<?php
/**
 * GA4 traffic report.
 *
 * @package TurtleReport
 */

namespace TurtleReport\Reports;

use TurtleReport\Policy\Segments;
use TurtleReport\Profiles\Profile;

defined( 'ABSPATH' ) || exit;

/**
 * Totals for the GA4 metrics an admin chose for this site, this period and last.
 *
 * Only the chosen metrics are requested from Google.
 */
final class TrafficReport extends Report {

	/**
	 * {@inheritDoc}
	 *
	 * @return string
	 */
	public function id() {
		return 'traffic';
	}

	/**
	 * {@inheritDoc}
	 *
	 * @return string
	 */
	public function section() {
		return Profile::SECTION_TRAFFIC;
	}

	/**
	 * {@inheritDoc}
	 *
	 * @return string[]
	 */
	public function segment_types() {
		return array( Segments::TYPE_PAGE );
	}

	/**
	 * {@inheritDoc}
	 *
	 * @return array
	 */
	public function args() {
		$date = array(
			'type'     => 'string',
			'pattern'  => '^\d{4}-\d{2}-\d{2}$',
			'required' => true,
		);
		return array(
			'prev_start' => $date,
			'prev_end'   => $date,
		);
	}

	/**
	 * {@inheritDoc}
	 *
	 * @param Profile $site   Site.
	 * @param array   $params Parameters.
	 * @return array
	 */
	public function run( Profile $site, array $params ) {
		$metrics = array_slice( $site->traffic_metrics, 0, Profile::MAX_TRAFFIC_METRICS );
		if ( ! $metrics ) {
			return array(
				'cur'  => new \stdClass(),
				'prev' => new \stdClass(),
			);
		}
		$ga      = $this->google->for_site( $site, Profile::SOURCE_ANALYTICS )->analytics();
		$ttl     = $this->ttl( $params['end'] );
		$segment = $this->segment( $site, $params );
		$seg     = $segment ? SegmentFilter::ga( $segment ) : null;

		$totals = function ( $start, $end ) use ( $ga, $site, $metrics, $ttl, $seg ) {
			$body   = array(
				'dateRanges' => array(
					array(
						'startDate' => $start,
						'endDate'   => $end,
					),
				),
				'metrics'    => array_map(
					static function ( $m ) {
						return array( 'name' => $m );
					},
					$metrics
				),
			);
			$filter = Filters::all( Profile::SCOPE_ORGANIC === $site->traffic_scope ? Filters::exact( 'sessionDefaultChannelGroup', 'Organic Search' ) : null, $seg );
			if ( $filter ) {
				$body['dimensionFilter'] = $filter;
			}
			$rows = $ga->run_report( $site->ga_property, $body, $ttl );
			$out  = array();
			foreach ( $metrics as $i => $metric ) {
				$out[ $metric ] = isset( $rows[0]['m'][ $i ] ) ? (float) $rows[0]['m'][ $i ] : 0.0;
			}
			return $out;
		};

		return array(
			'cur'  => self::map( $totals( $params['start'], $params['end'] ) ),
			'prev' => self::map( $totals( $params['prev_start'], $params['prev_end'] ) ),
		);
	}
}