<?php

namespace RoosterLMS\Events;

use RoosterLMS\Blocks\Request;
use RoosterLMS\Content\Delivery;

defined( 'ABSPATH' ) || exit;

final class EventQuery {

	public const ARG_CATEGORY = 'rl_ev_cat';

	public const ARG_DELIVERY = 'rl_ev_delivery';

	public const ARG_CITY = 'rl_ev_city';

	public const ARG_MONTH = 'rl_ev_month';

	public const ARG_TRAINER = 'rl_ev_trainer';

	public const ARG_PAGE = 'rl_ev_page';

	public const DELIVERIES = array( 'online', 'in_person', 'hybrid' );

	public const MAX_PER_PAGE = 48;

	public const MAX_MONTHS = 24;

	public const MONTH_LIMIT = 300;

	public function __construct(
		public readonly array $term_ids = array(),
		public readonly array $course_posts = array(),
		public readonly string $delivery = '',
		public readonly string $city = '',
		public readonly int $trainer = 0,
		public readonly string $month = '',
		public readonly int $months = 3,
		public readonly int $per_page = 9,
		public readonly int $page = 1,
		public readonly bool $series = false,
		public readonly int $course_id = 0,
		public readonly int $unit_id = 0,
		public readonly int $occurrence = 0,
		public readonly int $filter_term = 0
	) {}

	public function with( array $fields ): self {
		$v = get_object_vars( $this );
		foreach ( $fields as $key => $value ) {
			if ( array_key_exists( $key, $v ) ) {
				$v[ $key ] = $value;
			}
		}
		return new self( ...array_values( $v ) );
	}

	public static function from_block( array $a, bool $request = true ): self {
		$q = new self(
			self::ids( $a['categories'] ?? '' ),
			self::ids( $a['courses'] ?? '' ),
			self::delivery( (string) ( $a['delivery'] ?? '' ) ),
			self::city( (string) ( $a['city'] ?? '' ) ),
			max( 0, (int) ( $a['trainer'] ?? 0 ) ),
			'',
			max( 1, min( self::MAX_MONTHS, (int) ( $a['months'] ?? 3 ) ) ),
			max( 1, min( self::MAX_PER_PAGE, (int) ( $a['count'] ?? 9 ) ) ),
			1,
			'series' === ( $a['group'] ?? '' )
		);
		if ( ! $request ) {
			return $q;
		}
		$fields = array(
			'page'  => max( 1, min( 1000, Request::int( self::ARG_PAGE ) ) ),
			'month' => self::month( self::text( self::ARG_MONTH ) ),
		);
		if ( ! empty( $a['showFilters'] ) ) {
			$fields['filter_term'] = Request::int( self::ARG_CATEGORY );
			$delivery              = self::delivery( Request::key( self::ARG_DELIVERY ) );
			if ( '' !== $delivery && '' === $q->delivery ) {
				$fields['delivery'] = $delivery;
			}
			$city = self::city( self::text( self::ARG_CITY ) );
			if ( '' !== $city && '' === $q->city ) {
				$fields['city'] = $city;
			}
			$trainer = Request::int( self::ARG_TRAINER );
			if ( $trainer > 0 && 0 === $q->trainer ) {
				$fields['trainer'] = $trainer;
			}
		}
		return $q->with( $fields );
	}

	public function window( \DateTimeImmutable $now ): array {
		$from = '';
		$to   = $now->setTimezone( wp_timezone() )->modify( '+' . $this->months . ' months' )->getTimestamp();
		$span = self::month_range( $this->month );
		if ( null !== $span ) {
			$from = gmdate( 'Y-m-d H:i:s', $span[0] );
			$to   = $span[1];
		}
		return array( $from, gmdate( 'Y-m-d H:i:s', max( $now->getTimestamp(), $to ) ), gmdate( 'Y-m-d H:i:s', $now->getTimestamp() ) );
	}

	public static function month_range( string $month ): ?array {
		if ( '' === self::month( $month ) ) {
			return null;
		}
		$start = \DateTimeImmutable::createFromFormat( '!Y-m-d', $month . '-01', wp_timezone() );
		if ( false === $start ) {
			return null;
		}
		return array( $start->getTimestamp(), $start->modify( '+1 month' )->getTimestamp() );
	}

	public static function month( string $month ): string {
		return 1 === preg_match( '/^\d{4}-(0[1-9]|1[0-2])$/', $month ) ? $month : '';
	}

	public static function delivery( string $slug ): string {
		return in_array( $slug, self::DELIVERIES, true ) && null !== Delivery::from_slug( $slug ) ? $slug : '';
	}

	public static function city( string $city ): string {
		return mb_substr( trim( sanitize_text_field( $city ) ), 0, 100 );
	}

	public static function ids( $raw ): array {
		$parts = is_array( $raw ) ? $raw : preg_split( '/[\s,]+/', (string) $raw );
		$out   = array();
		foreach ( is_array( $parts ) ? $parts : array() as $part ) {
			$id = absint( $part );
			if ( $id > 0 && ! in_array( $id, $out, true ) && count( $out ) < 50 ) {
				$out[] = $id;
			}
		}
		return $out;
	}

	private static function text( string $key ): string {
		$raw = \RoosterLMS\UI\TableRequest::get( $key );
		return is_scalar( $raw ) ? sanitize_text_field( (string) $raw ) : '';
	}
}