<?php
namespace ToDownload\Licenses;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

use ToDownload\Data\Orders;

final class Licenses {
	public static function register(): void {
		add_action('ToDownload_after_order_complete', [self::class, 'ensure_for_order'], 20, 1);
	}

	public static function ensure_for_order(int $order_id): void {
		$order = Orders::get_order($order_id);
		if (!$order || (string) ($order['status'] ?? '') !== 'complete') {
			return;
		}

		$items = Orders::get_order_items($order_id);
		if (empty($items)) {
			return;
		}

		global $wpdb;
		$table = esc_sql( $wpdb->prefix . 'ToDownload_license_keys' );
		$now = current_time('mysql');
		// phpcs:disable WordPress.DB.PreparedSQL.NotPrepared,WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Internal plugin table.

		$download_ids = [];
		foreach ($items as $it) {
			$download_id = (int) ($it['download_id'] ?? 0);
			if ($download_id) {
				$download_ids[$download_id] = true;
			}
		}

		foreach (array_keys($download_ids) as $download_id) {
			$existing = (string) $wpdb->get_var(
				$wpdb->prepare(
					"SELECT license_key FROM " . $table . " WHERE order_id = %d AND download_id = %d LIMIT 1",
					$order_id,
					$download_id
				)
			);
			if ($existing !== '') {
				continue;
			}

			$key = self::generate_key($order_id, $download_id);
			$wpdb->insert($table, [
				'order_id' => $order_id,
				'download_id' => $download_id,
				'license_key' => $key,
				'created_at' => $now,
			]);
		}
	}

	public static function get_for_order(int $order_id): array {
		global $wpdb;
		$table = esc_sql( $wpdb->prefix . 'ToDownload_license_keys' );
		$rows = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT download_id, license_key FROM " . $table . " WHERE order_id = %d ORDER BY download_id ASC",
				$order_id
			),
			ARRAY_A
		);
		return is_array($rows) ? $rows : [];
	}

	public static function get_for_item(int $order_id, int $download_id): string {
		global $wpdb;
		$table = esc_sql( $wpdb->prefix . 'ToDownload_license_keys' );
		$val = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT license_key FROM " . $table . " WHERE order_id = %d AND download_id = %d LIMIT 1",
				$order_id,
				$download_id
			)
		);
		// phpcs:enable WordPress.DB.PreparedSQL.NotPrepared,WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
		return is_string($val) ? $val : '';
	}

	private static function generate_key(int $order_id, int $download_id): string {
		// Format: XXXX-XXXX-XXXX-XXXX (no PII)
		$bytes = random_bytes(16);
		$hex = strtoupper(bin2hex($bytes));
		$hex = substr($hex, 0, 16) . substr($hex, 16, 16);
		$parts = str_split(substr($hex, 0, 16), 4);
		return implode('-', $parts);
	}
}