
    )
    .with_status_code(audit.status_code)
    .with_optional_status_class(audit.status_class)
    .with_timeout(audit.timeout)
    .with_retryable(audit.retryable)
    .with_error_source(audit.error_source.clone())
    .with_raw_excerpt(audit.raw_excerpt.clone())
    .with_latency_ms(audit.latency_ms)
    .with_prompt_chars(audit.prompt_chars)
    .with_reference_image_count(audit.reference_image_count)
    .with_image_model(audit.image_model)
    .with_user_id(None)
    .with_profile_id(None)
    .with_request_id(None)
}

/// 中文注释：下载图片、OSS 读写等非标准 HTTP 状态统一显式归类，避免 OTLP 低基数 label 误落到 `transport`。
#[cfg(test)]
pub(crate) fn app_error_status_class(status_code: StatusCode) -> &'static str {
    status_class(Some(status_code.as_u16()))
}

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
enum ExternalApiAuditPersistencePolicy {
    PreferOutboxThenSync,
    RequireOutboxDropOnFailure,
}

impl ExternalApiAuditPersistencePolicy {
    fn allows_sync_fallback(self) -> bool {
        matches!(self, Self::PreferOutboxThenSync)
    }
}

/// 中文注释：外部供应商失败同时进入 OTLP 和 tracking_event；失败审计不能反向阻断主业务错误返回。
pub(crate) async fn record_external_api_failure(state: &AppState, draft: ExternalApiFailureDraft) {
    record_external_api_failure_with_policy(
        state,
        draft,
        ExternalApiAuditPersistencePolicy::PreferOutboxThenSync,
    )
    .await;
}

async fn record_external_api_failure_with_policy(
    state: &AppState,
    draft: ExternalApiFailureDraft,
    persistence_policy: ExternalApiAuditPersistencePolicy,
) {
    record_external_api_failure_otlp(&draft);

    let tracking_event = build_external_api_failure_tracking_draft(&draft);
    if let Some(outbox) = state.tracking_outbox() {
        match outbox
            .enqueue(crate::tracking::build_tracking_event_input(
                tracking_event.clone(),
            ))
            .await
        {
            Ok(crate::tracking_outbox::TrackingOutboxEnqueueOutcome::Enqueued) => {}
            Ok(crate::tracking_outbox::TrackingOutboxEnqueueOutcome::Dropped { reason }) => {
                if !persistence_policy.allows_sync_fallback() {
                    crate::telemetry::record_external_api_audit_dropped(draft.provider, reason);
                    tracing::warn!(
                        provider = draft.provider,
                        endpoint = %draft.endpoint,
                        operation = %draft.operation,
                        failure_stage = draft.failure_stage,
                        reason,
                        "外部 API 失败审计写入专用 outbox 被保护阈值拒绝，已丢弃"
                    );
                    return;
                }
                tracing::warn!(
                    provider = draft.provider,
                    endpoint = %draft.endpoint,
                    operation = %draft.operation,
                    failure_stage = draft.failure_stage,
                    reason,
                    "外部 API 失败审计写入 outbox 被保护阈值拒绝，回退同步直写 SpacetimeDB"
                );
                crate::tracking::record_tracking_event_after_success(
                    state,
                    &audit_request_context(),
                    tracking_event,
                )
                .await;
            }
            Err(error) => {
                if !persistence_policy.allows_sync_fallback() {
                    crate::telemetry::record_external_api_audit_dropped(
                        draft.provider,
                        "outbox_error",
                    );
                    tracing::warn!(
                        provider = draft.provider,
                        endpoint = %draft.endpoint,
                        operation = %draft.operation,
                        failure_stage = draft.failure_stage,
                        error = %error,
                        "外部 API 失败审计写入专用 outbox 失败，已丢弃"
                    );
                    return;
                }
                tracing::warn!(
                    provider = draft.provider,
                    endpoint = %draft.endpoint,
                    operation = %draft.operation,
                    failure_stage = draft.failure_stage,
                    error = %error,
                    "外部 API 失败审计写入 outbox 失败，回退同步直写 SpacetimeDB"
                );
                crate::tracking::record_tracking_event_after_success(
                    state,
                    &audit_request_context(),
                    tracking_event,
                )
                .await;
            }
        }
        return;
    }

    if !persistence_policy.allows_sync_fallback() {
        crate::telemetry::record_external_api_audit_dropped(draft.provider, "outbox_missing");
        tracing::warn!(
            provider = draft.provider,
            endpoint = %draft.endpoint,
            operation = %draft.operation,
            failure_stage = draft.failure_stage,
            "外部 API 失败审计缺少专用 outbox，已丢弃"
        );
        return;
    }

    crate::tracking::record_tracking_event_after_success(
        state,
        &audit_request_context(),
        tracking_event,
    )
    .await;
}

pub(crate) fn build_external_api_failure_tracking_draft(
    failure: &ExternalApiFailureDraft,
) -> TrackingEventDraft {
    let mut draft = TrackingEventDraft::new(
        EXTERNAL_API_FAILURE_EVENT_KEY,
        EXTERNAL_API_AUDIT_MODULE_KEY,
    );
    draft.scope_kind = RuntimeTrackingScopeKind::Module;
    draft.scope_id = failure.provider.to_string();
    draft.user_id = failure.user_id.clone();
    draft.owner_user_id = failure.user_id.clone();
    draft.profile_id = failure.profile_id.clone();
    draft.metadata = build_external_api_failure_metadata(failure);
    draft
}

fn build_external_api_failure_metadata(failure: &ExternalApiFailureDraft) -> Value {
    let mut metadata = json!({
        "provider": failure.provider,
        "endpoint": failure.endpoint,
        "operation": failure.operation,
        "failureStage": failure.failure_stage,
        "statusCode": failure.status_code,
        "statusClass": failure.status_class.unwrap_or_else(|| status_class(failure.status_code)),
        "timeout": failure.timeout,
        "retryable": failure.retryable,
        "errorMessage": truncate_field(failure.error_message.as_str(), 1_000),
        "occurredAt": current_utc_iso_text(),
    });

    if let Some(latency_ms) = failure.latency_ms {
        metadata["latencyMs"] = json!(latency_ms);
    }
    if let Some(prompt_chars) = failure.prompt_chars {
        metadata["promptChars"] = json!(prompt_chars);
    }
    if let Some(reference_image_count) = failure.reference_image_count {
        metadata["referenceImageCount"] = json!(reference_image_count);
    }
    if let Some(image_model) = failure.image_model {
        metadata["imageModel"] = json!(image_model);
    }
    if let Some(user_id) = failure
        .user_id
        .as_deref()
        .map(str::trim)
        .filter(|value| !value.is_empty())
    {
        metadata["userId"] = json!(truncate_field(user_id, 1_000));
    }
    if let Some(profile_id) = failure
        .profile_id
        .as_deref()
        .map(str::trim)
        .filter(|value| !value.is_empty())
    {
        metadata["profileId"] = json!(truncate_field(profile_id, 1_000));
    }
    if let Some(request_id) = failure
        .request_id
        .as_deref()
        .map(str::trim)
        .filter(|value| !value.is_empty())
    {
        metadata["requestId"] = json!(truncate_field(request_id, 1_000));
    }
    if let Some(source) = failure
        .error_source
        .as_deref()
        .map(str::trim)
        .filter(|value| !value.is_empty())
    {
        metadata["errorSource"] = json!(truncate_field(source, 1_000));
    }
    if let Some(excerpt) = failure
        .raw_excerpt
        .as_deref()
        .map(str::trim)
        .filter(|value| !value.is_empty())
    {
        metadata["rawExcerpt"] = json!(truncate_field(excerpt, 800));
    }

    metadata
}

pub(crate) fn is_retryable_external_api_failure(
    status_code: Option<u16>,
    timeout: bool,
    connect: bool,
) -> bool {
    // 429 Too Many Requests / 408 Request Timeout / 5xx 视为可重试。
    timeout
        || connect
        || status_code.is_some_and(|status| status == 429 || status == 408 || status >= 500)
}

fn record_external_api_failure_otlp(failure: &ExternalApiFailureDraft) {
    crate::telemetry::record_external_api_failure(
        failure.provider,
        failure.failure_stage,
        failure
            .status_class
            .unwrap_or_else(|| status_class(failure.status_code)),
        failure.retryable,
    );

    tracing::error!(
        provider = failure.provider,
        endpoint = %failure.endpoint,
        operation = %failure.operation,
        failure_stage = failure.failure_stage,
        status_code = failure.status_code,
        status_class = failure.status_class.unwrap_or_else(|| status_class(failure.status_code)),
        timeout = failure.timeout,
        retryable = failure.retryable,
        latency_ms = failure.latency_ms,
        prompt_chars = failure.prompt_chars,
        reference_image_count = failure.reference_image_count,
        image_model = failure.image_model,
        request_id = %failure.request_id.as_deref().unwrap_or_default(),
        error_source = %failure.error_source.as_deref().unwrap_or_default(),
        error = %failure.error_message,
        "外部 API 调用失败"
    );
}

fn status_class(status_code: Option<u16>) -> &'static str {
    match status_code {
        Some(100..=199) => "1xx",
        Some(200..=299) => "2xx",
        Some(300..=399) => "3xx",
        Some(400..=499) => "4xx",
        Some(500..=599) => "5xx",
        Some(_) => "unknown",
        None => "transport",
    }
}

fn audit_request_context() -> crate::request_context::RequestContext {
    crate::request_context::RequestContext::new(
        format!("external-api-audit-{}", Uuid::new_v4()),
        "external-api audit".to_string(),
        std::time::Duration::ZERO,
        false,
    )
}

fn truncate_field(value: &str, max_chars: usize) -> String {
    value.chars().take(max_chars).collect()
}

fn current_utc_iso_text() -> String {
    shared_kernel::format_rfc3339(OffsetDateTime::now_utc())
        .unwrap_or_else(|_| "1970-01-01T00:00:00Z".to_string())
}

#[cfg(test)]
mod tests {
    use serde_json::Value;

    use super::*;

    #[test]
    fn bgfilter_outbox_only_policy_never_allows_sync_fallback() {
        assert!(ExternalApiAuditPersistencePolicy::PreferOutboxThenSync.allows_sync_fallback());
        assert!(
            !ExternalApiAuditPersistencePolicy::RequireOutboxDropOnFailure.allows_sync_fallback()
        );
    }

    #[test]
    fn external_api_failure_tracking_draft_uses_module_scope_and_safe_metadata() {
        let draft = build_external_api_failure_tracking_draft(
            &ExternalApiFailureDraft::new(
                "vector-engine",
                "https://vector.example/v1/images/generations",
                "拼图 UI 背景图生成失败",
                "upstream_status",
                "上游 429",
            )
            .with_status_code(Some(429))
            .with_retryable(true)
            .with_error_source(Some(
                "client error (SendRequest) -> connection closed before message completed"
                    .to_string(),
            ))
            .with_latency_ms(Some(1234))
            .with_prompt_chars(Some(88))
            .with_reference_image_count(Some(2))
            .with_image_model(Some("gpt-image-2-all")),
        );

        assert_eq!(draft.event_key, EXTERNAL_API_FAILURE_EVENT_KEY);
        assert_eq!(draft.scope_kind, RuntimeTrackingScopeKind::Module);
        assert_eq!(draft.scope_id, "vector-engine");
        assert_eq!(draft.module_key, Some(EXTERNAL_API_AUDIT_MODULE_KEY));

        let metadata = draft.metadata;
        assert_eq!(metadata["provider"], "vector-engine");
        assert_eq!(metadata["statusCode"], 429);
        assert_eq!(metadata["statusClass"], "4xx");
        assert_eq!(metadata["retryable"], true);
        assert_eq!(metadata["latencyMs"], 1234);
        assert_eq!(metadata["promptChars"], 88);
        assert_eq!(metadata["referenceImageCount"], 2);
        assert_eq!(metadata["imageModel"], "gpt-image-2-all");
        assert_eq!(
            metadata["errorSource"],
            "client error (SendRequest) -> connection closed before message completed"
        );
        assert!(matches!(metadata["occurredAt"], Value::String(_)));
    }

    #[test]
    fn retryable_classification_keeps_transport_and_overload_failures_actionable() {
        assert!(is_retryable_external_api_failure(None, true, false));
        assert!(is_retryable_external_api_failure(None, false, true));
        assert!(is_retryable_external_api_failure(Some(429), false, false));
        assert!(is_retryable_external_api_failure(Some(502), false, false));
        assert!(!is_retryable_external_api_failure(Some(400), false, false));
    }

    #[test]
    fn matting_failure_draft_marks_non_timeout_transport_retryable() {
        // status_code=None、timeout=false、transport=true 的非超时传输故障：
        // statusClass 必须是 transport 且 retryable=true，否则与 "transport failures actionable" 冲突。
        let draft = build_matting_external_api_failure_draft(
            "bgfilter",
            "https://bgfilter.example/remove-background".to_string(),
            "editor-screen-background-removal",
            "bgfilter_segment",
            None,
            false,
            true,
            Some(67),
            "请求 BgFilter 服务失败：dns error".to_string(),
            Some("dns error".to_string()),
            &ExternalApiAuditContext::default(),
        );

        assert_eq!(draft.status_code, None);
        assert_eq!(draft.status_class, Some("transport"));
        assert!(!draft.timeout);
        assert!(
            draft.retryable,
            "非超时 transport 失败应当 retryable=true，与 statusClass=transport 保持一致"
        );
    }

    #[test]
    fn matting_failure_draft_marks_local_processing_non_retryable() {
        // 本地处理失败没有上游 HTTP 状态，也不是 transport；不得记成可重试 5xx/transport。
        let draft = build_matting_external_api_failure_draft(
            "aliyun-matting",
            "imageseg.example".to_string(),
            "editor-screen-background-removal",
            "source_decode",
            None,
            false,
            false,
            Some(3),
            "解析待抠图图片失败：invalid png".to_string(),
            Some("invalid png".to_string()),
            &ExternalApiAuditContext::default(),
        );

        assert_eq!(draft.status_code, None);
        assert_eq!(draft.status_class, Some("local"));
        assert!(!draft.timeout);
        assert!(!draft.retryable);
    }

    #[test]
    fn matting_failure_draft_keeps_client_error_non_retryable() {
        // 真实上游 4xx（非 429 / 408）不是传输故障，仍应 retryable=false，不能被误判为可重试。
        let draft = build_matting_external_api_failure_draft(
            "aliyun-matting",
            "imageseg.example".to_string(),
            "editor-screen-background-removal",
            "aliyun_segment",
            Some(400),
            false,
            false,
            Some(12),
            "通用抠图接口返回失败（HTTP 400，Code=InvalidImage）：bad image".to_string(),
            None,
            &ExternalApiAuditContext::default(),
        );

        assert_eq!(draft.status_code, Some(400));
        assert_eq!(draft.status_class, Some("4xx"));
        assert!(!draft.retryable);
    }

    #[test]
    fn app_error_status_class_can_override_successful_upstream_status() {
        let draft = build_external_api_failure_tracking_draft(
            &ExternalApiFailureDraft::new(
                "vector-engine",
                "https://cdn.example/generated.png",
                "下载生成图片",
                "image_download",
                "下载生成图片失败",
            )
            .with_status_code(Some(200))
            .with_optional_status_class(Some(app_error_status_class(StatusCode::BAD_GATEWAY))),
        );

        assert_eq!(draft.metadata["statusCode"], 200);
        assert_eq!(draft.metadata["statusClass"], "5xx");
    }

    #[test]
    fn matting_failure_audit_uses_upstream_status_instead_of_wrapped_status() {
        let error = AppError::from_status(StatusCode::BAD_GATEWAY).with_details(json!({
            "provider": "bgfilter",
            "message": "BgFilter 服务返回非成功状态",
            "upstreamStatus": 429,
            "upstreamMessage": "too many requests",
            "latencyMs": 345,
        }));

        let status_code = matting_failure_audit_status_code(&error);
        let timeout = matting_failure_audit_timeout(&error);
        let tracking = build_external_api_failure_tracking_draft(
            &ExternalApiFailureDraft::new(
                "bgfilter",
                "https://bgfilter.example/remove-background",
                "editor-screen-background-removal",
                "bgfilter_segment",
                error.message(),
            )
            .with_status_code(status_code)
            .with_optional_status_class(Some(status_class(status_code)))
            .with_timeout(timeout)
            .with_latency_ms(matting_failure_audit_latency_ms(&error))
            .with_retryable(is_retryable_external_api_failure(
                status_code,
                timeout,
                false,
            ))
            .with_raw_excerpt(matting_failure_audit_raw_excerpt(&error)),
        );

        assert_eq!(tracking.metadata["statusCode"], 429);
        assert_eq!(tracking.metadata["statusClass"], "4xx");
        assert_eq!(tracking.metadata["timeout"], false);
        assert_eq!(tracking.metadata["retryable"], true);
        assert_eq!(tracking.metadata["latencyMs"], 345);
        assert_eq!(tracking.metadata["rawExcerpt"], "too many requests");
    }

    #[test]
    fn matting_failure_audit_keeps_transport_timeout_classification() {
        let error = AppError::from_status(StatusCode::GATEWAY_TIMEOUT).with_details(json!({
            "provider": "bgfilter",
            "message": "请求 BgFilter 服务失败：operation timed out",
            "timeout": true,
        }));

        let status_code = matting_failure_audit_status_code(&error);
        let timeout = matting_failure_audit_timeout(&error);
        let tracking = build_external_api_failure_tracking_draft(
            &ExternalApiFailureDraft::new(
                "bgfilter",
                "https://bgfilter.example/remove-background",
                "editor-screen-background-removal",
                "bgfilter_segment",
                error.message(),
            )
            .with_status_code(status_code)
            .with_optional_status_class(Some(status_class(status_code)))
            .with_timeout(timeout)
            .with_retryable(is_retryable_external_api_failure(
                status_code,
                timeout,
                false,
            )),
        );

        assert_eq!(tracking.metadata["statusCode"], Value::Null);
        assert_eq!(tracking.metadata["statusClass"], "transport");
        assert_eq!(tracking.metadata["timeout"], true);
        assert_eq!(tracking.metadata["retryable"], true);
    }

    #[test]
    fn matting_failure_audit_keeps_non_timeout_transport_classification() {
        let error = AppError::from_status(StatusCode::BAD_GATEWAY).with_details(json!({
            "provider": "bgfilter",
            "message": "请求 BgFilter 服务失败：dns error",
            "timeout": false,
            "transport": true,
            "latencyMs": 67,
        }));

        let status_code = matting_failure_audit_status_code(&error);
        let timeout = matting_failure_audit_timeout(&error);
        let tracking = build_external_api_failure_tracking_draft(
            &ExternalApiFailureDraft::new(
                "bgfilter",
                "https://bgfilter.example/remove-background",
                "editor-screen-background-removal",
                "bgfilter_segment",
                error.message(),
            )
            .with_status_code(status_code)
            .with_optional_status_class(Some(status_class(status_code)))
            .with_timeout(timeout)
            .with_latency_ms(matting_failure_audit_latency_ms(&error))
            .with_retryable(is_retryable_external_api_failure(
                status_code,
                timeout,
                false,
            )),
        );

        assert_eq!(tracking.metadata["statusCode"], Value::Null);
        assert_eq!(tracking.metadata["statusClass"], "transport");
        assert_eq!(tracking.metadata["timeout"], false);
        assert_eq!(tracking.metadata["retryable"], false);
        assert_eq!(tracking.metadata["latencyMs"], 67);
    }

    #[test]
    fn matting_failure_external_call_attempted_defaults_to_true() {
        let attempted = AppError::from_status(StatusCode::BAD_GATEWAY).with_details(json!({
            "provider": "aliyun-matting",
            "message": "真实上游失败",
        }));
        let skipped = AppError::from_status(StatusCode::SERVICE_UNAVAILABLE).with_details(json!({
            "provider": "aliyun-matting",
            "message": "阿里云抠图客户端未配置或未启用。",
            "externalCallAttempted": false,
        }));

        assert!(matting_failure_external_call_attempted(&attempted));
        assert!(!matting_failure_external_call_attempted(&skipped));
    }
}