<?php
namespace Advently\Stats;

defined( 'ABSPATH' ) || exit;

/**
 * The Results tab: doors opened, coupons handed out and emails collected, per
 * door and in total.
 *
 * summarize() is pure (tested without WordPress); build() runs the queries.
 */
final class Report {

	/**
	 * @param array[] $opens Rows: door, subscriber_id (int|null), coupon_id (int|null).
	 * @param int     $doors Number of doors in the calendar.
	 * @return array{doors: array<int, array>, totals: array}
	 */
	public static function summarize( array $opens, int $doors ): array {
		$perDoor = [];
		for ( $n = 1; $n <= $doors; $n++ ) {
			$perDoor[ $n ] = [
				'door'    => $n,
				'opens'   => 0,
				'coupons' => 0,
			];
		}

		$people = [];
		foreach ( $opens as $row ) {
			$n = (int) $row['door'];
			if ( ! isset( $perDoor[ $n ] ) ) {
				continue;
			}
			++$perDoor[ $n ]['opens'];
			if ( ! empty( $row['coupon_id'] ) ) {
				++$perDoor[ $n ]['coupons'];
			}
			if ( ! empty( $row['subscriber_id'] ) ) {
				$people[ (int) $row['subscriber_id'] ] = true;
			}
		}

		return [
			'doors'  => $perDoor,
			'totals' => [
				'opens'   => array_sum( array_column( $perDoor, 'opens' ) ),
				'people'  => count( $people ),
				'coupons' => array_sum( array_column( $perDoor, 'coupons' ) ),
			],
		];
	}

	/**
	 * The report for a saved calendar, plus subscriber counts.
	 */
	public static function build( array $config ): array {
		global $wpdb;
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- custom table, admin report.
		$opens = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT door, subscriber_id, coupon_id FROM {$wpdb->prefix}advently_opens WHERE calendar_start = %s",
				$config['start']
			),
			ARRAY_A
		);

		$report = self::summarize( is_array( $opens ) ? $opens : [], $config['doors'] );

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- custom table, admin report.
		$report['totals']['subscribers'] = (int) $wpdb->get_var( "SELECT COUNT(*) FROM {$wpdb->prefix}advently_subscribers" );
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- custom table, admin report.
		$report['totals']['optin'] = (int) $wpdb->get_var( "SELECT COUNT(*) FROM {$wpdb->prefix}advently_subscribers WHERE consent_at IS NOT NULL" );
		$report['currency']        = html_entity_decode( get_woocommerce_currency_symbol(), ENT_QUOTES, 'UTF-8' );

		/**
		 * Filters the Results report before the admin app receives it.
		 *
		 * @param array $report Report: doors (per door) and totals.
		 * @param array $config Calendar config.
		 */
		return (array) apply_filters( 'advently_report', $report, $config );
	}
}