Meta Titles & Descriptions

class GeoAI_Meta {
    private static $instance = null;

    public static function get_instance() {
        if ( null === self::$instance ) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    private function __construct() {
        add_action( 'wp_head', array( $this, 'output_meta_tags' ), 1 );
        add_filter( 'pre_get_document_title', array( $this, 'filter_title' ), 10 );
        add_action( 'add_meta_boxes', array( $this, 'add_meta_box' ) );
        add_action( 'save_post', array( $this, 'save_meta_box' ) );
    }
}

private function parse_template( $template ) {
    $replacements = array(
        '%%title%%'    => get_the_title(),
        '%%sitename%%' => get_bloginfo( 'name' ),
        '%%sitedesc%%' => get_bloginfo( 'description' ),
        '%%sep%%'      => '|',
        '%%excerpt%%'  => get_the_excerpt(),
        '%%date%%'     => get_the_date(),
        '%%modified%%' => get_the_modified_date(),
        '%%id%%'       => get_the_ID(),
        '%%author%%'   => get_the_author(),
    );

    return str_replace( 
        array_keys( $replacements ), 
        array_values( $replacements ), 
        $template 
    );
}

public function output_meta_tags() {
    if ( ! GeoAI_Compat::get_instance()->should_output_meta() ) {
        return;
    }

    $description = $this->get_current_description();
    $robots      = $this->get_current_robots();
    $canonical   = $this->get_current_canonical();

    if ( $description ) {
        echo '<meta name="description" content="' . esc_attr( $description ) . '" />' . "\n";
    }

    if ( $robots ) {
        echo '<meta name="robots" content="' . esc_attr( $robots ) . '" />' . "\n";
    }

    if ( $canonical ) {
        echo '<link rel="canonical" href="' . esc_url( $canonical ) . '" />' . "\n";
    }
}

public function generate_meta_content( $post_id ) {
    $post = get_post( $post_id );
    if ( ! $post ) {
        return new \WP_Error( 'invalid_post', __( 'Post not found.', 'geo-ai' ) );
    }

    $api_key = $this->get_api_key();
    if ( empty( $api_key ) ) {
        return new \WP_Error( 'no_api_key', __( 'Google Gemini API key not configured.', 'geo-ai' ) );
    }

    // Get content preview
    $content = $this->get_rendered_content( $post );
    $content_preview = substr( $content, 0, 5000 );

    // Build prompt
    $prompt = $this->build_meta_prompt( $post->post_title, $content_preview );

    // Call API
    $response = $this->call_gemini_meta_api( $prompt, $api_key );

    if ( is_wp_error( $response ) ) {
        return $response;
    }

    return $response;
}

private function build_meta_prompt( $title, $content ) {
    return sprintf(
        'You are an expert SEO copywriter. Based on the following content, generate an optimized meta title and meta description for maximum search engine and social media performance.

Guidelines:
- Meta Title: 50-60 characters, compelling, includes primary keyword, action-oriented
- Meta Description: 150-160 characters, persuasive, includes call-to-action, enticing click-through

Return ONLY a JSON object with this exact structure (no markdown, no code blocks):
{
  "title": "Your optimized meta title here",
  "description": "Your optimized meta description here"
}

Current Title: %s

Content Preview:
%s

Return the JSON now:',
        $title,
        $content
    );
}

public function render_meta_box( $post ) {
    wp_nonce_field( 'geoai_meta_box', 'geoai_meta_box_nonce' );

    $title       = get_post_meta( $post->ID, '_geoai_title', true );
    $description = get_post_meta( $post->ID, '_geoai_meta_desc', true );
    $robots      = get_post_meta( $post->ID, '_geoai_robots', true );
    ?>
    <div class="geoai-meta-box">
        <div style="background: #f0f6fc; padding: 12px; border-radius: 4px;">
            <p style="margin: 0;">
                <strong><?php esc_html_e( 'AI-Powered Generation', 'geo-ai' ); ?></strong>
            </p>
            <button type="button" id="geoai-generate-meta-btn" 
                    class="button button-primary" 
                    data-post-id="<?php echo esc_attr( $post->ID ); ?>">
                <?php esc_html_e( 'Generate with AI', 'geo-ai' ); ?>
            </button>
        </div>

        <p>
            <label for="geoai_title">
                <strong><?php esc_html_e( 'SEO Title', 'geo-ai' ); ?></strong>
            </label><br/>
            <input type="text" id="geoai_title" name="geoai_title" 
                   value="<?php echo esc_attr( $title ); ?>" 
                   class="large-text" maxlength="70" />
            <p class="description">
                <?php esc_html_e( 'Optimal length: 50-60 characters', 'geo-ai' ); ?>
            </p>
        </p>
        
        <p>
            <label for="geoai_meta_desc">
                <strong><?php esc_html_e( 'Meta Description', 'geo-ai' ); ?></strong>
            </label><br/>
            <textarea id="geoai_meta_desc" name="geoai_meta_desc" 
                      rows="3" class="large-text" maxlength="165">
                <?php echo esc_textarea( $description ); ?>
            </textarea>
            <p class="description">
                <?php esc_html_e( 'Optimal length: 150-160 characters', 'geo-ai' ); ?>
            </p>
        </p>
    </div>
    <?php
}