package router

import (
	errors "ai_scheduler/internal/data/error"
	"ai_scheduler/internal/gateway"
	"ai_scheduler/internal/services"
	"encoding/json"
	"fmt"
	"strings"
	"sync"
	"time"

	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/websocket/v2"
)

// SetupRoutes 设置路由
func SetupRoutes(app *fiber.App, ChatService *services.ChatService, sessionService *services.SessionService, gateway *gateway.Gateway) {
	app.Use(func(c *fiber.Ctx) error {
		// 设置 CORS 头
		c.Set("Access-Control-Allow-Origin", "*")
		c.Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
		c.Set("Access-Control-Allow-Headers", "Content-Type, Authorization")

		// 如果是预检请求（OPTIONS），直接返回 204
		if c.Method() == "OPTIONS" {
			return c.SendStatus(fiber.StatusNoContent) // 204
		}

		// 继续处理后续中间件或路由
		return c.Next()
	})
	routerHttp(app, sessionService, gateway)
	routerSocket(app, ChatService)

}

func routerSocket(app *fiber.App, chatService *services.ChatService) {
	ws := app.Group("ws/v1/")
	// WebSocket 路由配置
	ws.Get("/chat", websocket.New(func(c *websocket.Conn) {
		// 可以在这里添加握手前的中间件逻辑（如头校验）
		chatService.Chat(c) // 调用实际的 Chat 处理函数
	}, websocket.Config{
		// 可选配置：跨域检查、最大负载大小等
		HandshakeTimeout: 10 * time.Second,
		//Subprotocols: []string{"json", "msgpack"},
		//Origins: []string{"http://localhost:3000", "https://yourdomain.com"} //验证 Origin 头，防止跨站请求伪造（CSRF）。如果为空，则允许所有来源。
		ReadBufferSize:  8192,
		WriteBufferSize: 8192,
		WriteBufferPool: bufferPool, // 使用缓冲池
	}))
}

var bufferPool = &sync.Pool{
	New: func() interface{} {
		return make([]byte, 4096) // 4KB 缓冲区
	},
}

func routerHttp(app *fiber.App, sessionService *services.SessionService, gateway *gateway.Gateway) {
	r := app.Group("api/v1/")
	registerResponse(r)
	// 注册 CORS 中间件
	r.Get("/health", func(c *fiber.Ctx) error {
		c.Response().SetBody([]byte("1"))
		return nil
	})

	r.Post("/session/init", sessionService.SessionInit) // 会话初始化,不存在则创建,存在则返回会话ID和默认条数会话历史
	r.Post("/session/list", sessionService.SessionList)
	//广播
	r.Get("/broadcast", func(ctx *fiber.Ctx) error {
		action := ctx.Query("action")
		uid := ctx.Query("uid")
		msg := ctx.Query("msg")

		switch action {
		case "sendToAll":
			gateway.SendToAll([]byte(msg))
			return ctx.SendString("sent to all")
		case "sendToUid":
			if uid == "" {
				return ctx.Status(400).SendString("missing uid")
			}
			gateway.SendToUid(uid, []byte(msg))
			return ctx.SendString(fmt.Sprintf("sent to uid %s", uid))
		default:
			return ctx.Status(400).SendString("unknown action")
		}
	})
}

func registerResponse(router fiber.Router) {
	// 自定义返回
	router.Use(func(c *fiber.Ctx) error {
		err := c.Next()
		return registerCommon(c, err)
	})

}

func registerCommon(c *fiber.Ctx, err error) error {
	// 调用下一个中间件或路由处理函数

	bsErr, ok := err.(*errors.BusinessErr)
	if !ok {
		bsErr = errors.SystemError
	}
	// 如果有错误发生
	if err != nil {
		// 返回自定义错误响应
		return c.JSON(fiber.Map{
			"message": bsErr.Error(),
			"code":    bsErr.Code(),
			"data":    nil,
		})
	}
	contentType := strings.ToLower(string(c.Response().Header.Peek("Content-Type")))
	if strings.Contains(strings.ToLower(contentType), "text/event-stream") {
		// 是 SSE 请求
		return c.SendString("这是 SSE 请求")
	}
	var data interface{}
	json.Unmarshal(c.Response().Body(), &data)
	return c.JSON(fiber.Map{
		"data":    data,
		"message": errors.Success.Error(),
		"code":    errors.Success.Code(),
	})
}