<?php
defined( 'ABSPATH' ) || exit;

/**
 * WooCommerce SEO - Pro feature.
 *
 * Enriches Product schema with live WooCommerce data (price, stock,
 * SKU, brand, rating) instead of requiring manual schema_data entry,
 * auto-generates SEO titles/descriptions from a template for products
 * that don't have a custom one set, can automatically noindex
 * out-of-stock products, and offers a bulk alt-text fixer for product
 * images. Gracefully no-ops everywhere if WooCommerce isn't active.
 */
class AWBSEO_Woocommerce_SEO {

    const OPTION_SETTINGS = 'awbseo_woo_settings';

    public static function is_woocommerce_active() {
        return class_exists( 'WooCommerce' );
    }

    public static function init() {
        if ( ! self::is_woocommerce_active() ) return;

        add_filter( 'awbseo_post_schema', [ __CLASS__, 'enrich_product_schema' ], 10, 2 );
        add_action( 'save_post_product', [ __CLASS__, 'maybe_apply_templates' ] );
        add_action( 'woocommerce_product_set_stock_status', [ __CLASS__, 'maybe_noindex_out_of_stock' ], 10, 3 );
    }

    // ── Settings ─────────────────────────────────────────────────────────────

    public static function get_settings() {
        return wp_parse_args( get_option( self::OPTION_SETTINGS, [] ), [
            'out_of_stock_noindex' => false,
            'title_template'       => '{title} | {sitename}',
            'meta_template'        => 'Shop {title} for {price}. Fast shipping, easy returns. Order online today.',
        ] );
    }

    public static function save_settings( $data ) {
        $clean = [
            'out_of_stock_noindex' => ! empty( $data['out_of_stock_noindex'] ),
            'title_template'       => sanitize_text_field( $data['title_template'] ?? '{title} | {sitename}' ),
            'meta_template'        => sanitize_textarea_field( $data['meta_template'] ?? '' ),
        ];
        update_option( self::OPTION_SETTINGS, $clean );
        return $clean;
    }

    private static function render_template( $template, $product ) {
        if ( ! $product ) return $template;
        $replacements = [
            '{title}'    => $product->get_name(),
            '{price}'    => wp_strip_all_tags( wc_price( $product->get_price() ) ),
            '{sku}'      => $product->get_sku(),
            '{sitename}' => get_bloginfo( 'name' ),
        ];
        return str_replace( array_keys( $replacements ), array_values( $replacements ), $template );
    }

    // ── Auto title/description from template ────────────────────────────────

    /**
     * Fills the AWBSEO title/description meta from the template - but only
     * when the user hasn't already set a custom one, so this never clobbers
     * manual edits.
     */
    public static function maybe_apply_templates( $post_id ) {
        if ( wp_is_post_autosave( $post_id ) || wp_is_post_revision( $post_id ) ) return;
        if ( ! current_user_can( 'edit_post', $post_id ) ) return;

        $product = function_exists( 'wc_get_product' ) ? wc_get_product( $post_id ) : null;
        if ( ! $product ) return;

        $settings = self::get_settings();
        $prefix   = AWBSEO_Meta_Manager::META_PREFIX;

        if ( ! get_post_meta( $post_id, $prefix . 'title', true ) && $settings['title_template'] ) {
            update_post_meta( $post_id, $prefix . 'title', sanitize_text_field( self::render_template( $settings['title_template'], $product ) ) );
        }
        if ( ! get_post_meta( $post_id, $prefix . 'description', true ) && $settings['meta_template'] ) {
            update_post_meta( $post_id, $prefix . 'description', sanitize_textarea_field( self::render_template( $settings['meta_template'], $product ) ) );
        }
    }

    // ── Out-of-stock noindex automation ─────────────────────────────────────

    public static function maybe_noindex_out_of_stock( $product_id, $status, $product ) {
        $settings = self::get_settings();
        if ( empty( $settings['out_of_stock_noindex'] ) ) return;

        $prefix = AWBSEO_Meta_Manager::META_PREFIX;
        if ( $status === 'outofstock' ) {
            update_post_meta( $product_id, $prefix . 'robots_index', 'noindex' );
        } else {
            // Back in stock - only clear it if we were the ones who set it
            // (don't override an intentional manual noindex).
            $current = get_post_meta( $product_id, $prefix . 'robots_index', true );
            if ( $current === 'noindex' ) {
                delete_post_meta( $product_id, $prefix . 'robots_index' );
            }
        }
    }

    // ── Schema enrichment ────────────────────────────────────────────────────

    /**
     * Hooked to the `awbseo_post_schema` filter - replaces the manually-entered
     * Product schema fields with live WooCommerce data whenever the post is a
     * WC product, so schema stays accurate without the user maintaining it.
     */
    public static function enrich_product_schema( $schema, $post_id ) {
        if ( get_post_type( $post_id ) !== 'product' || ! function_exists( 'wc_get_product' ) ) {
            return $schema;
        }
        $product = wc_get_product( $post_id );
        if ( ! $product ) return $schema;

        $schema['@type'] = 'Product';
        $schema['sku']   = $product->get_sku() ?: ( $schema['sku'] ?? '' );
        $schema['name']  = $product->get_name();

        $image_id = $product->get_image_id();
        if ( $image_id ) {
            $schema['image'] = wp_get_attachment_url( $image_id );
        }

        $brand_terms = get_the_terms( $post_id, 'product_brand' );
        $schema['brand'] = [
            '@type' => 'Brand',
            'name'  => ( $brand_terms && ! is_wp_error( $brand_terms ) ) ? $brand_terms[0]->name : get_bloginfo( 'name' ),
        ];

        $schema['offers'] = [
            '@type'         => 'Offer',
            'url'           => get_permalink( $post_id ),
            'priceCurrency' => function_exists( 'get_woocommerce_currency' ) ? get_woocommerce_currency() : 'USD',
            'price'         => $product->get_price() ?: '0',
            'availability'  => 'https://schema.org/' . ( $product->is_in_stock() ? 'InStock' : 'OutOfStock' ),
        ];

        $review_count = (int) $product->get_review_count();
        if ( $review_count > 0 ) {
            $schema['aggregateRating'] = [
                '@type'       => 'AggregateRating',
                'ratingValue' => $product->get_average_rating(),
                'reviewCount' => $review_count,
            ];
        }

        return $schema;
    }

    // ── Catalog scan & bulk tools ────────────────────────────────────────────

    /**
     * Scans published products for common SEO gaps: missing SEO title/desc,
     * missing featured image alt text, missing SKU.
     */
    public static function scan_missing_data( $limit = 200 ) {
        if ( ! function_exists( 'wc_get_products' ) ) return [];

        $products = wc_get_products( [ 'status' => 'publish', 'limit' => $limit ] );
        $prefix   = AWBSEO_Meta_Manager::META_PREFIX;
        $issues   = [];

        foreach ( $products as $product ) {
            $id     = $product->get_id();
            $gaps   = [];

            if ( ! get_post_meta( $id, $prefix . 'title', true ) ) $gaps[] = 'Missing custom SEO title';
            if ( ! get_post_meta( $id, $prefix . 'description', true ) ) $gaps[] = 'Missing meta description';
            if ( ! $product->get_sku() ) $gaps[] = 'Missing SKU';

            $image_id = $product->get_image_id();
            if ( $image_id && ! get_post_meta( $image_id, '_wp_attachment_image_alt', true ) ) {
                $gaps[] = 'Missing image alt text';
            }

            if ( $gaps ) {
                $issues[] = [
                    'id'    => $id,
                    'title' => $product->get_name(),
                    'edit'  => get_edit_post_link( $id, '' ),
                    'gaps'  => $gaps,
                ];
            }
        }

        return $issues;
    }

    /**
     * Sets alt text = product name (falling back to "{name} product photo"
     * if the featured image is shared/generic) for every published product
     * missing alt text. Returns the number of images fixed.
     */
    public static function bulk_fix_alt_text() {
        if ( ! function_exists( 'wc_get_products' ) ) return 0;

        $products = wc_get_products( [ 'status' => 'publish', 'limit' => -1 ] );
        $fixed    = 0;

        foreach ( $products as $product ) {
            $image_id = $product->get_image_id();
            if ( ! $image_id ) continue;
            if ( get_post_meta( $image_id, '_wp_attachment_image_alt', true ) ) continue;

            update_post_meta( $image_id, '_wp_attachment_image_alt', sanitize_text_field( $product->get_name() ) );
            $fixed++;
        }

        return $fixed;
    }

    public static function get_stats() {
        if ( ! function_exists( 'wc_get_products' ) ) {
            return [ 'total' => 0, 'missing_data' => 0 ];
        }
        $total  = (int) wp_count_posts( 'product' )->publish;
        $issues = self::scan_missing_data( 500 );
        return [ 'total' => $total, 'missing_data' => count( $issues ) ];
    }
}