# Split Payment

An `invoice` object must be attached to the basic request creating the transaction as described in the section [Creating a payment](#topic-creating-a-payment). This object consists of a `buyer` object and a `positions` array with the following parameters:

`buyer` object:

| Parameter | Type | Parameter required | Description |
|-------------------|-----------------------------------------------|-|-|
| `invoiceId`       | string      | `YES`             | Invoice number |
| `type`    | string | `YES` | It takes the value `PERSON` *individual buyer or `COMPANY` *company* |
| `email`   | string(200) | `YES` | E-mail address in the format compliant with RFC 5322 and RFC 6531 |
| `fullName`| string(200) | `YES` | Buyer's name/company name, <br> **available characters:** A-Za-z0-9#&_-"',.\/ space (0x20) and the UNICODE characters from the range 00C0 - 02C0 (e.g. Polish diacritic characters), 0400 - 04FF (Cyrillic script) |
| `street`  | string(200) | `YES` | Street |
| `city`    | string(100) | `YES` | City
| `postalCode` | string(30) | `YES` | Postal code |
| `countryCodeAlpha2` | string(2) | `YES` | Country code `Alpha2` |
| `idCountryCodeAlpha2` | string(2) | `NO` | `Alpha2` country code identifier. Required for the `VAT_ID` value of the `idType` parameter. |
| `idType`  | string | `NO` | Identification number type. Required for the `COMPANY` value of the `type` parameter. Takes the value of `ID` *TIN* or `VAT_ID` *CRN* |
| `idNumber`| string(30) | `NO` | CRN or TIN number. Required for the `COMPANY` value of the `type` parameter |

`positions` array:

| Parameter | Type | Parameter required | Description |
|-------------------|-----------------------------------------------|-|-|
| `name` | string | `YES` | Product name |
| `code` | string | `YES` | Product code |
| `quantity` | number | `YES` | Quantity. The **minimum value is 0** |
| `unit` | string | `YES` | Unit |
| `grossAmount` | integer | `YES` | Gross unit value |
| `taxStake` | string | `YES` | Tax rate. Available values: `TAX_23`, `TAX_22`, `TAX_8`, `TAX_7`, `TAX_5`, `TAX_3`, `TAX_0`, `TAX_EXEMPT`, `TAX_NOT_LIABLE`, `TAX_REVERSE_CHARGE`, `TAX_EXCLUDING` |
| `taxAmount`       | integer     | `YES`             | Value of tax in pennies |
| `discountAmount` | integer | `NO` | Discount value |

### Example data structure

```php
$invoiceData = [
    "invoiceId" => "04/12/23",
    "buyer"     => [
        "type"                => "COMPANY",
        "idType"              => "VAT_ID",
        "idNumber"            => "5354235387",
        "email"               => "nazwafirmy@example.com",
        "fullName"            => "Nazwa firmy",
        "street"              => "Ulica",
        "city"                => "Miasto",
        "postalCode"          => "12-345",
        "countryCodeAlpha2"   => "PL",
        "idCountryCodeAlpha2" => "PL"
    ],
    "positions" => [
        [
            "name"        => "Produkt",
            "code"        => "produkt-01",
            "quantity"    => 1,
            "unit"        => "Sztuki",
            "taxStake"    => "TAX_23",
            "grossAmount" => 12300,
            "taxAmount" =>  2300
        ],
    ],
];
```

The above parameters should be taken into account when calculating the signature in accordance with the section [Authorisation](#topic-authorisation)

### Preparing the invoice object

### Using the PHP function
The data collected from the above parameters should be encoded using the function:
`base64_encode(gzencode(json_encode($invoiceData), 5));` 

where:

`$invoiceData` - previously prepared parameters

```php
$invoiceData = [
    "invoiceId" => "04/12/23",
    "buyer"     => [
        "type"                => "COMPANY",
        "idType"              => "VAT_ID",
        "idNumber"            => "5354235387",
        "email"               => "nazwafirmy@example.com",
        "fullName"            => "Nazwa firmy",
        "street"              => "Ulica",
        "city"                => "Miasto",
        "postalCode"          => "12-345",
        "countryCodeAlpha2"   => "PL",
        "idCountryCodeAlpha2" => "PL"
    ],
    "positions" => [
        [
            "name"        => "Produkt",
            "code"        => "produkt-01",
            "quantity"    => 1,
            "unit"        => "Sztuki",
            "taxStake"    => "TAX_23",
            "grossAmount" => 12300,
            "taxAmount" =>  2300
        ],
    ],
];
$invoice = base64_encode(gzencode(json_encode($invoiceData), 5));

$fields = [
    'serviceId' => '63f574ed-d90d-4abe-9cs1-39117584a7b7',
    'merchantId' => '6yt3gjtm9p1odfgx8491',
    'amount' => '12300',
    'currency' => 'PLN',
    'orderId' => 'Split payment',
    'orderDescription' => 'Split payment',
    'customerFirstName' => 'Jan',
    'customerLastName' => 'Kowalski',
    'customerEmail' => 'jan.kowalski@example.com',
    'customerPhone' => '501501501',
    'visibleMethod' => 'wt',
    'urlSuccess' => 'https://domain.com/success',
    'urlFailure' => 'https://domain.com/failure',
    'urlReturn' => 'https://domain.com/return',
    'invoice' => $invoice,
];
$serviceKey = 'eAyhFLuHgwl5hu-32GM8QVlCVMWRU0dGjH1c';
$hashMethod = 'sha256';
$signature= createSignature(
    $fields,
    $serviceKey,
    $hashMethod
) . ';' . $hashMethod;
```

### Example of an encoded invoice object

```php
H4sIAAAAAAAACm2QXU+DMBSG/4rp9eaAQjRcSfBmiUOSodE4s3TQaUM/EE51jPDfPe3inZfneT/6phMR+tuImq8bkpIg3q3CaLeKKFmQgx15T9KJwNhxFPPHTZkVr6iIprqg56zar+89Kaw6ODtJaBJHNKG3N8i5YkIi1Oz8w46iV+MdPzHVSX5dG4WGo5WyYMqVFc5z5U0oDNBzDoifpKgZglrAiOdGsAEM3p0ZgMncNC4bRksaJ85lrIZ+dDiT3SeLUCwf/ML8f2n2VQKE0QNJ3ybc6ueUvWlsC77Tv9FdwDIIkX1ZpsEvChfEauGWbs9gW4EisNMWWOtCVfay97/50ZthyJTbgJmIBoH3/REH5vf5FyK2JcWPAQAA
```
### Example HTML form content

```html
<input type="hidden" value="63f574ed-d90d-4abe-9cs1-39117584a7b7" name="serviceId">
<input type="hidden" value="6yt3gjtm9p1odfgx8491" name="merchantId">
<input type="hidden" value="12300" name="amount">
<input type="hidden" value="PLN" name="currency">
<input type="hidden" value="Split payment" name="orderId">
<input type="hidden" value="Split payment" name="orderDescription">
<input type="hidden" value="Jan" name="customerFirstName">
<input type="hidden" value="Kowalski" name="customerLastName">
<input type="hidden" value="jan.kowalski@example.com" name="customerEmail">
<input type="hidden" value="501501501" name="customerPhone">
<input type="hidden" value="wt" name="visibleMethod">
<input type="hidden" value="https://domain.com/success" name="urlSuccess">
<input type="hidden" value="https://domain.com/failure" name="urlFailure">
<input type="hidden" value="https://domain.com/return" name="urlReturn">
<input type="hidden" value="<?= $invoice ?>" name="invoice">
```