<?php

/**

 * WordPress Administration Revisions API

 *

 * @package WordPress

 * @subpackage Administration

 */

/**

 * Get the revision UI diff.

 *

 * @since 3.6.0

 *

 * @param object|int $post         The post object. Also accepts a post ID.

 * @param int        $compare_from The revision ID to compare from.

 * @param int        $compare_to   The revision ID to come to.

 *

 * @return array|bool Associative array of a post's revisioned fields and their diffs.

 *                    Or, false on failure.

 */

function wp_get_revision_ui_diff( $post, $compare_from, $compare_to ) {

	if ( ! $post = get_post( $post ) )

		return false;

	if ( $compare_from ) {

		if ( ! $compare_from = get_post( $compare_from ) )

			return false;

	} else {

		// If we're dealing with the first revision...

		$compare_from = false;

	}

	if ( ! $compare_to = get_post( $compare_to ) )

		return false;

	// If comparing revisions, make sure we're dealing with the right post parent.

	// The parent post may be a 'revision' when revisions are disabled and we're looking at autosaves.

	if ( $compare_from && $compare_from->post_parent !== $post->ID && $compare_from->ID !== $post->ID )

		return false;

	if ( $compare_to->post_parent !== $post->ID && $compare_to->ID !== $post->ID )

		return false;

	if ( $compare_from && strtotime( $compare_from->post_date_gmt ) > strtotime( $compare_to->post_date_gmt ) ) {

		$temp = $compare_from;

		$compare_from = $compare_to;

		$compare_to = $temp;

	}

	// Add default title if title field is empty

	if ( $compare_from && empty( $compare_from->post_title ) )

		$compare_from->post_title = __( '(no title)' );

	if ( empty( $compare_to->post_title ) )

		$compare_to->post_title = __( '(no title)' );

	$return = array();

		/**

		 * Contextually filter a post revision field.

		 *

		 * The dynamic portion of the hook name, `$field`, corresponds to each of the post

		 * fields of the revision object being iterated over in a foreach statement.

		 *

		 * @since 3.6.0

		 *

		 * @param string  $compare_from->$field The current revision field to compare to or from.

		 * @param string  $field                The current revision field.

		 * @param WP_Post $compare_from         The revision post object to compare to or from.

		 * @param string  null                  The context of whether the current revision is the old

		 *                                      or the new one. Values are 'to' or 'from'.

		 */

		/** This filter is documented in wp-admin/includes/revision.php */

		$args = array(

			'show_split_view' => true

		);

		/**

		 *

		 *

		 * @since 4.1.0

		 *

		 * @param array   $args {

		 *

		 *     @type bool $show_split_view True for split view (two columns), false for

		 *                                 un-split view (single column). Default true.

		 * }

		 * @param string  $field        The current revision field.

		 * @param WP_Post $compare_from The revision post to compare from.

		 * @param WP_Post $compare_to   The revision post to compare to.

		 */

		$args = apply_filters( 'revision_text_diff_options', $args, $field, $compare_from, $compare_to );

		$diff = wp_text_diff( $content_from, $content_to, $args );

		if ( ! $diff && 'post_title' === $field ) {

			// It's a better user experience to still show the Title, even if it didn't change.

			// No, you didn't see this.

			$diff = '<table class="diff"><colgroup><col class="content diffsplit left"><col class="content diffsplit middle"><col class="content diffsplit right"></colgroup><tbody><tr>';

			$diff .= '<td>' . esc_html( $compare_from->post_title ) . '</td><td></td><td>' . esc_html( $compare_to->post_title ) . '</td>';

			$diff .= '</tr></tbody>';

			$diff .= '</table>';

		}

		if ( $diff ) {

			$return[] = array(

				'id' => $field,

				'name' => $name,

				'diff' => $diff,

			);

		}

	}

	/**

	 *

	 * @since 4.1.0

	 *

	 * @param array   $return       Revision UI fields. Each item is an array of id, name and diff.

	 * @param WP_Post $compare_from The revision post to compare from.

	 * @param WP_Post $compare_to   The revision post to compare to.

	 */

	return apply_filters( 'wp_get_revision_ui_diff', $return, $compare_from, $compare_to );

}

/**

 * Prepare revisions for JavaScript.

 *

 * @since 3.6.0

 *

 * @param object|int $post                 The post object. Also accepts a post ID.

 * @param int        $selected_revision_id The selected revision ID.

 * @param int        $from                 Optional. The revision ID to compare from.

 *

 * @return array An associative array of revision data and related settings.

 */

function wp_prepare_revisions_for_js( $post, $selected_revision_id, $from = null ) {

	$post = get_post( $post );

	$authors = array();

	$now_gmt = time();

	$revisions = wp_get_post_revisions( $post->ID, array( 'order' => 'ASC', 'check_enabled' => false ) );

	// If revisions are disabled, we only want autosaves and the current post.

	if ( ! wp_revisions_enabled( $post ) ) {

		foreach ( $revisions as $revision_id => $revision ) {

			if ( ! wp_is_post_autosave( $revision ) )

				unset( $revisions[ $revision_id ] );

		}

		$revisions = array( $post->ID => $post ) + $revisions;

	}

	$show_avatars = get_option( 'show_avatars' );

	cache_users( wp_list_pluck( $revisions, 'post_author' ) );

	$can_restore = current_user_can( 'edit_post', $post->ID );

	$current_id = false;

	foreach ( $revisions as $revision ) {

		$modified = strtotime( $revision->post_modified );

		if ( $can_restore ) {

			$restore_link = str_replace( '&', '&', wp_nonce_url(

				add_query_arg(

					array( 'revision' => $revision->ID,

						'action' => 'restore' ),

						admin_url( 'revision.php' )

				),

				"restore-post_{$revision->ID}"

			) );

		}

		if ( ! isset( $authors[ $revision->post_author ] ) ) {

			$authors[ $revision->post_author ] = array(

				'id' => (int) $revision->post_author,

				'avatar' => $show_avatars ? get_avatar( $revision->post_author, 32 ) : '',

				'name' => get_the_author_meta( 'display_name', $revision->post_author ),

			);

		}

		$autosave = (bool) wp_is_post_autosave( $revision );

		$current = ! $autosave && $revision->post_modified_gmt === $post->post_modified_gmt;

		if ( $current && ! empty( $current_id ) ) {

			// If multiple revisions have the same post_modified_gmt, highest ID is current.

			if ( $current_id < $revision->ID ) {

				$revisions[ $current_id ]['current'] = false;

				$current_id = $revision->ID;

			} else {

				$current = false;

			}

		} elseif ( $current ) {

			$current_id = $revision->ID;

		}

			'id'         => $revision->ID,

			'title'      => get_the_title( $post->ID ),

			'author'     => $authors[ $revision->post_author ],

			'date'       => date_i18n( __( 'M j, Y @ H:i' ), $modified ),

			'dateShort'  => date_i18n( _x( 'j M @ H:i', 'revision date short format' ), $modified ),

			'timeAgo'    => sprintf( __( '%s ago' ), human_time_diff( $modified_gmt, $now_gmt ) ),

			'autosave'   => $autosave,

			'current'    => $current,

			'restoreUrl' => $can_restore ? $restore_link : false,

		);

	}

	/**

	 * If we only have one revision, the initial revision is missing; This happens

	 * when we have an autsosave and the user has clicked 'View the Autosave'

	 */

	if ( 1 === sizeof( $revisions ) ) {

		$revisions[ $post->ID ] = array(

			'id'         => $post->ID,

			'title'      => get_the_title( $post->ID ),

			'author'     => $authors[ $post->post_author ],

			'date'       => date_i18n( __( 'M j, Y @ H:i' ), strtotime( $post->post_modified ) ),

			'dateShort'  => date_i18n( _x( 'j M @ H:i', 'revision date short format' ), strtotime( $post->post_modified ) ),

			'timeAgo'    => sprintf( __( '%s ago' ), human_time_diff( strtotime( $post->post_modified_gmt ), $now_gmt ) ),

			'autosave'   => false,

			'current'    => true,

			'restoreUrl' => false,

		);

		$current_id = $post->ID;

	}

	/*

	 * If a post has been saved since the last revision (no revisioned fields

	 * were changed), we may not have a "current" revision. Mark the latest

	 * revision as "current".

	 */

	if ( empty( $current_id ) ) {

		if ( $revisions[ $revision->ID ]['autosave'] ) {

			$revision = end( $revisions );

			while ( $revision['autosave'] ) {

				$revision = prev( $revisions );

			}

			$current_id = $revision['id'];

		} else {

			$current_id = $revision->ID;

		}

		$revisions[ $current_id ]['current'] = true;

	}

	// Now, grab the initial diff.

	$compare_two_mode = is_numeric( $from );

	if ( ! $compare_two_mode ) {

		$found = array_search( $selected_revision_id, array_keys( $revisions ) );

		if ( $found ) {

			$from = array_keys( array_slice( $revisions, $found - 1, 1, true ) );

			$from = reset( $from );

		} else {

			$from = 0;

		}

	}

	$from = absint( $from );

	$diffs = array( array(

		'id' => $from . ':' . $selected_revision_id,

		'fields' => wp_get_revision_ui_diff( $post->ID, $from, $selected_revision_id ),

	));

	return array(

		'postId'           => $post->ID,

		'nonce'            => wp_create_nonce( 'revisions-ajax-nonce' ),

		'revisionData'     => array_values( $revisions ),

		'to'               => $selected_revision_id,

		'from'             => $from,

		'diffData'         => $diffs,

		'baseUrl'          => parse_url( admin_url( 'revision.php' ), PHP_URL_PATH ),

		'compareTwoMode'   => absint( $compare_two_mode ), // Apparently booleans are not allowed

		'revisionIds'      => array_keys( $revisions ),

	);

}

/**

 * Print JavaScript templates required for the revisions experience.

 *

 * @since 4.1.0

 *

 * @global WP_Post $post The global `$post` object.

 */

function wp_print_revision_templates() {

	global $post;

	?><script id="tmpl-revisions-frame" type="text/html">

		<div class="revisions-control-frame"></div>

		<div class="revisions-diff-frame"></div>

	</script>

	<script id="tmpl-revisions-buttons" type="text/html">

		<div class="revisions-previous">

			<input class="button" type="button" value="<?php echo esc_attr_x( 'Previous', 'Button label for a previous revision' ); ?>" />

		</div>

		<div class="revisions-next">

			<input class="button" type="button" value="<?php echo esc_attr_x( 'Next', 'Button label for a next revision' ); ?>" />

		</div>

	</script>

	<script id="tmpl-revisions-checkbox" type="text/html">

		<div class="revision-toggle-compare-mode">

			<label>

				<input type="checkbox" class="compare-two-revisions"

				<#

				if ( 'undefined' !== typeof data && data.model.attributes.compareTwoMode ) {

					#> checked="checked"<#

				}

				#>

				/>

			</label>

		</div>

	</script>

	<script id="tmpl-revisions-meta" type="text/html">

		<# if ( ! _.isUndefined( data.attributes ) ) { #>

			<div class="diff-title">

				<# if ( 'from' === data.type ) { #>

					<strong><?php _ex( 'From:', 'Followed by post revision info' ); ?></strong>

				<# } else if ( 'to' === data.type ) { #>

					<strong><?php _ex( 'To:', 'Followed by post revision info' ); ?></strong>

				<# } #>

				<div class="author-card<# if ( data.attributes.autosave ) { #> autosave<# } #>">

					{{{ data.attributes.author.avatar }}}

					<div class="author-info">

					<# if ( data.attributes.autosave ) { #>

						<span class="byline"><?php printf( __( 'Autosave by %s' ),

							'<span class="author-name">{{ data.attributes.author.name }}</span>' ); ?></span>

					<# } else if ( data.attributes.current ) { #>

						<span class="byline"><?php printf( __( 'Current Revision by %s' ),

							'<span class="author-name">{{ data.attributes.author.name }}</span>' ); ?></span>

					<# } else { #>

						<span class="byline"><?php printf( __( 'Revision by %s' ),

							'<span class="author-name">{{ data.attributes.author.name }}</span>' ); ?></span>

					<# } #>

						<span class="time-ago">{{ data.attributes.timeAgo }}</span>

						<span class="date">({{ data.attributes.dateShort }})</span>

					</div>

				<# if ( 'to' === data.type && data.attributes.restoreUrl ) { #>

					<input  <?php if ( wp_check_post_lock( $post->ID ) ) { ?>

						disabled="disabled"

					<?php } else { ?>

						<# if ( data.attributes.current ) { #>

							disabled="disabled"

						<# } #>

					<?php } ?>

					<# if ( data.attributes.autosave ) { #>

						type="button" class="restore-revision button button-primary" value="<?php esc_attr_e( 'Restore This Autosave' ); ?>" />

					<# } else { #>

						type="button" class="restore-revision button button-primary" value="<?php esc_attr_e( 'Restore This Revision' ); ?>" />

					<# } #>

				<# } #>

			</div>

		<# if ( 'tooltip' === data.type ) { #>

			<div class="revisions-tooltip-arrow"><span></span></div>

		<# } #>

	<# } #>

	</script>

	<script id="tmpl-revisions-diff" type="text/html">

		<div class="loading-indicator"><span class="spinner"></span></div>

		<div class="diff-error"><?php _e( 'Sorry, something went wrong. The requested comparison could not be loaded.' ); ?></div>

		<div class="diff">

		<# _.each( data.fields, function( field ) { #>

			<h3>{{ field.name }}</h3>

			{{{ field.diff }}}

		<# }); #>

		</div>

	</script><?php