<?php
/**
 * Preserve legacy configuration when upgrading WordPress identifiers.
 *
 * @package ABeCeBooking
 */

namespace ABeCe\Booking\Support;

/** One-time legacy compatibility. Old identifiers below are never names for new settings. */
final class LegacyIdentifiers {
	public const MARKER       = 'abece_booking_identifier_migration_version';
	public const OPTIONS      = array(
		'asb_online_booking_resources_v1' => 'abece_booking_online_booking_resources_v1',
		'asb_privacy_retention'                      => 'abece_booking_privacy_retention',
		'asb_privacy_reviews'                        => 'abece_booking_privacy_reviews',
		'asb_privacy_cleanup_audit'                  => 'abece_booking_privacy_cleanup_audit',
		'asb_privacy_retention_cursor'               => 'abece_booking_privacy_retention_cursor',
		'asb_db_version'                             => 'abece_booking_db_version',
		'asb_capabilities_version'                   => 'abece_booking_capabilities_version',
		'asb_club_location'                          => 'abece_booking_club_location',
		'asb_require_phone'                          => 'abece_booking_require_phone',
		'asb_public_calendar_visibility'             => 'abece_booking_public_calendar_visibility',
		'asb_enable_credit'                          => 'abece_booking_enable_credit',
		'asb_enable_pay_on_site'                     => 'abece_booking_enable_pay_on_site',
		'asb_enable_bank_transfer'                   => 'abece_booking_enable_bank_transfer',
		'asb_enable_qr_payment'                      => 'abece_booking_enable_qr_payment',
		'asb_bank_account'                           => 'abece_booking_bank_account',
		'asb_bank_payment_profiles'                  => 'abece_booking_bank_payment_profiles',
		'asb_bank_profiles_version'                  => 'abece_booking_bank_profiles_version',
		'asb_block_booking_with_outstanding_balance' => 'abece_booking_block_booking_with_outstanding_balance',
		'asb_outstanding_balance_grace_hours'        => 'abece_booking_outstanding_balance_grace_hours',
		'asb_self_link_enabled'                      => 'abece_booking_self_link_enabled',
		'asb_self_link_method'                       => 'abece_booking_self_link_method',
		'asb_memberships_enabled'                    => 'abece_booking_memberships_enabled',
		'asb_reservation_page_id'                    => 'abece_booking_reservation_page_id',
		'asb_max_daily_customer_bookings'            => 'abece_booking_max_daily_customer_bookings',
		'asb_online_booking_cutoff_mode'             => 'abece_booking_online_booking_cutoff_mode',
		'asb_online_booking_cutoff_hours'            => 'abece_booking_online_booking_cutoff_hours',
		'asb_booking_contact_phone'                  => 'abece_booking_booking_contact_phone',
		'asb_confirmation_email_intro'               => 'abece_booking_confirmation_email_intro',
		'asb_confirmation_email_outro'               => 'abece_booking_confirmation_email_outro',
		'asb_registration_privacy_acknowledgement'   => 'abece_booking_registration_privacy_acknowledgement',
	);
	public const USER_META    = array(
		'asb_phone'                   => 'abece_booking_phone',
		'asb_onboarding_dismissed'    => 'abece_booking_onboarding_dismissed',
		'asb_privacy_acknowledgement' => 'abece_booking_privacy_acknowledgement',
		'asb_privacy_request_rate'    => 'abece_booking_privacy_request_rate',
		'asb_membership_link_audit'   => 'abece_booking_membership_link_audit',
		'asb_membership_batch_audit'  => 'abece_booking_membership_batch_audit',
	);
	public const POST_META    = array(
		'asb_privacy_export_plan'     => 'abece_booking_privacy_export_plan',
		'asb_privacy_identity'        => 'abece_booking_privacy_identity',
		'asb_privacy_review_required' => 'abece_booking_privacy_review_required',
		'asb_privacy_retained'        => 'abece_booking_privacy_retained',
		'asb_privacy_request_owner'   => 'abece_booking_privacy_request_owner',
		'asb_privacy_mail_failed'     => 'abece_booking_privacy_mail_failed',
	);
	public const CAPS         = array(
		'asb_manage_resources'             => 'abece_booking_manage_resources',
		'asb_manage_members'               => 'abece_booking_manage_members',
		'asb_manage_bookings'              => 'abece_booking_manage_bookings',
		'asb_manage_prices'                => 'abece_booking_manage_prices',
		'asb_manage_credit'                => 'abece_booking_manage_credit',
		'asb_manage_cancellation_policies' => 'abece_booking_manage_cancellation_policies',
		'asb_override_cancellation_fees'   => 'abece_booking_override_cancellation_fees',
	);
	public const CRON         = array(
		'asb_privacy_retention'    => 'abece_booking_privacy_retention',
		'asb_privacy_plan_expire'  => 'abece_booking_privacy_plan_expire',
		'asb_member_import_expire' => 'abece_booking_member_import_expire',
	);
	public const TRANSIENTS   = array(
		'asb_privacy_export_'        => 'abece_booking_privacy_export_',
		'asb_privacy_erase_'         => 'abece_booking_privacy_erase_',
		'asb_geo_'                   => 'abece_booking_geo_',
		'asb_geocoding_last_request' => 'abece_booking_geocoding_last_request',
		'asb_member_import_'         => 'abece_booking_member_import_',
		'asb_link_rate_'             => 'abece_booking_link_rate_',
		'asb_test_email_'            => 'abece_booking_test_email_',
	);
	public const REQUEST_DATA = array(
		'asb_self_service'              => 'abece_booking_self_service',
		'asb_account_closure_requested' => 'abece_booking_account_closure_requested',
	);

	/**
	 * Complete the resumable identifier upgrade before defaults or API registration.
	 *
	 * @return void
	 */
	public static function migrate(): void {
		if ( (int) get_option( self::MARKER, 0 ) >= 1 ) {
			return;
		}
		global $wpdb;
		$lock = 'abece_booking_identifiers_' . substr( hash( 'sha256', DB_NAME . ':' . $wpdb->prefix ), 0, 32 );
		$previous_errors = $wpdb->suppress_errors( true );
		$locked = false;
		try {
			if ( (int) $wpdb->get_var( $wpdb->prepare( 'SELECT GET_LOCK(%s, 5)', $lock ) ) !== 1 ) {
				self::fail();
			}
			$locked = true;
			self::options();
			self::capabilities();
			self::metadata( 'user', self::USER_META );
			self::metadata( 'post', self::POST_META );
			self::request_data();
			self::cron();
			self::transients();
			update_option( self::MARKER, 1, false );
			if ( (int) get_option( self::MARKER ) !== 1 ) {
				self::fail();
			}
		} finally {
			if ( $locked ) {
				$wpdb->get_var( $wpdb->prepare( 'SELECT RELEASE_LOCK(%s)', $lock ) );
			}
			// Option/meta values may contain personal or financial details. Keep
			// failed prepared SQL out of debug logs, then restore the caller's state.
			$wpdb->suppress_errors( $previous_errors );
		}
	}

	/**
	 * Copy only missing options, preserving raw values and autoload metadata.
	 *
	 * @return void
	 */
	private static function options(): void {
		global $wpdb;
		foreach ( self::OPTIONS as $old => $new ) {
			// Raw SQL preserves serialized bytes, false/null, and WP 6.6+ autoload states exactly.
			$source = $wpdb->get_row( $wpdb->prepare( 'SELECT option_value,autoload FROM %i WHERE option_name=%s', $wpdb->options, $old ), ARRAY_A );
			if ( $wpdb->last_error ) {
				self::fail();
			}
			if ( $source === null ) {
				continue;
			}
			$existing = $wpdb->get_var( $wpdb->prepare( 'SELECT option_id FROM %i WHERE option_name=%s', $wpdb->options, $new ) );
			if ( $wpdb->last_error ) {
				self::fail();
			}
			if ( $existing !== null ) {
				continue; // New configuration, including false/null/empty, wins.
			}
			// Use the exact raw source already read above. A self-referencing
			// INSERT ... SELECT would require a second table alias under LOCK TABLES.
			$inserted = $wpdb->query( $wpdb->prepare( 'INSERT IGNORE INTO %i (option_name,option_value,autoload) VALUES (%s,%s,%s)', $wpdb->options, $new, $source['option_value'], $source['autoload'] ) );
			if ( $inserted === false ) {
				self::fail();
			}
			self::option_cache( $new );
			$copied = $wpdb->get_row( $wpdb->prepare( 'SELECT option_value,autoload FROM %i WHERE option_name=%s', $wpdb->options, $new ), ARRAY_A );
			if ( $wpdb->last_error || $copied === null || ( $inserted === 1 && $copied !== $source ) ) {
				self::fail();
			}
			// A concurrent new writer is authoritative; INSERT IGNORE never replaces its value.
			// Old values remain available for inspection/rollback and are not read by runtime defaults.
		}
	}

	/**
	 * Invalidate option caches after a verified raw insert.
	 *
	 * @param string $key Option name.
	 * @return void
	 */
	private static function option_cache( string $key ): void {
		wp_cache_delete( $key, 'options' );
		wp_cache_delete( 'alloptions', 'options' );
		wp_cache_delete( 'notoptions', 'options' );
	}

	/**
	 * Keep grants, denials and unrelated role or user capabilities.
	 *
	 * @return void
	 */
	private static function capabilities(): void {
		global $wpdb;
		$key     = $wpdb->prefix . 'user_roles';
		$roles   = get_option( $key, array() );
		$updated = $roles;
		foreach ( $updated as &$role ) {
			foreach ( self::CAPS as $old => $new ) {
				if ( array_key_exists( $old, $role['capabilities'] ) && ! array_key_exists( $new, $role['capabilities'] ) ) {
					$role['capabilities'][ $new ] = $role['capabilities'][ $old ];
				}
			}
		}
		unset( $role );
		if ( $roles !== $updated ) {
			update_option( $key, $updated );
			if ( get_option( $key ) !== $updated ) {
				self::fail();
			}
			wp_roles()->for_site();
		}
		$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT umeta_id,user_id,meta_value FROM %i WHERE meta_key=%s', $wpdb->usermeta, $wpdb->prefix . 'capabilities' ), ARRAY_A );
		if ( $wpdb->last_error ) {
			self::fail();
		}
		foreach ( $rows as $row ) {
			$caps = maybe_unserialize( $row['meta_value'] );
			if ( ! is_array( $caps ) ) {
				continue;
			}
			$next = $caps;
			foreach ( self::CAPS as $old => $new ) {
				if ( array_key_exists( $old, $caps ) && ! array_key_exists( $new, $caps ) ) {
					$next[ $new ] = $caps[ $old ];
				}
			}
			if ( $next === $caps ) {
				continue;
			}
			if ( false === $wpdb->update( $wpdb->usermeta, array( 'meta_value' => maybe_serialize( $next ) ), array( 'umeta_id' => (int) $row['umeta_id'] ) ) ) {
				self::fail();
			}
			wp_cache_delete( (int) $row['user_id'], 'user_meta' );
		}
		// The SDK or another plugin may already have loaded this request's WP_User object.
		if ( isset( $GLOBALS['current_user'] ) && $GLOBALS['current_user'] instanceof \WP_User ) {
			$GLOBALS['current_user']->for_site();
		}

	}

	/**
	 * Rename metadata in place without decoding values or losing repeated audit rows.
	 *
	 * @param string $type User or post metadata.
	 * @param array  $map  Explicit legacy-to-current identifiers.
	 * @return void
	 */
	private static function metadata( string $type, array $map ): void {
		global $wpdb;
		$table = $type === 'user' ? $wpdb->usermeta : $wpdb->postmeta;
		$owner = $type === 'user' ? 'user_id' : 'post_id';
		foreach ( $map as $old => $new ) {
			$ids = $wpdb->get_col( $wpdb->prepare( 'SELECT DISTINCT %i FROM %i WHERE meta_key=%s', $owner, $table, $old ) );
			if ( $wpdb->last_error ) {
				self::fail();
			}
			foreach ( $ids as $id ) {
				// Rename all repeated audit rows together without decoding or changing their values.
				// An existing new key is authoritative. Preserve its legacy shadow for GDPR review.
				if ( metadata_exists( $type, (int) $id, $new ) ) {
					continue;
				}
				if ( false === $wpdb->query( $wpdb->prepare( 'UPDATE %i SET meta_key=%s WHERE %i=%d AND meta_key=%s', $table, $new, $owner, (int) $id, $old ) ) ) {
					self::fail();
				}
				wp_cache_delete( (int) $id, $type . '_meta' );
			}
		}
	}

	/**
	 * Rename only owned keys in native privacy-request JSON.
	 *
	 * @return void
	 */
	private static function request_data(): void {
		global $wpdb;
		$rows = $wpdb->get_results( $wpdb->prepare( 'SELECT ID,post_content FROM %i WHERE post_type=%s', $wpdb->posts, 'user_request' ), ARRAY_A );
		if ( $wpdb->last_error ) {
			self::fail();
		}
		foreach ( $rows as $row ) {
			$data = json_decode( $row['post_content'], true );
			if ( ! is_array( $data ) ) {
				continue;
			}
			$changed = false;
			foreach ( self::REQUEST_DATA as $old => $new ) {
				if ( array_key_exists( $old, $data ) ) {
					if ( ! array_key_exists( $new, $data ) ) {
						$data[ $new ] = $data[ $old ];
					}
					unset( $data[ $old ] );
					$changed = true;
				}
			}
			if ( $changed ) {
				if ( false === $wpdb->update( $wpdb->posts, array( 'post_content' => wp_json_encode( $data ) ), array( 'ID' => (int) $row['ID'] ) ) ) {
					self::fail();
				}
				clean_post_cache( (int) $row['ID'] );
			}
		}
	}

	/**
	 * Move owned events with their timestamps, arguments and recurrence.
	 *
	 * @return void
	 */
	private static function cron(): void {
		foreach ( _get_cron_array() ?: array() as $timestamp => $hooks ) {
			foreach ( self::CRON as $old => $new ) {
				foreach ( $hooks[ $old ] ?? array() as $event ) {
								$args = $event['args'];
								// Existing exact new events win; a retry cannot create a second event.
					if ( ! wp_get_scheduled_event( $new, $args, (int) $timestamp ) ) {
						$result = $event['schedule'] ? wp_schedule_event( (int) $timestamp, $event['schedule'], $new, $args, true ) : wp_schedule_single_event( (int) $timestamp, $new, $args, true );
						if ( is_wp_error( $result ) || ! $result ) {
							self::fail();
						}
					}
					$result = wp_unschedule_event( (int) $timestamp, $old, $args, true );
					if ( is_wp_error( $result ) || ! $result ) {
						self::fail();
					}
				}
			}
		}
	}

	/**
	 * Invalidate temporary legacy plans without renewing their expiry.
	 *
	 * @return void
	 */
	private static function transients(): void {
		global $wpdb;
		// Temporary import/export plans are invalidated, never revived with a fresh lifetime.
		foreach ( self::TRANSIENTS as $old => $new ) {
			$names = $wpdb->get_col( $wpdb->prepare( 'SELECT option_name FROM %i WHERE option_name LIKE %s', $wpdb->options, $wpdb->esc_like( '_transient_' . $old ) . '%' ) );
			if ( $wpdb->last_error ) {
				self::fail();
			}
			foreach ( $names as $name ) {
				delete_transient( substr( $name, strlen( '_transient_' ) ) );
			}
		}
		foreach ( _get_cron_array() ?: array() as $hooks ) {
			foreach ( $hooks['abece_booking_member_import_expire'] ?? array() as $event ) {
				$key = $event['args'][0] ?? null;
				if ( is_string( $key ) && str_starts_with( $key, 'asb_member_import_' ) ) {
					delete_transient( $key );
				}
			}
		}
	}

	/**
	 * Include preserved pre-upgrade shadow metadata in GDPR handling.
	 *
	 * @param int    $user WordPress user ID.
	 * @param string $key  Current metadata identifier.
	 * @return array
	 */
	public static function user_metadata( int $user, string $key ): array {
		$values = get_user_meta( $user, $key, false );
		$old    = array_search( $key, self::USER_META, true );
		return $old === false ? $values : array_merge( $values, get_user_meta( $user, $old, false ) );
	}

	/**
	 * Erase current and preserved legacy metadata in the same authorized privacy action.
	 *
	 * @param int    $user WordPress user ID.
	 * @param string $key  Current metadata identifier.
	 * @return bool
	 */
	public static function delete_user_metadata( int $user, string $key ): bool {
		$removed = delete_user_meta( $user, $key );
		$old     = array_search( $key, self::USER_META, true );
		return ( $old !== false && delete_user_meta( $user, $old ) ) || $removed;
	}

	/**
	 * Abort initialization without exposing database details or credentials.
	 *
	 * @return never
	 */
	public static function fail(): never {
		throw new \RuntimeException( __( 'ABeCe Booking could not complete the settings upgrade. Existing data was retained. Please try again.', 'abece-booking' ) );
	}
}