package handler

import (
	"crypto/rand"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"github.com/gin-gonic/gin"
	"github.com/gorilla/websocket"
	"log"
	"net/http"
	"strconv"
	"sync"
	"time"
	"videoplayer/proto"
	"videoplayer/worker"
)

var (
	upgrader = websocket.Upgrader{
		ReadBufferSize:  1024,
		WriteBufferSize: 1024,
		CheckOrigin: func(r *http.Request) bool {
			// 允许所有来源的连接
			return true
		},
	}
)

// 创建一个用于存储WebSocket连接的map和互斥锁
var (
	clients    = make(map[*websocket.Conn]bool)
	clientsMux sync.Mutex
)

func SetUpIMGroup(router *gin.Engine) {
	imGroup := router.Group("/im")
	imGroup.POST("/get_imKey", GetImKey)
	imGroup.GET("/ws", SRMessage)

}
func generateRandomHexString(length int) (string, error) {
	bytes := make([]byte, length/2) // 16字节的字符串需要32个十六进制字符，即16个字节
	if _, err := rand.Read(bytes); err != nil {
		return "", err
	}
	return hex.EncodeToString(bytes), nil
}

func GetImKey(c *gin.Context) {
	id, _ := c.Get("id")
	var req proto.ImKeyReq
	if err := c.ShouldBind(&req); err == nil {
		id1 := int(id.(float64))
		var redis_key string
		if id1 < req.To_user_id {
			redis_key = strconv.Itoa(id1) + "_" + strconv.Itoa(req.To_user_id) + "_imKey"
		} else {
			redis_key = strconv.Itoa(req.To_user_id) + "_" + strconv.Itoa(id1) + "_imKey"
		}
		if worker.IsContainKey(redis_key) == true {
			res := worker.GetRedis(redis_key)
			var retrievedData map[string]interface{}
			err2 := json.Unmarshal([]byte(res), &retrievedData)
			if err2 != nil {
				c.JSON(http.StatusOK, gin.H{"error": err2.Error(), "code": proto.OperationFailed, "message": "failed"})
				return
			}
			if int(retrievedData["from_user_id"].(float64)) == id1 {
				if int(retrievedData["is_read"].(float64)) == 1 {
					worker.DelRedis(redis_key)
				}
				c.JSON(http.StatusOK, gin.H{"code": proto.SuccessCode, "data": retrievedData, "message": "success"})
				return
			} else if int(retrievedData["to_user_id"].(float64)) == id1 {
				retrievedData["is_read"] = 1
				str, _ := json.Marshal(retrievedData)
				res3 := worker.SetRedisWithExpire(redis_key, string(str), time.Second*300)
				res2 := worker.SetRedisWithExpire(redis_key+"_connection", retrievedData["im_session"].(string), time.Second*300)
				if res2 == false || res3 == false {
					c.JSON(http.StatusOK, gin.H{"error": "set key failed", "code": proto.OperationFailed, "message": "failed"})
					return
				}
				c.JSON(http.StatusOK, gin.H{"code": proto.SuccessCode, "data": retrievedData, "message": "success"})
				return
			} else {
				c.JSON(http.StatusOK, gin.H{"error": "parameter error", "code": proto.ParameterError, "message": "failed"})
				return
			}
		}

		//生成随机字符串
		imkey, err2 := generateRandomHexString(16)
		imSession, err3 := generateRandomHexString(8)
		if err2 != nil || err3 != nil {
			c.JSON(http.StatusOK, gin.H{"error": "generate key failed", "code": proto.OperationFailed, "message": "failed"})
			return
		}

		data := make(map[string]interface{})
		data["im_key"] = imkey
		data["from_user_id"] = id1
		data["to_user_id"] = req.To_user_id
		data["im_session"] = imSession
		data["is_read"] = 0
		str, _ := json.Marshal(data)
		//将key存入redis
		res := worker.SetRedisWithExpire(redis_key, string(str), time.Second*300)
		if res == false {
			c.JSON(http.StatusOK, gin.H{"error": "set key failed", "code": proto.OperationFailed, "message": "failed"})
			return
		}
		c.JSON(http.StatusOK, gin.H{"code": proto.SuccessCode, "data": data, "message": "success"})
		return
	} else {
		c.JSON(http.StatusOK, gin.H{"error": err.Error(), "code": proto.ParameterError, "message": "failed"})
	}
}

// 接收及发送消息
func SRMessage(c *gin.Context) {
	id, _ := c.Get("id")
	id1 := int(id.(float64))
	var redis_key string
	to_user_id := c.Query("to_user_id")
	to_user_id_num, _ := strconv.ParseInt(to_user_id, 10, 64)
	if id1 < int(to_user_id_num) {
		redis_key = strconv.Itoa(id1) + "_" + to_user_id + "_imKey"
	} else {
		redis_key = to_user_id + "_" + strconv.Itoa(id1) + "_imKey"
	}
	if worker.IsContainKey(redis_key+"_connection") == false {
		c.JSON(http.StatusOK, gin.H{"code": proto.OperationFailed, "message": "failed"})
		return
	}

	// 升级HTTP连接为WebSocket连接
	ws, err := upgrader.Upgrade(c.Writer, c.Request, nil)
	clients[ws] = true
	if err != nil {
		// log.Println(err)
		fmt.Println(err)
		return
	}
	defer ws.Close()
	res := worker.GetRedis(redis_key + "_connection")
	worker.SetRedisWithExpire("user_"+id.(string)+"_status", "1", time.Second*5)
	if res == "" {
		return
	}

	// 接收客户端消息并发送到指定用户
	go func(ws *websocket.Conn, session string, to_id string) {
		for {
			_, message, err_r := ws.ReadMessage()
			if err_r != nil {
				// 当连接关闭时，退出循环
				clientsMux.Lock()
				clients[ws] = false
				clientsMux.Unlock()
				//设置ws关闭状态信息
				break
			}

			// 将接收到的消息解析为JSON
			var msg proto.Message
			if err2 := json.Unmarshal(message, &msg); err2 != nil {
				log.Println("unmarshal:", err2)
				continue
			}
			if msg.Type == "msg" {
				// 将消息发送到指定用户
				worker.PushRedisListWithExpire(session+"_"+to_user_id, msg.Msg, time.Hour*1) //将消息存入redis
			}
		}
	}(ws, res, to_user_id)

	// 从Redis中读取消息并发送到客户端
	for {
		if v := clients[ws]; v == true {
			res2 := worker.PopRedisListLeft(res + "_" + strconv.Itoa(id1))
			var res3 []byte
			var msg proto.Message
			if res2 != "" {
				//若有消息则发送消息
				msg.Type = "msg"
				msg.Msg = res2
				msg.From_user_id = id1
				msg.Session = res
				res3, _ = json.Marshal(msg)
			} else {
				//若无消息则发送心跳包
				msg.Type = "check"
				msg.Msg = "check"
				msg.From_user_id = -1
				msg.Session = res
				res3, _ = json.Marshal(msg)
			}
			//判断对方是否在线,若不在线则发送离线消息,否则正常发送消息
			if worker.IsContainKey(to_user_id+"_status") == true {
				if worker.GetRedis(to_user_id+"_status") == "0" {
					msg.Type = "offline"
					msg.Msg = "offline"
					msg.From_user_id = -1
					msg.Session = res
					res3, _ = json.Marshal(msg)
				}
			}
			err2 := ws.WriteMessage(websocket.TextMessage, res3)
			if err2 != nil {
				worker.SetRedisWithExpire("user_"+id.(string)+"_status", "0", time.Second*120) //设置用户在线状态,1为在线,0为离线,5秒后过期
				clientsMux.Lock()
				delete(clients, ws)
				clientsMux.Unlock()
				break
			} else {
				worker.SetRedisWithExpire("user_"+id.(string)+"_status", "1", time.Second*5) //设置用户在线状态,1为在线,0为离线,5秒后过期
			}
			time.Sleep(time.Second * 1) // 每1秒查询一次
		} else {
			clientsMux.Lock()
			delete(clients, ws)
			clientsMux.Unlock()
			break
		}
	}
}