<?php
include_once dirname(__FILE__,3).'/config.php';

class paypalCurl {

    private $url ; // base url of PayPal
    private $id; // client id
    private $secret; // secret id
    private $accessToken = null; // changed by each request

    public function init($id,$secret,$base):void
    {
        $this->url = $base;
        $this->id = $id;
        $this->secret = $secret;

    }

    private function makeAccessToken():bool
    {
        $url = $this->url;
        $id = $this->id;
        $secret = $this->secret;

        $ch = curl_init();

        curl_setopt($ch, CURLOPT_URL, $url . '/v1/oauth2/token');
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, "grant_type=client_credentials");
        curl_setopt($ch, CURLOPT_USERPWD, $id . ':' . $secret);

        $headers = array();
        $headers[] = 'Content-Type: application/x-www-form-urlencoded';
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

        $result = curl_exec($ch);
        curl_close($ch);

        $result = json_decode($result);
        if (!empty($result->access_token)) {
            $this->accessToken = $result->access_token;
            return true;
        }

        return false;
    }

    public function makePaymentURL($orderId,$price,$currency)
    {
        $url = $this->url;
        $response = new stdClass();
        $response->status = false;

        //first request for a new access token
        if ($this->makeAccessToken()) $accessToken = $this->accessToken;
        else {
            $response->msg = "could not create access token!";
            return $response;
        }

        //then request for a payment url
        $ch = curl_init();

        curl_setopt($ch, CURLOPT_URL, $url . '/v2/checkout/orders');
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, '{
          "intent": "CAPTURE",
          "purchase_units": [
                {   "reference_id": "'.$orderId.'",
                    "description": "MorvalWatches",
                    "items": [
                        {
                            "name": "MorvalWatches",
                            "description":  "Pay For ' . $orderId.'",
                            "quantity": "1",
                            "unit_amount": {
                                "currency_code": "'.$currency.'",
                                "value": "'.$price.'"
                            }
                        }
                    ],
                    "amount": {
                        "currency_code": "'.$currency.'",
                        "value": "'.$price.'",
                        "breakdown": {
                            "item_total": {
                                "currency_code": "'.$currency.'",
                                "value": "'.$price.'"
                            }
                        }
                    }
                }
            ],
            "application_context":{
                "shipping_preference":"NO_SHIPPING",
                "return_url": "'.PAYPAL_WEBHOOK.'",
                "cancel_url": "'.PAYPAL_WEBHOOK.'?txn='.$orderId.'"
            }
        }');

        $headers = array();
        $headers[] = 'Content-Type: application/json';
        $headers[] = 'Authorization: Bearer '.$accessToken;
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

        $result = curl_exec($ch);
        if (curl_errno($ch)) {

            $response->msg = curl_error($ch);
            curl_close($ch);
            return $response;
        }

        $result = json_decode($result);
        if (!empty($result->links[1]->href)) { // success

            $PayURL = $result->links[1]->href;
            $response -> url = $PayURL;
            $response -> status = true;
            return $response;

        }
        elseif(!empty($result->message)){ // failed
            $response->msg = $result->message;
        }
        
        curl_close($ch);
        return $response;
    }

    public function verify($token) { // to verify payment

        if (empty($token)) return false;

        $response = new stdClass();
        $response-> state = false;

        //first create another access token
        if ($this->makeAccessToken()) $accessToken = $this->accessToken;
        else {
            $response-> ref = "could not make access token!";
            return $response;
        }

        $url = $this->url;

        $ch = curl_init();

        curl_setopt($ch, CURLOPT_URL, $url . '/v2/checkout/orders/'.$token.'/capture');
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);

        $headers = array();
        $headers[] = 'Content-Type: application/json';
        $headers[] = 'Authorization: Bearer '.$accessToken;
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

        $result = curl_exec($ch);
        if (curl_errno($ch)) {
            $response-> ref = "could not connect to paypal gateway";
            curl_close($ch);
            return $response;
        }

        //retrieve data from json
        if (!empty($result)) {

            $pay = json_decode($result);

            if (!empty($pay->status) && $pay->status == 'COMPLETED') {

                //success!
                $response->state = true;
                $response->ref = $pay->status;

                //get details
                $punits = $pay->purchase_units;
                $captures = $punits[0]->payments->captures;

                $response->id = $captures[0]->id; // transaction id
                $response->amount = $captures[0]->amount->value; // returns float value
                $response->currency = $captures[0]->amount->currency_code;
                $response->email = $pay->payment_source->paypal->email_address; //payer email
                $response->txn = $punits[0]->reference_id;
            
            } else {

                //maybe captured already! [ORDER_ALREADY_CAPTURED]
                $details = $pay->details;
                $response->ref = $details[0]->issue;

            }

            //echo "<pre>";var_dump($pay);echo "</pre>";

        } else {
            $response->ref = "result was empty!";
        }

        curl_close($ch);
        return $response;

    }

}