<?php
if ( ! defined( 'ABSPATH' ) ) { exit; }

class AIT_AIRCE_Renderer {

    protected $logger;
    protected $cache;

    public function __construct( $logger, $cache ) {
        $this->logger = $logger;
        $this->cache  = $cache;

        add_action( 'wp_enqueue_scripts', [ $this, 'register_frontend_assets' ] );
    }

    public function register_frontend_assets() {
        wp_register_style(
            'ait-airce-frontend',
            AIT_AIRCE_URL . 'assets/css/frontend.css',
            [],
            AIT_AIRCE_VERSION
        );
    }

    protected function ensure_frontend_assets() {
        if ( ! wp_style_is( 'ait-airce-frontend', 'enqueued' ) ) {
            wp_enqueue_style( 'ait-airce-frontend' );
        }
    }

    protected function post_has_index( $post_id ) {
        global $wpdb;

        $t_index = esc_sql( AIT_AIRCE_DB::table( 'index_item' ) );
        
        // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- table name from trusted source
        $found = $wpdb->get_var( $wpdb->prepare(
            "SELECT id FROM {$t_index} WHERE post_id = %d AND status = 'active' LIMIT 1",
            (int) $post_id
        ) );

        return ! empty( $found );
    }

    /**
     * Render related content for a post.
     *
     * @param int $post_id
     * @param array $args
     * @return string
     */
    public function render( $post_id, $args = [] ) {
        $post_id = intval( $post_id );
        if ( $post_id <= 0 ) { return ''; }
        $this->ensure_frontend_assets();

        $defaults = [
            'context_key'     => 'default',
            'location'        => 'default',
            'count'           => intval( AIT_AIRCE_Settings::get( 'related_count' ) ),
            'label'           => strval( AIT_AIRCE_Settings::get( 'related_label' ) ),
            'show_thumbnails' => (bool) AIT_AIRCE_Settings::get( 'show_thumbnails' ),
        ];

        $args = array_merge( $defaults, (array) $args );

        $args['count'] = max( 1, intval( $args['count'] ) );
        
        // Respect per-post disable flag.
        $disabled = get_post_meta( $post_id, '_ait_airce_disable', true );
        if ( $disabled ) { return ''; }

        // If there is no index yet, schedule an initial background index so the plugin
        // starts working seamlessly without requiring a manual “Rebuild Index”.
        if ( function_exists( 'AIT_AIRCE' ) ) {
            $plugin = AIT_AIRCE();
            if ( $plugin && ! empty( $plugin->indexer ) ) {
                $plugin->indexer->schedule_initial_index_if_needed( 'render' );
            }
        }
        // If a caller provides fixed IDs (e.g. WooCommerce “frequently bought together”), render those
        // instead of generating semantic recommendations.
        if ( ! empty( $args['fixed_ids'] ) && is_array( $args['fixed_ids'] ) ) {
            $fixed = array_values( array_filter( array_map( 'intval', (array) $args['fixed_ids'] ) ) );
            $fixed = array_slice( $fixed, 0, intval( $args['count'] ) );
            $items = [];
            foreach ( $fixed as $fid ) {
                if ( $fid && $fid !== $post_id ) {
                    $items[] = [ 'post_id' => $fid, 'score' => 1.0 ];
                }
            }
        } else {

            $items = $this->cache->get_cached( $post_id, $args['context_key'] );
            if ( ! is_array( $items ) ) {
                $items = $this->cache->generate_for_post( $post_id, $args['context_key'] );
            }

            if ( empty( $items ) && ! $this->post_has_index( $post_id ) && function_exists( 'AIT_AIRCE' ) ) {
                $plugin = AIT_AIRCE();
                if ( $plugin && ! empty( $plugin->indexer ) ) {
                    $indexed = $plugin->indexer->index_post( $post_id );
                    if ( ! is_wp_error( $indexed ) ) {
                        $items = $this->cache->generate_for_post( $post_id, $args['context_key'] );
                    }
                }
            }
        }

        if ( empty( $items ) ) { return ''; }
        // Enforce requested count.
        $items = array_slice( (array) $items, 0, intval( $args['count'] ) );

        /**
         * Fired when AIRCE prepares to render related content.
         * Pro can hook this to track impressions.
         */
        do_action( 'ait_airce/rendered', $post_id, $args, $items );

        $html  = '<div class="ait-airce-root">';
        if ( ! empty( $args['label'] ) ) {
            $html .= '<div class="ait-airce-heading">' . esc_html( $args['label'] ) . '</div>';
        }
        $html .= '<ul class="ait-airce-list">';

        foreach ( $items as $row ) {
            $rid = isset( $row['post_id'] ) ? intval( $row['post_id'] ) : 0;
            if ( $rid <= 0 ) { continue; }

            $permalink = get_permalink( $rid );
            if ( ! $permalink ) { continue; }

            // Allow Pro to replace with a tracking URL / add UTMs.
            $permalink = apply_filters( 'ait_airce/related_link', $permalink, $post_id, $rid, $args );

            $title = get_the_title( $rid );
            if ( ! $title ) { $title = __( '(No title)', 'ait-ai-related-posts' ); }

            $thumb_html = '';
            if ( ! empty( $args['show_thumbnails'] ) && has_post_thumbnail( $rid ) ) {
                $thumb_html = get_the_post_thumbnail(
                    $rid,
                    'thumbnail',
                    [ 'class' => 'ait-airce-thumb', 'loading' => 'lazy' ]
                );
            }

            $html .= '<li class="ait-airce-item">';
            if ( $thumb_html ) {
                $html .= '<a class="ait-airce-thumb-link" href="' . esc_url( $permalink ) . '">' . wp_kses_post( $thumb_html ) . '</a>';
            }
            $html .= '<a class="ait-airce-link" href="' . esc_url( $permalink ) . '">' . esc_html( $title ) . '</a>';
            $html .= '</li>';
        }

        $html .= '</ul></div>';

        return $html;
    }
}