//! 请求处理器
//!
//! 处理各种API端点的HTTP请求
//!
//! 重构后的结构：
//! - 通用逻辑提取到 `handler_context` 和 `response_processor` 模块
//! - 各 handler 只保留独特的业务逻辑
//! - Claude 的格式转换逻辑保留在此文件（用于 OpenRouter 旧接口回退）

use super::{
    error_mapper::{get_error_message, map_proxy_error_to_status},
    forwarder::ActiveConnectionGuard,
    handler_config::{
        claude_stream_usage_event_filter, codex_stream_usage_event_filter, CLAUDE_PARSER_CONFIG,
        CODEX_PARSER_CONFIG, GEMINI_PARSER_CONFIG, OPENAI_PARSER_CONFIG,
    },
    handler_context::RequestContext,
    providers::{
        codex_chat_history::record_responses_sse_stream, get_adapter, get_claude_api_format,
        streaming::create_anthropic_sse_stream,
        streaming_codex_chat::create_responses_sse_stream_from_chat,
        streaming_gemini::create_anthropic_sse_stream_from_gemini,
        streaming_responses::create_anthropic_sse_stream_from_responses, transform,
        transform_codex_chat, transform_gemini, transform_responses,
    },
    response_processor::{
        create_logged_passthrough_stream, process_response, read_decoded_body,
        strip_entity_headers_for_rebuilt_body, strip_hop_by_hop_response_headers,
        usage_logging_enabled, SseUsageCollector,
    },
    server::ProxyState,
    sse::{strip_sse_field, take_sse_block},
    types::*,
    usage::parser::TokenUsage,
    ProxyError,
};
use crate::app_config::AppType;
use crate::database::PRICING_SOURCE_REQUEST;
use axum::{extract::State, http::StatusCode, response::IntoResponse, Json};
use bytes::Bytes;
use http_body_util::BodyExt;
use serde_json::{json, Value};

// ============================================================================
// 健康检查和状态查询（简单端点）
// ============================================================================

/// 健康检查
pub async fn health_check() -> (StatusCode, Json<Value>) {
    (
        StatusCode::OK,
        Json(json!({
            "status": "healthy",
            "timestamp": chrono::Utc::now().to_rfc3339(),
        })),
    )
}

/// 获取服务状态
pub async fn get_status(State(state): State<ProxyState>) -> Result<Json<ProxyStatus>, ProxyError> {
    let status = state.status.read().await.clone();
    Ok(Json(status))
}

// ============================================================================
// Claude API 处理器（包含格式转换逻辑）
// ============================================================================

/// 处理 /v1/messages 请求（Claude API）
///
/// Claude 处理器包含独特的格式转换逻辑：
/// - 过去用于 OpenRouter 的 OpenAI Chat Completions 兼容接口（Anthropic ↔ OpenAI 转换）
/// - 现在 OpenRouter 已推出 Claude Code 兼容接口，默认不再启用该转换（逻辑保留以备回退）
pub async fn handle_messages(
    State(state): State<ProxyState>,
    request: axum::extract::Request,
) -> Result<axum::response::Response, ProxyError> {
    handle_messages_for_app(state, request, AppType::Claude, "Claude", "claude", None).await
}

pub async fn handle_claude_desktop_messages(
    State(state): State<ProxyState>,
    request: axum::extract::Request,
) -> Result<axum::response::Response, ProxyError> {
    validate_claude_desktop_gateway_auth(&state, request.headers())?;
    handle_messages_for_app(
        state,
        request,
        AppType::ClaudeDesktop,
        "Claude Desktop",
        "claude-desktop",
        Some("/claude-desktop"),
    )
    .await
}

pub async fn handle_claude_desktop_models(
    State(state): State<ProxyState>,
    headers: axum::http::HeaderMap,
) -> Result<Json<Value>, ProxyError> {
    validate_claude_desktop_gateway_auth(&state, &headers)?;
    let providers = state
        .provider_router
        .select_providers("claude-desktop")
        .await
        .map_err(|e| ProxyError::DatabaseError(e.to_string()))?;
    let provider = providers.first().ok_or(ProxyError::NoAvailableProvider)?;
    let response = crate::claude_desktop_config::model_list_response(provider)
        .map_err(|e| ProxyError::ConfigError(e.to_string()))?;
    Ok(Json(response))
}

async fn handle_messages_for_app(
    state: ProxyState,
    request: axum::extract::Request,
    app_type: AppType,
    tag: &'static str,
    app_type_str: &'static str,
    strip_prefix: Option<&'static str>,
) -> Result<axum::response::Response, ProxyError> {
    let (parts, body) = request.into_parts();
    let method = parts.method.clone();
    let uri = parts.uri;
    let headers = parts.headers;
    let extensions = parts.extensions;
    let body_bytes = body
        .collect()
        .await
        .map_err(|e| ProxyError::Internal(format!("Failed to read request body: {e}")))?
        .to_bytes();
    let body: Value = serde_json::from_slice(&body_bytes)
        .map_err(|e| ProxyError::Internal(format!("Failed to parse request body: {e}")))?;

    let mut ctx =
        RequestContext::new(&state, &body, &headers, app_type.clone(), tag, app_type_str).await?;

    let raw_endpoint = uri
        .path_and_query()
        .map(|path_and_query| path_and_query.as_str())
        .unwrap_or(uri.path());
    let endpoint = strip_prefix
        .and_then(|prefix| raw_endpoint.strip_prefix(prefix))
        .unwrap_or(raw_endpoint);

    let is_stream = body
        .get("stream")
        .and_then(|s| s.as_bool())
        .unwrap_or(false);

    // 转发请求
    let forwarder = ctx.create_forwarder(&state);
    let mut result = match forwarder
        .forward_with_retry(
            &app_type,
            method,
            endpoint,
            body.clone(),
            headers,
            extensions,
            ctx.get_providers(),
        )
        .await
    {
        Ok(result) => result,
        Err(mut err) => {
            if let Some(provider) = err.provider.take() {
                ctx.provider = provider;
            }
            log_forward_error(&state, &ctx, is_stream, &err.error);
            return Err(err.error);
        }
    };

    let connection_guard = result.connection_guard.take();
    ctx.provider = result.provider;
    let api_format = result
        .claude_api_format
        .as_deref()
        .unwrap_or_else(|| get_claude_api_format(&ctx.provider))
        .to_string();
    let response = result.response;

    // 检查是否需要格式转换（OpenRouter 等中转服务）
    let adapter = get_adapter(&app_type);
    let needs_transform = adapter.needs_transform(&ctx.provider);

    // Claude 特有：格式转换处理
    if needs_transform {
        return handle_claude_transform(
            response,
            &ctx,
            &state,
            &body,
            is_stream,
            &api_format,
            connection_guard,
        )
        .await;
    }

    // 通用响应处理（透传模式）
    process_response(
        response,
        &ctx,
        &state,
        &CLAUDE_PARSER_CONFIG,
        connection_guard,
    )
    .await
}

fn validate_claude_desktop_gateway_auth(
    state: &ProxyState,
    headers: &axum::http::HeaderMap,
) -> Result<(), ProxyError> {
    let expected = crate::claude_desktop_config::get_or_create_gateway_token(state.db.as_ref())
        .map_err(|e| ProxyError::AuthError(e.to_string()))?;
    let Some(value) = headers.get(axum::http::header::AUTHORIZATION) else {
        return Err(ProxyError::AuthError(
            "Claude Desktop gateway 缺少 Authorization 头".to_string(),
        ));
    };
    let value = value
        .to_str()
        .map_err(|_| ProxyError::AuthError("Authorization 头格式无效".to_string()))?;
    let token = value
        .strip_prefix("Bearer ")
        .or_else(|| value.strip_prefix("bearer "))
        .unwrap_or("")
        .trim();
    if token != expected {
        return Err(ProxyError::AuthError(
            "Claude Desktop gateway token 无效".to_string(),
        ));
    }
    Ok(())
}

/// Claude 格式转换处理（独有逻辑）
///
/// 支持 OpenAI Chat Completions 和 Responses API 两种格式的转换
async fn handle_claude_transform(
    response: super::hyper_client::ProxyResponse,
    ctx: &RequestContext,
    state: &ProxyState,
    original_body: &Value,
    is_stream: bool,
    api_format: &str,
    connection_guard: Option<ActiveConnectionGuard>,
) -> Result<axum::response::Response, ProxyError> {
    let status = response.status();
    let is_codex_oauth = ctx
        .provider
        .meta
        .as_ref()
        .and_then(|meta| meta.provider_type.as_deref())
        == Some("codex_oauth");
    // Codex OAuth 会把 openai_responses 响应强制升级为 SSE，即使客户端发的是 stream:false。
    // should_use_claude_transform_streaming 默认会把这个组合路由到流式转换器——虽然能避免
    // JSON parse 报 422，但会让非流客户端收到 text/event-stream，违反 Anthropic 非流语义。
    // 这里为这个特定组合打开 override：把上游 SSE 聚合成 Anthropic JSON 回给客户端，其它
    // 场景（任意上游 is_sse、非 Codex OAuth 等）仍沿用原有流式兜底。
    let aggregate_codex_oauth_responses_sse =
        !is_stream && is_codex_oauth && api_format == "openai_responses";
    let use_streaming = if aggregate_codex_oauth_responses_sse {
        false
    } else {
        should_use_claude_transform_streaming(
            is_stream,
            response.is_sse(),
            api_format,
            is_codex_oauth,
        )
    };
    let tool_schema_hints = transform_gemini::extract_anthropic_tool_schema_hints(original_body);
    let tool_schema_hints = (!tool_schema_hints.is_empty()).then_some(tool_schema_hints);

    if use_streaming {
        // 根据 api_format 选择流式转换器
        let stream = response.bytes_stream();
        let sse_stream: Box<
            dyn futures::Stream<Item = Result<Bytes, std::io::Error>> + Send + Unpin,
        > = if api_format == "openai_responses" {
            Box::new(Box::pin(create_anthropic_sse_stream_from_responses(stream)))
        } else if api_format == "gemini_native" {
            Box::new(Box::pin(create_anthropic_sse_stream_from_gemini(
                stream,
                Some(state.gemini_shadow.clone()),
                Some(ctx.provider.id.clone()),
                Some(ctx.session_id.clone()),
                tool_schema_hints.clone(),
            )))
        } else {
            Box::new(Box::pin(create_anthropic_sse_stream(stream)))
        };

        // 创建使用量收集器；关闭 usage logging 时不要再解析转换后的 SSE。
        let usage_collector = if usage_logging_enabled(state) {
            let state = state.clone();
            let provider_id = ctx.provider.id.clone();
            let model = ctx.request_model.clone();
            let status_code = status.as_u16();
            let start_time = ctx.start_time;
            let session_id = ctx.session_id.clone();

            Some(SseUsageCollector::new(
                start_time,
                Some(claude_stream_usage_event_filter),
                move |events, first_token_ms| {
                    if let Some(usage) = TokenUsage::from_claude_stream_events(&events) {
                        let latency_ms = start_time.elapsed().as_millis() as u64;
                        let state = state.clone();
                        let provider_id = provider_id.clone();
                        let model = model.clone();
                        let session_id = session_id.clone();

                        tokio::spawn(async move {
                            log_usage(
                                &state,
                                &provider_id,
                                "claude",
                                &model,
                                &model,
                                usage,
                                latency_ms,
                                first_token_ms,
                                true,
                                status_code,
                                Some(session_id),
                            )
                            .await;
                        });
                    } else {
                        log::debug!("[Claude] OpenRouter 流式响应缺少 usage 统计，跳过消费记录");
                    }
                },
            ))
        } else {
            None
        };

        // 获取流式超时配置
        let timeout_config = ctx.streaming_timeout_config();

        let logged_stream = create_logged_passthrough_stream(
            sse_stream,
            "Claude/OpenRouter",
            usage_collector,
            timeout_config,
            connection_guard,
        );

        let mut headers = axum::http::HeaderMap::new();
        headers.insert(
            "Content-Type",
            axum::http::HeaderValue::from_static("text/event-stream"),
        );
        headers.insert(
            "Cache-Control",
            axum::http::HeaderValue::from_static("no-cache"),
        );

        let body = axum::body::Body::from_stream(logged_stream);
        return Ok((headers, body).into_response());
    }

    // 非流式响应转换 (OpenAI/Responses → Anthropic)
    let body_timeout =
        if ctx.app_config.auto_failover_enabled && ctx.app_config.non_streaming_timeout > 0 {
            std::time::Duration::from_secs(ctx.app_config.non_streaming_timeout as u64)
        } else {
            std::time::Duration::ZERO
        };
    let (mut response_headers, _status, body_bytes) =
        read_decoded_body(response, ctx.tag, body_timeout).await?;

    let body_str = String::from_utf8_lossy(&body_bytes);

    let upstream_response: Value = if aggregate_codex_oauth_responses_sse {
        responses_sse_to_response_value(&body_str)?
    } else {
        serde_json::from_slice(&body_bytes).map_err(|e| {
            log::error!("[Claude] 解析上游响应失败: {e}, body: {body_str}");
            ProxyError::TransformError(format!("Failed to parse upstream response: {e}"))
        })?
    };

    // 根据 api_format 选择非流式转换器
    let anthropic_response = if api_format == "openai_responses" {
        transform_responses::responses_to_anthropic(upstream_response)
    } else if api_format == "gemini_native" {
        transform_gemini::gemini_to_anthropic_with_shadow_and_hints(
            upstream_response,
            Some(state.gemini_shadow.as_ref()),
            Some(&ctx.provider.id),
            Some(&ctx.session_id),
            tool_schema_hints.as_ref(),
        )
    } else {
        transform::openai_to_anthropic(upstream_response)
    }
    .map_err(|e| {
        log::error!("[Claude] 转换响应失败: {e}");
        e
    })?;

    // 记录使用量
    if let Some(usage) = TokenUsage::from_claude_response(&anthropic_response) {
        let model = anthropic_response
            .get("model")
            .and_then(|m| m.as_str())
            .unwrap_or("unknown");
        let latency_ms = ctx.latency_ms();

        let request_model = ctx.request_model.clone();
        tokio::spawn({
            let state = state.clone();
            let provider_id = ctx.provider.id.clone();
            let model = model.to_string();
            let session_id = ctx.session_id.clone();
            async move {
                log_usage(
                    &state,
                    &provider_id,
                    "claude",
                    &model,
                    &request_model,
                    usage,
                    latency_ms,
                    None,
                    false,
                    status.as_u16(),
                    Some(session_id),
                )
                .await;
            }
        });
    }

    // 构建响应
    let mut builder = axum::response::Response::builder().status(status);
    strip_entity_headers_for_rebuilt_body(&mut response_headers);
    strip_hop_by_hop_response_headers(&mut response_headers);
    // Builder::header 是 append 语义；不先 remove 会和上游 Content-Type 双发。
    response_headers.remove(axum::http::header::CONTENT_TYPE);

    for (key, value) in response_headers.iter() {
        builder = builder.header(key, value);
    }

    builder = builder.header(
        axum::http::header::CONTENT_TYPE,
        axum::http::HeaderValue::from_static("application/json"),
    );

    let response_body = serde_json::to_vec(&anthropic_response).map_err(|e| {
        log::error!("[Claude] 序列化响应失败: {e}");
        ProxyError::TransformError(format!("Failed to serialize response: {e}"))
    })?;

    let body = axum::body::Body::from(response_body);
    builder.body(body).map_err(|e| {
        log::error!("[Claude] 构建响应失败: {e}");
        ProxyError::Internal(format!("Failed to build response: {e}"))
    })
}

fn endpoint_with_query(uri: &axum::http::Uri, endpoint: &str) -> String {
    match uri.query() {
        Some(query) => format!("{endpoint}?{query}"),
        None => endpoint.to_string(),
    }
}

// ============================================================================
// Codex API 处理器
// ============================================================================

/// 处理 /v1/chat/completions 请求（OpenAI Chat Completions API - Codex CLI）
pub async fn handle_chat_completions(
    State(state): State<ProxyState>,
    request: axum::extract::Request,
) -> Result<axum::response::Response, ProxyError> {
    let (parts, req_body) = request.into_parts();
    let method = parts.method.clone();
    let uri = parts.uri;
    let headers = parts.headers;
    let extensions = parts.extensions;
    let body_bytes = req_body
        .collect()
        .await
        .map_err(|e| ProxyError::Internal(format!("Failed to read request body: {e}")))?
        .to_bytes();
    let body: Value = serde_json::from_slice(&body_bytes)
        .map_err(|e| ProxyError::Internal(format!("Failed to parse request body: {e}")))?;

    let mut ctx =
        RequestContext::new(&state, &body, &headers, AppType::Codex, "Codex", "codex").await?;
    let endpoint = endpoint_with_query(&uri, "/chat/completions");

    let is_stream = body
        .get("stream")
        .and_then(|v| v.as_bool())
        .unwrap_or(false);

    let forwarder = ctx.create_forwarder(&state);
    let mut result = match forwarder
        .forward_with_retry(
            &AppType::Codex,
            method,
            &endpoint,
            body,
            headers,
            extensions,
            ctx.get_providers(),
        )
        .await
    {
        Ok(result) => result,
        Err(mut err) => {
            if let Some(provider) = err.provider.take() {
                ctx.provider = provider;
            }
            log_forward_error(&state, &ctx, is_stream, &err.error);
            return Err(err.error);
        }
    };

    let connection_guard = result.connection_guard.take();
    ctx.provider = result.provider;
    let response = result.response;

    process_response(
        response,
        &ctx,
        &state,
        &OPENAI_PARSER_CONFIG,
        connection_guard,
    )
    .await
}

/// 处理 /v1/responses 请求（OpenAI Responses API - Codex CLI 透传）
pub async fn handle_responses(
    State(state): State<ProxyState>,
    request: axum::extract::Request,
) -> Result<axum::response::Response, ProxyError> {
    let (parts, req_body) = request.into_parts();
    let method = parts.method.clone();
    let uri = parts.uri;
    let headers = parts.headers;
    let extensions = parts.extensions;
    let body_bytes = req_body
        .collect()
        .await
        .map_err(|e| ProxyError::Internal(format!("Failed to read request body: {e}")))?
        .to_bytes();
    let body: Value = serde_json::from_slice(&body_bytes)
        .map_err(|e| ProxyError::Internal(format!("Failed to parse request body: {e}")))?;

    let mut ctx =
        RequestContext::new(&state, &body, &headers, AppType::Codex, "Codex", "codex").await?;
    let endpoint = endpoint_with_query(&uri, "/responses");

    let is_stream = body
        .get("stream")
        .and_then(|v| v.as_bool())
        .unwrap_or(false);

    let forwarder = ctx.create_forwarder(&state);
    let mut result = match forwarder
        .forward_with_retry(
            &AppType::Codex,
            method,
            &endpoint,
            body,
            headers,
            extensions,
            ctx.get_providers(),
        )
        .await
    {
        Ok(result) => result,
        Err(mut err) => {
            if let Some(provider) = err.provider.take() {
                ctx.provider = provider;
            }
            log_forward_error(&state, &ctx, is_stream, &err.error);
            return Err(err.error);
        }
    };

    let connection_guard = result.connection_guard.take();
    ctx.provider = result.provider;
    let response = result.response;

    if super::providers::should_convert_codex_responses_to_chat(&ctx.provider, &endpoint) {
        return handle_codex_chat_to_responses_transform(
            response,
            &ctx,
            &state,
            is_stream,
            connection_guard,
        )
        .await;
    }

    process_response(
        response,
        &ctx,
        &state,
        &CODEX_PARSER_CONFIG,
        connection_guard,
    )
    .await
}

/// 处理 /v1/responses/compact 请求（OpenAI Responses Compact API - Codex CLI 透传）
pub async fn handle_responses_compact(
    State(state): State<ProxyState>,
    request: axum::extract::Request,
) -> Result<axum::response::Response, ProxyError> {
    let (parts, req_body) = request.into_parts();
    let method = parts.method.clone();
    let uri = parts.uri;
    let headers = parts.headers;
    let extensions = parts.extensions;
    let body_bytes = req_body
        .collect()
        .await
        .map_err(|e| ProxyError::Internal(format!("Failed to read request body: {e}")))?
        .to_bytes();
    let body: Value = serde_json::from_slice(&body_bytes)
        .map_err(|e| ProxyError::Internal(format!("Failed to parse request body: {e}")))?;

    let mut ctx =
        RequestContext::new(&state, &body, &headers, AppType::Codex, "Codex", "codex").await?;
    let endpoint = endpoint_with_query(&uri, "/responses/compact");

    let is_stream = body
        .get("stream")
        .and_then(|v| v.as_bool())
        .unwrap_or(false);

    let forwarder = ctx.create_forwarder(&state);
    let mut result = match forwarder
        .forward_with_retry(
            &AppType::Codex,
            method,
            &endpoint,
            body,
            headers,
            extensions,
            ctx.get_providers(),
        )
        .await
    {
        Ok(result) => result,
        Err(mut err) => {
            if let Some(provider) = err.provider.take() {
                ctx.provider = provider;
            }
            log_forward_error(&state, &ctx, is_stream, &err.error);
            return Err(err.error);
        }
    };

    let connection_guard = result.connection_guard.take();
    ctx.provider = result.provider;
    let response = result.response;

    if super::providers::should_convert_codex_responses_to_chat(&ctx.provider, &endpoint) {
        return handle_codex_chat_to_responses_transform(
            response,
            &ctx,
            &state,
            is_stream,
            connection_guard,
        )
        .await;
    }

    process_response(
        response,
        &ctx,
        &state,
        &CODEX_PARSER_CONFIG,
        connection_guard,
    )
    .await
}

async fn handle_codex_chat_to_responses_transform(
    response: super::hyper_client::ProxyResponse,
    ctx: &RequestContext,
    state: &ProxyState,
    is_stream: bool,
    connection_guard: Option<ActiveConnectionGuard>,
) -> Result<axum::response::Response, ProxyError> {
    let status = response.status();

    if !status.is_success() {
        // 上游 Chat 错误体形状与 Responses 不一致（如 MiniMax 的 base_resp、自定义 detail 字段）；
        // 直接透传会让 Codex 客户端无法识别错误码。这里统一转换为 Responses 风格
        // `{"error": {message, type, code, param}}`，保留原始 HTTP 状态码。
        return handle_codex_chat_error_response(response, ctx, status).await;
    }

    if is_stream || response.is_sse() {
        let stream = response.bytes_stream();
        let sse_stream = create_responses_sse_stream_from_chat(stream);
        let sse_stream = record_responses_sse_stream(sse_stream, state.codex_chat_history.clone());

        let usage_collector = if usage_logging_enabled(state) {
            let state = state.clone();
            let provider_id = ctx.provider.id.clone();
            let request_model = ctx.request_model.clone();
            let start_time = ctx.start_time;
            let session_id = ctx.session_id.clone();

            Some(SseUsageCollector::new(
                start_time,
                Some(codex_stream_usage_event_filter),
                move |events, first_token_ms| {
                    let usage =
                        TokenUsage::from_codex_stream_events_auto(&events).unwrap_or_default();
                    let model = usage.model.clone().unwrap_or_else(|| request_model.clone());
                    let latency_ms = start_time.elapsed().as_millis() as u64;

                    let state = state.clone();
                    let provider_id = provider_id.clone();
                    let request_model = request_model.clone();
                    let session_id = session_id.clone();

                    tokio::spawn(async move {
                        log_usage(
                            &state,
                            &provider_id,
                            "codex",
                            &model,
                            &request_model,
                            usage,
                            latency_ms,
                            first_token_ms,
                            true,
                            status.as_u16(),
                            Some(session_id),
                        )
                        .await;
                    });
                },
            ))
        } else {
            None
        };

        let logged_stream = create_logged_passthrough_stream(
            sse_stream,
            ctx.tag,
            usage_collector,
            ctx.streaming_timeout_config(),
            connection_guard,
        );

        let mut headers = axum::http::HeaderMap::new();
        headers.insert(
            "Content-Type",
            axum::http::HeaderValue::from_static("text/event-stream"),
        );
        headers.insert(
            "Cache-Control",
            axum::http::HeaderValue::from_static("no-cache"),
        );

        let body = axum::body::Body::from_stream(logged_stream);
        return Ok((headers, body).into_response());
    }

    let _connection_guard = connection_guard;
    let body_timeout =
        if ctx.app_config.auto_failover_enabled && ctx.app_config.non_streaming_timeout > 0 {
            std::time::Duration::from_secs(ctx.app_config.non_streaming_timeout as u64)
        } else {
            std::time::Duration::ZERO
        };
    let (mut response_headers, status, body_bytes) =
        read_decoded_body(response, ctx.tag, body_timeout).await?;
    let body_str = String::from_utf8_lossy(&body_bytes);
    let chat_response: Value = serde_json::from_slice(&body_bytes).map_err(|e| {
        log::error!("[Codex] 解析 Chat 上游响应失败: {e}, body: {body_str}");
        ProxyError::TransformError(format!("Failed to parse upstream chat response: {e}"))
    })?;
    let responses_response = transform_codex_chat::chat_completion_to_response(chat_response)
        .map_err(|e| {
            log::error!("[Codex] Chat → Responses 响应转换失败: {e}");
            e
        })?;
    state
        .codex_chat_history
        .record_response(&responses_response)
        .await;

    if let Some(usage) = TokenUsage::from_codex_response_auto(&responses_response) {
        let model = responses_response
            .get("model")
            .and_then(|m| m.as_str())
            .unwrap_or(&ctx.request_model);
        let request_model = ctx.request_model.clone();
        tokio::spawn({
            let state = state.clone();
            let provider_id = ctx.provider.id.clone();
            let model = model.to_string();
            let session_id = ctx.session_id.clone();
            let latency_ms = ctx.latency_ms();
            async move {
                log_usage(
                    &state,
                    &provider_id,
                    "codex",
                    &model,
                    &request_model,
                    usage,
                    latency_ms,
                    None,
                    false,
                    status.as_u16(),
                    Some(session_id),
                )
                .await;
            }
        });
    }

    strip_entity_headers_for_rebuilt_body(&mut response_headers);
    strip_hop_by_hop_response_headers(&mut response_headers);
    // Builder::header 是 append 语义；不先 remove 会和上游 Content-Type 双发。
    response_headers.remove(axum::http::header::CONTENT_TYPE);

    let mut builder = axum::response::Response::builder().status(status);
    for (key, value) in response_headers.iter() {
        builder = builder.header(key, value);
    }
    builder = builder.header(
        axum::http::header::CONTENT_TYPE,
        axum::http::HeaderValue::from_static("application/json"),
    );

    let response_body = serde_json::to_vec(&responses_response).map_err(|e| {
        log::error!("[Codex] 序列化 Responses 响应失败: {e}");
        ProxyError::TransformError(format!("Failed to serialize responses response: {e}"))
    })?;

    builder
        .body(axum::body::Body::from(response_body))
        .map_err(|e| {
            log::error!("[Codex] 构建 Responses 响应失败: {e}");
            ProxyError::Internal(format!("Failed to build response: {e}"))
        })
}

/// 把上游 Chat Completions 的错误响应转换为 Responses API 错误形状。
///
/// 与正常响应分支配套：正常响应已经被改写成 Responses 形式，错误响应若仍保留
/// Chat 错误体（如 MiniMax 的 `{"base_resp": {"status_code": 2013}}`），Codex
/// 客户端的错误处理就无法对齐字段。这里读取上游 body、规整成
/// `{"error": {message, type, code, param}}` 并保留原始 HTTP 状态码。
async fn handle_codex_chat_error_response(
    response: super::hyper_client::ProxyResponse,
    ctx: &RequestContext,
    status: axum::http::StatusCode,
) -> Result<axum::response::Response, ProxyError> {
    let body_timeout =
        if ctx.app_config.auto_failover_enabled && ctx.app_config.non_streaming_timeout > 0 {
            std::time::Duration::from_secs(ctx.app_config.non_streaming_timeout as u64)
        } else {
            std::time::Duration::ZERO
        };
    let (mut response_headers, _status, body_bytes) =
        read_decoded_body(response, ctx.tag, body_timeout).await?;

    // 非 JSON 上游错误体（Cloudflare HTML、纯文本 "Unauthorized" 等）若丢成 None，
    // 客户端就看不到原始诊断信息；包成 Value::String 走转换函数的字符串分支。
    let parsed_value: Value = match serde_json::from_slice::<Value>(&body_bytes) {
        Ok(value) => value,
        Err(_) => {
            const MAX_RAW_ERROR_BYTES: usize = 1024;
            let lossy = String::from_utf8_lossy(&body_bytes);
            let truncated = if lossy.len() > MAX_RAW_ERROR_BYTES {
                let mut end = MAX_RAW_ERROR_BYTES;
                while end > 0 && !lossy.is_char_boundary(end) {
                    end -= 1;
                }
                format!("{}…(truncated)", &lossy[..end])
            } else {
                lossy.into_owned()
            };
            log::warn!("[Codex] Chat 错误响应不是合法 JSON，按文本透传: {truncated}");
            Value::String(truncated)
        }
    };

    let responses_error = transform_codex_chat::chat_error_to_response_error(Some(&parsed_value));

    strip_entity_headers_for_rebuilt_body(&mut response_headers);
    strip_hop_by_hop_response_headers(&mut response_headers);
    // Builder::header 是 append 语义；不先 remove 会和上游 Content-Type 双发。
    response_headers.remove(axum::http::header::CONTENT_TYPE);

    let mut builder = axum::response::Response::builder().status(status);
    for (key, value) in response_headers.iter() {
        builder = builder.header(key, value);
    }
    builder = builder.header(
        axum::http::header::CONTENT_TYPE,
        axum::http::HeaderValue::from_static("application/json"),
    );

    let body = serde_json::to_vec(&responses_error).map_err(|e| {
        log::error!("[Codex] 序列化 Responses 错误体失败: {e}");
        ProxyError::TransformError(format!("Failed to serialize responses error: {e}"))
    })?;

    builder.body(axum::body::Body::from(body)).map_err(|e| {
        log::error!("[Codex] 构建 Responses 错误响应失败: {e}");
        ProxyError::Internal(format!("Failed to build response: {e}"))
    })
}

// ============================================================================
// Gemini API 处理器
// ============================================================================

/// 处理 Gemini API 请求（透传，包括查询参数）
pub async fn handle_gemini(
    State(state): State<ProxyState>,
    uri: axum::http::Uri,
    request: axum::extract::Request,
) -> Result<axum::response::Response, ProxyError> {
    let (parts, req_body) = request.into_parts();
    let method = parts.method.clone();
    let headers = parts.headers;
    let extensions = parts.extensions;
    let body_bytes = req_body
        .collect()
        .await
        .map_err(|e| ProxyError::Internal(format!("Failed to read request body: {e}")))?
        .to_bytes();
    // GET 类只读端点（/v1beta/models、/v1beta/models/<model> 等）没有请求体，
    // 不能强制 parse 为 JSON —— 否则空 body 会被拒绝。
    let body: Value = if body_bytes.is_empty() {
        Value::Null
    } else {
        serde_json::from_slice(&body_bytes)
            .map_err(|e| ProxyError::Internal(format!("Failed to parse request body: {e}")))?
    };

    // Gemini 的模型名称在 URI 中
    let mut ctx = RequestContext::new(&state, &body, &headers, AppType::Gemini, "Gemini", "gemini")
        .await?
        .with_model_from_uri(&uri);

    // 提取完整的路径和查询参数
    let endpoint = uri
        .path_and_query()
        .map(|pq| pq.as_str())
        .unwrap_or(uri.path());

    let is_stream = body
        .get("stream")
        .and_then(|v| v.as_bool())
        .unwrap_or(false);

    let forwarder = ctx.create_forwarder(&state);
    let mut result = match forwarder
        .forward_with_retry(
            &AppType::Gemini,
            method,
            endpoint,
            body,
            headers,
            extensions,
            ctx.get_providers(),
        )
        .await
    {
        Ok(result) => result,
        Err(mut err) => {
            if let Some(provider) = err.provider.take() {
                ctx.provider = provider;
            }
            log_forward_error(&state, &ctx, is_stream, &err.error);
            return Err(err.error);
        }
    };

    let connection_guard = result.connection_guard.take();
    ctx.provider = result.provider;
    let response = result.response;

    process_response(
        response,
        &ctx,
        &state,
        &GEMINI_PARSER_CONFIG,
        connection_guard,
    )
    .await
}

fn should_use_claude_transform_streaming(
    requested_streaming: bool,
    upstream_is_sse: bool,
    api_format: &str,
    is_codex_oauth: bool,
) -> bool {
    requested_streaming || upstream_is_sse || (is_codex_oauth && api_format == "openai_responses")
}

/// 把 OpenAI Responses SSE 流聚合成一个完整的 Responses JSON 对象，供下游转成 Anthropic
/// 非流响应。仅在 Codex OAuth 把 `stream:false` 强制升级为 SSE 的场景下调用。
///
/// 复用 `proxy::sse` 的 `take_sse_block`/`strip_sse_field`：`take_sse_block` 同时支持
/// `\n\n` 与 `\r\n\r\n` 两种分隔符，`strip_sse_field` 兼容带/不带空格的字段写法。
fn responses_sse_to_response_value(body: &str) -> Result<Value, ProxyError> {
    let mut buffer = body.to_string();
    let mut completed_response: Option<Value> = None;
    let mut output_items = Vec::new();

    while let Some(block) = take_sse_block(&mut buffer) {
        let mut event_name = "";
        let mut data_lines: Vec<&str> = Vec::new();

        for line in block.lines() {
            if let Some(evt) = strip_sse_field(line, "event") {
                event_name = evt.trim();
            } else if let Some(d) = strip_sse_field(line, "data") {
                data_lines.push(d);
            }
        }

        if data_lines.is_empty() {
            continue;
        }

        let data_str = data_lines.join("\n");
        if data_str.trim() == "[DONE]" {
            continue;
        }

        let data: Value = serde_json::from_str(&data_str).map_err(|e| {
            ProxyError::TransformError(format!("Failed to parse upstream SSE event: {e}"))
        })?;

        match event_name {
            "response.output_item.done" => {
                if let Some(item) = data.get("item") {
                    output_items.push(item.clone());
                }
            }
            "response.completed" => {
                completed_response = Some(data.get("response").cloned().unwrap_or(data));
            }
            "response.failed" => {
                let message = data
                    .pointer("/response/error/message")
                    .and_then(|v| v.as_str())
                    .unwrap_or("response.failed event received");
                return Err(ProxyError::TransformError(message.to_string()));
            }
            _ => {}
        }
    }

    let mut response = completed_response.ok_or_else(|| {
        ProxyError::TransformError("No response.completed event in upstream SSE".to_string())
    })?;

    if !output_items.is_empty() {
        if let Some(obj) = response.as_object_mut() {
            obj.insert("output".to_string(), Value::Array(output_items));
        } else {
            return Err(ProxyError::TransformError(
                "response.completed payload is not an object".to_string(),
            ));
        }
    }

    Ok(response)
}

// ============================================================================
// 使用量记录（保留用于 Claude 转换逻辑）
// ============================================================================

fn log_forward_error(
    state: &ProxyState,
    ctx: &RequestContext,
    is_streaming: bool,
    error: &ProxyError,
) {
    use super::usage::logger::UsageLogger;

    let logger = UsageLogger::new(&state.db);
    let status_code = map_proxy_error_to_status(error);
    let error_message = get_error_message(error);
    let request_id = uuid::Uuid::new_v4().to_string();

    if let Err(e) = logger.log_error_with_context(
        request_id,
        ctx.provider.id.clone(),
        ctx.app_type_str.to_string(),
        ctx.request_model.clone(),
        status_code,
        error_message,
        ctx.latency_ms(),
        is_streaming,
        Some(ctx.session_id.clone()),
        None,
    ) {
        log::warn!("记录失败请求日志失败: {e}");
    }
}

/// 记录请求使用量
#[allow(clippy::too_many_arguments)]
async fn log_usage(
    state: &ProxyState,
    provider_id: &str,
    app_type: &str,
    model: &str,
    request_model: &str,
    usage: TokenUsage,
    latency_ms: u64,
    first_token_ms: Option<u64>,
    is_streaming: bool,
    status_code: u16,
    session_id: Option<String>,
) {
    use super::usage::logger::UsageLogger;

    if !usage_logging_enabled(state) {
        return;
    }

    let logger = UsageLogger::new(&state.db);

    let (multiplier, pricing_model_source) =
        logger.resolve_pricing_config(provider_id, app_type).await;
    let pricing_model = if pricing_model_source == PRICING_SOURCE_REQUEST {
        request_model
    } else {
        model
    };

    let request_id = usage.dedup_request_id();

    if let Err(e) = logger.log_with_calculation(
        request_id,
        provider_id.to_string(),
        app_type.to_string(),
        model.to_string(),
        request_model.to_string(),
        pricing_model.to_string(),
        usage,
        multiplier,
        latency_ms,
        first_token_ms,
        status_code,
        session_id,
        None, // provider_type
        is_streaming,
    ) {
        log::warn!("[USG-001] 记录使用量失败: {e}");
    }
}

#[cfg(test)]
mod tests {
    use super::{responses_sse_to_response_value, should_use_claude_transform_streaming};
    use crate::proxy::ProxyError;

    #[test]
    fn codex_oauth_responses_force_streaming_even_if_client_sent_false() {
        assert!(should_use_claude_transform_streaming(
            false,
            false,
            "openai_responses",
            true,
        ));
    }

    #[test]
    fn upstream_sse_response_always_uses_streaming_path() {
        assert!(should_use_claude_transform_streaming(
            false,
            true,
            "openai_chat",
            false,
        ));
    }

    #[test]
    fn non_streaming_response_stays_non_streaming_for_regular_openai_responses() {
        assert!(!should_use_claude_transform_streaming(
            false,
            false,
            "openai_responses",
            false,
        ));
    }

    #[test]
    fn responses_sse_to_response_value_collects_output_items() {
        let sse = r#"event: response.output_item.done
data: {"type":"response.output_item.done","item":{"type":"message","role":"assistant","content":[{"type":"output_text","text":"hello"}]}}

event: response.completed
data: {"type":"response.completed","response":{"id":"resp_1","status":"completed","model":"gpt-5.4","output":[],"usage":{"input_tokens":10,"output_tokens":2}}}

"#;

        let response = responses_sse_to_response_value(sse).unwrap();

        assert_eq!(response["id"], "resp_1");
        assert_eq!(response["output"][0]["type"], "message");
        assert_eq!(response["output"][0]["content"][0]["text"], "hello");
    }

    #[test]
    fn responses_sse_to_response_value_handles_crlf_delimiters() {
        // 真实 HTTP SSE 按规范使用 \r\n\r\n 分隔事件；take_sse_block 必须同时处理两种分隔符，
        // 否则此路径在任何标准上游（含 Codex OAuth HTTPS 后端）下都会 TransformError。
        let sse = "event: response.output_item.done\r\n\
data: {\"type\":\"response.output_item.done\",\"item\":{\"type\":\"message\",\"role\":\"assistant\",\"content\":[{\"type\":\"output_text\",\"text\":\"hi\"}]}}\r\n\
\r\n\
event: response.completed\r\n\
data: {\"type\":\"response.completed\",\"response\":{\"id\":\"resp_crlf\",\"status\":\"completed\",\"model\":\"gpt-5.4\",\"output\":[],\"usage\":{\"input_tokens\":5,\"output_tokens\":1}}}\r\n\
\r\n";

        let response = responses_sse_to_response_value(sse).unwrap();

        assert_eq!(response["id"], "resp_crlf");
        assert_eq!(response["output"][0]["type"], "message");
        assert_eq!(response["output"][0]["content"][0]["text"], "hi");
    }

    #[test]
    fn responses_sse_to_response_value_returns_err_on_response_failed() {
        let sse = "event: response.failed\n\
data: {\"type\":\"response.failed\",\"response\":{\"error\":{\"message\":\"upstream blew up\"}}}\n\n";

        let err = responses_sse_to_response_value(sse).unwrap_err();
        match err {
            ProxyError::TransformError(msg) => assert!(msg.contains("upstream blew up")),
            other => panic!("expected TransformError, got {other:?}"),
        }
    }

    #[test]
    fn responses_sse_to_response_value_errors_when_no_completed_event() {
        let sse = "event: response.output_item.done\n\
data: {\"type\":\"response.output_item.done\",\"item\":{\"type\":\"message\"}}\n\n";

        assert!(responses_sse_to_response_value(sse).is_err());
    }
}