class DeleteCategoryViewController extends TimeCardsViewController {
	constructor(element) {
		super(element);

		TimeCards.dataManager.addDataListener("card_category", null, this.onCategoryUpdate.bind(this));
		TimeCards.dataManager.addStoreErrorListener("card_category", this.onCategoryStoreError.bind(this));
	}

	setCategory(category) {
		this.category = category;

		this.categoryNameLabel1.innerText = category.name;
		this.categoryNameLabel2.innerText = category.name;

		//Show or hide the migration box depending on whether there are cards in the category or not.
		this.migrationBox.style.display = (Object.keys(TimeCards.dataManager.getEntities("card", {
			id_category: this.category.category_id
		})).length > 0 ? "" : "none");

		var previouslySelectedCategory = this.categoryDropdown.value;

		//Remove all but the first option of the category dropdown.
		for (var i = this.categoryDropdown.children.length - 1; i > 0; i--) {
			this.categoryDropdown.removeChild(this.categoryDropdown.children[i]);
		}

		//Add the names of the other categories to the migration dropdown.
		var allCategories = TimeCards.dataManager.getEntities("card_category");
		for (var categoryId in allCategories) {
			if (categoryId != category.category_id) {
				var optionElement = document.createElement("OPTION");
				optionElement.value = categoryId;
				optionElement.innerText = "Move to \"" + allCategories[categoryId].name + "\"";
				this.categoryDropdown.appendChild(optionElement);
				this.categoryDropdown.value = categoryId;
			}
		}

		//Preselect the category that was selected before the update.
		if (previouslySelectedCategory in allCategories) {
			this.categoryDropdown.value = previouslySelectedCategory;
		}
	}

	onCancelButtonPressed(event) {
		this.dismissModally();
	}

	onDeleteButtonPressed(event) {
		this.deleteButton.disabled = true;
		TimeCards.dataManager.store("card_category", this.category.category_id, {
			migration_target: this.categoryDropdown.value
		});
	}

	onCategoryUpdate(categoryId, category) {
		//Dismiss the view when the deleted category is the one that the view is currently about to delete.
		if (!category && categoryId == this.category.category_id) {
			this.deleteButton.disabled = false;
			this.dismissModally();
			return;
		}

		//Refresh the dropdown if any other category has changed.
		if (this.category) {
			this.setCategory(this.category);
		}
	}

	onCategoryStoreError(categoryId, category, error) {
		if (!this.category || this.category.category_id != categoryId) {
			return;
		}

		this.deleteButton.disabled = false;
	}
}

UIKit.registerViewControllerType(DeleteCategoryViewController);