<?php
add_action( 'save_post_product', 'caz_generate_ai_seo_meta_description', 20, 2 );

function caz_generate_ai_seo_meta_description( int $post_id, WP_Post $post ): void {
    // Skip auto-saves, revisions, and if meta already set manually
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) return;
    if ( wp_is_post_revision( $post_id ) ) return;

    $product = wc_get_product( $post_id );
    if ( ! $product ) return;

    // Only generate if the WooCommerce AI SEO meta description is empty
    $existing = get_post_meta( $post_id, 'rank_math_description', true );
    if ( ! empty( $existing ) ) return;

    $name        = $product->get_name();
    $short_desc  = wp_strip_all_tags( $product->get_short_description() );
    $attributes  = [];
    foreach ( $product->get_attributes() as $attr ) {
        $attributes[] = $attr->get_name() . ': ' . implode( ', ', $attr->get_options() );
    }

    $prompt = "Write a WooCommerce SEO meta description for this product.
Product: {$name}
Short description: {$short_desc}
Key attributes: " . implode( ' | ', array_slice( $attributes, 0, 5 ) ) . "
Requirements:
- Under 155 characters (count carefully)
- Include the product name naturally
- Mention 1-2 key selling points
- End with a soft call to action
- British English
- No quotes or special characters
Return only the meta description text, nothing else.";

    $meta = caz_call_ai_for_meta( $prompt );

    if ( $meta && strlen( $meta ) <= 160 ) {
        update_post_meta( $post_id, 'rank_math_description', sanitize_text_field( $meta ) );
    }
}

function caz_call_ai_for_meta( string $prompt ): string {
    $response = wp_remote_post( 'https://api.openai.com/v1/chat/completions', [
        'headers' => [
            'Authorization' => 'Bearer ' . get_option( 'caz_openai_key' ),
            'Content-Type'  => 'application/json',
        ],
        'body' => wp_json_encode([
            'model'      => 'gpt-4o-mini',
            'max_tokens' => 80,
            'messages'   => [
                [ 'role' => 'user', 'content' => $prompt ],
            ],
        ]),
        'timeout' => 20,
    ]);

    if ( is_wp_error( $response ) ) return '';
    $body = json_decode( wp_remote_retrieve_body( $response ), true );
    return trim( $body['choices'][0]['message']['content'] ?? '' );
}

<?php
// Register WP-CLI command for bulk WooCommerce AI SEO meta description generation
if ( defined( 'WP_CLI' ) && WP_CLI ) {
    WP_CLI::add_command( 'caz generate-meta', function( $args, $assoc ) {
        $products = wc_get_products([
            'limit'    => -1,
            'status'   => 'publish',
            'return'   => 'ids',
        ]);

        $count = 0;
        foreach ( $products as $id ) {
            $existing = get_post_meta( $id, 'rank_math_description', true );
            if ( ! empty( $existing ) ) continue;

            caz_generate_ai_seo_meta_description( $id, get_post( $id ) );
            $count++;
            WP_CLI::line( "Generated WooCommerce AI SEO meta description for product #{$id}" );
            sleep( 1 ); // Rate limit respect
        }
        WP_CLI::success( "Generated {$count} WooCommerce AI SEO meta descriptions." );
    });
}