<?php
/**
 * Plugin settings stored in WordPress.
 *
 * @package StandChat
 */

namespace StandChat;

defined( 'ABSPATH' ) || exit;

/**
 * Reads, validates and saves the plugin's WordPress-side settings.
 *
 * Stand-side settings (Behavior rules, Stand-ins, knowledge) live in Stand and
 * are never copied here. These settings only decide what the plugin prints.
 */
final class Settings {

	const OPTION = 'stand_chat_settings';

	const CONSENT_CATEGORIES = array( 'functional', 'preferences', 'statistics', 'statistics-anonymous', 'marketing' );

	const NON_PRODUCTION_MODES = array( 'hide', 'demo', 'print' );

	const VISIBILITY_MODES = array( 'all', 'except', 'only' );

	/**
	 * Default settings. Chat stays off until a Site ID is saved or Go live runs.
	 *
	 * @return array<string, mixed>
	 */
	public static function defaults(): array {
		return array(
			'site_id'         => '',
			'chat_enabled'    => false,
			'corner_button'   => true,
			'visibility'      => array(
				'mode'  => 'all',
				'items' => array(),
			),
			'non_production'  => 'hide',
			'consent'         => array(
				'mode'     => 'immediate',
				'category' => 'functional',
			),
			'hide_for_admins' => false,
			'loader'          => false,
			'identity'        => array(
				'enabled' => false,
				'roles'   => array( 'subscriber', 'customer' ),
			),
			'read_on_publish' => true,
		);
	}

	/**
	 * All settings merged over the defaults.
	 *
	 * @return array<string, mixed>
	 */
	public static function all(): array {
		$stored = get_option( self::OPTION, array() );
		return self::sanitize( is_array( $stored ) ? $stored : array() );
	}

	/**
	 * One setting.
	 *
	 * @param string $key Setting key.
	 * @return mixed
	 */
	public static function get( string $key ) {
		$all = self::all();
		return $all[ $key ] ?? null;
	}

	/**
	 * Merges changes into the stored settings and saves them. The merge starts
	 * from what's stored when it's saved, so a change another request saved
	 * meanwhile, such as on another tab, stays.
	 *
	 * @param array<string, mixed> $changes Changed keys.
	 * @return array<string, mixed> The saved settings.
	 */
	public static function update( array $changes ): array {
		$saved = Option_Queue::change(
			self::OPTION,
			static function ( array $stored ) use ( $changes ): array {
				$current = self::sanitize( $stored );
				foreach ( $changes as $key => $value ) {
					if ( ! array_key_exists( $key, $current ) ) {
						continue;
					}
					if ( is_array( $current[ $key ] ) && is_array( $value ) ) {
						// Nested settings merge one level deep; lists inside them are replaced whole.
						$current[ $key ] = array_merge( $current[ $key ], $value );
					} else {
						$current[ $key ] = $value;
					}
				}
				return self::sanitize( $current );
			},
			true
		);
		// Null when other requests kept changing them: then this change isn't
		// saved, and what's stored is.
		return self::sanitize( $saved ?? Option_Queue::read( self::OPTION ) );
	}

	/**
	 * Validates every setting, falling back to defaults for anything unknown.
	 *
	 * @param array<string, mixed> $input Raw settings.
	 * @return array<string, mixed>
	 */
	public static function sanitize( array $input ): array {
		$defaults = self::defaults();
		$out      = $defaults;

		$out['site_id']         = self::sanitize_site_id( $input['site_id'] ?? '' );
		$out['chat_enabled']    = ! empty( $input['chat_enabled'] );
		$out['corner_button']   = array_key_exists( 'corner_button', $input ) ? (bool) $input['corner_button'] : true;
		$out['hide_for_admins'] = ! empty( $input['hide_for_admins'] );
		$out['loader']          = ! empty( $input['loader'] );
		$out['read_on_publish'] = array_key_exists( 'read_on_publish', $input ) ? (bool) $input['read_on_publish'] : true;

		$mode                  = $input['non_production'] ?? 'hide';
		$out['non_production'] = in_array( $mode, self::NON_PRODUCTION_MODES, true ) ? $mode : 'hide';

		$visibility        = is_array( $input['visibility'] ?? null ) ? $input['visibility'] : array();
		$visibility_mode   = (string) ( $visibility['mode'] ?? 'all' );
		$out['visibility'] = array(
			'mode'  => in_array( $visibility_mode, self::VISIBILITY_MODES, true ) ? $visibility_mode : 'all',
			'items' => self::sanitize_visibility_items( $visibility['items'] ?? array() ),
		);

		$consent          = is_array( $input['consent'] ?? null ) ? $input['consent'] : array();
		$consent_category = (string) ( $consent['category'] ?? '' );
		$out['consent']   = array(
			'mode'     => 'consent' === ( $consent['mode'] ?? '' ) ? 'consent' : 'immediate',
			'category' => in_array( $consent_category, self::CONSENT_CATEGORIES, true ) ? $consent_category : 'functional',
		);

		$identity        = is_array( $input['identity'] ?? null ) ? $input['identity'] : array();
		$roles           = is_array( $identity['roles'] ?? null ) ? $identity['roles'] : $defaults['identity']['roles'];
		$out['identity'] = array(
			'enabled' => ! empty( $identity['enabled'] ),
			'roles'   => array_values( array_unique( array_filter( array_map( 'sanitize_key', $roles ) ) ) ),
		);

		return $out;
	}

	/**
	 * A Stand Site ID: the UUID shown in Sites, or "demo".
	 *
	 * @param mixed $value Raw value.
	 */
	public static function sanitize_site_id( $value ): string {
		$value = is_string( $value ) ? trim( $value ) : '';
		return preg_match( '/^[A-Za-z0-9][A-Za-z0-9-]{2,63}$/', $value ) ? $value : '';
	}

	/**
	 * Where-chat-appears entries: pages and posts by ID, the front page, content
	 * types, and archives and search results.
	 *
	 * @param mixed $items Raw entries.
	 * @return array<int, array<string, mixed>>
	 */
	private static function sanitize_visibility_items( $items ): array {
		if ( ! is_array( $items ) ) {
			return array();
		}
		$out  = array();
		$seen = array();
		foreach ( $items as $item ) {
			if ( ! is_array( $item ) ) {
				continue;
			}
			$type = $item['type'] ?? '';
			if ( 'post' === $type && absint( $item['id'] ?? 0 ) > 0 ) {
				$clean = array(
					'type' => 'post',
					'id'   => absint( $item['id'] ),
				);
			} elseif ( 'post_type' === $type && '' !== sanitize_key( $item['name'] ?? '' ) ) {
				$clean = array(
					'type' => 'post_type',
					'name' => sanitize_key( $item['name'] ),
				);
			} elseif ( 'front' === $type || 'archives' === $type ) {
				$clean = array( 'type' => $type );
			} else {
				continue;
			}
			$key = wp_json_encode( $clean );
			if ( isset( $seen[ $key ] ) ) {
				continue;
			}
			$seen[ $key ] = true;
			$out[]        = $clean;
			if ( count( $out ) >= 500 ) {
				break;
			}
		}
		return $out;
	}
}