<?php
/**
 * Meta Box Class
 *
 * Provides per-post Open Graph and social media customization fields
 * in the WordPress post editor.
 *
 * @package ROBOTSTXT_OG
 * @since 1.2.0
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly.
}

/**
 * Class Robotstxt_OG_Meta_Box
 *
 * Registers and handles the Open Graph meta box in the post editor,
 * and registers the underlying post meta for REST API access.
 *
 * @since 1.2.0
 */
class Robotstxt_OG_Meta_Box {

	/**
	 * Allowed og:type override values (the auto-derived default is stored as empty).
	 *
	 * @since 1.2.0
	 * @var string[]
	 */
	public const ALLOWED_OG_TYPES = array( 'website', 'article' );

	/**
	 * Sanitize an og:type override value to a safe value or empty string.
	 *
	 * @since 1.2.0
	 *
	 * @param mixed $value Raw value.
	 * @return string
	 */
	public static function sanitize_og_type( $value ): string {
		$value = is_string( $value ) ? $value : '';

		return in_array( $value, self::ALLOWED_OG_TYPES, true ) ? $value : '';
	}


	/**
	 * Initialize hooks.
	 *
	 * @since 1.2.0
	 *
	 * @return void
	 */
	public function init(): void {
		// Register post meta for REST API access (block editor).
		add_action( 'init', array( $this, 'register_post_meta' ) );

		// Meta box UI is admin-only.
		if ( is_admin() ) {
			add_action( 'add_meta_boxes', array( $this, 'register_meta_box' ) );
			add_action( 'save_post', array( $this, 'save_meta_box' ), 10, 2 );
		}
	}

	/**
	 * Register custom post meta for all public post types.
	 *
	 * Exposes _og_title and _og_description via the REST API so the
	 * block editor can read and write them via useEntityProp.
	 *
	 * @since 1.2.0
	 *
	 * @return void
	 */
	public function register_post_meta(): void {
		$post_types = get_post_types( array( 'public' => true ), 'names' );

		foreach ( $post_types as $post_type ) {
			register_post_meta(
				$post_type,
				'_og_title',
				array(
					'type'              => 'string',
					'single'            => true,
					'sanitize_callback' => 'sanitize_text_field',
					'auth_callback'     => static function () {
						return current_user_can( 'edit_posts' );
					},
					'show_in_rest'      => true,
				)
			);

			register_post_meta(
				$post_type,
				'_og_description',
				array(
					'type'              => 'string',
					'single'            => true,
					'sanitize_callback' => 'sanitize_textarea_field',
					'auth_callback'     => static function () {
						return current_user_can( 'edit_posts' );
					},
					'show_in_rest'      => true,
				)
			);

			register_post_meta(
				$post_type,
				'_og_image_alt',
				array(
					'type'              => 'string',
					'single'            => true,
					'sanitize_callback' => 'sanitize_text_field',
					'auth_callback'     => static function () {
						return current_user_can( 'edit_posts' );
					},
					'show_in_rest'      => true,
				)
			);

			register_post_meta(
				$post_type,
				'_og_type',
				array(
					'type'              => 'string',
					'single'            => true,
					'sanitize_callback' => array( __CLASS__, 'sanitize_og_type' ),
					'auth_callback'     => static function () {
						return current_user_can( 'edit_posts' );
					},
					'show_in_rest'      => true,
				)
			);

			register_post_meta(
				$post_type,
				'_twitter_creator',
				array(
					'type'              => 'string',
					'single'            => true,
					'sanitize_callback' => 'sanitize_text_field',
					'auth_callback'     => static function () {
						return current_user_can( 'edit_posts' );
					},
					'show_in_rest'      => true,
				)
			);
		}
	}

	/**
	 * Register the meta box for all public post types.
	 *
	 * @since 1.2.0
	 *
	 * @return void
	 */
	public function register_meta_box(): void {
		$post_types = get_post_types( array( 'public' => true ), 'names' );

		foreach ( $post_types as $post_type ) {
			add_meta_box(
				'robotstxt-og-meta-box',
				__( 'Open Graph / Social Media', 'robotstxt-og' ),
				array( $this, 'render_meta_box' ),
				$post_type,
				'normal',
				'default'
			);
		}
	}

	/**
	 * Render the meta box HTML.
	 *
	 * @since 1.2.0
	 *
	 * @param WP_Post $post The current post object.
	 * @return void
	 */
	public function render_meta_box( WP_Post $post ): void {
		wp_nonce_field( 'robotstxt_og_meta_box', 'robotstxt_og_meta_box_nonce' );

		$raw_title       = get_post_meta( $post->ID, '_og_title', true );
		$og_title        = is_string( $raw_title ) ? $raw_title : '';
		$raw_desc        = get_post_meta( $post->ID, '_og_description', true );
		$og_description  = is_string( $raw_desc ) ? $raw_desc : '';
		$raw_alt         = get_post_meta( $post->ID, '_og_image_alt', true );
		$og_image_alt    = is_string( $raw_alt ) ? $raw_alt : '';
		$raw_type        = get_post_meta( $post->ID, '_og_type', true );
		$og_type         = self::sanitize_og_type( $raw_type );
		$raw_creator     = get_post_meta( $post->ID, '_twitter_creator', true );
		$twitter_creator = is_string( $raw_creator ) ? $raw_creator : '';
		?>
		<table class="form-table" role="presentation">
			<tbody>
				<tr>
					<th scope="row">
						<label for="robotstxt_og_type">
							<?php esc_html_e( 'Open Graph Type', 'robotstxt-og' ); ?>
						</label>
					</th>
					<td>
						<select id="robotstxt_og_type" name="robotstxt_og_type">
							<option value="" <?php selected( $og_type, '' ); ?>>
								<?php esc_html_e( 'Default (auto: article for posts, website otherwise)', 'robotstxt-og' ); ?>
							</option>
							<option value="website" <?php selected( $og_type, 'website' ); ?>>
								<?php esc_html_e( 'website', 'robotstxt-og' ); ?>
							</option>
							<option value="article" <?php selected( $og_type, 'article' ); ?>>
								<?php esc_html_e( 'article', 'robotstxt-og' ); ?>
							</option>
						</select>
						<p class="description">
							<?php esc_html_e( 'Overrides og:type for this post. Selecting "article" also emits the article:* meta tags (published/modified time, section, tags).', 'robotstxt-og' ); ?>
						</p>
					</td>
				</tr>
				<tr>
					<th scope="row">
						<label for="robotstxt_og_twitter_creator">
							<?php esc_html_e( 'Twitter Author Handle', 'robotstxt-og' ); ?>
						</label>
					</th>
					<td>
						<input
							type="text"
							id="robotstxt_og_twitter_creator"
							name="robotstxt_og_twitter_creator"
							value="<?php echo esc_attr( $twitter_creator ); ?>"
							class="large-text"
							placeholder="@username"
						/>
						<p class="description">
							<?php esc_html_e( 'Twitter/X handle of the post author, emitted as twitter:creator. Leave blank to omit.', 'robotstxt-og' ); ?>
						</p>
					</td>
				</tr>
				<tr>
					<th scope="row">
						<label for="robotstxt_og_title">
							<?php esc_html_e( 'Custom Title', 'robotstxt-og' ); ?>
						</label>
					</th>
					<td>
						<input
							type="text"
							id="robotstxt_og_title"
							name="robotstxt_og_title"
							value="<?php echo esc_attr( $og_title ); ?>"
							class="large-text"
						/>
						<p class="description">
							<?php esc_html_e( 'Overrides the default og:title for this post. Leave blank to use the post title automatically.', 'robotstxt-og' ); ?>
						</p>
					</td>
				</tr>
				<tr>
					<th scope="row">
						<label for="robotstxt_og_description">
							<?php esc_html_e( 'Custom Description', 'robotstxt-og' ); ?>
						</label>
					</th>
					<td>
						<textarea
							id="robotstxt_og_description"
							name="robotstxt_og_description"
							class="large-text"
							rows="3"
						><?php echo esc_textarea( $og_description ); ?></textarea>
						<p class="description">
							<?php esc_html_e( 'Overrides the default og:description for this post. Leave blank to use the excerpt automatically.', 'robotstxt-og' ); ?>
						</p>
					</td>
				</tr>
				<tr>
					<th scope="row">
						<label for="robotstxt_og_image_alt">
							<?php esc_html_e( 'Custom OG Image Alt', 'robotstxt-og' ); ?>
						</label>
					</th>
					<td>
						<input
							type="text"
							id="robotstxt_og_image_alt"
							name="robotstxt_og_image_alt"
							value="<?php echo esc_attr( $og_image_alt ); ?>"
							class="large-text"
						/>
						<p class="description">
							<?php esc_html_e( 'Alt text for the og:image of this post. Leave blank to use the featured image alt text from the media library.', 'robotstxt-og' ); ?>
						</p>
					</td>
				</tr>
			</tbody>
		</table>
		<?php
	}

	/**
	 * Save meta box values on post save.
	 *
	 * @since 1.2.0
	 *
	 * @param int     $post_id The post ID.
	 * @param WP_Post $post    The post object.
	 * @return void
	 */
	public function save_meta_box( int $post_id, WP_Post $post ): void {
		// Skip autosaves and revisions.
		if ( wp_is_post_autosave( $post_id ) || wp_is_post_revision( $post_id ) ) {
			return;
		}

		// Verify nonce.
		$nonce_raw = filter_input( INPUT_POST, 'robotstxt_og_meta_box_nonce', FILTER_SANITIZE_FULL_SPECIAL_CHARS );
		$nonce     = $nonce_raw ? sanitize_text_field( wp_unslash( $nonce_raw ) ) : '';

		if ( ! wp_verify_nonce( $nonce, 'robotstxt_og_meta_box' ) ) {
			return;
		}

		// Check permissions.
		$post_type_obj = get_post_type_object( $post->post_type );

		if ( ! $post_type_obj || ! current_user_can( $post_type_obj->cap->edit_post, $post_id ) ) {
			return;
		}

		// Save og:title.
		$og_title_raw = filter_input( INPUT_POST, 'robotstxt_og_title', FILTER_SANITIZE_FULL_SPECIAL_CHARS );
		$og_title     = $og_title_raw ? sanitize_text_field( wp_unslash( $og_title_raw ) ) : '';

		if ( empty( $og_title ) ) {
			delete_post_meta( $post_id, '_og_title' );
		} else {
			update_post_meta( $post_id, '_og_title', $og_title );
		}

		// Save og:description.
		$og_desc_raw = filter_input( INPUT_POST, 'robotstxt_og_description', FILTER_UNSAFE_RAW );
		$og_desc     = $og_desc_raw ? sanitize_textarea_field( wp_unslash( $og_desc_raw ) ) : '';

		if ( empty( $og_desc ) ) {
			delete_post_meta( $post_id, '_og_description' );
		} else {
			update_post_meta( $post_id, '_og_description', $og_desc );
		}

		// Save og:image:alt.
		$og_alt_raw = filter_input( INPUT_POST, 'robotstxt_og_image_alt', FILTER_SANITIZE_FULL_SPECIAL_CHARS );
		$og_alt     = $og_alt_raw ? sanitize_text_field( wp_unslash( $og_alt_raw ) ) : '';

		if ( empty( $og_alt ) ) {
			delete_post_meta( $post_id, '_og_image_alt' );
		} else {
			update_post_meta( $post_id, '_og_image_alt', $og_alt );
		}

		// Save og:type override (whitelisted).
		$og_type_raw = filter_input( INPUT_POST, 'robotstxt_og_type', FILTER_SANITIZE_FULL_SPECIAL_CHARS );
		$og_type     = self::sanitize_og_type( $og_type_raw ? wp_unslash( $og_type_raw ) : '' );

		if ( '' === $og_type ) {
			delete_post_meta( $post_id, '_og_type' );
		} else {
			update_post_meta( $post_id, '_og_type', $og_type );
		}

		// Save twitter:creator handle.
		$creator_raw = filter_input( INPUT_POST, 'robotstxt_og_twitter_creator', FILTER_SANITIZE_FULL_SPECIAL_CHARS );
		$creator     = $creator_raw ? sanitize_text_field( wp_unslash( $creator_raw ) ) : '';

		if ( '' === $creator ) {
			delete_post_meta( $post_id, '_twitter_creator' );
		} else {
			update_post_meta( $post_id, '_twitter_creator', $creator );
		}
	}
}