package handler

import (
	"encoding/json"
	"log"
	"net/http"

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

// TTSHandler TTS HTTP API 处理器
type TTSHandler struct {
	svc *service.TTSService
}

// NewTTSHandler 创建 TTS 处理器
func NewTTSHandler(svc *service.TTSService) *TTSHandler {
	return &TTSHandler{svc: svc}
}

// RegisterRoutes 注册 TTS 路由
func (h *TTSHandler) RegisterRoutes(mux *http.ServeMux) {
	mux.HandleFunc("/api/v1/tts/synthesize", h.handleSynthesize)
	mux.HandleFunc("/api/v1/tts/voices", h.handleVoices)
	mux.HandleFunc("/api/v1/tts/status", h.handleStatus)
}

// TTSSynthesizeRequest TTS 合成请求体
type TTSSynthesizeRequest struct {
	Text  string `json:"text"`
	Voice string `json:"voice"`
	Rate  string `json:"rate"`
}

// handleSynthesize POST /api/v1/tts/synthesize
func (h *TTSHandler) handleSynthesize(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	// 解析 JSON 请求体
	var req TTSSynthesizeRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "请求体解析失败: "+err.Error())
		return
	}

	if req.Text == "" {
		writeError(w, http.StatusBadRequest, "text 字段不能为空")
		return
	}

	// 检查 TTS 引擎是否可用
	if !h.svc.IsAvailable() {
		log.Printf("[tts-handler] TTS 引擎不可用")
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusServiceUnavailable)
		json.NewEncoder(w).Encode(map[string]interface{}{
			"error":   "TTS 引擎不可用，请安装 edge-tts (pip install edge-tts) 或 espeak-ng",
			"code":    "TTS_UNAVAILABLE",
			"install": "pip install edge-tts",
		})
		return
	}

	// 调用合成
	audioData, format, err := h.svc.Synthesize(req.Text, req.Voice, req.Rate)
	if err != nil {
		log.Printf("[tts-handler] TTS 合成失败: %v", err)
		writeError(w, http.StatusInternalServerError, "TTS 合成失败: "+err.Error())
		return
	}

	// 返回音频流
	contentType := "audio/mpeg"
	if format == "wav" {
		contentType = "audio/wav"
	}

	w.Header().Set("Content-Type", contentType)
	w.Header().Set("Content-Disposition", "inline; filename=synthesized."+format)
	w.WriteHeader(http.StatusOK)
	w.Write(audioData)
}

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

	voices := h.svc.GetVoices()

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]interface{}{
		"voices": voices,
		"count":  len(voices),
	})
}

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

	status := h.svc.GetEngineStatus()

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]interface{}{
		"service": "voice-service",
		"tts":     status,
	})
}