<?php
/**
 * A1 Tools Media Management
 *
 * Provides a Media Library browser with SEO-friendly file renaming.
 * Renames physical files, thumbnails, and updates all WordPress metadata.
 *
 * @package A1_Tools
 * @since   1.9.4
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Class A1Tools_Media_Management
 */
class A1Tools_Media_Management {

	/** @var A1Tools_Media_Management|null */
	private static $instance = null;

	/**
	 * Get singleton instance.
	 *
	 * @return A1Tools_Media_Management
	 */
	public static function get_instance() {
		if ( null === self::$instance ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	/**
	 * Constructor — registers hooks.
	 */
	private function __construct() {
		add_action( 'wp_ajax_a1tools_load_media', array( $this, 'ajax_load_media' ) );
		add_action( 'wp_ajax_a1tools_rename_media', array( $this, 'ajax_rename_media' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_admin_assets' ) );
	}

	// =========================================================================
	// Admin Assets
	// =========================================================================

	/**
	 * Enqueue admin CSS and JS on the Media Management page only.
	 *
	 * @param string $hook The admin page hook.
	 */
	public function enqueue_admin_assets( $hook ) {
		if ( 'a1-tools_page_a1-tools-media-management' !== $hook ) {
			return;
		}

		wp_register_style( 'a1tools-media-mgmt', false, array(), A1TOOLS_VERSION );
		wp_enqueue_style( 'a1tools-media-mgmt' );
		wp_add_inline_style( 'a1tools-media-mgmt', $this->get_admin_css() );

		wp_register_script( 'a1tools-media-mgmt', false, array( 'jquery' ), A1TOOLS_VERSION, true );
		wp_enqueue_script( 'a1tools-media-mgmt' );

		wp_localize_script( 'a1tools-media-mgmt', 'a1toolsMM', array(
			'ajaxUrl'     => admin_url( 'admin-ajax.php' ),
			'nonceLoad'   => wp_create_nonce( 'a1tools_load_media' ),
			'nonceRename' => wp_create_nonce( 'a1tools_rename_media' ),
		) );

		wp_add_inline_script( 'a1tools-media-mgmt', $this->get_admin_js() );
	}

	// =========================================================================
	// AJAX: Load Media Items
	// =========================================================================

	/**
	 * AJAX handler — return paginated media items.
	 */
	public function ajax_load_media() {
		check_ajax_referer( 'a1tools_load_media', 'nonce' );

		if ( ! current_user_can( 'upload_files' ) ) {
			wp_send_json_error( array( 'message' => 'Permission denied.' ) );
		}

		$page       = max( 1, absint( $_POST['page'] ?? 1 ) );
		$per_page   = min( 100, max( 1, absint( $_POST['per_page'] ?? 40 ) ) );
		$search     = sanitize_text_field( $_POST['search'] ?? '' );
		$mime       = sanitize_text_field( $_POST['mime_filter'] ?? '' );
		$orderby    = sanitize_text_field( $_POST['orderby'] ?? 'date' );
		$order      = strtoupper( sanitize_text_field( $_POST['order'] ?? 'DESC' ) );

		if ( ! in_array( $orderby, array( 'date', 'title', 'name' ), true ) ) {
			$orderby = 'date';
		}
		if ( ! in_array( $order, array( 'ASC', 'DESC' ), true ) ) {
			$order = 'DESC';
		}

		$args = array(
			'post_type'      => 'attachment',
			'post_status'    => 'inherit',
			'posts_per_page' => $per_page,
			'paged'          => $page,
			'orderby'        => $orderby,
			'order'          => $order,
		);

		if ( ! empty( $search ) ) {
			$args['s'] = $search;
		}
		if ( ! empty( $mime ) ) {
			$args['post_mime_type'] = $mime;
		}

		$query = new WP_Query( $args );
		$items = array();

		foreach ( $query->posts as $post ) {
			$filepath  = get_attached_file( $post->ID );
			$filename  = $filepath ? basename( $filepath ) : '';
			$meta      = wp_get_attachment_metadata( $post->ID );
			$thumb     = wp_get_attachment_image_src( $post->ID, 'thumbnail' );
			$filesize  = ( $filepath && file_exists( $filepath ) ) ? filesize( $filepath ) : 0;

			$items[] = array(
				'id'                 => $post->ID,
				'title'              => $post->post_title,
				'filename'           => $filename,
				'url'                => wp_get_attachment_url( $post->ID ),
				'thumbnail_url'      => $thumb ? $thumb[0] : wp_mime_type_icon( $post->ID ),
				'is_image'           => wp_attachment_is_image( $post->ID ),
				'mime_type'          => $post->post_mime_type,
				'file_size'          => $filesize,
				'file_size_formatted' => size_format( $filesize ),
				'width'              => isset( $meta['width'] ) ? (int) $meta['width'] : 0,
				'height'             => isset( $meta['height'] ) ? (int) $meta['height'] : 0,
				'date'               => get_the_date( 'Y-m-d', $post ),
			);
		}

		wp_send_json_success( array(
			'items'        => $items,
			'total'        => (int) $query->found_posts,
			'pages'        => (int) $query->max_num_pages,
			'current_page' => $page,
		) );
	}

	// =========================================================================
	// AJAX: Rename Media
	// =========================================================================

	/**
	 * AJAX handler — rename a single media attachment.
	 */
	public function ajax_rename_media() {
		check_ajax_referer( 'a1tools_rename_media', 'nonce' );

		if ( ! current_user_can( 'upload_files' ) ) {
			wp_send_json_error( array( 'message' => 'Permission denied.' ) );
		}

		$attachment_id = absint( $_POST['attachment_id'] ?? 0 );
		$new_name      = sanitize_text_field( $_POST['new_filename'] ?? '' );
		$update_refs   = ! empty( $_POST['update_refs'] );

		if ( ! $attachment_id ) {
			wp_send_json_error( array( 'message' => 'Invalid attachment ID.' ) );
		}

		$result = $this->do_rename( $attachment_id, $new_name, $update_refs );

		if ( is_wp_error( $result ) ) {
			wp_send_json_error( array( 'message' => $result->get_error_message() ) );
		}

		wp_send_json_success( $result );
	}

	// =========================================================================
	// Rename Logic
	// =========================================================================

	/**
	 * Sanitize a filename for SEO: lowercase, alphanumeric + hyphens.
	 *
	 * @param string $name Raw name (no extension).
	 * @return string Sanitized name.
	 */
	private function sanitize_seo_filename( $name ) {
		$name = strtolower( $name );
		$name = preg_replace( '/[\s_]+/', '-', $name );
		$name = preg_replace( '/[^a-z0-9\-]/', '', $name );
		$name = preg_replace( '/-+/', '-', $name );
		$name = trim( $name, '-' );
		return $name;
	}

	/**
	 * Get a unique filename in a directory.
	 *
	 * @param string $dir      Directory path.
	 * @param string $basename Desired filename with extension.
	 * @return string Unique filename.
	 */
	private function get_unique_filename( $dir, $basename ) {
		if ( ! file_exists( trailingslashit( $dir ) . $basename ) ) {
			return $basename;
		}
		$name = pathinfo( $basename, PATHINFO_FILENAME );
		$ext  = pathinfo( $basename, PATHINFO_EXTENSION );
		$i    = 2;
		while ( file_exists( trailingslashit( $dir ) . $name . '-' . $i . '.' . $ext ) ) {
			$i++;
		}
		return $name . '-' . $i . '.' . $ext;
	}

	/**
	 * Perform the full rename operation for one attachment.
	 *
	 * @param int    $attachment_id The attachment ID.
	 * @param string $new_name      Desired new filename (no extension).
	 * @param bool   $update_refs   Whether to update post_content references.
	 * @return array|WP_Error Result array or error.
	 */
	private function do_rename( $attachment_id, $new_name, $update_refs = false ) {
		$post = get_post( $attachment_id );
		if ( ! $post || 'attachment' !== $post->post_type ) {
			return new WP_Error( 'invalid', 'Attachment not found.' );
		}

		// Transient lock to prevent concurrent renames.
		$lock_key = 'a1tools_rename_lock_' . $attachment_id;
		if ( get_transient( $lock_key ) ) {
			return new WP_Error( 'locked', 'This file is currently being renamed. Try again in a moment.' );
		}
		set_transient( $lock_key, true, 30 );

		$old_filepath = get_attached_file( $attachment_id );
		if ( ! $old_filepath || ! file_exists( $old_filepath ) ) {
			delete_transient( $lock_key );
			return new WP_Error( 'missing', 'Original file not found on disk.' );
		}

		$upload_dir = wp_get_upload_dir();
		$dir        = dirname( $old_filepath );
		$old_ext    = strtolower( pathinfo( $old_filepath, PATHINFO_EXTENSION ) );
		$old_name   = pathinfo( $old_filepath, PATHINFO_FILENAME );

		// Sanitize new name.
		$new_name = $this->sanitize_seo_filename( $new_name );
		if ( empty( $new_name ) ) {
			delete_transient( $lock_key );
			return new WP_Error( 'empty', 'Filename cannot be empty after sanitization.' );
		}

		if ( $new_name === $old_name ) {
			delete_transient( $lock_key );
			return new WP_Error( 'same', 'New filename is the same as the current one.' );
		}

		// Security: ensure we stay within the uploads directory.
		$real_dir     = realpath( $dir );
		$real_uploads = realpath( $upload_dir['basedir'] );
		if ( false === $real_dir || false === $real_uploads || 0 !== strpos( $real_dir, $real_uploads ) ) {
			delete_transient( $lock_key );
			return new WP_Error( 'security', 'File is outside the uploads directory.' );
		}

		// Compute unique filename.
		$new_basename = $this->get_unique_filename( $dir, $new_name . '.' . $old_ext );
		$new_name     = pathinfo( $new_basename, PATHINFO_FILENAME );
		$new_filepath = trailingslashit( $dir ) . $new_basename;

		// Save old relative path and metadata BEFORE any changes.
		$old_relative = get_post_meta( $attachment_id, '_wp_attached_file', true );
		$old_url      = trailingslashit( $upload_dir['baseurl'] ) . $old_relative;
		$metadata     = wp_get_attachment_metadata( $attachment_id );
		$old_sizes    = ( is_array( $metadata ) && ! empty( $metadata['sizes'] ) ) ? $metadata['sizes'] : array();

		// STEP 1: Rename main file.
		if ( ! @rename( $old_filepath, $new_filepath ) ) {
			delete_transient( $lock_key );
			return new WP_Error( 'disk', 'Could not rename file on disk. Check directory permissions.' );
		}

		// STEP 2: Rename thumbnail files.
		$renamed_sizes = array();
		foreach ( $old_sizes as $size_key => $size_data ) {
			$old_thumb_path = trailingslashit( $dir ) . $size_data['file'];
			$new_thumb_file = str_replace( $old_name, $new_name, $size_data['file'] );
			$new_thumb_path = trailingslashit( $dir ) . $new_thumb_file;

			if ( file_exists( $old_thumb_path ) ) {
				@rename( $old_thumb_path, $new_thumb_path );
			}
			$renamed_sizes[ $size_key ] = $new_thumb_file;
		}

		// STEP 3: Handle WP 5.3+ original_image.
		if ( is_array( $metadata ) && ! empty( $metadata['original_image'] ) ) {
			$old_orig      = $metadata['original_image'];
			$new_orig      = str_replace( $old_name, $new_name, $old_orig );
			$old_orig_path = trailingslashit( $dir ) . $old_orig;
			$new_orig_path = trailingslashit( $dir ) . $new_orig;
			if ( file_exists( $old_orig_path ) ) {
				@rename( $old_orig_path, $new_orig_path );
			}
			$metadata['original_image'] = $new_orig;
		}

		// STEP 4: Update _wp_attached_file.
		$new_relative = str_replace( basename( $old_relative ), $new_basename, $old_relative );
		update_post_meta( $attachment_id, '_wp_attached_file', $new_relative );

		// STEP 5: Update _wp_attachment_metadata.
		if ( is_array( $metadata ) ) {
			$metadata['file'] = $new_relative;
			foreach ( $renamed_sizes as $size_key => $new_thumb_file ) {
				if ( isset( $metadata['sizes'][ $size_key ] ) ) {
					$metadata['sizes'][ $size_key ]['file'] = $new_thumb_file;
				}
			}
			wp_update_attachment_metadata( $attachment_id, $metadata );
		}

		// STEP 6: Update guid.
		$new_url = trailingslashit( $upload_dir['baseurl'] ) . $new_relative;
		global $wpdb;
		$wpdb->update(
			$wpdb->posts,
			array( 'guid' => $new_url ),
			array( 'ID'   => $attachment_id )
		);

		// STEP 7: Update post_title and post_name.
		wp_update_post( array(
			'ID'         => $attachment_id,
			'post_title' => ucwords( str_replace( '-', ' ', $new_name ) ),
			'post_name'  => $new_name,
		) );

		// STEP 8: Optionally update references in posts and postmeta.
		$refs_updated = 0;
		if ( $update_refs ) {
			// Replace main file URL.
			$refs_updated += (int) $wpdb->query(
				$wpdb->prepare(
					"UPDATE {$wpdb->posts} SET post_content = REPLACE(post_content, %s, %s) WHERE post_content LIKE %s AND ID != %d",
					$old_url,
					$new_url,
					'%' . $wpdb->esc_like( $old_url ) . '%',
					$attachment_id
				)
			);

			// Replace each thumbnail URL.
			$sub_dir = dirname( $old_relative );
			foreach ( $old_sizes as $size_key => $size_data ) {
				if ( ! isset( $renamed_sizes[ $size_key ] ) ) {
					continue;
				}
				$old_size_url = trailingslashit( $upload_dir['baseurl'] ) . trailingslashit( $sub_dir ) . $size_data['file'];
				$new_size_url = trailingslashit( $upload_dir['baseurl'] ) . trailingslashit( $sub_dir ) . $renamed_sizes[ $size_key ];

				$wpdb->query(
					$wpdb->prepare(
						"UPDATE {$wpdb->posts} SET post_content = REPLACE(post_content, %s, %s) WHERE post_content LIKE %s",
						$old_size_url,
						$new_size_url,
						'%' . $wpdb->esc_like( $old_size_url ) . '%'
					)
				);
			}

			// Update postmeta (Elementor data, page builder JSON, etc.).
			$wpdb->query(
				$wpdb->prepare(
					"UPDATE {$wpdb->postmeta} SET meta_value = REPLACE(meta_value, %s, %s) WHERE meta_value LIKE %s",
					$old_url,
					$new_url,
					'%' . $wpdb->esc_like( $old_url ) . '%'
				)
			);
			foreach ( $old_sizes as $size_key => $size_data ) {
				if ( ! isset( $renamed_sizes[ $size_key ] ) ) {
					continue;
				}
				$old_size_url = trailingslashit( $upload_dir['baseurl'] ) . trailingslashit( $sub_dir ) . $size_data['file'];
				$new_size_url = trailingslashit( $upload_dir['baseurl'] ) . trailingslashit( $sub_dir ) . $renamed_sizes[ $size_key ];

				$wpdb->query(
					$wpdb->prepare(
						"UPDATE {$wpdb->postmeta} SET meta_value = REPLACE(meta_value, %s, %s) WHERE meta_value LIKE %s",
						$old_size_url,
						$new_size_url,
						'%' . $wpdb->esc_like( $old_size_url ) . '%'
					)
				);
			}
		}

		// Clean caches.
		clean_post_cache( $attachment_id );
		delete_transient( $lock_key );

		// Build new thumbnail URL for response.
		$new_thumb_url = $new_url;
		if ( ! empty( $renamed_sizes['thumbnail'] ) ) {
			$new_thumb_url = trailingslashit( $upload_dir['baseurl'] ) . trailingslashit( dirname( $new_relative ) ) . $renamed_sizes['thumbnail'];
		}

		return array(
			'attachment_id'     => $attachment_id,
			'old_filename'      => basename( $old_relative ),
			'new_filename'      => $new_basename,
			'new_url'           => $new_url,
			'new_thumbnail_url' => $new_thumb_url,
			'new_title'         => ucwords( str_replace( '-', ' ', $new_name ) ),
			'refs_updated'      => $refs_updated,
			'message'           => 'File renamed successfully.',
		);
	}

	// =========================================================================
	// Page Rendering
	// =========================================================================

	/**
	 * Render the Media Management admin page.
	 */
	public function render_page() {
		?>
		<div class="wrap">
			<h1><?php esc_html_e( 'Media Management', 'a1-tools' ); ?></h1>
			<p class="description">
				<?php esc_html_e( 'Rename your media files with SEO-friendly filenames. This updates the physical file, all thumbnails, and WordPress metadata.', 'a1-tools' ); ?>
			</p>

			<!-- Toolbar -->
			<div class="a1mm-toolbar">
				<input type="text" id="a1mm-search" placeholder="<?php esc_attr_e( 'Search media...', 'a1-tools' ); ?>" />
				<select id="a1mm-mime-filter">
					<option value=""><?php esc_html_e( 'All Types', 'a1-tools' ); ?></option>
					<option value="image"><?php esc_html_e( 'Images', 'a1-tools' ); ?></option>
					<option value="application/pdf"><?php esc_html_e( 'PDFs', 'a1-tools' ); ?></option>
					<option value="video"><?php esc_html_e( 'Videos', 'a1-tools' ); ?></option>
					<option value="audio"><?php esc_html_e( 'Audio', 'a1-tools' ); ?></option>
				</select>
				<button type="button" class="button" id="a1mm-search-btn">
					<?php esc_html_e( 'Search', 'a1-tools' ); ?>
				</button>
				<span id="a1mm-status" class="a1mm-status"></span>
			</div>

			<!-- Media List -->
			<div id="a1mm-list"></div>

			<!-- Loading -->
			<div id="a1mm-loading" style="display:none;text-align:center;padding:40px;">
				<span class="spinner is-active" style="float:none;"></span>
				<p><?php esc_html_e( 'Loading media...', 'a1-tools' ); ?></p>
			</div>

			<!-- Empty State -->
			<div id="a1mm-empty" style="display:none;text-align:center;padding:40px;color:#666;">
				<p><?php esc_html_e( 'No media items found.', 'a1-tools' ); ?></p>
			</div>

			<!-- Pagination -->
			<div id="a1mm-pagination" class="a1mm-pagination"></div>
		</div>
		<?php
	}

	// =========================================================================
	// Inline CSS
	// =========================================================================

	/**
	 * Return admin CSS.
	 *
	 * @return string
	 */
	private function get_admin_css() {
		return '
		.a1mm-toolbar {
			display: flex;
			align-items: center;
			gap: 8px;
			margin: 16px 0;
			flex-wrap: wrap;
		}
		#a1mm-search {
			width: 280px;
			padding: 6px 10px;
		}
		#a1mm-mime-filter {
			padding: 6px 10px;
		}
		.a1mm-status {
			margin-left: 12px;
			color: #666;
			font-style: italic;
		}
		.a1mm-item {
			display: flex;
			align-items: flex-start;
			gap: 16px;
			padding: 16px;
			border: 1px solid #e0e0e0;
			border-radius: 6px;
			margin-bottom: 8px;
			background: #fff;
			transition: border-color 0.2s;
		}
		.a1mm-item:hover {
			border-color: #2271b1;
		}
		.a1mm-item.a1mm-renamed {
			border-color: #00a32a;
			background: #f0faf0;
		}
		.a1mm-thumb {
			flex-shrink: 0;
			width: 80px;
			height: 80px;
			border-radius: 4px;
			overflow: hidden;
			background: #f0f0f0;
			display: flex;
			align-items: center;
			justify-content: center;
		}
		.a1mm-thumb img {
			width: 100%;
			height: 100%;
			object-fit: cover;
			display: block;
		}
		.a1mm-thumb .dashicons {
			font-size: 36px;
			width: 36px;
			height: 36px;
			color: #999;
		}
		.a1mm-info {
			flex: 1;
			min-width: 0;
		}
		.a1mm-current {
			margin-bottom: 4px;
		}
		.a1mm-current code {
			font-size: 13px;
			background: #f0f0f1;
			padding: 2px 6px;
			border-radius: 3px;
			word-break: break-all;
		}
		.a1mm-meta {
			font-size: 12px;
			color: #888;
			margin-bottom: 8px;
		}
		.a1mm-rename-row {
			display: flex;
			align-items: center;
			gap: 4px;
			flex-wrap: wrap;
		}
		.a1mm-new-name {
			width: 280px;
			padding: 5px 8px;
			font-size: 13px;
			font-family: monospace;
		}
		.a1mm-ext {
			font-size: 13px;
			color: #666;
			font-family: monospace;
			margin-right: 8px;
		}
		.a1mm-refs-label {
			font-size: 12px;
			color: #555;
			margin-right: 8px;
			cursor: pointer;
			display: inline-flex;
			align-items: center;
			gap: 3px;
		}
		.a1mm-item-msg {
			font-size: 12px;
			margin-left: 8px;
		}
		.a1mm-item-msg.success { color: #00a32a; }
		.a1mm-item-msg.error { color: #d63638; }
		.a1mm-pagination {
			display: flex;
			align-items: center;
			justify-content: center;
			gap: 8px;
			padding: 16px 0;
		}
		.a1mm-pagination .a1mm-page-info {
			font-size: 13px;
			color: #555;
		}
		';
	}

	// =========================================================================
	// Inline JS
	// =========================================================================

	/**
	 * Return admin JS.
	 *
	 * @return string
	 */
	private function get_admin_js() {
		// Using nowdoc to avoid PHP variable interpolation ($item, $btn, $msg, $p).
		return <<<'JSEOF'
(function($){
	'use strict';

	var currentPage = 1;
	var perPage     = 40;

	function escHtml(s) {
		var d = document.createElement('div');
		d.textContent = s;
		return d.innerHTML;
	}

	function escAttr(s) {
		return s.replace(/&/g,'&amp;').replace(/"/g,'&quot;').replace(/'/g,'&#39;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
	}

	function loadMedia(page) {
		currentPage = page || 1;
		$('#a1mm-list').empty();
		$('#a1mm-pagination').empty();
		$('#a1mm-empty').hide();
		$('#a1mm-loading').show();

		$.post(a1toolsMM.ajaxUrl, {
			action:      'a1tools_load_media',
			nonce:       a1toolsMM.nonceLoad,
			page:        currentPage,
			per_page:    perPage,
			search:      $('#a1mm-search').val(),
			mime_filter: $('#a1mm-mime-filter').val(),
			orderby:     'date',
			order:       'DESC'
		}, function(res) {
			$('#a1mm-loading').hide();

			if (!res || !res.success) {
				var msg = (res && res.data && res.data.message) ? res.data.message : 'Failed to load media.';
				$('#a1mm-empty').show().find('p').text(msg);
				$('#a1mm-status').text('');
				return;
			}

			if (!res.data.items.length) {
				$('#a1mm-empty').show();
				$('#a1mm-status').text('0 items');
				return;
			}

			var d    = res.data;
			var from = (d.current_page - 1) * perPage + 1;
			var to   = Math.min(d.current_page * perPage, d.total);
			$('#a1mm-status').text('Showing ' + from + '-' + to + ' of ' + d.total + ' items');

			$.each(d.items, function(i, item) {
				$('#a1mm-list').append(buildItem(item));
			});

			buildPagination(d.current_page, d.pages, d.total);
		}).fail(function() {
			$('#a1mm-loading').hide();
			$('#a1mm-empty').show().find('p').text('Error loading media. Check browser console.');
		});
	}

	function buildItem(item) {
		var nameNoExt = item.filename.replace(/\.[^.]+$/, '');
		var ext       = item.filename.split('.').pop();
		var thumbHtml = item.is_image
			? '<img src="' + escAttr(item.thumbnail_url) + '" alt="" />'
			: '<span class="dashicons dashicons-media-default"></span>';

		var metaParts = [escHtml(item.mime_type), escHtml(item.file_size_formatted)];
		if (item.width && item.height) {
			metaParts.push(item.width + '&times;' + item.height);
		}
		metaParts.push(escHtml(item.date));

		var html = '<div class="a1mm-item" data-id="' + item.id + '">'
			+ '<div class="a1mm-thumb">' + thumbHtml + '</div>'
			+ '<div class="a1mm-info">'
			+ '  <div class="a1mm-current"><code>' + escHtml(item.filename) + '</code></div>'
			+ '  <div class="a1mm-meta">' + metaParts.join(' &nbsp;|&nbsp; ') + '</div>'
			+ '  <div class="a1mm-rename-row">'
			+ '    <input type="text" class="a1mm-new-name" value="' + escAttr(nameNoExt) + '" />'
			+ '    <span class="a1mm-ext">.' + escHtml(ext) + '</span>'
			+ '    <label class="a1mm-refs-label"><input type="checkbox" class="a1mm-refs-cb" /> Update refs</label>'
			+ '    <button type="button" class="button button-primary a1mm-rename-btn">Rename</button>'
			+ '    <span class="a1mm-item-msg"></span>'
			+ '  </div>'
			+ '</div>'
			+ '</div>';
		return html;
	}

	function buildPagination(current, total, totalItems) {
		if (total <= 1) return;
		var $p = $('#a1mm-pagination');
		if (current > 1) {
			$p.append('<button type="button" class="button a1mm-page-btn" data-page="' + (current - 1) + '">&lsaquo; Prev</button>');
		}
		$p.append('<span class="a1mm-page-info">Page ' + current + ' of ' + total + '</span>');
		if (current < total) {
			$p.append('<button type="button" class="button a1mm-page-btn" data-page="' + (current + 1) + '">Next &rsaquo;</button>');
		}
	}

	function doRename($item) {
		var id        = $item.data('id');
		var newName   = $item.find('.a1mm-new-name').val().trim();
		var updateRef = $item.find('.a1mm-refs-cb').is(':checked') ? 1 : 0;
		var $btn      = $item.find('.a1mm-rename-btn');
		var $msg      = $item.find('.a1mm-item-msg');

		if (!newName) {
			$msg.text('Name cannot be empty.').attr('class', 'a1mm-item-msg error');
			return;
		}

		$btn.prop('disabled', true).text('Renaming...');
		$msg.text('').attr('class', 'a1mm-item-msg');

		$.post(a1toolsMM.ajaxUrl, {
			action:        'a1tools_rename_media',
			nonce:         a1toolsMM.nonceRename,
			attachment_id: id,
			new_filename:  newName,
			update_refs:   updateRef
		}, function(res) {
			$btn.prop('disabled', false).text('Rename');

			if (res.success) {
				var d = res.data;
				var msgText = 'Renamed to ' + d.new_filename;
				if (updateRef && d.refs_updated > 0) {
					msgText += ' (' + d.refs_updated + ' references updated)';
				}
				$msg.text(msgText).attr('class', 'a1mm-item-msg success');
				$item.addClass('a1mm-renamed');

				// Update displayed info.
				$item.find('.a1mm-current code').text(d.new_filename);
				var nameNoExt = d.new_filename.replace(/\.[^.]+$/, '');
				$item.find('.a1mm-new-name').val(nameNoExt);
				if (d.new_thumbnail_url) {
					$item.find('.a1mm-thumb img').attr('src', d.new_thumbnail_url);
				}
			} else {
				$msg.text(res.data.message || 'Rename failed.').attr('class', 'a1mm-item-msg error');
			}
		}).fail(function() {
			$btn.prop('disabled', false).text('Rename');
			$msg.text('Network error.').attr('class', 'a1mm-item-msg error');
		});
	}

	// Event handlers.
	$(document).on('click', '.a1mm-rename-btn', function() {
		doRename($(this).closest('.a1mm-item'));
	});

	$(document).on('click', '.a1mm-page-btn', function() {
		loadMedia(parseInt($(this).data('page'), 10));
		$('html, body').animate({ scrollTop: 0 }, 200);
	});

	$('#a1mm-search-btn').on('click', function() {
		loadMedia(1);
	});

	$('#a1mm-search').on('keypress', function(e) {
		if (e.which === 13) { loadMedia(1); }
	});

	$('#a1mm-mime-filter').on('change', function() {
		loadMedia(1);
	});

	// Enter key in rename field triggers rename.
	$(document).on('keypress', '.a1mm-new-name', function(e) {
		if (e.which === 13) {
			doRename($(this).closest('.a1mm-item'));
		}
	});

	// Initial load.
	loadMedia(1);

})(jQuery);
JSEOF;
	}
}