<?php
namespace Syntopia_Pay;

defined( 'ABSPATH' ) || exit;

class Request_Builder {
	private const PAGES = [ 'credit_paydirect', 'paylogin' ];

	public static function amount( \WC_Order $order ): string {
		return number_format( (float) $order->get_total( 'edit' ), 2, '.', '' );
	}

	/**
	 * @return array{text: string, ts: int}
	 */
	public static function expiry( int $now, int $hours ): array {
		$ts = intdiv( $now + $hours * 3600, 60 ) * 60;
		return [
			'text' => ( new \DateTimeImmutable( '@' . $ts ) )->setTimezone( new \DateTimeZone( 'Europe/Sofia' ) )->format( 'd.m.Y H:i' ),
			'ts'   => $ts,
		];
	}

	public static function description( \WC_Order $order ): string {
		$name = html_entity_decode( get_bloginfo( 'name' ), ENT_QUOTES, 'UTF-8' );
		$text = 'Order ' . $order->get_order_number() . ' ' . $name;
		$text = (string) preg_replace( '/[\x00-\x1F\x7F]/', '', $text );
		return mb_substr( $text, 0, 100, 'UTF-8' );
	}

	public static function lang(): string {
		return str_starts_with( get_locale(), 'bg' ) ? 'bg' : 'en';
	}

	/**
	 * @return array{amount: string, currency: string, expires: int, created: int, encoded: string, checksum: string}
	 */
	public static function attempt_entry( \WC_Order $order, string $invoice, int $hours, int $now ): array {
		$settings = Settings::get();
		$amount   = self::amount( $order );
		$expiry   = self::expiry( $now, $hours );
		$encoded  = Codec::encode(
			[
				'MIN'      => $settings['min'],
				'INVOICE'  => $invoice,
				'AMOUNT'   => $amount,
				'CURRENCY' => 'EUR',
				'EXP_TIME' => $expiry['text'],
				'DESCR'    => self::description( $order ),
				'ENCODING' => 'utf-8',
			]
		);
		return [
			'amount'   => $amount,
			'currency' => 'EUR',
			'expires'  => $expiry['ts'],
			'created'  => $now,
			'encoded'  => $encoded,
			'checksum' => Codec::checksum( $encoded, $settings['secret'] ),
		];
	}

	public static function ok_url( \WC_Order $order ): string {
		return $order->get_checkout_order_received_url();
	}

	public static function cancel_url( \WC_Order $order ): string {
		return add_query_arg( 'syntopia_pay_cancelled', '1', $order->get_checkout_payment_url() );
	}

	/**
	 * @param array<string,mixed> $entry
	 * @return array<string,string>
	 */
	public static function form_fields( string $page, \WC_Order $order, array $entry ): array {
		if ( ! in_array( $page, self::PAGES, true ) ) {
			throw new \InvalidArgumentException( 'Unknown ePay page.' );
		}
		return [
			'PAGE'       => $page,
			'ENCODED'    => (string) $entry['encoded'],
			'CHECKSUM'   => (string) $entry['checksum'],
			'LANG'       => self::lang(),
			'URL_OK'     => self::ok_url( $order ),
			'URL_CANCEL' => self::cancel_url( $order ),
		];
	}

	/**
	 * @param array<string,mixed> $entry
	 */
	public static function easypay_url( array $entry ): string {
		return Settings::host() . '/ezp/reg_bill.cgi?ENCODED=' . rawurlencode( (string) $entry['encoded'] ) . '&CHECKSUM=' . rawurlencode( (string) $entry['checksum'] );
	}
}