bbp_map_topic_meta_caps( array $caps = array(), string $cap = '', int $user_id, mixed $args = array() )

function bbp_map_topic_meta_caps( $caps = array(), $cap = '', $user_id = 0, $args = array() ) {

	// What capability is being checked?
	switch ( $cap ) {

		/** Reading ***********************************************************/

		case 'read_topic' :

			// User cannot spectate
			if ( ! user_can( $user_id, 'spectate' ) ) {
				$caps = array( 'do_not_allow' );

			// Do some post ID based logic
			} else {

				// Get the post
				$_post = get_post( $args[0] );
				if ( !empty( $_post ) ) {

					// Get caps for post type object
					$post_type = get_post_type_object( $_post->post_type );

					// Post is public
					if ( bbp_get_public_status_id() === $_post->post_status ) {
						$caps = array( 'spectate' );

					// User is author so allow read
					} elseif ( (int) $user_id === (int) $_post->post_author ) {
						$caps = array( 'spectate' );

					// Unknown so map to private posts
					} else {
						$caps = array( $post_type->cap->read_private_posts );
					}
				}
			}

			break;

		/** Publishing ********************************************************/

		case 'publish_topics'  :

			// Moderators can always publish
			if ( user_can( $user_id, 'moderate' ) ) {
				$caps = array( 'moderate' );
			}

			break;

		/** Editing ***********************************************************/

		// Used primarily in wp-admin
		case 'edit_topics'        :
		case 'edit_others_topics' :

			// Moderators can always edit
			if ( user_can( $user_id, 'moderate' ) ) {
				$caps = array( $cap );

			// Otherwise, block
			} else {
				$caps = array( 'do_not_allow' );
			}

			break;

		// Used everywhere
		case 'edit_topic' :

			// Get the post
			$_post = get_post( $args[0] );
			if ( !empty( $_post ) ) {

				// Get caps for post type object
				$post_type = get_post_type_object( $_post->post_type );
				$caps      = array();

				// Add 'do_not_allow' cap if user is spam or deleted
				if ( bbp_is_user_inactive( $user_id ) ) {
					$caps[] = 'do_not_allow';

				// User is author so allow edit if not in admin
				} elseif ( !is_admin() && ( (int) $user_id === (int) $_post->post_author ) ) {
					$caps[] = $post_type->cap->edit_posts;

				// Unknown, so map to edit_others_posts
				} else {
					$caps[] = $post_type->cap->edit_others_posts;
				}
			}

			break;

		/** Deleting **********************************************************/

		case 'delete_topic' :

			// Get the post
			$_post = get_post( $args[0] );
			if ( !empty( $_post ) ) {

				// Get caps for post type object
				$post_type = get_post_type_object( $_post->post_type );
				$caps      = array();

				// Add 'do_not_allow' cap if user is spam or deleted
				if ( bbp_is_user_inactive( $user_id ) ) {
					$caps[] = 'do_not_allow';

				// Moderators can always edit forum content
				} elseif ( user_can( $user_id, 'moderate' ) ) {
					$caps[] = 'moderate';

				// Unknown so map to delete_others_posts
				} else {
					$caps[] = $post_type->cap->delete_others_posts;
				}
			}

			break;

		// Moderation override
		case 'delete_topics'         :
		case 'delete_others_topics'  :

			// Moderators can always delete
			if ( user_can( $user_id, 'moderate' ) ) {
				$caps = array( $cap );
			}

			break;

		/** Admin *************************************************************/

		case 'bbp_topics_admin' :
			$caps = array( 'moderate' );
			break;
	}

	return apply_filters( 'bbp_map_topic_meta_caps', $caps, $cap, $user_id, $args );
}