<?php
/**
 * Who the log leaves out, by the administrator's choice.
 *
 * A site owner's own routine clicks, or a role whose work is noise, can be
 * kept out of the log. Two lists, both empty by default: user IDs and role
 * slugs. A person is excluded when their ID is listed or any of their roles
 * is.
 *
 * Three things an exclusion never touches, because a log that can be muted
 * without trace is not an audit log: events with no signed-in actor (failed
 * logins, WP-CLI, cron), the recording of a change to these two settings
 * themselves, and rows already written.
 *
 * @package ActivityLog404
 */

namespace ActivityLog404;

class Exclusions {

	const OPTION_USERS = 'ops_activity_log_excluded_users';
	const OPTION_ROLES = 'ops_activity_log_excluded_roles';

	/** What the log calls each option when a change to it is recorded. */
	const LABELS = array(
		self::OPTION_USERS => 'Users excluded from the log',
		self::OPTION_ROLES => 'Roles excluded from the log',
	);

	/**
	 * Whether events attributed to this user are left out of the log.
	 */
	public static function excludes( int $user_id ): bool {
		if ( $user_id <= 0 ) {
			return false;
		}

		if ( in_array( $user_id, self::users(), true ) ) {
			return true;
		}

		$roles = self::roles();
		if ( array() === $roles ) {
			return false;
		}

		$user = get_userdata( $user_id );
		if ( ! $user instanceof \WP_User ) {
			return false;
		}

		return array() !== array_intersect( $roles, array_map( 'strval', (array) $user->roles ) );
	}

	/**
	 * Whether this event is the record of a change to the exclusion lists,
	 * which is written whoever makes it.
	 *
	 * @param array<string,mixed>|null $details The event's details.
	 */
	public static function is_change_to_exclusions( string $event_type, ?array $details ): bool {
		return 'setting_changed' === $event_type
			&& is_array( $details )
			&& isset( self::LABELS[ (string) ( $details['option'] ?? '' ) ] );
	}

	/**
	 * The excluded user IDs.
	 *
	 * @return int[]
	 */
	public static function users(): array {
		return self::ids( get_option( self::OPTION_USERS, array() ) );
	}

	/**
	 * The excluded role slugs.
	 *
	 * @return string[]
	 */
	public static function roles(): array {
		$stored = get_option( self::OPTION_ROLES, array() );
		if ( ! is_array( $stored ) ) {
			return array();
		}
		$roles = array();
		foreach ( $stored as $role ) {
			if ( is_string( $role ) && '' !== $role && ! in_array( $role, $roles, true ) ) {
				$roles[] = $role;
			}
		}

		return $roles;
	}

	/**
	 * Role slugs as posted, kept to the roles the site has.
	 *
	 * @param mixed $posted The ticked slugs, or anything else for none.
	 * @return string[]
	 */
	public static function sanitize_roles( $posted ): array {
		if ( ! is_array( $posted ) ) {
			return array();
		}
		$known = array_keys( wp_roles()->get_names() );
		$roles = array();
		foreach ( $posted as $role ) {
			$role = is_string( $role ) ? sanitize_key( $role ) : '';
			if ( in_array( $role, $known, true ) && ! in_array( $role, $roles, true ) ) {
				$roles[] = $role;
			}
		}

		return $roles;
	}

	/**
	 * Usernames typed one per line (or comma-separated), resolved to the IDs
	 * of the users that exist. Stored by ID, so renaming a user does not
	 * quietly lift their exclusion; a name that matches nobody is dropped.
	 *
	 * @return int[]
	 */
	public static function ids_from_logins( string $typed ): array {
		$ids   = array();
		$lines = preg_split( '/[\r\n,]+/', $typed );
		foreach ( is_array( $lines ) ? $lines : array() as $login ) {
			$login = sanitize_user( trim( $login ), true );
			if ( '' === $login ) {
				continue;
			}
			$user = get_user_by( 'login', $login );
			if ( $user instanceof \WP_User && ! in_array( (int) $user->ID, $ids, true ) ) {
				$ids[] = (int) $user->ID;
			}
		}

		return $ids;
	}

	/**
	 * The excluded users' logins, one per line, for the settings screen.
	 * A deleted user has no login to show and cannot act anyway.
	 */
	public static function logins(): string {
		$logins = array();
		foreach ( self::users() as $id ) {
			$user = get_userdata( $id );
			if ( $user instanceof \WP_User ) {
				$logins[] = (string) $user->user_login;
			}
		}

		return implode( "\n", $logins );
	}

	/**
	 * @param mixed $stored An option value.
	 * @return int[]
	 */
	private static function ids( $stored ): array {
		if ( ! is_array( $stored ) ) {
			return array();
		}
		$ids = array();
		foreach ( $stored as $id ) {
			$id = is_numeric( $id ) ? (int) $id : 0;
			if ( $id > 0 && ! in_array( $id, $ids, true ) ) {
				$ids[] = $id;
			}
		}

		return $ids;
	}
}