package handler

import (
	"encoding/json"
	"net/http"
	"reflect"

	"gitea.kleinsense.nl/DariusKlein/kleinTodo/common"
	"gitea.kleinsense.nl/DariusKlein/kleinTodo/common/jwt"
)

func SyncHandler(w http.ResponseWriter, r *http.Request) {
	user, err := jwt.GetVerifiedUser(r)
	if handleError(w, http.StatusUnauthorized, err) {
		return
	}

	var todoList common.TodoList
	err = json.NewDecoder(r.Body).Decode(&todoList)
	if handleError(w, http.StatusBadRequest, err) {
		return
	}

	store, err := common.GetTodoDataStore()
	if handleError(w, http.StatusInternalServerError, err) {
		return
	}

	storedTodoJsons := store.GetAllFromBucket(user)

	serverTodos := make(map[string]common.Todo)
	for key, val := range storedTodoJsons {
		var todo common.Todo
		if json.Unmarshal([]byte(val), &todo) == nil {
			serverTodos[key] = todo
		}
	}

	var response = common.SyncResponse{
		SyncedTodos:      []common.Todo{},
		MisMatchingTodos: []common.MisMatchingTodo{},
	}

	for _, clientTodo := range todoList.Todos {
		serverTodo, exists := serverTodos[clientTodo.Name]

		if !exists {
			err = clientTodo.Store(store, user)
			if handleError(w, http.StatusInternalServerError, err) {
				return
			}
			serverTodos[clientTodo.Name] = clientTodo
		} else {
			if !reflect.DeepEqual(serverTodo, clientTodo) {
				response.MisMatchingTodos = append(response.MisMatchingTodos, common.MisMatchingTodo{
					ServerTodo: serverTodo,
					LocalTodo:  clientTodo,
				})
			}
		}
	}

	for _, todo := range serverTodos {
		response.SyncedTodos = append(response.SyncedTodos, todo)
	}

	w.Header().Set("Content-Type", "application/json")
	err = json.NewEncoder(w).Encode(response)
	if handleError(w, http.StatusInternalServerError, err) {
		return
	}
}