package core

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"reflect"
	"strings"
	"time"

	"github.com/go-redis/redis/v8"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"repositories.action2quare.com/ayo/gocommon"
	"repositories.action2quare.com/ayo/gocommon/logger"
	"repositories.action2quare.com/ayo/gocommon/wshandler"
)

func init() {
	groupTypeContainer()["chat"] = reflect.TypeOf(&groupChat{})
}

type channelID = string
type channelConfig struct {
	Capacity  int64  `json:"capacity"`
	Size      int64  `json:"size"`
	Key       string `json:"key"`
	emptyJson string
}

type chatConfig struct {
	DefaultCapacity int64                    `json:"default_capacity"`
	Channels        map[string]channelConfig `json:"channels"`
}

type groupChat struct {
	chatConfig
	rh                  *gocommon.RedisonHandler
	enterRoom           func(channelID, accountID)
	leaveRoom           func(channelID, accountID)
	sendUpstreamMessage func(msg *wshandler.UpstreamMessage)
}

var accidHex func(primitive.ObjectID) string
var accidstrHex func(string) string

func (gc *groupChat) Initialize(sub *subTavern, cfg configDocument) error {
	rem, _ := json.Marshal(cfg)
	if err := json.Unmarshal(rem, &gc.chatConfig); err != nil {
		return err
	}

	gc.enterRoom = func(chanid channelID, accid accountID) {
		sub.wsh.EnterRoom(sub.region, string(chanid), accid)
	}
	gc.leaveRoom = func(chanid channelID, accid accountID) {
		sub.wsh.LeaveRoom(sub.region, string(chanid), accid)
	}
	gc.sendUpstreamMessage = func(msg *wshandler.UpstreamMessage) {
		sub.wsh.SendUpstreamMessage(sub.region, msg)
	}

	gc.rh = sub.redison

	sub.apiFuncs.registApiFunction("FetchChattingChannels", gc.FetchChattingChannels)
	sub.apiFuncs.registApiFunction("BroadcastMessageOnChannel", gc.BroadcastMessageOnChannel)
	sub.apiFuncs.registApiFunction("QueryPlayerChattingChannel", gc.QueryPlayerChattingChannel)
	sub.apiFuncs.registApiFunction("SendMessageOnChannel", gc.SendMessageOnChannel)
	for name, cfg := range gc.chatConfig.Channels {
		if cfg.Capacity == 0 {
			cfg.Capacity = gc.chatConfig.DefaultCapacity
		}
		cfg.Key = name
		cfg.Size = 0

		jm, _ := json.Marshal(cfg)
		cfg.emptyJson = fmt.Sprintf("[%s]", string(jm))

		_, err := gc.rh.JSONSet(name, "$", cfg)
		if *devflag && err != nil {
			gc.rh.Del(gc.rh.Context(), name).Result()
			_, err = gc.rh.JSONSet(name, "$", cfg)
		}

		if err != nil {
			return err
		}
	}

	ts := fmt.Sprintf("%x-", time.Now().Unix())
	if *devflag {
		accidHex = func(accid primitive.ObjectID) string {
			return ts + accid.Hex()
		}
		accidstrHex = func(accid string) string {
			return ts + accid
		}
	} else {
		accidHex = func(accid primitive.ObjectID) string {
			return accid.Hex()
		}
		accidstrHex = func(accid string) string {
			return accid
		}
	}
	return nil
}

func (gc *groupChat) ClientMessageReceived(sender *wshandler.Sender, mt wshandler.WebSocketMessageType, message any) {
	if mt == wshandler.Disconnected {
		if _, err := gc.rh.Del(gc.rh.Context(), accidHex(sender.Accid)).Result(); err != nil {
			logger.Println(err)
		}
	} else if mt == wshandler.BinaryMessage {
		commandline := message.([]any)
		cmd := commandline[0].(string)
		args := commandline[1:]
		switch cmd {
		case "EnterPublicChannel":
			chanid := args[0].(string)
			if cfg, ok := gc.chatConfig.Channels[chanid]; ok {
				size, err := gc.rh.JSONGetInt64(chanid, "$.size")
				if err != nil || len(size) == 0 {
					logger.Println("JSONGetInt64 failed :", chanid, err)
				} else if size[0] < cfg.Capacity {
					// 입장
					newsize, err := gc.rh.JSONNumIncrBy(chanid, "$.size", 1)
					if err == nil {
						gc.enterRoom(chanid, sender.Accid)
						sender.RegistDisconnectedCallback(chanid, func() {
							size, err := gc.rh.JSONNumIncrBy(chanid, "$.size", -1)
							if err == nil {
								gc.sendUpstreamMessage(&wshandler.UpstreamMessage{
									Target: "#" + chanid,
									Body:   map[string]any{"size": size},
									Tag:    []string{"ChattingChannelProperties"},
								})
							}
						})

						gc.rh.HSet(gc.rh.Context(), accidHex(sender.Accid), "cc_pub", chanid)
						gc.sendUpstreamMessage(&wshandler.UpstreamMessage{
							Target: "#" + chanid,
							Body:   map[string]any{"size": newsize[0]},
							Tag:    []string{"ChattingChannelProperties"},
						})
					}
				} else {
					// 풀방
					logger.Println("chatting channel is full :", chanid, size)
				}
			} else {
				logger.Println("chatting channel not valid :", chanid)
			}

		case "LeavePublicChannel":
			chanid := args[0].(string)
			gc.rh.HDel(gc.rh.Context(), accidHex(sender.Accid), "cc_pub")
			gc.leaveRoom(chanid, sender.Accid)
			if f := sender.PopDisconnectedCallback(chanid); f != nil {
				f()
			}

		case "TextMessage":
			chanid := args[0].(string)
			msg := args[1].(string)
			gc.sendUpstreamMessage(&wshandler.UpstreamMessage{
				Target: "#" + chanid,
				Body:   map[string]any{"sender": sender.Alias, "msg": msg},
				Tag:    []string{"TextMessage"},
			})

		case "EnterPrivateChannel":
			typename := args[0].(string)
			channel := args[1].(string)
			var reason string
			if len(args) > 2 {
				reason = args[2].(string)
			}

			if len(reason) > 0 {
				// 수락
				ok, err := gc.rh.HSetNX(gc.rh.Context(), accidHex(sender.Accid), "cc_"+typename, channel).Result()
				if err != nil || !ok {
					// 이미 다른 private channel 참여 중
					logger.Println("EnterPrivateChannel failed. HSetNX return err :", err, sender.Accid.Hex(), typename, channel)
					return
				}
				gc.enterRoom(channel, sender.Accid)

				sender.RegistDisconnectedCallback(channel, func() {
					gc.rh.JSONDel(channel, "$."+sender.Accid.Hex())
					cnt, _ := gc.rh.HDel(gc.rh.Context(), accidHex(sender.Accid), "cc_"+typename).Result()
					if cnt > 0 {
						gc.sendUpstreamMessage(&wshandler.UpstreamMessage{
							Target: "#" + channel,
							Body:   map[string]any{"sender": sender.Alias, "typename": typename},
							Tag:    []string{"LeavePrivateChannel"},
						})
					}
				})
			}

			gc.sendUpstreamMessage(&wshandler.UpstreamMessage{
				Target: "#" + channel,
				Body: map[string]any{
					"sender":   sender.Alias,
					"msg":      reason,
					"typename": typename,
				},
				Tag: []string{"EnterPrivateChannel"},
			})

		case "LeavePrivateChannel":
			channel := args[1].(string)
			gc.leaveRoom(channel, sender.Accid)
			if f := sender.PopDisconnectedCallback(channel); f != nil {
				f()
			}
		}
	}
}

func (gc *groupChat) FetchChattingChannels(w http.ResponseWriter, r *http.Request) {
	prefix, _ := gocommon.ReadStringFormValue(r.Form, "prefix")
	if len(prefix) == 0 {
		logger.Println("FetchChattingChannel failed. prefix is missing")
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	var rows []string
	for name, cfg := range gc.chatConfig.Channels {
		if len(prefix) > 0 {
			if !strings.HasPrefix(name, prefix) {
				continue
			}
		}

		onechan, err := gc.rh.JSONGet(name, "$")
		if err != nil && err != redis.Nil {
			logger.Println("FetchChattingChannel failed. HGetAll return err :", err)
			w.WriteHeader(http.StatusInternalServerError)
			return
		}

		if err == redis.Nil || onechan == nil {
			rows = append(rows, cfg.emptyJson)
		} else {
			rows = append(rows, onechan.(string))
		}
	}

	if len(rows) == 0 {
		w.Write([]byte("[]"))
	} else if len(rows) == 1 {
		w.Write([]byte(rows[0]))
	} else {
		first := rows[0]
		w.Write([]byte(first[:len(first)-1]))
		for i := 1; i < len(rows); i++ {
			mid := rows[i]
			w.Write([]byte(","))
			w.Write([]byte(mid[1 : len(mid)-1]))
		}
		w.Write([]byte("]"))
	}
}

func (gc *groupChat) QueryPlayerChattingChannel(w http.ResponseWriter, r *http.Request) {
	accid, _ := gocommon.ReadStringFormValue(r.Form, "accid")
	typename, _ := gocommon.ReadStringFormValue(r.Form, "typename")

	var fields []string
	if len(typename) == 0 {
		fields = []string{"cc_pub"}
	} else {
		fields = []string{"cc_pub", "cc_" + typename}
	}

	chans, err := gc.rh.HMGet(gc.rh.Context(), accidstrHex(accid), fields...).Result()
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		return
	}

	output := make(map[string]string)
	if len(chans) > 0 && chans[0] != nil {
		output["public"] = chans[0].(string)
	}
	if len(chans) > 1 && chans[1] != nil {
		output[typename] = chans[1].(string)
	}

	enc := json.NewEncoder(w)
	enc.Encode(output)
}

func (gc *groupChat) SendMessageOnChannel(w http.ResponseWriter, r *http.Request) {
	channel, _ := gocommon.ReadStringFormValue(r.Form, "channel")
	target, _ := gocommon.ReadStringFormValue(r.Form, "target")
	tag, _ := gocommon.ReadStringFormValue(r.Form, "tag")
	if len(channel) == 0 || len(target) == 0 || len(tag) == 0 {
		logger.Println("SendMessageOnChannel failed. channel or target or tag is empty")
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	var doc map[string]any
	bt, err := io.ReadAll(r.Body)
	if err != nil {
		logger.Println("SendMessageOnChannel failed. io.ReadAll returns err :", err)
		w.WriteHeader(http.StatusInternalServerError)
		return
	}

	if len(bt) > 0 {
		if err := bson.Unmarshal(bt, &doc); err != nil {
			logger.Println("SendMessageOnChannel failed. decode returns err :", err)
			w.WriteHeader(http.StatusBadRequest)
			return
		}
	}

	gc.sendUpstreamMessage(&wshandler.UpstreamMessage{
		Target: fmt.Sprintf("%s@%s", target, channel),
		Body:   doc,
		Tag:    []string{tag},
	})
}

func (gc *groupChat) BroadcastMessageOnChannel(w http.ResponseWriter, r *http.Request) {
	nickname, _ := gocommon.ReadStringFormValue(r.Form, "nickname")
	channel, _ := gocommon.ReadStringFormValue(r.Form, "channel")
	tag, _ := gocommon.ReadStringFormValue(r.Form, "tag")
	text, _ := io.ReadAll(r.Body)

	if len(tag) > 0 {
		var doc map[string]any
		if err := bson.Unmarshal(text, &doc); err == nil {
			gc.sendUpstreamMessage(&wshandler.UpstreamMessage{
				Target: "#" + channel,
				Body:   doc,
				Tag:    []string{tag},
			})
		} else {
			logger.Println("BroadcastMessageOnChannel failed :", err)
		}
	} else {
		gc.sendUpstreamMessage(&wshandler.UpstreamMessage{
			Target: "#" + channel,
			Body:   map[string]any{"sender": nickname, "msg": string(text)},
			Tag:    []string{"TextMessage"},
		})
	}
}