<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class ANFOWO_Date_Resolver {

	/**
	 * Resolves a period string (e.g., 'this_month') to a start and end SQL date string.
	 *
	 * @param string|array $period Filter period.
	 * @param string $custom_start Custom start date.
	 * @param string $custom_end Custom end date.
	 *
	 * @return array
	 */
	public static function resolve( $period, $custom_start = '', $custom_end = '' ) {

		if ( is_array( $period ) ) {
			if ( ! empty( $period['start'] ) && ! empty( $period['end'] ) ) {
				return array(
					'start' => $period['start'],
					'end'   => $period['end'],
				);
			}

			$custom_start = $period['start_date'] ?? '';
			$custom_end   = $period['end_date'] ?? '';
			$period       = $period['period'] ?? 'last_30_days';
		}

		if ( function_exists( 'current_datetime' ) ) {
			$now = current_datetime();
		} else {
			$tz  = function_exists( 'wp_timezone' ) ? wp_timezone() : new DateTimeZone( 'UTC' );
			$now = new DateTimeImmutable( 'now', $tz );
		}

		$start_dt = $now->setTime( 0, 0, 0 );
		$end_dt   = $now->setTime( 23, 59, 59 );

		switch ( $period ) {

			case 'today':
				$start_dt = $now->setTime( 0, 0, 0 );
				$end_dt   = $now->setTime( 23, 59, 59 );
				break;

			case 'yesterday':
				$yesterday = $now->modify( '-1 day' );
				$start_dt  = $yesterday->setTime( 0, 0, 0 );
				$end_dt    = $yesterday->setTime( 23, 59, 59 );
				break;

			case 'last_7_days':
				$start_dt = $now->modify( '-7 days' )->setTime( 0, 0, 0 );
				$end_dt   = $now->setTime( 23, 59, 59 );
				break;

			case 'last_30_days':
				$start_dt = $now->modify( '-30 days' )->setTime( 0, 0, 0 );
				$end_dt   = $now->setTime( 23, 59, 59 );
				break;

			case 'this_month':
				$start_dt = $now->modify( 'first day of this month' )->setTime( 0, 0, 0 );
				$end_dt   = $now->setTime( 23, 59, 59 );
				break;

			case 'last_month':
				$last_month = $now->modify( 'first day of last month' );
				$start_dt   = $last_month->setTime( 0, 0, 0 );
				$end_dt     = $now->modify( 'last day of last month' )->setTime( 23, 59, 59 );
				break;

			case 'this_year':
				$start_dt = $now->setDate( (int) $now->format( 'Y' ), 1, 1 )->setTime( 0, 0, 0 );
				$end_dt   = $now->setTime( 23, 59, 59 );
				break;

			case 'last_year':
				$last_year_num = (int) $now->format( 'Y' ) - 1;
				$start_dt      = $now->setDate( $last_year_num, 1, 1 )->setTime( 0, 0, 0 );
				$end_dt        = $now->setDate( $last_year_num, 12, 31 )->setTime( 23, 59, 59 );
				break;

			case 'last_12_months':
				$start_dt = $now->modify( '-12 months' )->setTime( 0, 0, 0 );
				$end_dt   = $now->setTime( 23, 59, 59 );
				break;

			case 'all_time':
				return array(
					'start' => '1970-01-01 00:00:00',
					'end'   => $end_dt->format( 'Y-m-d H:i:s' ),
				);

			case 'custom':
				$start_str = ! empty( $custom_start ) ? gmdate( 'Y-m-d 00:00:00', strtotime( $custom_start ) ) : '1970-01-01 00:00:00';
				$end_str   = ! empty( $custom_end ) ? gmdate( 'Y-m-d 23:59:59', strtotime( $custom_end ) ) : $end_dt->format( 'Y-m-d H:i:s' );
				return array(
					'start' => $start_str,
					'end'   => $end_str,
				);

			default:
				$start_dt = $now->modify( '-30 days' )->setTime( 0, 0, 0 );
				$end_dt   = $now->setTime( 23, 59, 59 );
				break;
		}

		return array(
			'start' => $start_dt->format( 'Y-m-d H:i:s' ),
			'end'   => $end_dt->format( 'Y-m-d H:i:s' ),
		);
	}
}