package localserver

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/dgraph-io/badger/v3"
	"github.com/pion/webrtc/v3"
)

type SquadChatConfig struct {
	ChatId   string   `json:"chatId"`
	ChatType string   `json:"chatType"`
	Owner    string   `json:"owner"`
	Members  []string `json:"members"`
}

type SquadChat struct {
	ChatId        string               `json:"chatId"`
	ChatType      string               `json:"chatType"`
	Owner         string               `json:"owner"`
	Members       []string             `json:"members"`
	LastReadIndex uint                 `json:"lastReadIndex"`
	Unread        uint                 `json:"unread"`
	DB            *SquadChatDBHandler  `json:"-"`
	Tracking      *SquadChatTrackingDB `json:"-"`
}

type SquadChatsHandler[T ZippytalFSInstance] struct {
	SquadName            string
	SquadId              string
	HostId               string
	ChatFSInstance       T
	SquadMembersId       []string
	DataChannels         map[string]*DataChannel
	ChatDataChannels     map[string]*DataChannel
	ChatDataChannelsFlag *uint32
	Flag                 *uint32
	ChatFSInstanceFlag   *uint32
	ChatFlag             *uint32
	Chat                 *SquadChat
	reqChans             []chan<- *SquadRequest
	init                 bool
}

func NewSquadChatsHandler(hostId, squadId, squadName, owner string, authorizedMembers []string, dataChannels map[string]*DataChannel, flag *uint32) (squadChatsHandler *SquadChatsHandler[*SquadFSInstance], err error) {
	_, err = os.ReadDir(filepath.Join(dataPath, "data", "squads", squadId, "chat"))
	if err != nil {
		if os.IsNotExist(err) {
			logger.Printf("creating chat directory for squad %s...\n", squadId)
			mkdirErr := os.MkdirAll(filepath.Join(dataPath, "data", "squads", squadId, "chat"), 0700)
			if mkdirErr != nil {
				return nil, mkdirErr
			}
			file, ferr := os.Create(filepath.Join(dataPath, "data", "squads", squadId, "chat", "chatConfig.json"))
			if ferr != nil {
				return nil, ferr
			}
			baseConfig := ChatConfig{
				ChatId:   squadName,
				Owner:    owner,
				ChatType: "public",
				Members:  authorizedMembers,
			}
			bs, jsonErr := json.Marshal(baseConfig)
			if jsonErr != nil {
				return nil, jsonErr
			}
			if _, writeErr := file.WriteString(string(bs)); writeErr != nil {
				return nil, writeErr
			}
			_ = file.Close()
			_, err = os.ReadDir(filepath.Join(dataPath, "data", "squads", squadId, "chat"))
			if err != nil {
				return nil, err
			}
		} else {
			return
		}
	}
	squadChatDBHandler, err := NewSquadChatDBHandler(squadId)
	if err != nil {
		return nil, err
	}
	var bs []byte
	bs, err = os.ReadFile(filepath.Join(dataPath, "data", "squads", squadId, "chat", "chatConfig.json"))
	if err != nil {
		return nil, err
	}
	logger.Println(string(bs))
	var c SquadChat
	if err = json.Unmarshal(bs, &c); err != nil {
		return nil, err
	}
	squadChatTracking, err := NewSquadChatTracking(squadId, c.ChatId, c.Members...)
	if err != nil {
		return nil, err
	}
	logger.Println("chats data :", c.ChatId, c.ChatType, c.Owner, c.Members)
	c.DB = squadChatDBHandler
	c.Tracking = squadChatTracking

	chatFlag := uint32(0)
	chatFSFlag := uint32(0)
	chatDCFlag := uint32(0)
	squadChatsHandler = &SquadChatsHandler[*SquadFSInstance]{
		HostId:               hostId,
		SquadName:            squadName,
		ChatFSInstance:       NewSquadFSInstance(squadId, owner, authorizedMembers),
		ChatFSInstanceFlag:   &chatFSFlag,
		SquadId:              squadId,
		SquadMembersId:       authorizedMembers,
		DataChannels:         dataChannels,
		ChatDataChannels:     make(map[string]*DataChannel),
		ChatDataChannelsFlag: &chatDCFlag,
		Flag:                 flag,
		Chat:                 &c,
		ChatFlag:             &chatFlag,
		init:                 false,
	}
	return
}

func (sch *SquadChatsHandler[T]) sendSquadRequest(reqType string, from string, payload map[string]interface{}) {
	go func() {
		for _, rc := range sch.reqChans {
			rc <- &SquadRequest{
				ReqType: reqType,
				From:    from,
				Payload: payload,
			}
		}
	}()
}

func (sch *SquadChatsHandler[T]) sendDataChannelMessage(reqType string, from string, to string, payload map[string]interface{}) (<-chan struct{}, <-chan error) {
	done, errCh := make(chan struct{}), make(chan error)
	go func() {
		if err := atomicallyExecute(sch.ChatDataChannelsFlag, func() (err error) {
			if _, ok := sch.ChatDataChannels[to]; ok {
				bs, jsonErr := json.Marshal(&SquadResponse{
					Type:    reqType,
					From:    from,
					To:      to,
					Payload: payload,
				})
				if jsonErr != nil {
					return jsonErr
				}
				err = sch.ChatDataChannels[to].DataChannel.SendText(string(bs))
			} else {
				err = fmt.Errorf("no corresponding dataChannel")
			}
			return
		}); err != nil {
			errCh <- err
			return
		}
		done <- struct{}{}
	}()
	return done, errCh
}

func (sch *SquadChatsHandler[T]) Init(ctx context.Context, authorizedMembers []string) (err error) {
	sch.init = true
	return
}

func (sch *SquadChatsHandler[T]) Subscribe(ctx context.Context, publisher <-chan *SquadRequest) (reqChan chan *SquadRequest, done chan struct{}, errCh chan error) {
	reqChan, done, errCh = make(chan *SquadRequest), make(chan struct{}), make(chan error)
	sch.reqChans = append(sch.reqChans, reqChan)
	go func() {
		for {
			select {
			case <-ctx.Done():
				done <- struct{}{}
				return
			case req := <-publisher:
				if err := sch.handleSquadRequest(ctx, req); err != nil {
					errCh <- err
				}
			}
		}
	}()
	return
}

func (sch *SquadChatsHandler[T]) ReadLastMessage(userId, chatId string) (err error) {
	err = atomicallyExecute(sch.ChatFlag, func() (err error) {

		err = sch.Chat.Tracking.SetUserLastIndex(userId, sch.Chat.DB.PreviousId)

		return
	})
	return
}

func (sch *SquadChatsHandler[T]) ListLatestChatMessages(userId, chatId string, lastIndex, limit float64) (err error) {
	var list []*ChatMessage
	var i int
	var done bool
	if err = atomicallyExecute(sch.ChatFlag, func() (err error) {
		list, i, done, err = sch.Chat.DB.ListChatMessages(int(lastIndex), int(limit))
		if err != nil {
			return
		}
		err = sch.Chat.Tracking.SetUserLastIndex(userId, sch.Chat.DB.PreviousId)

		return
	}); err != nil {
		return
	}
	success, e := sch.sendDataChannelMessage(CHAT_MESSAGE_LIST, "node", userId, map[string]interface{}{
		"done":         done || i <= 0,
		"lastIndex":    i - 1,
		"chatId":       chatId,
		"chatMessages": list,
	})
	select {
	case <-success:
		fmt.Println("done getting latest messages")
	case err = <-e:
	}
	return
}

func (sch *SquadChatsHandler[T]) ListLatestChatFiles(userId, chatId string, lastIndex, limit float64) (err error) {
	var list []*ChatFile
	var i int
	if err = atomicallyExecute(sch.ChatFlag, func() (err error) {

		list, i, err = sch.Chat.DB.ListChatFiles(int(lastIndex), int(limit))
		return
	}); err != nil {
		return
	}
	done, e := sch.sendDataChannelMessage(CHAT_FILES_LIST, "node", userId, map[string]interface{}{
		"done":         i <= 0,
		"lastIndex":    i,
		"chatId":       chatId,
		"chatMessages": list,
	})
	select {
	case <-done:
	case err = <-e:
	}
	return
}

func (sch *SquadChatsHandler[T]) AddChatMessage(userId, chatId, content string, isResponse bool, chatResponseId uint64, file *ChatFile) (err error) {
	chatMessage := &ChatMessage{
		Content:    content,
		From:       userId,
		IsResponse: isResponse,
		ResponseOf: nil,
		File:       file,
		Tags:       make([]string, 0),
		Date:       time.Now().Format(time.RFC3339),
	}
	if err = atomicallyExecute(sch.ChatFlag, func() (err error) {
		if isResponse {
			parentMessage, getErr := sch.Chat.DB.GetChatMessage(chatResponseId)
			if err != nil {
				if getErr != badger.ErrKeyNotFound {
					return getErr
				}
			}
			chatMessage.ResponseOf = parentMessage
		}
		if err = sch.Chat.DB.AddNewChatMessage(chatMessage); err != nil {
			return
		}
		chatMessage.ID = sch.Chat.DB.PreviousId
		return
	}); err != nil {
		return
	}

	notifyActivity := func(done <-chan struct{}, e <-chan error, member string) {
		select {
		case <-done:
		case <-e:
			chat := sch.Chat
			_ = atomicallyExecute(sch.ChatFlag, func() (err error) {

				li, err := chat.Tracking.GetUserLastIndex(member)
				if err != nil {
					return err
				}
				count, err := chat.DB.calculateNewChatCount(uint64(li))
				if err != nil {
					return err
				}
				if count == 1 {
					bs, err := json.Marshal(map[string]any{
						"squadId":   sch.SquadId,
						"chatId":    chatId,
						"squadHost": NodeID,
					})
					if err != nil {
						return err
					}
					sch.sendSquadRequest(CREATE_NOTIFICATION, "node", map[string]interface{}{
						"type":       "new_chat_activity",
						"title":      "Unread messages 👀",
						"body":       fmt.Sprintf("New messages in %s", sch.SquadName),
						"isPushed":   true,
						"payload":    string(bs),
						"recipients": []string{member},
					})
				}

				return
			})
		}
	}

	for _, v := range sch.SquadMembersId {
		done, e := sch.sendDataChannelMessage(NEW_CHAT_MESSAGE, "node", v, map[string]interface{}{
			"chatMessage": chatMessage,
			"chatId":      chatId,
		})
		go notifyActivity(done, e, v)
	}
	return
}

// func (sch *SquadChatsHandler[T]) ConnectToChatFSInstance(channelId string, userId string, sdp string) (err error) {
// 	err = atomicallyExecute(sch.ChatFSInstanceFlag, func() (err error) {
// 		d, e := sch.ChatFSInstance.HandleOffer(context.Background(), channelId, userId, sdp, sch.HostId, sch.sendDataChannelMessage, sch.signalCandidate)
// 		select {
// 		case <-d:
// 		case <-e:
// 		}
// 		return
// 	})
// 	return
// }

// func (sch *SquadChatsHandler[T]) LeaveChatFSInstance(
// 	userId string) (err error) {
// 	sch.ChatFSInstance.HandleLeavingMember(userId)
// 	return
// }

func (sch *SquadChatsHandler[T]) DeleteChatMessage(key uint64, chatId string) (err error) {
	err = atomicallyExecute(sch.ChatFlag, func() (err error) {
		chat := sch.Chat
		if err = chat.DB.DeleteChatMessage(key); err != nil {
			return
		}
		if chat.ChatType == PRIVATE {
			for _, member := range chat.Members {
				d, e := sch.sendDataChannelMessage(CHAT_MESSAGE_DELETED, "node", member, map[string]interface{}{
					"chatId":    chatId,
					"messageId": key,
				})
				select {
				case <-d:
				case tempErr := <-e:
					logger.Println(tempErr)
				}
			}
		} else {
			for _, member := range sch.SquadMembersId {
				d, e := sch.sendDataChannelMessage(CHAT_MESSAGE_DELETED, "node", member, map[string]interface{}{
					"chatId":    chatId,
					"messageId": key,
				})
				select {
				case <-d:
				case tempErr := <-e:
					logger.Println(tempErr)
				}
			}
		}
		previousId := chat.DB.PreviousId
		if previousId == key {
			if err = chat.DB.revertPreviousId(); err != nil {
				return
			}
			previousId = chat.DB.PreviousId
			if previousId == 1 {
				previousId = 0
			}
			if err = chat.Tracking.RevertTrackingLastIndex(previousId); err != nil {
				return
			}
		}
		return
	})
	return
}

func (sch *SquadChatsHandler[T]) UpdateChatMessage(key uint64, chatId, newContent string) (err error) {
	err = atomicallyExecute(sch.ChatFlag, func() (err error) {
		chat := sch.Chat
		if err = chat.DB.ModifyChatMessage(key, newContent); err != nil {
			return
		}
		if chat.ChatType == PRIVATE {
			for _, member := range chat.Members {
				d, e := sch.sendDataChannelMessage(CHAT_MESSAGE_EDITED, "node", member, map[string]interface{}{
					"chatId":     chatId,
					"messageId":  key,
					"newContent": newContent,
				})
				select {
				case <-d:
				case tempErr := <-e:
					logger.Println(tempErr)
				}
			}
		} else {
			for _, member := range sch.SquadMembersId {
				d, e := sch.sendDataChannelMessage(CHAT_MESSAGE_EDITED, "node", member, map[string]interface{}{
					"chatId":     chatId,
					"messageId":  key,
					"newContent": newContent,
				})
				select {
				case <-d:
				case tempErr := <-e:
					logger.Println(tempErr)
				}
			}
		}
		return
	})
	return
}

func (sch *SquadChatsHandler[T]) DeleteChatFile(key uint64, fileName, chatId string) (err error) {
	err = atomicallyExecute(sch.ChatFlag, func() (err error) {
		chat := sch.Chat
		if err = chat.DB.DeleteChatFile(fileName, key); err != nil {
			return
		}
		if chat.ChatType == PRIVATE {
			for _, member := range chat.Members {
				d, e := sch.sendDataChannelMessage(CHAT_FILE_DELETED, "node", member, map[string]interface{}{
					"chatId":   chatId,
					"fileId":   key,
					"fileName": fileName,
				})
				select {
				case <-d:
				case tempErr := <-e:
					logger.Println(tempErr)
				}
			}
		} else {
			for _, member := range sch.SquadMembersId {
				d, e := sch.sendDataChannelMessage(CHAT_FILE_DELETED, "node", member, map[string]interface{}{
					"chatId":   chatId,
					"fileId":   key,
					"fileName": fileName,
				})
				select {
				case <-d:
				case tempErr := <-e:
					logger.Println(tempErr)
				}
			}
		}
		return
	})
	return
}

func (sch *SquadChatsHandler[T]) chatFileUpload(chatId string, filename string, userId string, dc *DataChannel) {
	var writePipe chan<- []byte
	var done bool
	uploadDone := func() {
		if writePipe != nil {
			close(writePipe)
			writePipe = nil
		}
		done = true
	}
	dc.DataChannel.OnError(func(err error) {
		logger.Println(err)
		logger.Println("abort...")
		if !done {
			uploadDone()
		}
		if fufErr := sch.ChatFSInstance.FileUploadFailed(chatId, filename, userId); fufErr != nil {
			logger.Println(fufErr)
		}
	})
	dc.DataChannel.OnClose(func() {
		if done {
			logger.Println("closing gracefully...")
		} else {
			logger.Println("abort...")
			uploadDone()
			if fufErr := sch.ChatFSInstance.FileUploadFailed(chatId, filename, userId); fufErr != nil {
				logger.Println(fufErr)
			}
		}
	})
	dc.DataChannel.OnMessage(func(msg webrtc.DataChannelMessage) {
		if msg.IsString {
			if string(msg.Data) == "init_upload" {
				logger.Println("init upload....")
				var initErr error
				if writePipe, initErr = sch.ChatFSInstance.SetupFileUpload(chatId, filename, userId, dc.DataChannel); initErr != nil {
					_ = dc.DataChannel.SendText("abort")
					_ = dc.DataChannel.Close()
					return
				}
				logger.Println("upload ready !")
				_ = dc.DataChannel.SendText("upload_ready")
			} else if string(msg.Data) == "upload_done" {
				uploadDone()
			}
		} else {
			writePipe <- msg.Data
		}
	})
	dc.DataChannel.OnOpen(func() {
		_ = dc.DataChannel.SendText("channel_ready")
	})
}

func (sch *SquadChatsHandler[T]) chatFileDownload(chatId string, filename string, userId string, dc *DataChannel) {
	var done bool
	dc.DataChannel.OnError(func(err error) {
		if !done {
			logger.Println("abort...")
			if fdf := sch.ChatFSInstance.FileDownloadFailed(chatId, filename, userId); fdf != nil {
				logger.Println(fdf)
			}
		}
	})
	dc.DataChannel.OnClose(func() {
		if !done {
			logger.Println("abort...")
			if fdf := sch.ChatFSInstance.FileDownloadFailed(chatId, filename, userId); fdf != nil {
				logger.Println(fdf)
			}
		}
	})
	dc.DataChannel.OnMessage(func(msg webrtc.DataChannelMessage) {
		if msg.IsString {
			if string(msg.Data) == "init_download" {
				logger.Println("init download....")
				var initErr error
				if initErr = sch.ChatFSInstance.SetupFileDownload(chatId, filename, userId, dc.DataChannel); initErr != nil {
					fmt.Println("uwuwuwuwuwuwuwuwu")
					fmt.Println(initErr)
					_ = dc.DataChannel.SendText("abort")
					_ = dc.DataChannel.Close()
					return
				}
				logger.Println("download started !")
			} else if string(msg.Data) == "download_done" {
				done = true
			}
		}
	})
	dc.DataChannel.OnOpen(func() {
		_ = dc.DataChannel.SendText("channel_ready")
	})
}

func (sch *SquadChatsHandler[T]) handleDataChannel(ctx context.Context, dc *DataChannel) (catched bool) {
	var label string
	_ = atomicallyExecute(dc.l, func() (err error) {
		label = dc.DataChannel.Label()
		return
	})
	if strings.Contains(label, "chat_upload") {
		command := strings.Split(label, "|")
		if len(command) == 4 {
			catched = true
			go sch.chatFileUpload(command[1], command[2], command[3], dc)
		}
		logger.Println(command)
	} else if strings.Contains(label, "chat_download") {
		command := strings.Split(label, "|")
		catched = true
		go sch.chatFileDownload(command[1], command[2], command[3], dc)
		logger.Println(command)
	} else if strings.Contains(label, "chat_data") {
		command := strings.Split(label, "|")
		catched = true
		_ = atomicallyExecute(sch.ChatDataChannelsFlag, func() (err error) {
			sch.ChatDataChannels[command[1]] = dc
			return
		})
		dc.DataChannel.OnOpen(func() {
			fmt.Println("datachann in squad chat fking created")
			bs, err := json.Marshal(map[string]any{
				"type": "chat_init",
				"from": NodeID,
				"to":   command[1],
				"payload": map[string]any{
					"chatId": sch.SquadId,
				},
			})
			if err != nil {
				fmt.Println(err)
			}
			_ = dc.DataChannel.SendText(string(bs))
		})
		dc.DataChannel.OnClose(func() {
			fmt.Println("closing gratefully chat dc...")
			_ = atomicallyExecute(sch.ChatDataChannelsFlag, func() (err error) {
				delete(sch.ChatDataChannels, command[1])
				return
			})
		})
		dc.DataChannel.OnError(func(err error) {
			fmt.Println("error in chat dc...")
			_ = atomicallyExecute(sch.ChatDataChannelsFlag, func() (err error) {
				delete(sch.ChatDataChannels, command[1])
				return
			})
		})
	}
	return
}

func (sch *SquadChatsHandler[T]) handleSquadRequest(ctx context.Context, req *SquadRequest) (err error) {
	logger.Println("got request in squad chat handler", req)
	switch req.ReqType {
	case LEAVE_ZONE:
		if err = VerifyFieldsString(req.Payload, "userId"); err != nil {
			return
		}
		// err = sch.LeaveChatFSInstance(req.Payload["userId"].(string))
	case string(NEW_AUTHORIZED_SQUAD_MEMBER):
		if err = VerifyFieldsString(req.Payload, "userId"); err != nil {
			return
		}
		var contain bool
		for _, m := range sch.SquadMembersId {
			if m == req.Payload["userId"].(string) {
				contain = true
				break
			}
		}
		if !contain {
			sch.SquadMembersId = append(sch.SquadMembersId, req.Payload["userId"].(string))
		}
		return
	case string(REMOVED_SQUAD_AUTHORIZED_MEMBER):
		if err = VerifyFieldsString(req.Payload, "userId"); err != nil {
			return
		}
		var index int
		var found bool
		for i, m := range sch.SquadMembersId {
			if m == req.Payload["userId"].(string) {
				index = i
				found = true
				break
			}
		}
		if !found {
			err = fmt.Errorf("no such user in zone")
			return
		}
		sch.SquadMembersId = append(sch.SquadMembersId[:index], sch.SquadMembersId[index+1:]...)
		return
	case LIST_LATEST_CHATS:
		if err = VerifyFieldsString(req.Payload, "chatId"); err != nil {
			return
		}
		if err = VerifyFieldsFloat64(req.Payload, "lastIndex", "limit"); err != nil {
			return
		}
		err = sch.ListLatestChatMessages(req.From, req.Payload["chatId"].(string), req.Payload["lastIndex"].(float64), req.Payload["limit"].(float64))
		return
	case LIST_LATEST_FILES:
		if err = VerifyFieldsString(req.Payload, "chatId"); err != nil {
			return
		}
		if err = VerifyFieldsFloat64(req.Payload, "lastIndex", "limit"); err != nil {
			return
		}
		err = sch.ListLatestChatFiles(req.From, req.Payload["chatId"].(string), req.Payload["lastIndex"].(float64), req.Payload["limit"].(float64))
		return
	case READ_LATEST_MESSAGE:
		if err = VerifyFieldsString(req.Payload, "chatId"); err != nil {
			return
		}
		err = sch.ReadLastMessage(req.From, req.Payload["chatId"].(string))
	case ADD_CHAT_MESSAGE:
		logger.Println("got request in squad chat handler", req)
		if err = VerifyFieldsString(req.Payload, "chatId", "content"); err != nil {
			return
		}
		if err = VerifyFieldsBool(req.Payload, "isResponse"); err != nil {
			return
		}
		var parentChatId uint64
		if req.Payload["isResponse"].(bool) {
			if err = VerifyFieldsFloat64(req.Payload, "parentChatId"); err != nil {
				return
			}
			parentChatId = uint64(req.Payload["parentChatId"].(float64))
		}
		var file *ChatFile = nil
		if _, ok := req.Payload["file"]; ok {
			bs, jsonErr := json.Marshal(req.Payload["file"])
			if jsonErr != nil {
				return jsonErr
			}
			var f ChatFile
			if err = json.Unmarshal(bs, &f); err != nil {
				err = fmt.Errorf("the file payload dont match ChatFile struct pattern : %v", err)
				return
			}
			file = &f
		}
		err = sch.AddChatMessage(req.From, req.Payload["chatId"].(string), req.Payload["content"].(string), req.Payload["isResponse"].(bool), parentChatId, file)
	case DELETE_CHAT_MESSAGE:
		if err = VerifyFieldsString(req.Payload, "chatId"); err != nil {
			return
		}
		if err = VerifyFieldsFloat64(req.Payload, "messageId"); err != nil {
			return
		}
		err = sch.DeleteChatMessage(uint64(req.Payload["messageId"].(float64)), req.Payload["chatId"].(string))
	case EDIT_CHAT_MESSAGE:
		if err = VerifyFieldsString(req.Payload, "chatId", "newContent"); err != nil {
			return
		}
		if err = VerifyFieldsFloat64(req.Payload, "messageId"); err != nil {
			return
		}
		err = sch.UpdateChatMessage(uint64(req.Payload["messageId"].(float64)), req.Payload["chatId"].(string), req.Payload["newContent"].(string))
	case DELETE_CHAT_FILE:
		if err = VerifyFieldsString(req.Payload, "chatId", "fileName"); err != nil {
			return
		}
		if err = VerifyFieldsFloat64(req.Payload, "fileId"); err != nil {
			return
		}
		err = sch.DeleteChatFile(uint64(req.Payload["fileId"].(float64)), req.Payload["fileName"].(string), req.Payload["chatId"].(string))
	}
	return
}