<?php
/**
 * @package AKSRT
 */

namespace AKSRT\Sms;

defined('ABSPATH') || exit;

/**
 * ZibLL-style SMS dispatcher and send-rate limiting.
 */
class SMS {

	private static $instance = null;

	public static function get_instance(): self {
		if (null === self::$instance) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	public function get_provider_config(): array {
		if (class_exists('\\AKSRT\\Settings\\Settings')) {
			return \AKSRT\Settings\Settings::get_sms_settings();
		}
		return ['sms_sdk' => 'null', 'sms_number_limit_ch' => true];
	}

	/**
	 * Phone-number validation follows the selected domestic/international mode.
	 */
	public static function is_phonenumber(string $phone, ?bool $domestic_only = null): bool {
		if ($domestic_only === null) {
			$config = self::get_instance()->get_provider_config();
			$domestic_only = !empty($config['sms_number_limit_ch']);
		}

		if ($domestic_only) {
			return (bool) preg_match('/^1[3-9]\d{9}$/', $phone);
		}

		return (bool) preg_match('/^(?:\d{5,}|\+\d{6,}|\+?\d{2,}[-\s]\d{2,}[0-9\-\s]{0,15})$/', $phone);
	}

	/**
	 * Send a six-digit verification code. The caller stores it after success.
	 *
	 * @return array{success: bool, message: string, remaining_time?: int}
	 */
	public function send_code(string $phone, string $code): array {
		$config = $this->get_provider_config();
		$sdk = sanitize_key((string) ($config['sms_sdk'] ?? 'null'));
		if ($sdk === '' || $sdk === 'null') {
			return ['success' => false, 'message' => __('短信接口未启用', 'aksrt')];
		}
		if (!self::is_phonenumber($phone, !empty($config['sms_number_limit_ch']))) {
			return ['success' => false, 'message' => __('手机号码格式有误', 'aksrt')];
		}

		$provider = SMSProviderFactory::get($sdk);
		if ($provider === null) {
			return ['success' => false, 'message' => __('暂无短信接口，请检查短信服务商设置', 'aksrt')];
		}

		$missing = $provider->validate_config($config);
		if ($missing) {
			return ['success' => false, 'message' => sprintf(__('短信接口缺少配置：%s', 'aksrt'), implode(', ', $missing))];
		}

		// [防刷机制]验证码发送限制（后台「扩展&增强 → 网站安全」）。
		$limit = \AKSRT\Extensions\SendLimit::check($phone);
		if (empty($limit['ok'])) {
			return [
				'success' => false,
				'message' => (string) $limit['message'],
				'remaining_time' => (int) $limit['remaining'],
			];
		}

		$result = $provider->send_code($phone, $code, $config);
		if (empty($result['success'])) {
			return ['success' => false, 'message' => (string) ($result['message'] ?? __('验证码发送失败，请稍后重试', 'aksrt'))];
		}

		$cooldown = \AKSRT\Extensions\SendLimit::record($phone);

		return [
			'success' => true,
			'message' => __('验证码短信已发送', 'aksrt'),
			'remaining_time' => $cooldown > 0 ? $cooldown : 60,
		];
	}
	public function get_provider_status(): array {
		$config = $this->get_provider_config();
		$key = sanitize_key((string) ($config['sms_sdk'] ?? 'null'));
		$enabled = $key !== '' && $key !== 'null';
		$provider = SMSProviderFactory::get($key);
		$status = [
			'enabled' => $enabled,
			'provider' => $enabled ? $key : 'none',
			'configured' => false,
			'available' => false,
			'verified' => false,
			'transport' => '',
			'missing_fields' => [],
		];
		if ($provider !== null) {
			$status = array_merge($status, $provider->get_status($config));
		}
		return $status;
	}

	/** Send the reference theme's fixed 888888 test message without storing a code. */
	public function test_send(string $phone): array {
		$config = $this->get_provider_config();
		$sdk = sanitize_key((string) ($config['sms_sdk'] ?? 'null'));
		if ($sdk === '' || $sdk === 'null') {
			return ['success' => false, 'message' => __('短信接口未启用', 'aksrt')];
		}
		if (!self::is_phonenumber($phone, !empty($config['sms_number_limit_ch']))) {
			return ['success' => false, 'message' => __('手机号码格式有误', 'aksrt')];
		}
		$provider = SMSProviderFactory::get($sdk);
		if ($provider === null) {
			return ['success' => false, 'message' => __('暂无短信接口，请检查短信服务商设置', 'aksrt')];
		}
		$missing = $provider->validate_config($config);
		if ($missing) {
			return ['success' => false, 'message' => sprintf(__('短信接口缺少配置：%s', 'aksrt'), implode(', ', $missing))];
		}
		return $provider->send_code($phone, '888888', $config);
	}

}