<?php
/**
 * Test data: coupons.
 *
 * @package AdminPowerups
 */

namespace SmartWP\AdminPowerups\Modules\TestData\Make;

use SmartWP\AdminPowerups\Modules\TestData\Data\Random;
use SmartWP\AdminPowerups\Modules\TestData\Marker;

defined( 'ABSPATH' ) || exit;

/**
 * Coupons `TEST-{10 characters}`, the characters derived from the batch with the site's secret
 * salt (the same on a resumed step, never workable out from the shop). Each coupon:
 *
 * - is restricted to the email domain used for test data;
 * - applies only to test products (the run's, or the ones its orders use); with none, to nothing
 *   (restricted to its own ID, which is never a product);
 * - is "individual use", and a percent or fixed product discount (never fixed cart, which would
 *   discount a real product in the same cart).
 *
 * @since 1.0.0
 */
final class Coupons {

	/**
	 * Characters of a code (no look-alikes).
	 */
	const ALPHABET = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789';

	/**
	 * Make coupon number $index.
	 *
	 * @since 1.0.0
	 * @param int     $index Index.
	 * @param Context $ctx   Context.
	 * @return int Coupon ID, 0 when skipped.
	 * @throws \Throwable What a save threw (after signing a half-made object).
	 */
	public static function make( int $index, Context $ctx ): int {
		$random = Random::for( $ctx->batch, 'coupons', $index );
		$type   = (string) $random->pick( array( 'percent', 'fixed_product' ) );
		$plan   = array(
			'code'        => self::code( $ctx->batch, $index ),
			'type'        => $type,
			'amount'      => 'percent' === $type ? $random->int( 5, 30 ) : $random->int( 2, 20 ),
			'usage_limit' => $random->chance( 30 ) ? $random->int( 10, 100 ) : 0,
			'expires'     => $random->chance( 30 ) ? $ctx->to + DAY_IN_SECONDS * $random->int( 30, 365 ) : 0,
		);

		/** This filter is documented in src/Modules/TestData/Make/Products.php */
		$plan = (array) apply_filters( 'apwc_test_data_item', $plan, 'coupon', $index, $ctx->batch );
		$code = wc_format_coupon_code( (string) ( $plan['code'] ?? '' ) );
		if ( '' === $code ) {
			$code = wc_format_coupon_code( self::code( $ctx->batch, $index ) );
		}

		$existing = (int) wc_get_coupon_id_by_code( $code );
		if ( $existing ) {
			// A resumed step made it already; a real coupon with this code is never touched.
			if ( (string) get_post_meta( $existing, Marker::META, true ) !== $ctx->batch ) {
				return 0;
			}
			if ( ! Marker::verified( 'post', $existing, $ctx->batch ) ) {
				Marker::sign( 'post', $existing, $ctx->batch );
			}
			return $existing;
		}

		$coupon = new \WC_Coupon();
		$coupon->update_meta_data( Marker::META, $ctx->batch );
		$coupon->set_code( $code );
		$coupon->set_description( __( 'Test coupon made by Admin Powerups test data.', 'admin-powerups-for-woocommerce' ) );
		// Whatever a filter did: never a whole-cart discount.
		$coupon->set_discount_type( 'fixed_product' === ( $plan['type'] ?? '' ) ? 'fixed_product' : 'percent' );
		$coupon->set_amount( max( 0, min( 'percent' === $coupon->get_discount_type() ? 100 : 1000000, (float) ( $plan['amount'] ?? 10 ) ) ) );
		$coupon->set_email_restrictions( array( '*@' . $ctx->domain ) );
		$coupon->set_individual_use( true );
		$products = $ctx->pool( 'products' );
		if ( $products ) {
			$coupon->set_product_ids( $products );
		}
		if ( (int) ( $plan['usage_limit'] ?? 0 ) > 0 ) {
			$coupon->set_usage_limit( (int) $plan['usage_limit'] );
		}
		if ( (int) ( $plan['expires'] ?? 0 ) > 0 ) {
			$coupon->set_date_expires( (int) $plan['expires'] );
		}
		try {
			$id = (int) $coupon->save();
			if ( $id && ! $products ) {
				// No test products: a restriction nothing matches (a coupon ID is never a product).
				$coupon->set_product_ids( array( $id ) );
				$coupon->save();
			}
		} catch ( \Throwable $e ) {
			// Inserted before the error: sign it, so Clean up can remove it.
			Products::half_made( (int) $coupon->get_id(), $ctx->batch );
			throw $e;
		}
		if ( $id ) {
			Marker::sign( 'post', $id, $ctx->batch );
			$ctx->created( 'coupon', $id );
		}
		return $id;
	}

	/**
	 * The code of coupon number $index: secret (the site's salt), the same on every call.
	 *
	 * @since 1.0.0
	 * @param string $batch Batch ID.
	 * @param int    $index Index.
	 * @return string
	 */
	public static function code( string $batch, int $index ): string {
		$hash = Marker::hmac( 'coupon|' . $batch . '|' . $index );
		$code = 'TEST-';
		for ( $i = 0; $i < 10; $i++ ) {
			$code .= self::ALPHABET[ hexdec( substr( $hash, $i * 2, 2 ) ) % strlen( self::ALPHABET ) ];
		}
		return $code;
	}
}