<?php
/**
 * Server-side rendering of the `core/cover` block.
 *
 * @package WordPress
 */

/**
 * Renders the `core/cover` block on server.
 *
 * @since 6.0.0
 *
 * @param array  $attributes The block attributes.
 * @param string $content    The block rendered content.
 *
 * @return string Returns the cover block markup, if useFeaturedImage is true.
 */
function render_block_core_cover( $attributes, $content ) {
    // Handle embed video background.
    if (
        isset( $attributes['backgroundType'] ) &&
        'embed-video' === $attributes['backgroundType'] &&
        isset( $attributes['url'] ) &&
        ! empty( $attributes['url'] ) &&
        is_string( $attributes['url'] )
    ) {
        $url = $attributes['url'];

        // Use WordPress's native oEmbed processing (includes caching).
        $oembed_html = wp_oembed_get( $url );

        if ( $oembed_html ) {
            // Extract iframe src from the oEmbed HTML.
            preg_match( '/src=["\']([^"\']+)["\']/', $oembed_html, $src_matches );
            if ( ! empty( $src_matches[1] ) ) {
                $iframe_src = $src_matches[1];

                // Detect provider from iframe src URL.
                $lower_src = strtolower( $iframe_src );
                $provider  = null;

                if ( strpos( $lower_src, 'youtube.com' ) !== false || strpos( $lower_src, 'youtu.be' ) !== false ) {
                    $provider = 'youtube';
                } elseif ( strpos( $lower_src, 'vimeo.com' ) !== false ) {
                    $provider = 'vimeo';
                } elseif ( strpos( $lower_src, 'videopress.com' ) !== false ) {
                    $provider = 'videopress';
                } elseif ( strpos( $lower_src, 'wordpress.tv' ) !== false ) {
                    $provider = 'wordpress-tv';
                }

                // Modify iframe src to add background video parameters based on provider.
                $parsed_url = wp_parse_url( $iframe_src );
                if ( $parsed_url && isset( $parsed_url['host'] ) ) {
                    // Parse existing query parameters.
                    $query_params = array();
                    if ( isset( $parsed_url['query'] ) ) {
                        parse_str( $parsed_url['query'], $query_params );
                    }

                    // Add background video parameters based on provider.
                    if ( 'youtube' === $provider ) {
                        $query_params['autoplay']       = '1';
                        $query_params['mute']           = '1';
                        $query_params['loop']           = '1';
                        $query_params['controls']       = '0';
                        $query_params['modestbranding'] = '1';
                        $query_params['playsinline']    = '1';

                        // For loop to work, we need the playlist parameter.
                        $path          = $parsed_url['path'] ?? '';
                        $path_segments = explode( '/', $path );
                        $video_id      = end( $path_segments );
                        if ( $video_id ) {
                                $query_params['playlist'] = $video_id;
                        }
                    } elseif ( 'vimeo' === $provider ) {
                        $query_params['autoplay']    = '1';
                        $query_params['muted']       = '1';
                        $query_params['loop']        = '1';
                        $query_params['background']  = '1';
                        $query_params['controls']    = '0';
                        $query_params['transparent'] = '0';
                    } elseif ( 'videopress' === $provider || 'wordpress-tv' === $provider ) {
                        $query_params['autoplay'] = '1';
                        $query_params['loop']     = '1';
                        $query_params['muted']    = '1';
                    }

                    // Rebuild the URL with new parameters.
                    $iframe_src = $parsed_url['scheme'] . '://' . $parsed_url['host'];
                    if ( isset( $parsed_url['path'] ) ) {
                        $iframe_src .= $parsed_url['path'];
                    }
                    if ( ! empty( $query_params ) ) {
                        $iframe_src .= '?' . http_build_query( $query_params );
                    }
                }

                // Build the iframe HTML that will replace the figure.
                $iframe_html = sprintf(
                    '<div class="wp-block-cover__video-background wp-block-cover__embed-background"><iframe src="%s" title="Background video" frameborder="0" allow="autoplay; fullscreen"></iframe></div>',
                    esc_url( $iframe_src )
                );

                // Use the HTML API to find and replace the figure.wp-block-embed element.
                $processor = new WP_HTML_Tag_Processor( $content );

                if ( $processor->next_tag(
                    array(
                        'tag_name'   => 'FIGURE',
                        'class_name' => 'wp-block-embed',
                    )
                ) ) {
                    // Use regex with PREG_OFFSET_CAPTURE to find the position of the figure element.
                    // This follows the same pattern used for featured image insertion below.
                    $figure_pattern = '/<figure\s+[^>]*\bwp-block-embed\b[^>]*>.*?<\/figure>/is';
                    if ( 1 === preg_match( $figure_pattern, $content, $matches, PREG_OFFSET_CAPTURE ) ) {
                        $figure_start  = $matches[0][1];
                        $figure_length = strlen( $matches[0][0] );
                        $figure_end    = $figure_start + $figure_length;

                        // Replace the figure element with the iframe HTML.
                        $content = substr( $content, 0, $figure_start ) . $iframe_html . substr( $content, $figure_end );
                    }
                }
            }
        }

        return $content;
    }

    if ( 'image' !== $attributes['backgroundType'] || false === $attributes['useFeaturedImage'] ) {
        return $content;
    }

    $object_position = isset( $attributes['focalPoint'] )
        ? round( $attributes['focalPoint']['x'] * 100 ) . '% ' . round( $attributes['focalPoint']['y'] * 100 ) . '%'
        : null;

    if ( ! ( $attributes['hasParallax'] || $attributes['isRepeated'] ) ) {
        $attr = array(
            'class'           => 'wp-block-cover__image-background',
            'data-object-fit' => 'cover',
        );

        if ( $object_position ) {
            $attr['data-object-position'] = $object_position;
            $attr['style']                = 'object-position:' . $object_position . ';';
        }

        $image = get_the_post_thumbnail( null, $attributes['sizeSlug'] ?? 'post-thumbnail', $attr );
    } else {
        if ( in_the_loop() ) {
            update_post_thumbnail_cache();
        }
        $current_featured_image = get_the_post_thumbnail_url( null, $attributes['sizeSlug'] ?? null );
        if ( ! $current_featured_image ) {
            return $content;
        }

        $current_thumbnail_id = get_post_thumbnail_id();

        $processor = new WP_HTML_Tag_Processor( '<div></div>' );
        $processor->next_tag();

        $current_alt = trim( strip_tags( get_post_meta( $current_thumbnail_id, '_wp_attachment_image_alt', true ) ) );
        if ( $current_alt ) {
            $processor->set_attribute( 'role', 'img' );
            $processor->set_attribute( 'aria-label', $current_alt );
        }

        $processor->add_class( 'wp-block-cover__image-background' );
        $processor->add_class( 'wp-image-' . $current_thumbnail_id );
        if ( $attributes['hasParallax'] ) {
            $processor->add_class( 'has-parallax' );
        }
        if ( $attributes['isRepeated'] ) {
            $processor->add_class( 'is-repeated' );
        }

        $styles  = 'background-position:' . ( $object_position ?? '50% 50%' ) . ';';
        $styles .= 'background-image:url(' . esc_url( $current_featured_image ) . ');';
        $processor->set_attribute( 'style', $styles );

        $image = $processor->get_updated_html();
    }

    /*
     * Inserts the featured image between the (1st) cover 'background' `span` and 'inner_container' `div`,
     * and removes eventual whitespace characters between the two (typically introduced at template level)
     */
    $inner_container_start = '/<div\b[^>]+wp-block-cover__inner-container[\s|"][^>]*>/U';
    if ( 1 === preg_match( $inner_container_start, $content, $matches, PREG_OFFSET_CAPTURE ) ) {
        $offset  = $matches[0][1];
        $content = substr( $content, 0, $offset ) . $image . substr( $content, $offset );
    }

    return $content;
}

/**
 * Registers the `core/cover` block renderer on server.
 *
 * @since 6.0.0
 */
function register_block_core_cover() {
    register_block_type_from_metadata(
        __DIR__ . '/cover',
        array(
            'render_callback' => 'render_block_core_cover',
        )
    );
}
add_action( 'init', 'register_block_core_cover' );