services

type ItemService interface {
	GetAllItems(ctx context.Context) ([]*entities.Item, error)
	GetItem(ctx context.Context, id int64) (*entities.Item, error)
	CreateItem(ctx context.Context, item *entities.Item) error
	UpdateItem(ctx context.Context, item *entities.Item) error
	DeleteItem(ctx context.Context, id int64) error
	PurchaseItem(ctx context.Context, id int64, userId int64) (*entities.Order, error)
}

type OrderService interface {
	GetOrder(ctx context.Context, id int64) (*entities.Order, error)
	GetOrders(ctx context.Context) ([]*entities.Order, error)
	GetOrdersByUser(ctx context.Context, userID int64) ([]*entities.Order, error)
	GetOrdersByUserAndStatus(ctx context.Context, userID int64, status string) ([]*entities.Order, error)
	CreateOrder(ctx context.Context, order *entities.Order) (*entities.Order, error)
	UpdateOrder(ctx context.Context, order *entities.Order) (*entities.Order, error)
	PayOrder(ctx context.Context, id int64, user *entities.User) (*entities.Order, error)
}

type StatService interface {
	GetItemsNotOrdered(ctx context.Context) ([]entities.ItemStat, error)
	GetUsersWhoSpendMore(ctx context.Context) ([]entities.UserStat, error)
	GetMostOrderedItems(ctx context.Context) ([]entities.ItemStat, error)
	GetStats(ctx context.Context) ([]entities.Stat, error)
	GetLeastOrderedItems(ctx context.Context) ([]entities.ItemStat, error)
	GetTotalNumberOfItems(ctx context.Context) (int, error)
	GetTotalNumberOfUsers(ctx context.Context) (int, error)
	GetTotalNumberOfOrders(ctx context.Context) (int, error)
}

type UserService interface {
	CreateUser(ctx context.Context, user *entities.User) error
	GetUserByID(ctx context.Context, id int64) (*entities.User, error)
}