/**
 * Image Model
 */
var EnviraGalleryImage = Backbone.Model.extend({
	/**
	 * Defaults
	 * As we always populate this model with existing data, we
	 * leave these blank to just show how this model is structured.
	 */
	defaults: {
		id: '',
		title: '',
		caption: '',
		alt: '',
		link: ''
	}
});

/**
 * Images Collection
 * - Comprises of all images in an Envira Gallery
 * - Each image is represented by an EnviraGalleryImage Model
 */
var EnviraGalleryImages = new Backbone.Collection();

/**
 * Modal Window
 * - Used by most Envira Backbone views to display information e.g. bulk edit, edit single image etc.
 */
if (typeof EnviraGalleryModalWindow == 'undefined') {
	var EnviraGalleryModalWindow = new wp.media.view.Modal({
		controller: {
			trigger: function () {}
		}
	});
}

/**
 * View
 */
var EnviraGalleryEditView = wp.Backbone.View.extend({
	/**
	 * The Tag Name and Tag's Class(es)
	 */
	tagName: 'div',
	className: 'edit-attachment-frame mode-select hide-menu hide-router',

	/**
	 * Template
	 * - The template to load inside the above tagName element
	 */
	template: wp.template('envira-meta-editor'),

	/**
	 * Events
	 * - Functions to call when specific events occur
	 */
	events: {
		'click .edit-media-header .left': 'loadPreviousItem',
		'click .edit-media-header .right': 'loadNextItem',

		'keyup input': 'updateItem',
		'keyup textarea': 'updateItem',
		'change input': 'updateItem',
		'change textarea': 'updateItem',
		'blur textarea': 'updateItem',
		'change select': 'updateItem',

		'click .actions a.envira-gallery-meta-submit': 'saveItem',

		'keyup input#link-search': 'searchLinks',
		'click div.query-results li': 'insertLink',

		'click button.media-file': 'insertMediaFileLink',
		'click button.attachment-page': 'insertAttachmentPageLink'
	},

	/**
	 * Initialize
	 *
	 * @param object model   EnviraGalleryImage Backbone Model
	 */
	initialize: function (args) {
		// Define loading and loaded events, which update the UI with what's happening.
		this.on('loading', this.loading, this);
		this.on('loaded', this.loaded, this);

		// Set some flags
		this.is_loading = false;
		this.collection = args.collection;
		this.child_views = args.child_views;
		this.attachment_id = args.attachment_id;
		this.attachment_index = 0;
		this.search_timer = '';

		// Get the model from the collection
		var count = 0;
		this.collection.each(function (model) {
			// If this model's id matches the attachment id, this is the model we want
			if (model.get('id') == this.attachment_id) {
				this.model = model;
				this.attachment_index = count;
				return false;
			}

			// Increment the index count
			count++;
		}, this);
	},

	/**
	 * Render
	 * - Binds the model to the view, so we populate the view's fields and data
	 */
	render: function () {
		// Get HTML
		this.$el.html(this.template(this.model.attributes));

		// If any child views exist, render them now
		if (this.child_views.length > 0) {
			this.child_views.forEach(function (view) {
				// Init with model
				var child_view = new view({
					model: this.model
				});

				// Render view within our main view
				this.$el.find('div.envira-addons').append(child_view.render().el);
			}, this);
		}

		// Set caption
		this.$el.find('textarea[name=caption]').val(this.model.get('caption'));

		// Init QuickTags on the caption editor
		// Delay is required for the first load for some reason
		setTimeout(function () {
			quicktags({
				id: 'caption',
				buttons: 'strong,em,link,ul,ol,li,close'
			});
			QTags._buttonsInit();
		}, 500);

		// Init Link Searching
		wpLink.init;

		// Enable / disable the buttons depending on the index
		if (this.attachment_index == 0) {
			// Disable left button
			this.$el.find('button.left').addClass('disabled');
		}
		if (this.attachment_index == this.collection.length - 1) {
			// Disable right button
			this.$el.find('button.right').addClass('disabled');
		}

		// Return
		return this;
	},

	/**
	 * Renders an error using
	 * wp.media.view.EnviraGalleryError
	 */
	renderError: function (error) {
		// Define model
		var model = {};
		model.error = error;

		// Define view
		var view = new wp.media.view.EnviraGalleryError({
			model: model
		});

		// Return rendered view
		return view.render().el;
	},

	/**
	 * Tells the view we're loading by displaying a spinner
	 */
	loading: function () {
		// Set a flag so we know we're loading data
		this.is_loading = true;

		// Show the spinner
		this.$el.find('.spinner').css('visibility', 'visible');
	},

	/**
	 * Hides the loading spinner
	 */
	loaded: function (response) {
		// Set a flag so we know we're not loading anything now
		this.is_loading = false;

		// Hide the spinner
		this.$el.find('.spinner').css('visibility', 'hidden');

		// Display the error message, if it's provided
		if (typeof response !== 'undefined') {
			this.$el.find('div.media-toolbar').after(this.renderError(response));
		}
	},

	/**
	 * Load the previous model in the collection
	 */
	loadPreviousItem: function () {
		// Decrement the index
		this.attachment_index--;

		// Get the model at the new index from the collection
		this.model = this.collection.at(this.attachment_index);

		// Update the attachment_id
		this.attachment_id = this.model.get('id');

		// Re-render the view
		this.render();
	},

	/**
	 * Load the next model in the collection
	 */
	loadNextItem: function () {
		// Increment the index
		this.attachment_index++;

		// Get the model at the new index from the collection
		this.model = this.collection.at(this.attachment_index);

		// Update the attachment_id
		this.attachment_id = this.model.get('id');

		// Re-render the view
		this.render();
	},

	/**
	 * Updates the model based on the changed view data
	 */
	updateItem: function (event) {
		// Check if the target has a name. If not, it's not a model value we want to store
		if (event.target.name == '') {
			return;
		}

		// Update the model's value, depending on the input type
		if (event.target.type == 'checkbox') {
			value = event.target.checked ? event.target.value : 0;
		} else {
			value = event.target.value;
		}

		// Update the model
		this.model.set(event.target.name, value);
	},

	/**
	 * Saves the image metadata
	 */
	saveItem: function (event) {
		var $error_element = jQuery('#envira-metabox-saving-error');
		if (0 !== $error_element.length) {
			$error_element.hide();
		}

		event.preventDefault();

		// Tell the View we're loading
		this.trigger('loading');

		// Make an AJAX request to save the image metadata
		wp.media.ajax('envira_gallery_save_meta', {
			context: this,
			data: {
				nonce: envira_gallery_metabox.save_nonce,
				post_id: envira_gallery_metabox.id,
				attach_id: this.model.get('id'),
				meta: this.model.attributes
			},
			success: function (response) {
				// Tell the view we've finished successfully
				this.trigger('loaded loaded:success');

				// Assign the model's JSON string back to the underlying item
				var item = JSON.stringify(this.model.attributes),
					item_element = jQuery('ul#envira-gallery-output li#' + this.model.get('id'));

				// Assign the JSON
				jQuery(item_element).attr('data-envira-gallery-image-model', item);

				// Update the title and hint
				jQuery('div.meta div.title span', item_element).text(this.model.get('title'));
				jQuery('div.meta div.title a.hint', item_element).attr('title', this.model.get('title'));

				// Display or hide the title hint depending on the title length
				if (this.model.get('title').length > 20) {
					jQuery('div.meta div.title a.hint', item_element).removeClass('hidden');
				} else {
					jQuery('div.meta div.title a.hint', item_element).addClass('hidden');
				}

				// Show the user the 'saved' notice for 1.5 seconds
				var saved = this.$el.find('.saved');
				saved.fadeIn();
				setTimeout(function () {
					saved.fadeOut();
				}, 1500);
			},
			error: function (error_message) {
				// Tell wp.media we've finished, but there was an error
				this.trigger('loaded loaded:error', error_message);
				if (0 === $error_element.length) {
					var saved = this.$el.find('.saved');
					jQuery(saved).after(
						`<span id='envira-metabox-saving-error' style='color: red'>${error_message}</span>`
					);
				} else {
					$error_element.show();
					$error_element.html(error_message);
				}
			}
		});
	},

	/**
	 * Searches Links
	 */
	searchLinks: function (event) {},

	/**
	 * Inserts the clicked link into the URL field
	 */
	insertLink: function (event) {},

	/**
	 * Inserts the direct media link for the Media Library item
	 *
	 * The button triggering this event is only displayed if we are editing a
	 * Media Library item, so there's no need to perform further checks
	 */
	insertMediaFileLink: function (event) {
		// Tell the View we're loading
		this.trigger('loading');

		// Make an AJAX request to get the media link
		wp.media.ajax('envira_gallery_get_attachment_links', {
			context: this,
			data: {
				nonce: envira_gallery_metabox.save_nonce,
				attachment_id: this.model.get('id')
			},
			success: function (response) {
				// Update model
				this.model.set('link', response.media_link);

				// Tell the view we've finished successfully
				this.trigger('loaded loaded:success');

				// Re-render the view
				this.render();
			},
			error: function (error_message) {
				// Tell wp.media we've finished, but there was an error
				this.trigger('loaded loaded:error', error_message);
			}
		});
	},

	/**
	 * Inserts the attachment page link for the Media Library item
	 *
	 * The button triggering this event is only displayed if we are editing a
	 * Media Library item, so there's no need to perform further checks
	 */
	insertAttachmentPageLink: function (event) {
		// Tell the View we're loading
		this.trigger('loading');

		// Make an AJAX request to get the media link
		wp.media.ajax('envira_gallery_get_attachment_links', {
			context: this,
			data: {
				nonce: envira_gallery_metabox.save_nonce,
				attachment_id: this.model.get('id')
			},
			success: function (response) {
				// Update model
				this.model.set('link', response.attachment_page);

				// Tell the view we've finished successfully
				this.trigger('loaded loaded:success');

				// Re-render the view
				this.render();
			},
			error: function (error_message) {
				// Tell wp.media we've finished, but there was an error
				this.trigger('loaded loaded:error', error_message);
			}
		});
	}
});

/**
 * Sub Views
 * - Addons must populate this array with their own Backbone Views, which will be appended
 * to the settings region
 */
var EnviraGalleryChildViews = [];

/**
 * DOM
 */
jQuery(document).ready(function ($) {
	// Edit Image
	$(document).on('click', '#envira-gallery-main a.envira-gallery-modify-image', function (e) {
		// Prevent default action
		e.preventDefault();

		// (Re)populate the collection
		// The collection can change based on whether the user previously selected specific images
		EnviraGalleryImagesUpdate(false);

		// Get the selected attachment
		var attachment_id = $(this).parent().data('envira-gallery-image');

		// Pass the collection of images for this gallery to the modal view, as well
		// as the selected attachment
		EnviraGalleryModalWindow.content(
			new EnviraGalleryEditView({
				collection: EnviraGalleryImages,
				child_views: EnviraGalleryChildViews,
				attachment_id: attachment_id
			})
		);

		// Open the modal window
		EnviraGalleryModalWindow.open();
	});
});

/**
 * Populates the EnviraGalleryImages Backbone collection, which comprises of a set of Envira Gallery Images
 *
 * Called when images are added, deleted, reordered or selected
 *
 * @global           EnviraGalleryImages     The backbone collection of images
 * @param    bool    selected_only           Only populate collection with images the user has selected
 */
function EnviraGalleryImagesUpdate(selected_only) {
	// Clear the collection
	EnviraGalleryImages.reset();

	// Iterate through the gallery images in the DOM, adding them to the collection
	var selector =
		'ul#envira-gallery-output li.envira-gallery-image' + (selected_only ? '.selected' : '');

	jQuery(selector).each(function () {
		// Build an EnviraGalleryImage Backbone Model from the JSON supplied in the element
		var envira_gallery_image = jQuery.parseJSON(
			jQuery(this).attr('data-envira-gallery-image-model')
		);

		// Strip slashes from some fields
		envira_gallery_image.alt = EnviraGalleryStripslashes(envira_gallery_image.alt);

		// Add the model to the collection
		EnviraGalleryImages.add(new EnviraGalleryImage(envira_gallery_image));
	});

	// Update the count in the UI
	jQuery('#envira-gallery-main span.count').text(
		jQuery('ul#envira-gallery-output li.envira-gallery-image').length
	);
}

/**
 * Strips slashes from the given string, which may have been added to escape certain characters
 *
 * @since 1.4.2.0
 *
 * @param    string  str     String
 * @return   string          String without slashes
 */
function EnviraGalleryStripslashes(str) {
	return (str + '').replace(/\\(.?)/g, function (s, n1) {
		switch (n1) {
			case '\\':
				return '\\';
			case '0':
				return '\u0000';
			case '':
				return '';
			default:
				return n1;
		}
	});
}
