/*
 * All script logic for product comparison.
 *
 * The code relies on the jQuery JS library to be also loaded.
 *
 * The logic extends the JS namespace app.*
 */

(function (app) {
	if (app) {
		var products = [null, null, null, null, null, null];
		var count = 0;
		var emptyImgSrc = '';
		var emptyImgAlt = '';
		var baseButtonLabel = '';
		var confirmationMessage = '';
		var openUrl = '';
		var addUrl = '';
		var removeUrl = '';
		var suppressRefresh = false;

		var refresh = function () {
				if (suppressRefresh) {
					return;
				}

				var buttonLabel = baseButtonLabel;
				if (count > 0) {
					buttonLabel += ' (' + count + ')';
				}

				var compareItemsButton = jQuery('#compareItemsButton');
				compareItemsButton.html(buttonLabel);
				compareItemsButton.each(function () {
					jQuery(this).attr('disabled', (count < 2));
				});

				$('#clearComparedItemsButton').each(function () {
					jQuery(this).attr('disabled', (count < 1));
				});

				$('DIV.compare .compareBtn').removeClass('enabled').attr('disabled', true);
				if (count > 1) {
					$('DIV.compare input[type=checkbox]:checked').siblings('button').attr('disabled', false).addClass('enabled');
				}

				if (count > 0) {
					jQuery('#compareItems').show();
				} else {
					jQuery('#compareItems').hide();
				}

				/**
	   		 * Gray out all unchecked compare check boxes if the maximum number of 
	   		 * comparable products is reached.
	   		 */
				if (count >= 4) {
					$('.compare input[type="checkbox"]').each(function (i) {
						if (!this.checked) {
							this.disabled = true;
							$(this).siblings('button').attr('disabled', true);
						}
					});
				} else {
					$('.compare input[type="checkbox"]').each(function (i) {
						if (!this.checked) {
							this.disabled = false;
							$(this).siblings('button').attr('disabled', false);
						}
					});
				}

			};

		var reset = function (options) {
				products = [null, null, null, null, null, null];
				count = 0;
				emptyImgSrc = options.emptyImgSrc;
				emptyImgAlt = options.emptyImgAlt;
				baseButtonLabel = options.baseButtonLabel;
				confirmationMessage = options.confirmation;
				openUrl = options.openUrl;
				addUrl = options.addUrl;
				removeUrl = options.removeUrl;

				refresh();
			};

		var addProduct = function (options) {
				var addIndex = count;
				products[addIndex] = {
					id: options.id,
					category: options.category
				};
				count++;
				return addIndex;
			};

		var setProductImage = function (options) {
				jQuery('#compareItemsProduct' + options.index).each(function () {
					var productImage = jQuery(this)[0];
					productImage.src = options.src;
					productImage.alt = options.alt;
				});

				jQuery('#compareItemsClear' + options.index).show();
			}

		app.compare = {
			initialize: function (options) {
				reset(options);

				// Buttons to remove compared products individually	
				for (var i = 0; i < 6; i++) {
					// new Function() syntax ensures loop index is used correctly
					jQuery('#compareItemsClear' + i).click(new Function('app.compare.removeProduct({index: ' + i + '})'));
				}

				// Button to go to compare page
				jQuery('#compareItemsButton').click(function () {
					if (count > 1) {
						window.location.href = options.openUrl;
					}
				});

				// Button to go to compare page
				$('.compareBtn').click(function () {
					if ($(this).hasClass('enabled') && count > 1) {
						window.location.href = options.openUrl;
					}
				});

				// Button to clear all compared items
				jQuery('#clearComparedItemsButton').click(function () {
					suppressRefresh = true;

					jQuery('#compareItems').hide();

					for (var i = count - 1; i >= 0; i--) {
						app.compare.removeProduct({
							index: i
						});
					}

					suppressRefresh = false;

					refresh();
				});

				// Check checkboxes for compared products on the current page 
				for (var i = 0; i < options.products.length; i++) {
					var product = options.products[i];
					var addIndex = addProduct({
						id: product.id,
						category: product.category
					});
					setProductImage({
						index: addIndex,
						src: product.imgSrc,
						alt: product.imgAlt
					});

					jQuery('#compareCheck' + product.id).each(function () {
						jQuery(this)[0].checked = true;
						jQuery(this).addClass("compared");
					});
				}

				refresh();
			},

			addProduct: function (options) {
				if (count >= 4) {
					if (!confirm(confirmationMessage)) {
						jQuery('#compareCheck' + options.id).each(function () {
							jQuery(this)[0].checked = false;
						});
						return;
					}
					app.compare.removeProduct({
						index: 0
					});
				}

				var complete = function () {
						var addIndex = addProduct(options);

						jQuery('#productThumbnail' + options.id).each(function () {
							var thumbnail = jQuery(this)[0];
							setProductImage({
								index: addIndex,
								src: thumbnail.src,
								alt: thumbnail.alt
							});
						});

						refresh();
					};

				var uncheck = function () {
						jQuery('#compareCheck' + options.id).each(function () {
							jQuery(this)[0].checked = false;
							jQuery(this).removeClass("compared");
						});
					};

				jQuery.ajax({
					type: 'POST',
					url: addUrl,
					data: {
						'pid': options.id,
						'category': options.category
					},
					dataType: 'json',
					success: function (data) {
						if (data.success === true) {
							complete();
						} else {
							uncheck();
						}
					},
					failure: function (data) {
						uncheck();
					}
				});
			},

			removeProduct: function (options) {
				var index = null;
				if (options.index != null) {
					index = options.index;
				} else {
					for (var i = 0; i < count; i++) {
						if (products[i].id === options.id) {
							index = i;
						}
					}
				}

				var clearedProduct = products[index];

				var complete = function () {
						for (var i = index; i < count - 1; i++) {
							products[i] = products[i + 1];

							jQuery('#productThumbnail' + products[i].id).each(function () {
								var thumbnail = jQuery(this)[0];

								jQuery('#compareItemsProduct' + i).each(function () {
									var productImage = jQuery(this)[0];
									productImage.src = thumbnail.src;
									productImage.alt = thumbnail.alt;
								});
							});
						}

						var clearedIndex = count - 1;
						products[clearedIndex] = null;
						count--;

						jQuery('#compareCheck' + clearedProduct.id).each(function () {
							jQuery(this)[0].checked = false;
							jQuery(this).removeClass("compared");
						});

						jQuery('#compareItemsProduct' + clearedIndex).each(function () {
							var productImage = jQuery(this)[0];
							productImage.src = emptyImgSrc;
							productImage.alt = emptyImgAlt;
						});

						jQuery('#compareItemsClear' + clearedIndex).hide();

						refresh();
					};

				var check = function () {
						jQuery('#compareCheck' + clearedProduct.id).each(function () {
							jQuery(this)[0].checked = true;
						});
					};

				jQuery.ajax({
					type: 'POST',
					url: removeUrl,
					data: {
						'pid': clearedProduct.id,
						'category': clearedProduct.category
					},
					dataType: 'json',
					success: function (data) {
						if (data.success === true) {
							complete();
						} else {
							check();
						}
					},
					failure: function (data) {
						check();
					}
				});
			}
		}
	} else {
		// namespace has not been defined yet
		alert("app namespace is not loaded yet!");
	}
})(app);