<?php
/**
 * Hourly order totals for the cloud report.
 *
 * @package Keepwatch
 */

namespace Keepwatch\WooCommerce;

defined( 'ABSPATH' ) || exit;

/**
 * Counts orders per hour for the last 7 days: placed orders (processing, completed, on-hold) and failed payments.
 * Only totals leave the site (CLAUDE.md rule 9): no order ids, amounts, customer names, e-mails or addresses.
 * The WPXLab cloud compares them with the store's usual rhythm to spot "orders stopped" and "failed payments
 * spiking" (paid cloud feature; runs only in the hourly WP-Cron report, never during a page load).
 * Hours without any order are omitted; the from/to range tells the cloud which hours are covered.
 */
final class OrderStats {

	public const HOURS = 168;

	public const PLACED = array( 'wc-processing', 'wc-completed', 'wc-on-hold' );

	public const FAILED = 'wc-failed';

	private const ORDER_UTIL = 'Automattic\\WooCommerce\\Utilities\\OrderUtil';

	/**
	 * Totals for the report, or null when WooCommerce is not active.
	 *
	 * @param int $now Current Unix time.
	 * @return array{from: int, to: int, hours: list<array{0: int, 1: int, 2: int}>}|null
	 */
	public static function collect( int $now = 0 ): ?array {
		if ( ! Module::active() ) {
			return null;
		}

		$now  = $now > 0 ? $now : time();
		$to   = intdiv( $now, HOUR_IN_SECONDS ) * HOUR_IN_SECONDS;
		$from = $to - self::HOURS * HOUR_IN_SECONDS;
		$rows = self::query( $from, $to );

		return null === $rows ? null : self::shape( $from, $to, $rows );
	}

	/**
	 * Pure shaping: rows of (hour "Y-m-d H" in UTC, status, count) → compact hourly list.
	 *
	 * @param int                                                                $from First covered hour (inclusive, Unix).
	 * @param int                                                                $to   End of the range (exclusive, Unix).
	 * @param array<int, array{hour: string, status: string, total: int|string}> $rows Query rows.
	 * @return array{from: int, to: int, hours: list<array{0: int, 1: int, 2: int}>}
	 */
	public static function shape( int $from, int $to, array $rows ): array {
		$hours = array();
		foreach ( $rows as $row ) {
			$time = strtotime( $row['hour'] . ':00:00 UTC' );
			if ( false === $time || $time < $from || $time >= $to ) {
				continue;
			}
			if ( ! isset( $hours[ $time ] ) ) {
				$hours[ $time ] = array( $time, 0, 0 );
			}
			$count = max( 0, (int) $row['total'] );
			if ( self::FAILED === $row['status'] ) {
				$hours[ $time ][2] += $count;
			} elseif ( in_array( $row['status'], self::PLACED, true ) ) {
				$hours[ $time ][1] += $count;
			}
		}
		ksort( $hours );

		return array(
			'from'  => $from,
			'to'    => $to,
			'hours' => array_values(
				array_filter(
					$hours,
					static function ( array $hour ): bool {
						return $hour[1] > 0 || $hour[2] > 0;
					}
				)
			),
		);
	}

	/**
	 * One grouped COUNT over the order table (HPOS or posts). Read-only.
	 *
	 * @param int $from Range start (Unix).
	 * @param int $to   Range end (Unix).
	 * @return array<int, array{hour: string, status: string, total: int|string}>|null
	 */
	private static function query( int $from, int $to ): ?array {
		global $wpdb;

		$hpos = is_callable( array( self::ORDER_UTIL, 'custom_orders_table_usage_is_enabled' ) )
			&& (bool) call_user_func( array( self::ORDER_UTIL, 'custom_orders_table_usage_is_enabled' ) );

		$start = gmdate( 'Y-m-d H:i:s', $from );
		$end   = gmdate( 'Y-m-d H:i:s', $to );

		if ( $hpos ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- single read-only aggregate in the hourly cron report.
			$rows = $wpdb->get_results(
				$wpdb->prepare(
					'SELECT DATE_FORMAT(date_created_gmt, %s) AS hour, status, COUNT(*) AS total FROM %i
					WHERE type = %s AND date_created_gmt >= %s AND date_created_gmt < %s AND status IN (%s, %s, %s, %s)
					GROUP BY hour, status',
					'%Y-%m-%d %H',
					$wpdb->prefix . 'wc_orders',
					'shop_order',
					$start,
					$end,
					self::PLACED[0],
					self::PLACED[1],
					self::PLACED[2],
					self::FAILED
				),
				ARRAY_A
			);
		} else {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- see above.
			$rows = $wpdb->get_results(
				$wpdb->prepare(
					'SELECT DATE_FORMAT(post_date_gmt, %s) AS hour, post_status AS status, COUNT(*) AS total FROM %i
					WHERE post_type = %s AND post_date_gmt >= %s AND post_date_gmt < %s AND post_status IN (%s, %s, %s, %s)
					GROUP BY hour, post_status',
					'%Y-%m-%d %H',
					$wpdb->posts,
					'shop_order',
					$start,
					$end,
					self::PLACED[0],
					self::PLACED[1],
					self::PLACED[2],
					self::FAILED
				),
				ARRAY_A
			);
		}

		return is_array( $rows ) ? $rows : null;
	}
}