package httpRequest

import (
	json2 "encoding/json"
	"maps"
	"net/http"
	"slices"
	"strings"
	"time"

	"go-socket/packages/Enums/ConnectionState"
	"go-socket/packages/Enums/WsEventType"
	"go-socket/packages/cache"
	"go-socket/packages/config"
	"go-socket/packages/convertions"
	"go-socket/packages/postgresql"
	"go-socket/packages/types"
	"go-socket/packages/wsServer"

	"github.com/google/uuid"
)

func HandleDm(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}

	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}

	conn, ok := getConnectionWithResponseOnFail(&response, request, user)
	if !ok {
		return
	}

	msgContent := request.FormValue("msgContent")
	attachedFile := request.FormValue("attachedFile")

	if msgContent == "" && attachedFile == "" {
		http.Error(response, "empty msgContent", http.StatusBadRequest)
		return
	}

	if attachedFile != "" && !strings.HasPrefix(attachedFile, conn.Id.String()+"/") {
		http.Error(response, "invalid attachedFile", http.StatusBadRequest)
		return
	}

	var target *types.User

	if user.Id == conn.RequestorId {
		target, err = getUserById(ctx, conn.RecipientId)
	} else if user.Id == conn.RecipientId {
		target, err = getUserById(ctx, conn.RequestorId)
	} else {
		http.Error(response, "invalid connectionid", http.StatusBadRequest)
		return
	}

	if err != nil {
		http.Error(response, "internal server error", http.StatusInternalServerError)
		return
	}
	message := &types.Message{
		Id:           uuid.New(),
		Content:      msgContent,
		AttachedFile: attachedFile,
		CreatedAt:    time.Now(),
		Sender:       user.Id,
		Receiver:     conn.Id,
	}

	if target.WsConn != nil {
		wsServer.WsSendMessageCloseIfTimeout(target, types.WsEventMessage{
			Type:  WsEventType.DirectMessage,
			Event: message,
		})
	} else {
		cache.IncrementConnectionsUnreadMessages(target.Id, conn.Id)
	}

	err = postgresql.ConnectionMessageSave(ctx, message)
	if err != nil {
		http.Error(response, "internal server error", http.StatusInternalServerError)
		return
	}

	response.WriteHeader(http.StatusAccepted)
}

func HandleUserGetConnectionsUnreadMessages(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}

	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}

	connectionIds, err := convertions.StringToUuidSlice(request.URL.Query().Get("connections"))
	if err != nil {
		http.Error(response, "invalid uuid format", http.StatusBadRequest)
		return
	}
	result := make([]uint32, 0, len(connectionIds))

	for _, connId := range connectionIds {
		_, ok := cache.GetConnection(user, connId)
		if !ok {
			http.Error(response, "no such connection: "+connId.String(), http.StatusUnauthorized)
			return
		}
	}

	for _, connId := range connectionIds {
		count, _ := cache.GetConnectionsUnreadMessages(user.Id, connId)
		cache.DeallocateConnectionsUnreadMessages(user.Id, connId)
		result = append(result, count)
	}

	json, err := json2.Marshal(result)
	if err != nil {
		http.Error(response, "internal server error", http.StatusInternalServerError)
		return
	}

	response.WriteHeader(http.StatusAccepted)
	response.Write(json)
}

func HandleUserGetConnectionMessages(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}
	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}

	conn, ok := getConnectionWithResponseOnFail(&response, request, user)
	if !ok {
		return
	}

	before, err := convertions.StringToTimestamp(request.URL.Query().Get("before"))
	if err != nil {
		before = time.Now()
	}

	messagesCap, err := convertions.StringToUint32(request.URL.Query().Get("messages"))
	if err != nil {
		messagesCap = config.MaxDirectMsgCache
	}

	buffer, bufferSize := conn.GetSortedMessagesBuff()

	var validBufCount uint32
	for validBufCount < bufferSize && buffer[validBufCount].CreatedAt.Before(before) {
		validBufCount++
	}

	var messages []*types.Message

	if validBufCount >= messagesCap {
		start := validBufCount - messagesCap
		messages = make([]*types.Message, messagesCap)
		for i := uint32(0); i < messagesCap; i++ {
			messages[i] = buffer[start+i]
		}
	} else {
		remaining := messagesCap - validBufCount
		cutoff := before
		if validBufCount > 0 {
			cutoff = buffer[0].CreatedAt
		}
		dbMessages, err := postgresql.ConnectionGetMessagesBefore(ctx, cutoff, conn.Id, remaining)
		if err != nil {
			http.Error(response, "internal server error", http.StatusInternalServerError)
			return
		}
		messages = make([]*types.Message, 0, uint32(len(dbMessages))+validBufCount)
		messages = append(messages, dbMessages...)
		for i := uint32(0); i < validBufCount; i++ {
			messages = append(messages, buffer[i])
		}
	}

	json, err := json2.Marshal(messages)
	if err != nil {
		http.Error(response, "internal server error", http.StatusInternalServerError)
		return
	}

	response.WriteHeader(http.StatusOK)
	response.Write(json)
}

func HandleUserNewConnection(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}
	ctx := request.Context()
	requestor, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}
	recipientId, err := convertions.StringToUuid(request.FormValue("recipient"))
	if err != nil {
		http.Error(response, "no such user", http.StatusUnauthorized)
		return
	}
	recipient, err := getUserById(ctx, recipientId)
	if err != nil {
		http.Error(response, "no such user", http.StatusUnauthorized)
		return
	}

	if requestor.Id == recipient.Id {
		http.Error(response, "cannot connect to yourself", http.StatusBadRequest)
		return
	}

	requestor.Mu.RLock()
	for _, connection := range requestor.Connections {
		if (connection.RequestorId == requestor.Id && connection.RecipientId == recipient.Id) ||
			(connection.RecipientId == requestor.Id && connection.RequestorId == recipient.Id) {
			requestor.Mu.RUnlock()
			http.Error(response, "connection already exists", http.StatusBadRequest)
			return
		}
	}
	requestor.Mu.RUnlock()

	connection := &types.Connection{
		CreatedAt:   time.Now(),
		RequestorId: requestor.Id,
		RecipientId: recipient.Id,
		State:       ConnectionState.Stranger,
	}
	err = postgresql.ConnectionSave(ctx, connection)
	if err != nil {
		http.Error(response, "internal server error", http.StatusInternalServerError)
		return
	}
	cache.AddConnection(requestor, recipient, connection)

	wsServer.WsSendMessageCloseIfTimeout(recipient, types.WsEventMessage{
		Type:  WsEventType.ConnectionCreated,
		Event: connection,
	})

	response.WriteHeader(http.StatusCreated)
	return
}

func HandleUserDeleteConnection(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}
	ctx := request.Context()

	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}

	conn, ok := getConnectionWithResponseOnFail(&response, request, user)
	if !ok {
		return
	}

	var user2 *types.User
	if conn.RequestorId == user.Id {
		recipient, err := getUserById(ctx, conn.RecipientId)
		if err != nil {
			http.Error(response, "internal server error", http.StatusInternalServerError)
			return
		}
		user2 = recipient
	} else if conn.RecipientId == user.Id {
		requestor, err := getUserById(ctx, conn.RequestorId)
		if err != nil {
			http.Error(response, "internal server error", http.StatusInternalServerError)
			return
		}
		user2 = requestor
	} else {
		http.Error(response, "invalid connectionid", http.StatusBadRequest)
		return
	}

	err = postgresql.ConnectionDelete(ctx, conn)
	if err != nil {
		http.Error(response, "internal server error", http.StatusInternalServerError)
		return
	}

	cache.DeleteConnection(user, user2, conn.Id)
	wsServer.WsSendMessageCloseIfTimeout(user2, types.WsEventMessage{
		Type:  WsEventType.ConnectionDeleted,
		Event: conn.Id,
	})

	response.WriteHeader(http.StatusAccepted)
	response.Write(conn.Id[:])
}

func HandleUserElevateConnection(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}
	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}
	conn, ok := getConnectionWithResponseOnFail(&response, request, user)
	if !ok {
		return
	}

	response.WriteHeader(http.StatusAccepted)

	if conn.UserWantingToElevate != (uuid.UUID{}) && conn.UserWantingToElevate != user.Id {
		switch conn.State {
		case ConnectionState.Stranger:
			conn.State = ConnectionState.Friend
			break
		default:
			http.Error(response, "cannot elevate further", http.StatusBadRequest)
			return
		}

		err = postgresql.ConnectionUpdateState(ctx, conn)
		if err != nil {
			http.Error(response, "internal server error", http.StatusInternalServerError)
			return
		}
		response.Write([]byte("elevated"))

		var user2 *types.User
		if conn.RequestorId == user.Id {
			user2, err = getUserById(ctx, conn.RecipientId)
		} else {
			user2, err = getUserById(ctx, conn.RequestorId)
		}
		if err != nil {
			http.Error(response, "internal server error", http.StatusInternalServerError)
			return
		}

		wsServer.WsSendMessageCloseIfTimeout(user2, types.WsEventMessage{
			Type: WsEventType.ConnectionElevated,
			Event: types.ConnectionStatusSetData{
				Id:       conn.Id,
				NewState: conn.State,
			},
		})

		return
	}

	conn.UserWantingToElevate = user.Id
	response.Write([]byte("waiting for second user to elevate"))
}

func HandleUserDeElevateConnection(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}

	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}

	conn, ok := getConnectionWithResponseOnFail(&response, request, user)
	if !ok {
		return
	}

	if conn.State != ConnectionState.Stranger {
		conn.State = ConnectionState.Stranger
		err = postgresql.ConnectionUpdateState(ctx, conn)
		if err != nil {
			http.Error(response, "internal server error", http.StatusInternalServerError)
			return
		}

		var user2 *types.User
		if conn.RequestorId == user.Id {
			user2, err = getUserById(ctx, conn.RecipientId)
		} else {
			user2, err = getUserById(ctx, conn.RequestorId)
		}

		wsServer.WsSendMessageCloseIfTimeout(user2, types.WsEventMessage{
			Type: WsEventType.ConnectionDeElevated,
			Event: types.ConnectionStatusSetData{
				Id:       conn.Id,
				NewState: conn.State,
			},
		})
		response.Write([]byte("de elevated"))
		return
	}

	response.WriteHeader(http.StatusConflict)
	response.Write([]byte("already lowest possible"))
}

func HandleUserGetConnections(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(&response, request, normal) {
		return
	}
	ctx := request.Context()

	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}

	user.Mu.RLock()
	connections := slices.Collect(maps.Values(user.Connections))
	user.Mu.RUnlock()
	json, err := json2.Marshal(connections)
	if err != nil {
		http.Error(response, "internal server error", http.StatusInternalServerError)
		return
	}

	response.WriteHeader(http.StatusOK)
	response.Write(json)
}