<?php
namespace WPCOM\Member\Payments;
use WPCOM\Member\Order;
use WPCOM\Themer\Session;

defined('ABSPATH') || exit;

class PayPal extends Payment {
    private $_config;
    public function __construct() {
        $this->id = 'paypal';
        $this->title = 'PayPal';
        $this->icon = WPCOM_MP_URI . 'payment/paypal.svg';
        $this->color = '#0544b5';
        $this->_config = [];

        add_action('wp_ajax_WPCOM_PayPal_order_status', [$this, 'order_status']);
        add_action('wp_ajax_nopriv_WPCOM_PayPal_order_status', [$this, 'order_status']);

        parent::__construct();
    }

    public function init($index){
        $client_id = wpcom_mp_options('paypal_client_id');
        $secret = wpcom_mp_options('paypal_secret');
        $currency = wpcom_mp_options('paypal_currency');
        $rate = wpcom_mp_options('paypal_rate');
        $sandbox = wpcom_mp_options('paypal_sandbox');
        $this->modal = false;
        $this->_config = [
            'client_id' => $client_id && isset($client_id[$index]) ? trim($client_id[$index]) : '',
            'secret' => $secret && isset($secret[$index]) ? trim($secret[$index]) : '',
            'currency' => $currency && isset($currency[$index]) ? trim($currency[$index]) : 'USD',
            'rate' => $rate && isset($rate[$index]) && (float) $rate[$index] > 0 ? number_format( (float) $rate[$index], 3, '.', '' ) : 1,
            'sandbox' => $sandbox && isset($sandbox[$index]) && $sandbox[$index] == 1
        ];
        $this->_config['api'] = $this->_config['sandbox'] ? 'https://api.sandbox.paypal.com/' : 'https://api.paypal.com/';
    }

    public function process_payment($order_id) {
        $url = Order::get_checkout_payment_url($order_id);
        return [
            'result' => 'success',
            'redirect' =>  $url
        ];
    }

    private function config($order_id) {
        $config = $this->_config + [
            //异步通知地址
            'notify_url' => Order::get_checkout_notify_url($order_id, $this->id),
            //同步跳转
            'return_url' => Order::get_checkout_return_url($order_id, $this->id),
        ];
        return $config;
    }

    public function receipt_page($order_id) {
        $order = Order::get_order($order_id);
        if (!$order || $order->status === 'paid') return;

        // 创建PayPal订单
        $paypal_order = $this->create_order( $order );

        $pay_url = '';
        $error = '';

        if(!$paypal_order) {
            $error = '发起支付失败';
        }else if(is_wp_error($paypal_order)) {
            $error = $paypal_order->get_error_message();
        }else if ( isset( $paypal_order['id'] ) &&  isset( $paypal_order['links'] ) ) {
            // 查找approve链接
            foreach ( $paypal_order['links'] as $link ) {
                if ( $link['rel'] === 'payer-action' ) {
                    $pay_url = $link['href'];
                }
            }
        }else if(isset( $paypal_order['message'] )){
            $error = $paypal_order['name'] . ' - ' . $paypal_order['message'];
        }
        ?>
        <div class="loading-img"></div>
        <p class="loading-text"><?php echo ($error !== '' ? '<span style="color: #f66;">' . $error . '</span>' : '正在转入支付平台...');?></p>
        <div class="wpcom-alipay-html">
            <?php if($error === '' && $pay_url !== '') {
                echo '<script> setTimeout(function(){ window.location.href = \' ' . $pay_url . '\';}, 200);</script>';
            }elseif($pay_url === '' && $error === ''){
                echo '支付异常，请稍后再试！';
            }?>
        </div>
    <?php }

    function return_page_render($order_id) {
        $token = isset($_GET['token']) && $_GET['token'] ? sanitize_text_field($_GET['token']) : '';
        $payer = isset($_GET['PayerID']) && $_GET['PayerID'] ? sanitize_text_field($_GET['PayerID']) : '';
        $order = Order::get_order($order_id);

        if($token !== '' && $payer !== '' && $order->status === 'unpaid'){
            $config = $this->config($order->ID);
            $api = $config['api'] . 'v2/checkout/orders/' . $token;

            // 查询订单状态
            $paypal_order = $this->api_request( $api, '', $config, 'GET' );

            if(!is_wp_error($paypal_order)) self::add_log('paypal 支付返回 - ' . $order_id . ' - ' . $paypal_order['status'], $this->id);

            if ( !is_wp_error($paypal_order) && isset( $paypal_order['status'] ) && $paypal_order['status'] === 'APPROVED' ) {
                $capture = $this->api_request( $api . '/capture', [], $config );
                if(!is_wp_error($capture)) $this->payment_complete($order, $capture);
            } else if ( !is_wp_error($paypal_order) ){
                $this->payment_complete($order, $paypal_order);
            }
        }

        parent::return_page_render($order_id);
    }

    function check_response($data){
        if(is_numeric($data)) return ;
        if(isset($data['event_type']) && $data['event_type'] === 'CHECKOUT.ORDER.APPROVED') {
            $order_id = isset($data['resource']['purchase_units']) ? $data['resource']['purchase_units'][0]['reference_id'] : '';
            self::add_log('paypal 异步通知 - ' . $order_id . ' - ' . $data['event_type'], $this->id);
            if($order_id){
                $token = $data['resource']['id'];
                Session::set('paypal_' . $token, $order_id);
                $order = Order::get_order_by_number($order_id);
                if($order && isset($order->status) && $order->status === 'unpaid'){
                    $config = $this->config($order->ID);
                    $api = $config['api'] . 'v2/checkout/orders/' . $token;
                    $capture = $this->api_request( $api . '/capture', [], $config );
                    if ( !is_wp_error($capture) ) $this->payment_complete($order, $capture);
                }
            }
        } else if(isset($data['event_type']) && $data['event_type'] === 'PAYMENT.CAPTURE.COMPLETED') {
            $token = isset($data['resource']['supplementary_data']) ? $data['resource']['supplementary_data']['related_ids']['order_id'] : '';
            $order_id = $token ? Session::get('paypal_' . $token) : '';
            self::add_log('paypal 异步通知 - ' . $order_id . ' - ' . $data['event_type'], $this->id);
            if($order_id) {
                $order = Order::get_order_by_number($order_id);
                if($order && isset($order->status) && $order->status === 'unpaid'){
                    Order::payment_complete( $order->ID,  $this->id);
                    self::add_log('#' . $order->number.' 订单支付完成！', $this->id);
                }
            }
        }
    }

    private function payment_complete($order, $data){
        if(isset($data['status']) && $data['status'] === 'COMPLETED') {
            $purchase = $data['purchase_units'][0];
            if($order && $order->number && $order->number == $purchase['reference_id'] && $order->status === 'unpaid'){ // 判断订单号，以及支付状态
                $config = $this->config($order->ID);
                $price = number_format( (float) $order->price * $config['rate'], 2, '.', '' );
                $currency = $config['currency'];
                $amount = isset($purchase['amount']) ? $purchase['amount'] : $purchase['payments']['captures'][0]['amount'];
                if($amount['value'] == $price && strtoupper($amount['currency_code']) === strtoupper($currency)) {
                    Order::payment_complete( $order->ID,  $this->id);
                    self::add_log('#' . $order->number.' 订单支付完成！', $this->id);
                } else {
                    self::add_log('#' . $order->number.' 价格核对出错，计算价格：' . $price . '，返回价格：' . $amount['value'], $this->id);
                }
            }
        }
    }

    // PayPal API 请求
    private function api_request( $url, $data, $config, $method = 'POST' ) {
        $access_token = $this->get_access_token($config);
        if($access_token){
            $args = [
                'timeout' => 30,
                'headers' => [
                    'Content-Type'  => 'application/json',
                    'Authorization' => 'Bearer ' . $access_token,
                ]
            ];

            if($method === 'POST' && !empty($data)) {
                $args['body'] = wp_json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
            }

            $response = $method === 'GET' ? wp_remote_get( $url, $args ) : wp_remote_post( $url, $args );

            if ( is_wp_error( $response ) ) return $response;

            return json_decode( wp_remote_retrieve_body( $response ), true );
        }else{
            return new \WP_Error('access_token_error', 'Access Token 获取失败，请检查接口配置是否正确');
        }
    }

    // 获取 PayPal access_token
    private function get_access_token($config) {
        $cache_key = $config['sandbox'] ? 'paypal_sandbox_access_token' : 'paypal_live_access_token';

        // 先尝试取缓存
        $token_data = is_multisite() ? get_network_option( 1, $cache_key ) : get_option($cache_key);
        $token_data = $token_data ? json_decode($token_data, true) : [];

        if ( $token_data && isset( $token_data['access_token'], $token_data['expires_at'] ) ) {
            if ( time() < $token_data['expires_at'] ) {
                // token未过期，直接用
                return $token_data['access_token'];
            }
        }

        // token过期或不存在，重新申请
        $response = wp_remote_post($config['api'] . 'v1/oauth2/token', [
            'body' => 'grant_type=client_credentials',
            'timeout' => 30,
            'headers' => [
                'Authorization' => 'Basic ' . base64_encode( $config['client_id'] . ':' . $config['secret'] ),
                'Content-Type'  => 'application/x-www-form-urlencoded',
            ],
        ]);

        if ( is_wp_error( $response ) ) {
            return false;
        }

        $data = json_decode( wp_remote_retrieve_body( $response ), true );

        if ( empty( $data['access_token'] ) || empty( $data['expires_in'] ) ) {
            return false;
        }

        // 缓存token
        $token_data = [
            'access_token' => $data['access_token'],
            'expires_at'   => time() + intval( $data['expires_in'] ) - 60
        ];

        if(is_multisite()){
            update_network_option( 1, $cache_key, wp_json_encode($token_data) );
        }else{
            update_option( $cache_key, wp_json_encode($token_data) );
        }

        return $data['access_token'];
    }

    // 创建 PayPal 订单
    private function create_order( $order ) {
        $config = $this->config($order->ID);
        $data = [
            'intent' => 'CAPTURE',
            'purchase_units' => [
                [
                    'reference_id' => (string) $order->number,
                    'amount' => [
                        'currency_code' => $config['currency'],
                        'value' => number_format( (float) $order->price * $config['rate'], 2, '.', '' ),
                    ],
                ]
            ],
            'payment_source' => [
                'paypal' => [
                    'experience_context' => [
                        'brand_name'          => get_bloginfo( 'name' ),
                        'landing_page'        => 'LOGIN',
                        'shipping_preference' => 'NO_SHIPPING',
                        'user_action'         => 'PAY_NOW',
                        'return_url'          => $config['return_url'],
                        'cancel_url'          => $config['return_url'],
                    ]
                ]
            ]
        ];

        return $this->api_request($config['api'] . 'v2/checkout/orders', $data, $config);
    }
}

new PayPal();