package main

import (
	"context"
	"errors"
	"net/http"
	"os/signal"
	"strings"
	"syscall"
	"time"

	"github.com/gin-gonic/gin"

	"github.com/hhs/camtalk/internal/api"
	"github.com/hhs/camtalk/internal/auth"
	"github.com/hhs/camtalk/internal/ai/llm"
	"github.com/hhs/camtalk/internal/ai/stt"
	"github.com/hhs/camtalk/internal/ai/tts"
	"github.com/hhs/camtalk/internal/config"
	"github.com/hhs/camtalk/internal/logger"
	"github.com/hhs/camtalk/internal/orchestrator"
	"github.com/hhs/camtalk/internal/session"
	"github.com/hhs/camtalk/internal/store"
	"github.com/hhs/camtalk/internal/ws"
	migrations "github.com/hhs/camtalk/migrations"
)

// Version 通过构建时 -ldflags 注入，如：
// go build -ldflags "-X main.Version=v1.0.0" ./cmd/server
var Version string

var startTime = time.Now()

func main() {
	// 加载配置
	cfg, err := config.Load()
	if err != nil {
		panic("failed to load config: " + err.Error())
	}

	// 初始化日志
	logger.Init(cfg.Log.Level, cfg.Log.Format)
	defer logger.Sync()

	logger.Log.Infow("config loaded",
		"env", cfg.App.Env,
		"addr", cfg.Server.Addr(),
	)

	// 初始化存储层（条件初始化 PostgreSQL）
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	var userRepo store.UserRepository
	var msgRepo store.MessageRepository
	var sessRepo store.SessionRepository

	if cfg.Storage.Driver == "postgres" {
		pool, err := store.NewPostgresPool(ctx, cfg.Storage.DSN)
		if err != nil {
			logger.Log.Fatalw("failed to connect to postgres", "error", err)
		}
		defer pool.Close()

		// 执行数据库迁移
		if err := store.RunMigrations(ctx, pool, migrations.FS); err != nil {
			logger.Log.Fatalw("failed to run migrations", "error", err)
		}

		userRepo = store.NewPgUserRepository(pool)
		msgRepo = store.NewPgMessageRepository(pool)
		sessRepo = store.NewPgSessionRepository(pool)
		logger.Log.Infow("postgres storage initialized", "driver", cfg.Storage.Driver)
	} else {
		userRepo = store.NewMemUserRepository()
		logger.Log.Info("using in-memory storage")
	}

	// 初始化 Session Manager
	var sessionMgr session.Manager
	var sessionOpts []session.Option
	if msgRepo != nil {
		sessionOpts = append(sessionOpts, session.WithMessageRepository(msgRepo))
	}
	if sessRepo != nil {
		sessionOpts = append(sessionOpts, session.WithSessionRepository(sessRepo))
	}
	sessionMgr = session.NewMemoryManager(
		time.Duration(cfg.Session.TTL)*time.Minute,
		cfg.Session.MaxHistory,
		sessionOpts...,
	)
	defer sessionMgr.(*session.MemoryManager).Stop()

	// 初始化 AI 服务
	logger.Log.Infow("initializing AI services",
		"stt.provider", cfg.AI.STT.Provider,
		"stt.model", cfg.AI.STT.Model,
		"llm.provider", cfg.AI.LLM.Provider,
		"llm.model", cfg.AI.LLM.Model,
		"tts.provider", cfg.AI.TTS.Provider,
		"tts.model", cfg.AI.TTS.Model,
		"tts.voice", cfg.AI.TTS.Voice,
	)

	var sttService stt.Service
	switch strings.ToLower(cfg.AI.STT.Provider) {
	case "mimo", "xiaomi":
		sttService = stt.NewMiMoService(cfg.AI.STT.APIKey, cfg.AI.STT.Model, cfg.AI.STT.Endpoint, cfg.AI.STT.Timeout, logger.Log)
		logger.Log.Infow("STT service initialized", "provider", "mimo", "model", cfg.AI.STT.Model, "endpoint", cfg.AI.STT.Endpoint)
	default:
		sttService = stt.NewDeepgramService(cfg.AI.STT.APIKey, cfg.AI.STT.Model, cfg.AI.STT.Endpoint, cfg.AI.STT.Timeout, logger.Log)
		logger.Log.Infow("STT service initialized", "provider", "deepgram", "model", cfg.AI.STT.Model)
	}
	llmService := llm.NewOpenAIService(cfg.AI.LLM.APIKey, cfg.AI.LLM.Model, cfg.AI.LLM.Endpoint, cfg.AI.LLM.Timeout, cfg.AI.LLM.HTTPClientTimeout, logger.Log)
	logger.Log.Infow("LLM service initialized", "provider", cfg.AI.LLM.Provider, "model", cfg.AI.LLM.Model, "endpoint", cfg.AI.LLM.Endpoint, "timeout", cfg.AI.LLM.Timeout)

	var ttsService tts.Service
	switch strings.ToLower(cfg.AI.TTS.Provider) {
	case "mimo", "xiaomi":
		ttsService = tts.NewMiMoService(cfg.AI.TTS.APIKey, cfg.AI.TTS.Model, cfg.AI.TTS.Voice, cfg.AI.TTS.Endpoint, cfg.AI.TTS.Timeout, cfg.AI.TTS.HTTPClientTimeout, logger.Log)
		logger.Log.Infow("TTS service initialized", "provider", "mimo", "model", cfg.AI.TTS.Model, "voice", cfg.AI.TTS.Voice, "endpoint", cfg.AI.TTS.Endpoint)
	default:
		ttsService = tts.NewOpenAIService(cfg.AI.TTS.APIKey, cfg.AI.TTS.Model, cfg.AI.TTS.Voice, cfg.AI.TTS.Endpoint, cfg.AI.TTS.Speed, cfg.AI.TTS.Timeout, cfg.AI.TTS.HTTPClientTimeout, logger.Log)
		logger.Log.Infow("TTS service initialized", "provider", "openai", "model", cfg.AI.TTS.Model, "voice", cfg.AI.TTS.Voice, "speed", cfg.AI.TTS.Speed)
	}

	// 初始化 Orchestrator
	orch := orchestrator.New(sttService, llmService, ttsService, sessionMgr, cfg)

	// 初始化认证服务
	tokenMgr := auth.NewTokenManager(
		cfg.Auth.JWTSecret,
		time.Duration(cfg.Auth.AccessTTL)*time.Minute,
		time.Duration(cfg.Auth.RefreshTTL)*time.Minute,
	)
	authService := auth.NewAuthService(tokenMgr, userRepo)

	// Gin 模式
	if cfg.App.Env == "prod" {
		gin.SetMode(gin.ReleaseMode)
	}

	r := gin.New()
	r.Use(gin.Recovery())

	// REST API
	apiGroup := r.Group("/api")
	{
		apiGroup.GET("/health", healthHandler(sessionMgr, cfg))
	}

	// Session REST 端点
	sessionHandler := api.NewSessionHandler(sessionMgr)
	sessionHandler.RegisterRoutes(apiGroup)

	// Auth REST 端点
	authHandler := api.NewAuthHandler(authService, tokenMgr)
	authHandler.RegisterRoutes(apiGroup)

	// Conversation REST 端点
	convHandler := api.NewConversationHandler(sessionMgr, tokenMgr, msgRepo)
	convHandler.RegisterRoutes(apiGroup)

	// WebSocket
	r.GET("/ws", ws.ServeWS(sessionMgr, orch, cfg, tokenMgr))

	// HTTP Server
	srv := &http.Server{
		Addr:         cfg.Server.Addr(),
		Handler:      r,
		ReadTimeout:  time.Duration(cfg.Server.ReadTimeout) * time.Second,
		WriteTimeout: time.Duration(cfg.Server.WriteTimeout) * time.Second,
	}

	// Graceful shutdown
	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
	defer stop()

	go func() {
		logger.Log.Infow("server starting", "addr", srv.Addr)
		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			logger.Log.Fatalw("listen failed", "error", err)
		}
	}()

	<-ctx.Done()
	logger.Log.Info("shutting down...")

	shutdownCtx, cancel := context.WithTimeout(context.Background(), time.Duration(cfg.Server.ShutdownTimeout)*time.Second)
	defer cancel()

	if err := srv.Shutdown(shutdownCtx); err != nil {
		logger.Log.Errorw("shutdown error", "error", err)
	}
	logger.Log.Info("server stopped")
}

// healthHandler 健康检查。
func healthHandler(sessionMgr session.Manager, cfg *config.Config) gin.HandlerFunc {
	return func(c *gin.Context) {
		version := Version
		if version == "" {
			version = cfg.App.Version
		}
		c.JSON(200, gin.H{
			"status":          "ok",
			"version":         version,
			"uptime_seconds":  int(time.Since(startTime).Seconds()),
			"active_sessions": sessionMgr.ActiveCount(),
		})
	}
}