package userHandler

import (
	"encoding/json"
	"errors"
	"fmt"
	"github.com/a-h/templ"
	"github.com/fossyy/filekeeper/app"
	"github.com/fossyy/filekeeper/session"
	"github.com/fossyy/filekeeper/types"
	"github.com/fossyy/filekeeper/types/models"
	"github.com/fossyy/filekeeper/view/client/user"
	"github.com/google/uuid"
	"github.com/gorilla/websocket"
	"gorm.io/gorm"
	"net/http"
	"os"
	"path/filepath"
)

var errorMessages = map[string]string{
	"password_not_match": "The passwords provided do not match. Please try again.",
}

var upgrader = websocket.Upgrader{
	ReadBufferSize:  1024,
	WriteBufferSize: 1024,
}

type ActionType string

const (
	UploadNewFile ActionType = "UploadNewFile"
	DeleteFile    ActionType = "DeleteFile"
	Ping          ActionType = "Ping"
)

type WebsocketAction struct {
	Action ActionType `json:"action"`
}

type ActionUploadNewFile struct {
	Action    string `json:"action"`
	Name      string `json:"name"`
	Size      uint64 `json:"size"`
	Chunk     uint64 `json:"chunk"`
	RequestID string `json:"requestID"`
}

func GET(w http.ResponseWriter, r *http.Request) {
	userSession := r.Context().Value("user").(types.User)
	if r.Header.Get("upgrade") == "websocket" {
		upgrade, err := upgrader.Upgrade(w, r, nil)
		if err != nil {
			panic(err)
			return
		}
		handlerWS(upgrade, userSession)
	}
	var component templ.Component
	sessions, err := session.GetSessions(userSession.Email)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		return
	}
	if err := r.URL.Query().Get("error"); err != "" {
		message, ok := errorMessages[err]
		if !ok {
			message = "Unknown error occurred. Please contact support at bagas@fossy.my.id for assistance."
		}

		component = userView.Main("Filekeeper - User Page", userSession, sessions, types.Message{
			Code:    0,
			Message: message,
		})
	} else {
		component = userView.Main("Filekeeper - User Page", userSession, sessions, types.Message{
			Code:    1,
			Message: "",
		})
	}
	err = component.Render(r.Context(), w)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		app.Server.Logger.Error(err.Error())
		return
	}
}

func handlerWS(conn *websocket.Conn, userSession types.User) {
	defer conn.Close()
	var err error
	var message []byte

	for {
		_, message, err = conn.ReadMessage()
		if err != nil {
			if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
				fmt.Println("Unexpected connection closure:", err)
			} else {
				fmt.Println("Connection closed:", err)
			}
			return
		}
		var action WebsocketAction
		err = json.Unmarshal(message, &action)
		if err != nil {
			fmt.Println("Error unmarshalling WebsocketAction:", err)
			sendErrorResponse(conn, action.Action)
			continue
		}

		switch action.Action {
		case UploadNewFile:
			var uploadNewFile ActionUploadNewFile
			err = json.Unmarshal(message, &uploadNewFile)
			if err != nil {
				fmt.Println("Error unmarshalling ActionUploadNewFile:", err)
				sendErrorResponse(conn, action.Action)
				continue
			}
			var file *models.File
			file, err = app.Server.Database.GetUserFile(uploadNewFile.Name, userSession.UserID.String())
			if err != nil {
				if errors.Is(err, gorm.ErrRecordNotFound) {
					newFile := models.File{
						ID:         uuid.New(),
						OwnerID:    userSession.UserID,
						Name:       uploadNewFile.Name,
						Size:       uploadNewFile.Size,
						TotalChunk: uploadNewFile.Chunk,
						Downloaded: 0,
					}
					err := app.Server.Database.CreateFile(&newFile)
					if err != nil {
						sendErrorResponse(conn, action.Action)
						continue
					}
					fileData := &types.FileWithDetail{
						ID:         newFile.ID,
						OwnerID:    newFile.OwnerID,
						Name:       newFile.Name,
						Size:       newFile.Size,
						Downloaded: newFile.Downloaded,
					}
					fileData.Chunk = make(map[string]bool)
					fileData.Done = true
					saveFolder := filepath.Join("uploads", userSession.UserID.String(), newFile.ID.String(), newFile.Name)
					for i := 0; i <= int(newFile.TotalChunk); i++ {
						fileName := fmt.Sprintf("%s/chunk_%d", saveFolder, i)
						if _, err := os.Stat(fileName); os.IsNotExist(err) {
							fileData.Chunk[fmt.Sprintf("chunk_%d", i)] = false
							fileData.Done = false
						} else {
							fileData.Chunk[fmt.Sprintf("chunk_%d", i)] = true
						}
					}
					sendSuccessResponseWithID(conn, action.Action, fileData, uploadNewFile.RequestID)
					continue
				} else {
					sendErrorResponse(conn, action.Action)
					continue
				}
			}
			fileData := &types.FileWithDetail{
				ID:         file.ID,
				OwnerID:    file.OwnerID,
				Name:       file.Name,
				Size:       file.Size,
				Downloaded: file.Downloaded,
				Done:       false,
			}
			fileData.Chunk = make(map[string]bool)
			fileData.Done = true
			saveFolder := filepath.Join("uploads", userSession.UserID.String(), fileData.ID.String(), fileData.Name)
			for i := 0; i <= int(file.TotalChunk-1); i++ {
				fileName := fmt.Sprintf("%s/chunk_%d", saveFolder, i)

				if _, err := os.Stat(fileName); os.IsNotExist(err) {
					fileData.Chunk[fmt.Sprintf("chunk_%d", i)] = false
					fileData.Done = false
				} else {
					fileData.Chunk[fmt.Sprintf("chunk_%d", i)] = true
				}
			}
			sendSuccessResponseWithID(conn, action.Action, fileData, uploadNewFile.RequestID)
			continue
		case Ping:
			sendSuccessResponse(conn, action.Action, map[string]string{"message": "received"})
			continue
		}
	}
}

func sendErrorResponse(conn *websocket.Conn, action ActionType) {
	response := map[string]interface{}{
		"action": action,
		"status": "error",
	}
	marshal, err := json.Marshal(response)
	if err != nil {
		fmt.Println("Error marshalling error response:", err)
		return
	}
	err = conn.WriteMessage(websocket.TextMessage, marshal)
	if err != nil {
		fmt.Println("Error writing error response:", err)
	}
}

func sendSuccessResponse(conn *websocket.Conn, action ActionType, response interface{}) {
	responseJSON := map[string]interface{}{
		"action":   action,
		"status":   "success",
		"response": response,
	}
	marshal, err := json.Marshal(responseJSON)
	if err != nil {
		fmt.Println("Error marshalling success response:", err)
		return
	}
	err = conn.WriteMessage(websocket.TextMessage, marshal)
	if err != nil {
		fmt.Println("Error writing success response:", err)
	}
}

func sendSuccessResponseWithID(conn *websocket.Conn, action ActionType, response interface{}, responseID string) {
	responseJSON := map[string]interface{}{
		"action":     action,
		"status":     "success",
		"response":   response,
		"responseID": responseID,
	}
	marshal, err := json.Marshal(responseJSON)
	if err != nil {
		fmt.Println("Error marshalling success response:", err)
		return
	}
	err = conn.WriteMessage(websocket.TextMessage, marshal)
	if err != nil {
		fmt.Println("Error writing success response:", err)
	}
}