package main

import (
	"context"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/gin-gonic/gin"

	"nex/backend/internal/config"
	"nex/backend/internal/handler"
)

func main() {
	// 初始化数据库
	if err := config.InitDB(); err != nil {
		log.Fatalf("初始化数据库失败: %v", err)
	}
	defer config.CloseDB()

	// 创建 Gin 引擎
	gin.SetMode(gin.ReleaseMode)
	r := gin.Default()

	// 配置 CORS
	r.Use(func(c *gin.Context) {
		c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
		c.Writer.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
		c.Writer.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")
		if c.Request.Method == "OPTIONS" {
			c.AbortWithStatus(204)
			return
		}
		c.Next()
	})

	// 注册路由
	setupRoutes(r)

	// 创建 HTTP 服务器
	srv := &http.Server{
		Addr:    ":9826",
		Handler: r,
	}

	// 启动服务器（在 goroutine 中）
	go func() {
		log.Printf("AI Gateway 启动在端口 9826")
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("服务器启动失败: %v", err)
		}
	}()

	// 等待中断信号以优雅关闭服务器
	quit := make(chan os.Signal, 1)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit
	log.Println("正在关闭服务器...")

	// 给服务器 5 秒时间完成当前请求
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	if err := srv.Shutdown(ctx); err != nil {
		log.Fatal("服务器强制关闭:", err)
	}

	log.Println("服务器已关闭")
}

// setupRoutes 配置路由
func setupRoutes(r *gin.Engine) {
	// OpenAI 协议代理
	openaiHandler := handler.NewOpenAIHandler()
	r.POST("/v1/chat/completions", openaiHandler.HandleChatCompletions)

	// Anthropic 协议代理
	anthropicHandler := handler.NewAnthropicHandler()
	r.POST("/v1/messages", anthropicHandler.HandleMessages)

	// 供应商管理 API
	providerHandler := handler.NewProviderHandler()
	providers := r.Group("/api/providers")
	{
		providers.GET("", providerHandler.ListProviders)
		providers.POST("", providerHandler.CreateProvider)
		providers.GET("/:id", providerHandler.GetProvider)
		providers.PUT("/:id", providerHandler.UpdateProvider)
		providers.DELETE("/:id", providerHandler.DeleteProvider)
	}

	// 模型管理 API
	modelHandler := handler.NewModelHandler()
	models := r.Group("/api/models")
	{
		models.GET("", modelHandler.ListModels)
		models.POST("", modelHandler.CreateModel)
		models.GET("/:id", modelHandler.GetModel)
		models.PUT("/:id", modelHandler.UpdateModel)
		models.DELETE("/:id", modelHandler.DeleteModel)
	}

	// 统计查询 API
	statsHandler := handler.NewStatsHandler()
	stats := r.Group("/api/stats")
	{
		stats.GET("", statsHandler.GetStats)
		stats.GET("/aggregate", statsHandler.AggregateStats)
	}

	// 健康检查
	r.GET("/health", func(c *gin.Context) {
		c.JSON(200, gin.H{"status": "ok"})
	})
}