package handler

import (
	"bytes"
	"chatplus/core"
	"chatplus/core/types"
	"chatplus/store"
	"chatplus/store/model"
	"chatplus/store/vo"
	"chatplus/utils"
	"chatplus/utils/resp"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"github.com/gin-gonic/gin"
	"github.com/go-redis/redis/v8"
	"github.com/gorilla/websocket"
	"gorm.io/gorm"
	"net/http"
	"net/url"
	"strings"
	"time"
)

const ErrorMsg = "抱歉，AI 助手开小差了，请稍后再试。"

type ChatHandler struct {
	BaseHandler
	db      *gorm.DB
	leveldb *store.LevelDB
	redis   *redis.Client
}

func NewChatHandler(app *core.AppServer, db *gorm.DB, levelDB *store.LevelDB, redis *redis.Client) *ChatHandler {
	handler := ChatHandler{db: db, leveldb: levelDB, redis: redis}
	handler.App = app
	return &handler
}

var chatConfig types.ChatConfig

// ChatHandle 处理聊天 WebSocket 请求
func (h *ChatHandler) ChatHandle(c *gin.Context) {
	ws, err := (&websocket.Upgrader{CheckOrigin: func(r *http.Request) bool { return true }}).Upgrade(c.Writer, c.Request, nil)
	if err != nil {
		logger.Error(err)
		return
	}

	sessionId := c.Query("session_id")
	roleId := h.GetInt(c, "role_id", 0)
	chatId := c.Query("chat_id")
	modelId := h.GetInt(c, "model_id", 0)

	client := types.NewWsClient(ws)
	// get model info
	var chatModel model.ChatModel
	res := h.db.First(&chatModel, modelId)
	if res.Error != nil || chatModel.Enabled == false {
		utils.ReplyMessage(client, "当前AI模型暂未启用，连接已关闭！！！")
		c.Abort()
		return
	}

	session := h.App.ChatSession.Get(sessionId)
	if session == nil {
		user, err := utils.GetLoginUser(c, h.db)
		if err != nil {
			logger.Info("用户未登录")
			c.Abort()
			return
		}
		session = &types.ChatSession{
			SessionId: sessionId,
			ClientIP:  c.ClientIP(),
			Username:  user.Mobile,
			UserId:    user.Id,
		}
		h.App.ChatSession.Put(sessionId, session)
	}

	// use old chat data override the chat model and role ID
	var chat model.ChatItem
	res = h.db.Where("chat_id=?", chatId).First(&chat)
	if res.Error == nil {
		chatModel.Id = chat.ModelId
		roleId = int(chat.RoleId)
	}

	session.ChatId = chatId
	session.Model = types.ChatModel{
		Id:       chatModel.Id,
		Value:    chatModel.Value,
		Platform: types.Platform(chatModel.Platform)}
	logger.Infof("New websocket connected, IP: %s, Username: %s", c.ClientIP(), session.Username)
	var chatRole model.ChatRole
	res = h.db.First(&chatRole, roleId)
	if res.Error != nil || !chatRole.Enable {
		utils.ReplyMessage(client, "当前聊天角色不存在或者未启用，连接已关闭！！！")
		c.Abort()
		return
	}

	// 初始化聊天配置
	var config model.Config
	h.db.Where("marker", "chat").First(&config)
	err = utils.JsonDecode(config.Config, &chatConfig)
	if err != nil {
		utils.ReplyMessage(client, "加载系统配置失败，连接已关闭！！！")
		c.Abort()
		return
	}

	// 保存会话连接
	h.App.ChatClients.Put(sessionId, client)
	go func() {
		for {
			_, msg, err := client.Receive()
			if err != nil {
				logger.Error(err)
				client.Close()
				h.App.ChatClients.Delete(sessionId)
				h.App.ReqCancelFunc.Delete(sessionId)
				return
			}

			message := string(msg)
			logger.Info("Receive a message: ", message)
			//utils.ReplyMessage(client, "这是一条测试消息！")
			ctx, cancel := context.WithCancel(context.Background())
			h.App.ReqCancelFunc.Put(sessionId, cancel)
			// 回复消息
			err = h.sendMessage(ctx, session, chatRole, message, client)
			if err != nil {
				logger.Error(err)
			} else {
				utils.ReplyChunkMessage(client, types.WsMessage{Type: types.WsEnd})
				logger.Info("回答完毕: " + string(message))
			}

		}
	}()
}

func (h *ChatHandler) sendMessage(ctx context.Context, session *types.ChatSession, role model.ChatRole, prompt string, ws *types.WsClient) error {
	defer func() {
		if r := recover(); r != nil {
			logger.Error("Recover message from error: ", r)
		}
	}()

	var user model.User
	res := h.db.Model(&model.User{}).First(&user, session.UserId)
	if res.Error != nil {
		utils.ReplyMessage(ws, "非法用户，请联系管理员！")
		return res.Error
	}
	var userVo vo.User
	err := utils.CopyObject(user, &userVo)
	userVo.Id = user.Id
	if err != nil {
		return errors.New("User 对象转换失败，" + err.Error())
	}

	if userVo.Status == false {
		utils.ReplyMessage(ws, "您的账号已经被禁用，如果疑问，请联系管理员！")
		utils.ReplyMessage(ws, "![](/images/wx.png)")
		return nil
	}

	if userVo.Calls <= 0 && userVo.ChatConfig.ApiKeys[session.Model.Platform] == "" {
		utils.ReplyMessage(ws, "您的对话次数已经用尽，请联系管理员或者点击左下角菜单加入众筹获得100次对话！")
		utils.ReplyMessage(ws, "![](/images/wx.png)")
		return nil
	}

	if userVo.ExpiredTime > 0 && userVo.ExpiredTime <= time.Now().Unix() {
		utils.ReplyMessage(ws, "您的账号已经过期，请联系管理员！")
		utils.ReplyMessage(ws, "![](/images/wx.png)")
		return nil
	}
	var req = types.ApiRequest{
		Model:  session.Model.Value,
		Stream: true,
	}
	switch session.Model.Platform {
	case types.Azure:
		req.Temperature = h.App.ChatConfig.Azure.Temperature
		req.MaxTokens = h.App.ChatConfig.Azure.MaxTokens
		break
	case types.ChatGLM:
		req.Temperature = h.App.ChatConfig.ChatGML.Temperature
		req.MaxTokens = h.App.ChatConfig.ChatGML.MaxTokens
		break
	default:
		req.Temperature = h.App.ChatConfig.OpenAI.Temperature
		req.MaxTokens = h.App.ChatConfig.OpenAI.MaxTokens
		var functions = make([]types.Function, 0)
		for _, f := range types.InnerFunctions {
			if !h.App.SysConfig.EnabledDraw && f.Name == types.FuncMidJourney {
				continue
			}
			functions = append(functions, f)
		}
		req.Functions = functions
	}

	// 加载聊天上下文
	var chatCtx []interface{}
	if h.App.ChatConfig.EnableContext {
		if h.App.ChatContexts.Has(session.ChatId) {
			chatCtx = h.App.ChatContexts.Get(session.ChatId)
		} else {
			// calculate the tokens of current request, to prevent to exceeding the max tokens num
			tokens := req.MaxTokens
			for _, f := range types.InnerFunctions {
				tks, _ := utils.CalcTokens(utils.JsonEncode(f), req.Model)
				tokens += tks
			}

			// loading the role context
			var messages []types.Message
			err := utils.JsonDecode(role.Context, &messages)
			if err == nil {
				for _, v := range messages {
					tks, _ := utils.CalcTokens(v.Content, req.Model)
					if tokens+tks >= types.ModelToTokens[req.Model] {
						break
					}
					tokens += tks
					chatCtx = append(chatCtx, v)
				}
			}

			// loading recent chat history as chat context
			if chatConfig.ContextDeep > 0 {
				var historyMessages []model.HistoryMessage
				res := h.db.Where("chat_id = ? and use_context = 1", session.ChatId).Limit(chatConfig.ContextDeep).Order("created_at desc").Find(&historyMessages)
				if res.Error == nil {
					for _, msg := range historyMessages {
						if tokens+msg.Tokens >= types.ModelToTokens[session.Model.Value] {
							break
						}
						tokens += msg.Tokens
						ms := types.Message{Role: "user", Content: msg.Content}
						if msg.Type == types.ReplyMsg {
							ms.Role = "assistant"
						}
						chatCtx = append(chatCtx, ms)
					}
				}
			}
		}
		logger.Debugf("聊天上下文：%+v", chatCtx)
	}
	reqMgs := make([]interface{}, 0)
	for _, m := range chatCtx {
		reqMgs = append(reqMgs, m)
	}

	req.Messages = append(reqMgs, map[string]interface{}{
		"role":    "user",
		"content": prompt,
	})

	switch session.Model.Platform {
	case types.Azure:
		return h.sendAzureMessage(chatCtx, req, userVo, ctx, session, role, prompt, ws)
	case types.OpenAI:
		return h.sendOpenAiMessage(chatCtx, req, userVo, ctx, session, role, prompt, ws)
	case types.ChatGLM:
		return h.sendChatGLMMessage(chatCtx, req, userVo, ctx, session, role, prompt, ws)
	}
	return fmt.Errorf("not supported platform: %s", session.Model.Platform)
}

// Tokens 统计 token 数量
func (h *ChatHandler) Tokens(c *gin.Context) {
	var data struct {
		Text  string `json:"text"`
		Model string `json:"model"`
	}
	if err := c.ShouldBindJSON(&data); err != nil {
		resp.ERROR(c, types.InvalidArgs)
		return
	}

	tokens, err := utils.CalcTokens(data.Text, data.Model)
	if err != nil {
		resp.ERROR(c, err.Error())
		return
	}

	resp.SUCCESS(c, tokens)
}

func getTotalTokens(req types.ApiRequest) int {
	encode := utils.JsonEncode(req.Messages)
	var items []map[string]interface{}
	err := utils.JsonDecode(encode, &items)
	if err != nil {
		return 0
	}
	tokens := 0
	for _, item := range items {
		content, ok := item["content"]
		if ok && !utils.IsEmptyValue(content) {
			t, err := utils.CalcTokens(utils.InterfaceToString(content), req.Model)
			if err == nil {
				tokens += t
			}
		}
	}
	return tokens
}

// StopGenerate 停止生成
func (h *ChatHandler) StopGenerate(c *gin.Context) {
	sessionId := c.Query("session_id")
	if h.App.ReqCancelFunc.Has(sessionId) {
		h.App.ReqCancelFunc.Get(sessionId)()
		h.App.ReqCancelFunc.Delete(sessionId)
	}
	resp.SUCCESS(c, types.OkMsg)
}

// 发送请求到 OpenAI 服务器
// useOwnApiKey: 是否使用了用户自己的 API KEY
func (h *ChatHandler) doRequest(ctx context.Context, req types.ApiRequest, platform types.Platform, apiKey *string) (*http.Response, error) {

	var apiURL string
	switch platform {
	case types.Azure:
		md := strings.Replace(req.Model, ".", "", 1)
		apiURL = strings.Replace(h.App.ChatConfig.Azure.ApiURL, "{model}", md, 1)
		break
	case types.ChatGLM:
		apiURL = strings.Replace(h.App.ChatConfig.ChatGML.ApiURL, "{model}", req.Model, 1)
		req.Prompt = req.Messages
		req.Messages = nil
		break
	default:
		apiURL = h.App.ChatConfig.OpenAI.ApiURL
	}
	// 创建 HttpClient 请求对象
	var client *http.Client
	requestBody, err := json.Marshal(req)
	if err != nil {
		return nil, err
	}
	request, err := http.NewRequest(http.MethodPost, apiURL, bytes.NewBuffer(requestBody))
	if err != nil {
		return nil, err
	}

	request = request.WithContext(ctx)
	request.Header.Set("Content-Type", "application/json")
	proxyURL := h.App.Config.ProxyURL
	if proxyURL != "" && platform == types.OpenAI { // 使用代理
		proxy, _ := url.Parse(proxyURL)
		client = &http.Client{
			Transport: &http.Transport{
				Proxy: http.ProxyURL(proxy),
			},
		}
	} else {
		client = http.DefaultClient
	}
	if *apiKey == "" {
		var key model.ApiKey
		res := h.db.Where("platform = ?", platform).Order("last_used_at ASC").First(&key)
		if res.Error != nil {
			return nil, errors.New("no available key, please import key")
		}
		// 更新 API KEY 的最后使用时间
		h.db.Model(&key).UpdateColumn("last_used_at", time.Now().Unix())
		*apiKey = key.Value
	}

	logger.Infof("Sending %s request, KEY: %s, PROXY: %s, Model: %s", platform, *apiKey, proxyURL, req.Model)
	switch platform {
	case types.Azure:
		request.Header.Set("api-key", *apiKey)
		break
	case types.ChatGLM:
		token, err := h.getChatGLMToken(*apiKey)
		if err != nil {
			return nil, err
		}
		logger.Info(token)
		request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
		break
	default:
		request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiKey))
	}
	return client.Do(request)
}