<?php

// Add metabox to Gutenberg editor for every page/post
if ( ! defined( 'ABSPATH' ) ) {
    exit; // Exit if accessed directly
}

function clarity_seo_add_metabox() {

    $post_types = ['page', 'post'];

    if (post_type_exists('product')) {

        $post_types[] = 'product'; // Add 'product' only if WooCommerce is active

    }

    add_meta_box(

        'clarity_seo_metabox',

        'Clarity SEO Settings',

        'clarity_seo_metabox_callback',

        $post_types,

        'side',

        'high'

    );

}

add_action('add_meta_boxes', 'clarity_seo_add_metabox');



function clarity_seo_metabox_callback($post) {

    wp_nonce_field('clarity_seo_save_meta', 'clarity_seo_nonce');

    $meta_title = get_post_meta($post->ID, '_clarity_seo_meta_title', true);

    $meta_description = get_post_meta($post->ID, '_clarity_seo_meta_description', true);

    $meta_keywords = get_post_meta($post->ID, '_clarity_seo_meta_keywords', true);

    $og_image = get_post_meta($post->ID, '_clarity_seo_og_image', true);

    $schema_service = get_post_meta($post->ID, '_clarity_seo_service', true);

    $focus_keywords = get_post_meta($post->ID, '_clarity_seo_focus_keywords', true);

    $schema_type = get_post_meta($post->ID, '_clarity_seo_type', true) ?: 'WebPage';

    $disable_schema = get_post_meta($post->ID, '_clarity_seo_disable', true);



    // Readability score (Flesch-Kincaid)

    $content = wp_strip_all_tags($post->post_content);

    $words = str_word_count($content);

    $sentences = preg_match_all('/[.!?]+/', $content) ?: 1;

    preg_match_all('/[aeiouy]+/i', $content, $syllable_matches);

    $syllables = count($syllable_matches[0]);

    $readability = 0;

    if ($words > 0 && $syllables > 0) {

        $asl = $words / $sentences;

        $asw = $syllables / $words;

        $readability = max(0, 206.835 - (1.015 * $asl) - (84.6 * $asw));

    }

    $readability_score = round($readability);

    $readability_tip = $readability_score < 60 ? 'Improve: Shorten sentences, use common words.' : 'Good: Easy to read.';



    // Focus keywords density

    $keyword_density = !empty($focus_keywords) && $words > 0 ? round((substr_count(strtolower($content), strtolower($focus_keywords)) / $words) * 100, 1) : 0;

    $density_tip = $keyword_density > 2.5 ? 'High—consider reducing.' : ($keyword_density < 0.5 ? 'Low—add more naturally.' : 'Optimal.');



    // SEO Score (simple: based on title, desc, keywords, density, readability)

    $seo_score = 0;

    if (!empty($meta_title)) $seo_score += 20;

    if (!empty($meta_description)) $seo_score += 20;

    if (!empty($meta_keywords)) $seo_score += 20;

    if ($keyword_density >= 0.5 && $keyword_density <= 2.5) $seo_score += 20;

    if ($readability_score >= 60) $seo_score += 20;



    // Internal linking suggestions (based on focus keywords)

    $linking_suggestions = [];

    if (!empty($focus_keywords)) {

        $related_posts = get_posts([

            's' => $focus_keywords,

            'numberposts' => 5, // Buffer for potential skip

            'post_status' => 'publish'

        ]);

        $count = 0;

        foreach ($related_posts as $related) {

            if ($related->ID === $post->ID) {

                continue; // Skip current post

            }

            if ($count >= 3) break; // Limit to 3

            $linking_suggestions[] = '<a href="' . esc_url(get_permalink($related->ID)) . '" target="_blank">' . esc_html($related->post_title) . '</a>';

            $count++;

        }

    }

    ?>

    <p>

        <label for="clarity_seo_meta_title">

            <?php esc_html_e('Meta Title:', 'clarity-seo'); ?>

        </label><br>

        <input type="text" id="clarity_seo_meta_title" name="clarity_seo_meta_title" value="<?php echo esc_attr($meta_title); ?>" style="width: 100%;">

    </p>

    <p>

        <label for="clarity_seo_meta_description">

            <?php esc_html_e('Meta Description:', 'clarity-seo'); ?>

        </label><br>

        <textarea id="clarity_seo_meta_description" name="clarity_seo_meta_description" style="width: 100%;"><?php echo esc_textarea($meta_description); ?></textarea>

    </p>

    <p>

        <label for="clarity_seo_meta_keywords">

            <?php esc_html_e('Meta Keywords:', 'clarity-seo'); ?>

        </label><br>

        <input type="text" id="clarity_seo_meta_keywords" name="clarity_seo_meta_keywords" value="<?php echo esc_attr($meta_keywords); ?>" style="width: 100%;">

    </p>

    <p>

        <label for="clarity_seo_focus_keywords">

            <?php esc_html_e('Focus Keywords:', 'clarity-seo'); ?>

        </label><br>

        <input type="text" id="clarity_seo_focus_keywords" name="clarity_seo_focus_keywords" value="<?php echo esc_attr($focus_keywords); ?>" style="width: 100%;" placeholder="comma, separated, keywords">

    </p>

    <p>

        <label for="clarity_seo_og_image">

            <?php esc_html_e('OG Image URL:', 'clarity-seo'); ?>

        </label><br>

        <input type="text" id="clarity_seo_og_image" name="clarity_seo_og_image" value="<?php echo esc_url($og_image); ?>" style="width: 100%;">

    </p>

    <p>

        <label for="clarity_seo_service">

            <?php esc_html_e('Service Schema Description:', 'clarity-seo'); ?>

        </label><br>

        <textarea id="clarity_seo_service" name="clarity_seo_service" style="width: 100%;"><?php echo esc_textarea($schema_service); ?></textarea>

    </p>

    <p>

        <label for="clarity_seo_type">

            <?php esc_html_e('Schema Type (comma for multiple):', 'clarity-seo'); ?>

        </label><br>

        <input type="text" id="clarity_seo_type" name="clarity_seo_type" value="<?php echo esc_attr($schema_type); ?>" style="width: 100%;" placeholder="WebPage,Article,Product,...">

    </p>

    <p>

        <label for="clarity_seo_disable">

            <?php esc_html_e('Disable Schema on this Post:', 'clarity-seo'); ?>

            <input type="checkbox" id="clarity_seo_disable" name="clarity_seo_disable" value="1" <?php checked($disable_schema, 1); ?>>

        </label>

    </p>

    <hr>

    <p><strong><?php esc_html_e('Readability Score:', 'clarity-seo'); ?></strong> <?php echo esc_html($readability_score); ?>/100</p>

    <p><small><?php echo esc_html($readability_tip); ?></small></p>

    <p><strong><?php esc_html_e('Keyword Density:', 'clarity-seo'); ?></strong> <?php echo esc_html($keyword_density); ?>%</p>

    <p><small><?php echo esc_html($density_tip); ?></small></p>

    <p><strong><?php esc_html_e('SEO Score:', 'clarity-seo'); ?></strong> <?php echo esc_html($seo_score); ?>/100</p>

    <hr>

    <p><strong><?php esc_html_e('Internal Linking Suggestions:', 'clarity-seo'); ?></strong></p>

    <?php if (!empty($linking_suggestions)): ?>

        <ul>

            <?php foreach ($linking_suggestions as $suggestion): ?>

                <li><?php echo wp_kses_post($suggestion); ?></li>

            <?php endforeach; ?>

        </ul>

    <?php else: ?>

        <p><small><?php esc_html_e('No suggestions - Add focus keywords to see related posts for linking.', 'clarity-seo'); ?></small></p>

    <?php endif; ?>

    <!-- New: Trends div -->

    <div id="clarity-seo-trends"></div>

    <?php

}



// Save metabox data

function clarity_seo_save_meta($post_id) {

    if ( ! isset( $_POST['clarity_seo_nonce'] ) || ! wp_verify_nonce( sanitize_text_field( wp_unslash( $_POST['clarity_seo_nonce'] ) ), 'clarity_seo_save_meta' ) ) {

        return;

    }

    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {

        return;

    }

    if ( ! current_user_can( 'edit_post', $post_id ) ) {

        return;

    }

    $fields = ['clarity_seo_meta_title', 'clarity_seo_meta_description', 'clarity_seo_meta_keywords', 'clarity_seo_og_image', 'clarity_seo_service', 'clarity_seo_focus_keywords', 'clarity_seo_type', 'clarity_seo_disable'];

    foreach ( $fields as $field ) {

        if ( isset( $_POST[ $field ] ) ) {

            $value = in_array( $field, ['clarity_seo_meta_description', 'clarity_seo_service'] )

                ? sanitize_textarea_field( wp_unslash( $_POST[ $field ] ) )

                : sanitize_text_field( wp_unslash( $_POST[ $field ] ) );

            update_post_meta( $post_id, '_' . $field, $value );

        } else if ($field === 'clarity_seo_disable') {

            delete_post_meta($post_id, '_clarity_seo_disable');

        }

    }

}

add_action('save_post', 'clarity_seo_save_meta');

?>