kleinTodo/server/handler/syncHandler.go

package handler

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

	"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
	}

	serverTodos := store.GetTodoMap(user)

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

	for _, clientTodo := range todoList.Todos {
		if clientTodo.LastModified.IsZero() {
			clientTodo.LastModified = time.Now().UTC()
		}
		serverTodo, exists := serverTodos[clientTodo.Id]

		if !exists {
			if clientTodo.Deleted {
				continue
			}
			err = clientTodo.Store(store, user)
			if handleError(w, http.StatusInternalServerError, err) {
				return
			}
			serverTodos[clientTodo.Id] = clientTodo
			continue
		}
		if clientTodo.Deleted {
			if clientTodo.LastModified.After(serverTodo.LastModified) {
				err = store.RemoveValueFromBucket(user, clientTodo.Id)
				if handleError(w, http.StatusInternalServerError, err) {
					return
				}
				delete(serverTodos, clientTodo.Id)
			}
		} else if !serverTodo.IsEqual(clientTodo) {
			if serverTodo.IsEqualIgnoringStatus(clientTodo) && clientTodo.LastModified.After(serverTodo.LastModified) {
				err = clientTodo.Store(store, user)
				if handleError(w, http.StatusInternalServerError, err) {
					return
				}
				serverTodos[clientTodo.Id] = clientTodo
			} else {
				response.MisMatchingTodos = append(response.MisMatchingTodos, common.MisMatchingTodo{
					ServerTodo: serverTodo,
					LocalTodo:  clientTodo,
				})
				delete(serverTodos, clientTodo.Id)
			}
		}
	}

	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
	}
}