<?php
/**
 * Resolves report range arguments into UTC datetime bounds.
 *
 * @package ProfitEngine
 */

declare( strict_types=1 );

namespace ProfitEngine\Support;

defined( 'ABSPATH' ) || exit;

/**
 * Shared range resolution used by profit, dashboard and reports.
 *
 * Explicit from/to (Y-m-d) win; otherwise a named preset. Bounds are UTC to
 * match the stored order_date / cost-record columns.
 */
class DateRange {

	/**
	 * Resolve range args to [from, to] UTC datetime strings.
	 *
	 * @param array<string,mixed> $args Args (range|from|to).
	 * @return array{0:string,1:string}
	 */
	public static function resolve( array $args ): array {
		$now = time();
		$to  = gmdate( 'Y-m-d H:i:s', $now );

		if ( ! empty( $args['from'] ) ) {
			$from = gmdate( 'Y-m-d 00:00:00', (int) strtotime( (string) $args['from'] ) );
			if ( ! empty( $args['to'] ) ) {
				$to = gmdate( 'Y-m-d 23:59:59', (int) strtotime( (string) $args['to'] ) );
			}
			return array( $from, $to );
		}

		switch ( (string) ( $args['range'] ?? '30d' ) ) {
			case 'today':
				// Midnight in the store's timezone, expressed in UTC like all
				// stored order dates.
				$from = get_gmt_from_date( current_time( 'Y-m-d' ) . ' 00:00:00' );
				break;
			case '7d':
				$from = gmdate( 'Y-m-d H:i:s', strtotime( '-7 days', $now ) );
				break;
			case '90d':
				$from = gmdate( 'Y-m-d H:i:s', strtotime( '-90 days', $now ) );
				break;
			case '365d':
				$from = gmdate( 'Y-m-d H:i:s', strtotime( '-365 days', $now ) );
				break;
			case 'ytd':
				$from = gmdate( 'Y-01-01 00:00:00', $now );
				break;
			case 'all':
				$from = '1970-01-01 00:00:00';
				break;
			case '30d':
			default:
				$from = gmdate( 'Y-m-d H:i:s', strtotime( '-30 days', $now ) );
				break;
		}

		return array( $from, $to );
	}

	/**
	 * Choose a sensible time-series bucket (day/week/month) for a span.
	 *
	 * @param string $from UTC lower bound.
	 * @param string $to   UTC upper bound.
	 * @return string 'day' | 'week' | 'month'
	 */
	public static function bucket_for( string $from, string $to ): string {
		$days = ( strtotime( $to ) - strtotime( $from ) ) / DAY_IN_SECONDS;
		if ( $days <= 45 ) {
			return 'day';
		}
		if ( $days <= 400 ) {
			return 'week';
		}
		return 'month';
	}
}