<?php

/**
 * P2 Filter module: theme specifics for filter views.
 *
 * e.g. injecting classes to control how unread content looks,
 * hiding elements from the page, etc.
 */
namespace Automattic\P2\Themes\P2020\Filter;

use Automattic\P2\Plugins\Core as P2_Core;
use Automattic\P2\Themes\P2020 as P2020;

const UNREAD_COUNT_DISPLAY_LIMIT = 99;

function enqueue_scripts() {
	add_action( 'wp_enqueue_scripts', __NAMESPACE__ . '\scripts' );
}

function add_hooks() {
	// For changing the page title at the top of the posts feed
	add_filter( 'o2_page_title', __NAMESPACE__ . '\o2_page_title', 11 );

	// Modify o2 options for hiding controls.
	add_filter( 'o2_options', __NAMESPACE__ . '\hide_editor_for_filter_views' );
	add_filter( 'o2_options', __NAMESPACE__ . '\hide_app_controls_for_comment_view' );

	add_filter( 'body_class', __NAMESPACE__ . '\custom_body_class' );

	// Set priority so they run later than the plugin.
	add_filter( 'o2_post_fragment', __NAMESPACE__ . '\filter_o2_post_fragment', 20 );
	add_filter( 'o2_comment_fragment', __NAMESPACE__ . '\filter_o2_comment_fragment', 20, 2 );

	// Modify display strings.
	add_filter( 'o2_options', __NAMESPACE__ . '\localized_strings_to_o2' );

	// Add support for infinite scroll.
	add_filter( 'infinite_scroll_ajax_url', __NAMESPACE__ . '\infinite_scroll_ajax_url' );
	add_filter( 'infinite_scroll_query_args', __NAMESPACE__ . '\infinite_scroll_query_args' );
}

function scripts() {
	if ( P2_Core\Filtering\View::is_filtering_active( 'comments' ) ) {
		wp_enqueue_script( 'p2020-filter-read-more', get_template_directory_uri() . '/inc/filter/js/read-more.js', [ 'jquery' ], '20210105', true );
		wp_set_script_translations( 'p2020-filter-read-more', 'p2020' );
	}
}

function custom_body_class( $classes ) {
	if ( ! empty( P2_Core\Filtering\View::get_active_filter() ) ) {
		return array_merge( $classes, [ 'is-p2020-filter-view' ] );
	}

	return $classes;
}

/**
 * Callback for 'o2_options' filter hook.
 * Modify the empty page message.
 */
function localized_strings_to_o2( $o2_options ) {
	$active_filter = P2_Core\Filtering\View::get_active_filter();

	if ( in_array( $active_filter, [ P2_Core\Filtering\View::FILTERING_MENTIONS ], true ) || is_archive() ) {
		$no_posts_message                       = __( 'We could not find any posts matching your criteria.', 'p2020' );
		$o2_options['strings']['noPosts']       = $no_posts_message;
		$o2_options['strings']['noPostsMobile'] = $no_posts_message;
		$o2_options['noPostsActionText']        = __( 'Return to home', 'p2020' );
		$o2_options['noPostsActionLink']        = P2_Core\Navigation\Urls::get_site_url();
	}

	if ( in_array( $active_filter, [ P2_Core\Filtering\View::FILTERING_POSTS, P2_Core\Filtering\View::FILTERING_COMMENTS ], true ) ) {
		$no_posts_message                       = __( 'You’re all caught up!', 'p2020' );
		$o2_options['strings']['noPosts']       = $no_posts_message;
		$o2_options['strings']['noPostsMobile'] = $no_posts_message;
		$o2_options['noPostsActionText']        = __( 'Return to home', 'p2020' );
		$o2_options['noPostsActionLink']        = P2_Core\Navigation\Urls::get_site_url();

		$filters                              = P2_Core\Filtering\View::get_links();
		$o2_options['strings']['newPosts']    = $filters['posts']['label'];
		$o2_options['strings']['newComments'] = $filters['comments']['label'];
	}

	// TODO. Look into how this will work on selfhosted. The string is the same
	// as the constant in \SeenPosts\Constants\SOURCE_FRONTEND_P2
	$o2_options['strings']['seenSource'] = 'frontend-p2';

	return $o2_options;
}

/**
 * Callback for 'o2_options' filter hook.
 * Hide the front-page editor when inside a filter view.
 */
function hide_editor_for_filter_views( $o2_options ) {
	$active_filter = P2_Core\Filtering\View::get_active_filter();
	if ( ! empty( $active_filter ) ) {
		$o2_options['options']['showFrontSidePostBox'] = false;
	}

	return $o2_options;
}

/**
 * Callback for 'o2_options' filter hook.
 * Hide the comments toggler when inside the recent comments filter view.
 */
function hide_app_controls_for_comment_view( $o2_options ) {
	if ( P2_Core\Filtering\View::is_filtering_active( 'comments' ) ) {
		$o2_options['appControls'] = [];
	}

	return $o2_options;
}

/**
 * Callback for 'o2_page_title' filter hook.
 * Modify the page/feed title when inside a filter view.
 */
function o2_page_title( $title ) {
	$active_filter = P2_Core\Filtering\View::get_active_filter();

	if ( empty( $active_filter ) ) {
		return $title;
	}

	$filters = P2_Core\Filtering\View::get_links();
	if ( ! empty( $filters[ $active_filter ]['label'] ) ) {
		return $filters[ $active_filter ]['label'];
	}

	return $title;
}

/**
 * Callback for 'infinite_scroll_ajax_url' filter hook.
 *    (https://opengrok.a8c.com/source/xref/jetpack/modules/infinite-scroll/infinity.php#762)
 * Add query args for making filter views work.
 */
function infinite_scroll_ajax_url( $ajax_url ) {
	$active_filter = P2_Core\Filtering\View::get_active_filter();
	if ( empty( $active_filter ) ) {
		return $ajax_url;
	}

	$query_args = [];
	if ( 'posts' === $active_filter ) {
		$query_args = [ 'p2filter_posts' => true ];
	} elseif ( 'comments' === $active_filter ) {
		$query_args = [ 'p2filter_comments' => true ];
	}
	$query_args['ts'] = P2_Core\Unread\Unread::get_content_cutoff_timestamp( $active_filter );

	$ajax_url = add_query_arg( $query_args, $ajax_url );

	return $ajax_url;
}

/**
 * Callback for 'infinite_scroll_query_args' filter hook.
 *    (https://opengrok.a8c.com/source/xref/jetpack/modules/infinite-scroll/infinity.php#1310)
 * Add query args for making filter views work.
 */
function infinite_scroll_query_args( $query_args ) {
	if ( ! is_array( $query_args ) ) {
		return $query_args;
	}

	$active_filter = P2_Core\Filtering\View::get_active_filter();
	if ( empty( $active_filter ) ) {
		return $query_args;
	}

	if ( 'posts' === $active_filter ) {
		$query_args['p2filter_posts'] = true;
	} elseif ( 'comments' === $active_filter ) {
		$query_args['p2filter_comments'] = true;
	}
	$query_args['ts'] = P2_Core\Unread\Unread::get_content_cutoff_timestamp( $active_filter );

	return $query_args;
}

function filter_o2_post_fragment( $fragment ) {
	$active_filter = P2_Core\Filtering\View::get_active_filter();

	// If we are not on a filter page, there is nothing more to do here.
	if ( empty( $active_filter ) ) {
		return $fragment;
	}

	if ( P2_Core\Filtering\View::FILTERING_COMMENTS === $active_filter ) {
		// Convert to array for easier manipulation.
		$css_classes = explode( ' ', $fragment['cssClasses'] );

		// If a post appears in the recent comments filter view,
		// automatically add "trim post" class
		$css_classes[] = 'p2020-post-read-more';

		if ( $fragment['isProjectThread'] ) {
			$fragment['isProjectThread'] = false;
			$css_classes                 = array_filter(
				$css_classes,
				function( $classname ) {
					return 'tag-project-thread' !== $classname;
				}
			);
		}

		if ( $fragment['postMeta']['isSticky'] ) {
			$fragment['postMeta']['isSticky'] = false;
		}

		// Convert back to string.
		$fragment['cssClasses'] = implode( ' ', $css_classes );
	}

	return $fragment;
}

function filter_o2_comment_fragment( $fragment ) {
	$active_filter = P2_Core\Filtering\View::get_active_filter();

	// If we are not on a filter page, there is nothing more to do here.
	if ( empty( $active_filter ) ) {
		return $fragment;
	}

	if ( ! empty( $fragment['isUnread'] ) ) {
		$fragment['cssClasses'] .= ' p2020-unread-comment';
	}

	// Flag unread comments, trim everything else.
	if ( P2_Core\Filtering\View::FILTERING_COMMENTS === $active_filter ) {
		if ( ! $fragment['isUnread'] ) {
			$fragment['cssClasses'] .= ' p2020-comment-read-more';
		}
	}

	return $fragment;
}