<?php
/**
 * Email notification preferences.
 *
 * @package SpaceBay
 */

namespace SpaceBay\Notifications;

defined( 'ABSPATH' ) || exit;

/**
 * Which kinds of notifications a member also wants by email.
 */
final class Preferences {

	/**
	 * User meta key.
	 *
	 * @var string
	 */
	const META = 'spacebay_email_prefs';

	/**
	 * Groups of notifications and whether email is on by default.
	 *
	 * @return array<string, bool>
	 */
	public static function defaults() {
		/**
		 * Filters the default email preferences of members.
		 *
		 * @since 1.0.0
		 *
		 * @param array<string, bool> $defaults Group => on.
		 */
		return apply_filters(
			'spacebay_email_preference_defaults',
			array(
				'mentions'   => true,
				'messages'   => true,
				'comments'   => true,
				'spaces'     => true,
				'likes'      => false,
				'events'     => true,
				'badges'     => false,
				'moderation' => true,
			)
		);
	}

	/**
	 * Returns a member's preferences merged with defaults.
	 *
	 * @param int $user_id User ID.
	 * @return array<string, bool>
	 */
	public static function get( $user_id ) {
		$saved    = get_user_option( self::META, $user_id );
		$saved    = is_array( $saved ) ? $saved : array();
		$defaults = self::defaults();
		$prefs    = array();

		foreach ( $defaults as $group => $on ) {
			$prefs[ $group ] = array_key_exists( $group, $saved ) ? (bool) $saved[ $group ] : (bool) $on;
		}

		return $prefs;
	}

	/**
	 * Saves a member's preferences.
	 *
	 * @param int   $user_id User ID.
	 * @param array $input   Group => bool.
	 * @return array<string, bool> Saved preferences.
	 */
	public static function update( $user_id, array $input ) {
		$prefs = self::get( $user_id );

		foreach ( array_keys( $prefs ) as $group ) {
			if ( array_key_exists( $group, $input ) ) {
				$prefs[ $group ] = rest_sanitize_boolean( $input[ $group ] );
			}
		}

		update_user_option( $user_id, self::META, $prefs );

		return $prefs;
	}

	/**
	 * Whether a member wants an email for an action.
	 *
	 * @param int    $user_id User ID.
	 * @param string $action  Notification action.
	 * @return bool
	 */
	public static function wants_email( $user_id, $action ) {
		$group = self::group( $action );
		$prefs = self::get( $user_id );

		return '' !== $group && ! empty( $prefs[ $group ] );
	}

	/**
	 * The preference group of an action.
	 *
	 * @param string $action Notification action.
	 * @return string
	 */
	public static function group( $action ) {
		$map = array(
			'message'          => 'messages',
			'mention_post'     => 'mentions',
			'mention_comment'  => 'mentions',
			'comment_post'     => 'comments',
			'reply_comment'    => 'comments',
			'like_post'        => 'likes',
			'like_comment'     => 'likes',
			'space_invite'     => 'spaces',
			'space_request'    => 'spaces',
			'space_approved'   => 'spaces',
			'review_needed'    => 'moderation',
			'member_pending'   => 'moderation',
			'post_approved'    => 'moderation',
			'comment_approved' => 'moderation',
			'post_removed'     => 'moderation',
			'comment_removed'  => 'moderation',
			'member_approved'  => 'moderation',
			'event_new'        => 'events',
			'event_updated'    => 'events',
			'event_cancelled'  => 'events',
			'event_reminder'   => 'events',
			'badge_earned'     => 'badges',
			'level_up'         => 'badges',
		);

		/**
		 * Filters the email preference group of a notification action, so
		 * add-ons can send emails for their own actions.
		 *
		 * @since 1.0.0
		 *
		 * @param string $group  Group key, or '' for no email.
		 * @param string $action Notification action.
		 */
		return (string) apply_filters( 'spacebay_notification_group', $map[ $action ] ?? '', $action );
	}
}