<?php
/**
 * WeChat Pay gateway via yansongda/pay (API v3).
 *
 * @package AKSRT
 */

namespace AKSRT\Payment\Gateways;

defined('ABSPATH') || exit;

use Yansongda\Pay\Pay;

class WechatPayGateway implements \AKSRT\Payment\GatewayInterface {

	public function get_id(): string {
		return 'wechatpay';
	}

	public function get_name(): string {
		return __('微信支付', 'aksrt');
	}

	public function is_configured(): bool {
		if (class_exists('\AKSRT\Settings\PaymentRuntime')
			&& !\AKSRT\Settings\PaymentRuntime::is_gateway_enabled('wechatpay')) {
			return false;
		}
		$c = $this->get_config();
		return $c['mch_id'] !== ''
			&& $c['appid'] !== ''
			&& $c['api_v3_key'] !== ''
			&& $c['private_key'] !== ''
			&& $c['cert_path'] !== '';
	}

	public function create_payment(array $order): array {
		if (!$this->is_configured()) {
			return ['success' => false, 'message' => __('微信支付未配置', 'aksrt')];
		}

		$order_number  = (string) ($order['order_number'] ?? '');
		// Prefer attempt-specific out_trade_no so re-pay does not reuse a frozen provider order.
		$out_trade_no  = (string) ($order['out_trade_no'] ?? '');
		if ($out_trade_no === '') {
			$out_trade_no = class_exists('\AKSRT\Payment\OrderRepository')
				? \AKSRT\Payment\OrderRepository::provider_out_trade_no($order)
				: $order_number;
		}
		$subject       = (string) ($order['subject'] ?? __('订单支付', 'aksrt'));
		$payment_type  = $this->get_config()['payment_type'];
		try {
			$total_fen = \AKSRT\Ledger\AssetAmount::balance(is_string($order['amount'] ?? null) ? trim($order['amount']) : '')->minor();
		} catch (\InvalidArgumentException $e) {
			$total_fen = 0;
		}

		if ($order_number === '' || $out_trade_no === '' || $total_fen <= 0) {
			return ['success' => false, 'message' => __('订单参数无效', 'aksrt')];
		}

		try {
			YansongdaPayFactory::boot_wechat();

			$payload = [
				'out_trade_no' => $out_trade_no,
				'description'  => mb_substr($subject, 0, 127),
				'amount'       => [
					'total'    => $total_fen,
					'currency' => 'CNY',
				],
			];

			switch ($payment_type) {
				case 'h5':
					$payload['scene_info'] = [
						'payer_client_ip' => (string) ($_SERVER['REMOTE_ADDR'] ?? '127.0.0.1'),
						'h5_info'         => ['type' => 'Wap'],
					];
					$result = Pay::wechat()->h5($payload);
					break;
				case 'native':
				default:
					$result = Pay::wechat()->scan($payload);
					break;
			}

			$data = YansongdaPayFactory::to_array($result);
			$payment_data = array_merge($data, [
				'order_number' => $order_number,
				'out_trade_no' => $out_trade_no,
			]);

			$result_data = [
				'success'      => true,
				'payment_data' => $payment_data,
				'message'      => __('微信支付订单已创建', 'aksrt'),
			];

			if ($payment_type === 'native' && !empty($data['code_url'])) {
				$result_data['payment_url'] = (string) $data['code_url'];
			} elseif ($payment_type === 'h5' && !empty($data['h5_url'])) {
				$result_data['payment_url'] = (string) $data['h5_url'];
			}

			return $result_data;
		} catch (\Throwable $e) {
			return ['success' => false, 'message' => $e->getMessage()];
		}
	}

	public function verify_callback(\WP_REST_Request $request): array {
		try {
			YansongdaPayFactory::boot_wechat();

			// Pass raw body + headers so callback works under WP REST (php://input may be drained).
			$raw = $request->get_body();
			$headers = [
				'Content-Type'          => (string) ($request->get_header('content-type') ?: 'application/json'),
				'Wechatpay-Serial'      => (string) $request->get_header('wechatpay-serial'),
				'Wechatpay-Timestamp'   => (string) $request->get_header('wechatpay-timestamp'),
				'Wechatpay-Nonce'       => (string) $request->get_header('wechatpay-nonce'),
				'Wechatpay-Signature'   => (string) $request->get_header('wechatpay-signature'),
			];
			$callback = Pay::wechat()->callback([
				'body'    => $raw !== '' ? $raw : file_get_contents('php://input'),
				'headers' => $headers,
			]);

			$data = YansongdaPayFactory::to_array($callback);
			// Decrypted resource is nested under resource (array) after CallbackPlugin.
			$resource = [];
			if (isset($data['resource']) && is_array($data['resource'])) {
				$resource = $data['resource'];
				// ciphertext decrypt may leave plaintext fields at resource root or under ciphertext key.
				if (isset($resource['ciphertext']) && is_array($resource['ciphertext'])) {
					$resource = $resource['ciphertext'];
				}
			}

			$order_number   = (string) ($resource['out_trade_no'] ?? $data['out_trade_no'] ?? '');
			$transaction_id = (string) ($resource['transaction_id'] ?? $data['transaction_id'] ?? '');
			$trade_state    = (string) ($resource['trade_state'] ?? $data['trade_state'] ?? '');
			$event_type     = (string) ($data['event_type'] ?? '');

			$total_fen = (int) YansongdaPayFactory::dig($resource, 'amount.total', 0);
			if ($total_fen <= 0) {
				$total_fen = (int) YansongdaPayFactory::dig($data, 'amount.total', 0);
			}

			$paid = ($trade_state === 'SUCCESS') || ($event_type === 'TRANSACTION.SUCCESS');

			// When event is pay success, resource has trade_state SUCCESS.
			if ($event_type !== '' && $event_type !== 'TRANSACTION.SUCCESS' && $trade_state !== 'SUCCESS') {
				$paid = false;
			}

			$config   = $this->get_config();
			$mch_id   = (string) ($resource['mchid'] ?? $data['mchid'] ?? '');
			$app_id   = (string) ($resource['appid'] ?? $data['appid'] ?? '');
			$currency = (string) YansongdaPayFactory::dig($resource, 'amount.currency', '');
			if ($order_number === ''
				|| ($paid && (
					$mch_id === ''
					|| $app_id === ''
					|| $currency === ''
					|| !hash_equals($config['mch_id'], $mch_id)
					|| !hash_equals($config['appid'], $app_id)
					|| $currency !== 'CNY'
					|| $transaction_id === ''
					|| $total_fen <= 0
				))
				|| (!$paid && (
					($mch_id !== '' && !hash_equals($config['mch_id'], $mch_id))
					|| ($app_id !== '' && !hash_equals($config['appid'], $app_id))
					|| ($currency !== '' && $currency !== 'CNY')
				))) {
				return ['success' => false, 'message' => __('微信支付回调身份或订单数据无效', 'aksrt')];
			}

			return [
				'success'        => true,
				'order_number'   => $order_number,
				'amount'         => $this->fen_decimal($total_fen),
				'currency'       => strtoupper((string) YansongdaPayFactory::dig($data, 'amount.currency', 'CNY')),
				'transaction_id' => $transaction_id,
				'status'         => $paid ? 'paid' : 'pending',
			];
		} catch (\Throwable $e) {
			return ['success' => false, 'message' => $e->getMessage()];
		}
	}

	/**
	 * Output WeChat v3 notify ACK (JSON).
	 */
	public function output_callback_response(array $result): void {
		try {
			YansongdaPayFactory::boot_wechat();
			if (!empty($result['success'])) {
				YansongdaPayFactory::emit_response(Pay::wechat()->success(), '{"code":"SUCCESS","message":"成功"}');
			}
		} catch (\Throwable $e) {
			// fall through to fail body
		}

		if (!headers_sent()) {
			http_response_code(500);
			header('Content-Type: application/json; charset=utf-8');
		}
		echo wp_json_encode([
			'code'    => 'FAIL',
			'message' => (string) ($result['message'] ?? 'FAIL'),
		]);
		exit;
	}

	public function query_status(string $order_number): array {
		if (!$this->is_configured()) {
			return ['success' => false, 'message' => __('微信支付未配置', 'aksrt')];
		}

		$out_trade_no = $this->resolve_out_trade_no($order_number);

		try {
			YansongdaPayFactory::boot_wechat();
			$action = $this->query_action();
			$result = Pay::wechat()->query([
				'out_trade_no' => $out_trade_no,
				'_action'      => $action,
			]);
			$data = YansongdaPayFactory::to_array($result);

			$trade_state = (string) ($data['trade_state'] ?? '');
			$status      = 'pending';
			if ($trade_state === 'SUCCESS') {
				$status = 'paid';
			} elseif (in_array($trade_state, ['CLOSED', 'REVOKED'], true)) {
				$status = 'cancelled';
			} elseif ($trade_state === 'REFUND') {
				$status = 'refunded';
			}

			return [
				'success'        => true,
				// Keep provider out_trade_no so Gateway::complete_order can resolve the local order.
				'order_number'   => (string) ($data['out_trade_no'] ?? $out_trade_no),
				'amount'         => $this->fen_decimal((int) YansongdaPayFactory::dig($data, 'amount.total', 0)),
				'currency'       => strtoupper((string) YansongdaPayFactory::dig($data, 'amount.currency', 'CNY')),
				'transaction_id' => (string) ($data['transaction_id'] ?? ''),
				'status'         => $status,
			];
		} catch (\Throwable $e) {
			return ['success' => false, 'message' => $e->getMessage()];
		}
	}

	/**
	 * Best-effort close of a previous provider trade before re-pay.
	 */
	public function close_trade(string $out_trade_no): void {
		$out_trade_no = sanitize_text_field($out_trade_no);
		if ($out_trade_no === '' || !$this->is_configured()) {
			return;
		}
		try {
			YansongdaPayFactory::boot_wechat();
			Pay::wechat()->close([
				'out_trade_no' => $out_trade_no,
				'_action'      => $this->query_action(),
			]);
		} catch (\Throwable $e) {
			// ignore — new attempt still uses a fresh out_trade_no
		}
	}

	public function refund(string $order_number, string $amount, string $request_id = ''): array {
		try {
			$refund_amount = \AKSRT\Ledger\AssetAmount::balance($amount);
		} catch (\InvalidArgumentException $e) {
			return ['success' => false, 'status' => 'failed', 'message' => __('退款金额无效', 'aksrt')];
		}
		if ($refund_amount->minor() <= 0) {
			return ['success' => false, 'status' => 'failed', 'message' => __('退款金额无效', 'aksrt')];
		}
		if (!$this->is_configured()) {
			return ['success' => false, 'message' => __('微信支付未配置', 'aksrt')];
		}

		$out_trade_no = $this->resolve_out_trade_no($order_number);

		try {
			YansongdaPayFactory::boot_wechat();
			$action = $this->query_action();

			$query = Pay::wechat()->query([
				'out_trade_no' => $out_trade_no,
				'_action'      => $action,
			]);
			$q = YansongdaPayFactory::to_array($query);
			$total_fen = (int) YansongdaPayFactory::dig($q, 'amount.total', 0);
			$refund_fen = $refund_amount->minor();
			if ($total_fen <= 0) {
				return ['success' => false, 'status' => 'failed', 'message' => __('无法确认原订单金额', 'aksrt')];
			}
			if ($refund_fen <= 0 || $refund_fen > $total_fen) {
				return ['success' => false, 'status' => 'failed', 'message' => __('退款金额无效', 'aksrt')];
			}

			$refund_request_id = (string) preg_replace(
				'/[^A-Za-z0-9_-]/',
				'',
				$request_id !== '' ? $request_id : 'REF_' . $order_number
			);
			$result = Pay::wechat()->refund([
				'_action'       => 'refund_' . $action,
				'out_trade_no'  => $out_trade_no,
				'out_refund_no' => $refund_request_id,
				'reason'        => __('用户申请退款', 'aksrt'),
				'amount'        => [
					'refund'   => $refund_fen,
					'total'    => $total_fen,
					'currency' => 'CNY',
				],
			]);
			$data = YansongdaPayFactory::to_array($result);

			$status = strtoupper((string) ($data['status'] ?? ''));
			$normalized = $status === 'SUCCESS'
				? 'succeeded'
				: (in_array($status, ['CLOSED', 'ABNORMAL'], true) ? 'failed' : 'pending');

			return [
				'success'    => true,
				'status'     => $normalized,
				'refund_id'  => (string) ($data['refund_id'] ?? $data['out_refund_no'] ?? ''),
				'request_id' => $refund_request_id,
				'message'    => $normalized === 'succeeded' ? __('退款成功', 'aksrt') : __('退款请求已受理', 'aksrt'),
			];
		} catch (\Throwable $e) {
			return ['success' => false, 'message' => $e->getMessage()];
		}
	}

	public function query_refund(string $request_id, string $order_number = ''): array {
		if (!$this->is_configured() || $request_id === '') {
			return ['success' => false, 'status' => 'failed', 'message' => __('微信退款查询参数无效', 'aksrt')];
		}

		try {
			YansongdaPayFactory::boot_wechat();
			$result = Pay::wechat()->query([
				'out_refund_no' => $request_id,
				'_action'       => 'refund_' . $this->query_action(),
			]);
			$data = YansongdaPayFactory::to_array($result);
			$status = strtoupper((string) ($data['status'] ?? ''));
			$normalized = $status === 'SUCCESS'
				? 'succeeded'
				: (in_array($status, ['CLOSED', 'ABNORMAL'], true) ? 'failed' : 'pending');
			return [
				'success'   => true,
				'status'    => $normalized,
				'refund_id' => (string) ($data['refund_id'] ?? $data['out_refund_no'] ?? ''),
			];
		} catch (\Throwable $e) {
			return ['success' => false, 'status' => 'unknown', 'message' => $e->getMessage()];
		}
	}

	/**
	 * @return array{mch_id:string,appid:string,api_v3_key:string,private_key:string,cert_path:string,payment_type:string}
	 */
	private function get_config(): array {
		$all = class_exists('\AKSRT\Settings\Settings')
			? \AKSRT\Settings\Settings::get_all()
			: [];
		$type = sanitize_key((string) ($all['wechat_payment_type'] ?? 'native'));
		if (!in_array($type, ['native', 'h5'], true)) {
			$type = 'native';
		}
		return [
			'mch_id'       => (string) ($all['wechat_merchantid'] ?? ''),
			'appid'        => (string) ($all['wechat_appid'] ?? ''),
			'api_v3_key'   => (string) ($all['wechat_api_v3_key'] ?? ''),
			'private_key'  => (string) ($all['wechat_private_key_path'] ?? ''),
			'cert_path'    => (string) ($all['wechat_cert_path'] ?? ''),
			'payment_type' => $type,
		];
	}

	private function query_action(): string {
		$map = [
			'native' => 'native',
			'h5'     => 'h5',
		];
		$type = $this->get_config()['payment_type'];
		return $map[$type] ?? 'native';
	}

	private function fen_decimal(int $amount): string {
		return \AKSRT\Ledger\AssetAmount::from_minor(
			\AKSRT\Ledger\AssetType::BALANCE,
			max(0, $amount)
		)->decimal();
	}

	/**
	 * Map local order_number → provider out_trade_no (supports resume attempts).
	 */
	private function resolve_out_trade_no(string $order_number): string {
		if (class_exists('\AKSRT\Payment\OrderRepository')) {
			$repo = \AKSRT\Payment\OrderRepository::get_instance();
			if ($repo->resolve_by_out_trade_no($order_number) && !$repo->get($order_number)) {
				return $order_number;
			}
			$order = $repo->get($order_number);
			if ($order) {
				return \AKSRT\Payment\OrderRepository::provider_out_trade_no($order);
			}
		}
		return $order_number;
	}
}