<?php

namespace DeliciousBrains\WPMDB\Common\Error;

use DeliciousBrains\WPMDB\Common\Util\Util;
use WP_Error;

/**
 * Adds log messages about migrations
 */
class Logger {
	/**
	 * register hooks
	 **/
	public function register() {
		add_filter( 'wpmdb_initiate_migration', [ $this, 'initiate' ] );
		add_action( 'wpmdb_after_finalize_migration', [ $this, 'complete' ], 20, 2 );
		add_action( 'wpmdb_cancellation', [ $this, 'cancellation' ] );
		add_action( 'wpmdb_respond_remote_initiate', [ $this, 'remoteInitiate' ] );
		add_action( 'wpmdb_remote_finalize', [ $this, 'remoteFinalize' ], 10, 2 );
		add_action( 'wpmdb_respond_to_push_cancellation', [ $this, 'remoteCancellation' ] );
	}

	/**
	 * Logs structured message to error log.
	 *
	 * @param array $args       type and location keys required, target key optional.
	 * @param array $state_data Optional.
	 **/
	private function logMessage( $args, $state_data = [] ) {
		// Bare minimum that is required.
		if ( ! isset( $args['type'], $args['location'] ) ) {
			return;
		}

		$state_data = Util::merge_existing_state_data( $state_data );

		$log_message = 'WPMDB: ';
		$stats       = [
			'type'     => $args['type'],
			'location' => $args['location'],
		];

		if ( isset( $args['target'] ) ) {
			$stats['target'] = $args['target'];
		} elseif ( isset( $state_data['intent'] ) ) {
			$stats['target'] = ( 'pull' === $state_data['intent'] && 'local' === $args['location'] ) || ( 'push' === $state_data['intent'] && 'remote' === $args['location'] );
		}

		if ( isset( $state_data['site_url'], $state_data['url'] ) ) {
			$stats['sites'] = [
				'local'  => $state_data['site_url'],
				'remote' => $state_data['url'],
			];
		}

		if ( isset( $state_data['migration_state_id'] ) ) {
			$stats['migration_id'] = $state_data['migration_state_id'];
		}

		if ( isset( $state_data['remote_state_id'] ) ) {
			$stats['migration_id'] = $state_data['remote_state_id'];
		}

		error_log( $log_message . json_encode( $stats ) );
	}

	/**
	 * Log initiate migration.
	 *
	 * @param array $state_data
	 *
	 * @return array
	 *
	 * @handles wpmdb_initiate_migration
	 **/
	public function initiate( $state_data ) {
		if ( is_wp_error( $state_data ) ) {
			return $state_data;
		}

		$args = [
			'type'     => 'initiate',
			'location' => 'local',
		];
		$this->logMessage( $args, $state_data );

		return $state_data;
	}

	/**
	 * Log initiate migration on remote.
	 *
	 * @param array $state_data
	 *
	 * @handles wpmdb_respond_remote_initiate
	 **/
	public function remoteInitiate( $state_data ) {
		if ( is_wp_error( $state_data ) ) {
			return;
		}

		$args = [
			'type'     => 'initiate',
			'location' => 'remote',
		];
		$this->logMessage( $args, $state_data );
	}

	/**
	 * Log migration complete on remote.
	 *
	 * @param array|WP_Error      $state_data
	 * @param array|bool|WP_Error $result
	 *
	 * @handles wpmdb_remote_finalize
	 **/
	public function remoteFinalize( $state_data, $result ) {
		if ( is_wp_error( $state_data ) || is_wp_error( $result ) ) {
			return;
		}

		$args = [
			'type'     => 'complete',
			'location' => 'remote',
			'target'   => true,
		];
		$this->logMessage( $args, $state_data );
	}

	/**
	 * Log migration complete.
	 *
	 * @param array|WP_Error      $state_data
	 * @param array|bool|WP_Error $result
	 *
	 * @handles wpmdb_after_finalize_migration
	 **/
	public function complete( $state_data, $result ) {
		if ( is_wp_error( $state_data ) || is_wp_error( $result ) ) {
			return;
		}

		$args = [
			'type'     => 'complete',
			'location' => 'local',
		];
		$this->logMessage( $args );
	}

	/**
	 * Log cancellation.
	 *
	 * @handles wpmdb_cancellation
	 **/
	public function cancellation() {
		$args = [
			'type'     => 'cancel',
			'location' => 'local',
		];
		$this->logMessage( $args );
	}

	/**
	 * Log cancellation on remote.
	 *
	 * @handles wpmdb_respond_to_push_cancellation
	 **/
	public function remoteCancellation() {
		$args = [
			'type'     => 'cancel',
			'location' => 'remote',
		];
		$this->logMessage( $args );
	}
}