package handler

import (
	"encoding/json"
	"io"
	"github.com/yourname/cyrene-ai/pkg/logger"
	"net/http"
	"path/filepath"
	"strings"
	"time"

	"github.com/yourname/cyrene-ai/voice-service/internal/config"
	"github.com/yourname/cyrene-ai/voice-service/internal/service"
)

// STTHandler HTTP API 处理器
type STTHandler struct {
	svc    *service.STTService
	ttsSvc *service.TTSService
	cfg    *config.Config
}

// NewSTTHandler 创建 STT 处理器（可选传入 TTSService 用于组合状态）
func NewSTTHandler(svc *service.STTService, cfg *config.Config) *STTHandler {
	return &STTHandler{svc: svc, cfg: cfg}
}

// SetTTSService 设置 TTS 服务引用，用于组合状态端点
func (h *STTHandler) SetTTSService(ttsSvc *service.TTSService) {
	h.ttsSvc = ttsSvc
}

// RegisterRoutes 注册所有路由到 mux
func (h *STTHandler) RegisterRoutes(mux *http.ServeMux) {
	mux.HandleFunc("/api/v1/transcribe", h.handleTranscribe)
	mux.HandleFunc("/api/v1/health", h.handleHealth)
	mux.HandleFunc("/api/v1/status", h.handleStatus)
}

// handleTranscribe POST /api/v1/transcribe
// 接受 multipart/form-data，字段 audio (文件) 和 language (可选)
func (h *STTHandler) handleTranscribe(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	// 限制上传大小
	r.Body = http.MaxBytesReader(w, r.Body, h.cfg.MaxAudioSize)

	if err := r.ParseMultipartForm(h.cfg.MaxAudioSize); err != nil {
		writeError(w, http.StatusBadRequest, "文件过大或解析失败，最大支持 10MB")
		return
	}

	// 获取上传的文件
	file, header, err := r.FormFile("audio")
	if err != nil {
		writeError(w, http.StatusBadRequest, "缺少 audio 文件字段")
		return
	}
	defer file.Close()

	// 读取文件内容
	audioData, err := io.ReadAll(file)
	if err != nil {
		writeError(w, http.StatusInternalServerError, "读取音频文件失败")
		return
	}

	if len(audioData) == 0 {
		writeError(w, http.StatusBadRequest, "音频文件为空")
		return
	}

	// 获取语言参数 (可选)
	language := r.FormValue("language")

	// 推断音频格式
	format := inferFormat(header.Filename)
	if !isSupportedFormat(format) {
		writeError(w, http.StatusBadRequest, "不支持的音频格式: "+format+"，支持的格式: WAV, MP3, OGG, FLAC, M4A")
		return
	}

	// 执行转录
	startTime := time.Now()
	text, err := h.svc.Transcribe(audioData, format, language)
	durationMs := time.Since(startTime).Milliseconds()

	if err != nil {
		logger.Printf("[stt-handler] 转录失败: %v", err)
		writeJSON(w, http.StatusInternalServerError, map[string]interface{}{
			"success": false,
			"error":   err.Error(),
		})
		return
	}

	actualLang := language
	if actualLang == "" {
		actualLang = h.cfg.WhisperLanguage
	}

	writeJSON(w, http.StatusOK, map[string]interface{}{
		"success":     true,
		"text":        text,
		"language":    actualLang,
		"duration_ms": durationMs,
	})
}

// handleHealth GET /api/v1/health
func (h *STTHandler) handleHealth(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	sttStatus := h.svc.GetStatus()
	healthStatus := "ok"
	if !sttStatus["available"].(bool) {
		healthStatus = "degraded"
	}

	resp := map[string]interface{}{
		"status":  healthStatus,
		"service": "voice-service",
		"stt":     sttStatus,
	}

	// 如果有 TTS 服务，也包含 TTS 状态
	if h.ttsSvc != nil {
		resp["tts"] = h.ttsSvc.GetEngineStatus()
	}

	writeJSON(w, http.StatusOK, resp)
}

// handleStatus GET /api/v1/status
func (h *STTHandler) handleStatus(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	resp := map[string]interface{}{
		"service": "voice-service",
		"stt":     h.svc.GetStatus(),
	}

	// 如果有 TTS 服务，也包含 TTS 状态
	if h.ttsSvc != nil {
		resp["tts"] = h.ttsSvc.GetEngineStatus()
	}

	writeJSON(w, http.StatusOK, resp)
}

// --- 辅助函数 ---

func writeJSON(w http.ResponseWriter, status int, data interface{}) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	json.NewEncoder(w).Encode(data)
}

func writeError(w http.ResponseWriter, status int, message string) {
	writeJSON(w, status, map[string]interface{}{
		"error": message,
	})
}

// inferFormat 根据文件名推断音频格式
func inferFormat(filename string) string {
	ext := strings.ToLower(filepath.Ext(filename))
	switch ext {
	case ".wav", ".wave":
		return "wav"
	case ".mp3", ".mpeg":
		return "mp3"
	case ".ogg", ".opus":
		return "ogg"
	case ".flac":
		return "flac"
	case ".m4a", ".mp4", ".aac":
		return "m4a"
	default:
		return ext
	}
}

// isSupportedFormat 检查是否支持的音频格式
func isSupportedFormat(format string) bool {
	switch format {
	case "wav", "mp3", "ogg", "flac", "m4a":
		return true
	default:
		return false
	}
}