MarcinOrlowski / bank-qrcode-formatter

src/Builder.php

Indentation +466 added lines, -466 removed lines

@@ -19,470 +19,470 @@
 
 class Builder
 {
-	/** @var int */
-	const TYPE_COMPANY = 1;
-
-	/** @var int */
-	const TYPE_PERSON = 2;
-
-	/** @var string */
-	protected $separator = '|';
-
-	/** @var int Maks. allowed length of result string */
-	const MAX_LEN = 160;
-
-
-	/**
-	 * Builder constructor.
-	 *
-	 * @param int  $recipient_type
-	 * @param bool $strict_mode
-	 */
-	public function __construct($recipient_type = self::TYPE_PERSON, $strict_mode = false)
-	{
-		if ($recipient_type !== self::TYPE_COMPANY && $recipient_type !== self::TYPE_PERSON) {
-			throw new RuntimeException('Invalid recipient type specified.');
-		}
-
-		$this->recipient_type = $recipient_type;
-		$this->strictMode($strict_mode);
-	}
-
-	/** @var bool */
-	protected $strict_mode = false;
-
-	/**
-	 * Controls strict mode. When mode is disabled (default) some methods may trim down string arguments
-	 * exceeding max allowed length. With strict mode on, such case would throw InvalidArgumentException.
-	 *
-	 * @param bool $mode Set to @true to enable strict mode, @false (default) otherwise.
-	 */
-	public function strictMode($mode)
-	{
-		if (!is_bool($mode)) {
-			throw new InvalidArgumentException('Mode argument must be a boolean.');
-		}
-
-		$this->strict_mode = (bool)$mode;
-	}
-
-	/** @var int */
-	protected $recipient_type = self::TYPE_PERSON;
-
-	/** @var string VAT ID (10 chars). required for TYPE_COMPANY (VAT ID), optional otherwise, digits */
-	protected $vat_id = '';
-
-	/**
-	 * Sets recipient Vat ID
-	 *
-	 * @param string|int|null $vat_id
-	 *
-	 * @return $this
-	 */
-	public function vatId($vat_id)
-	{
-		$this->vat_id = $this->validateVatId($vat_id);
-
-		return $this;
-	}
-
-	/**
-	 * @param string|int|null $vat_id
-	 *
-	 * @return string
-	 *
-	 * @throws \InvalidArgumentException
-	 * @throws \RuntimeException
-	 */
-	protected function validateVatId($vat_id)
-	{
-		if (is_string($vat_id)) {
-			$vat_id = trim(str_replace('-', '', $vat_id));
-		} elseif ($vat_id === null) {
-			$vat_id = '';
-		} elseif (is_int($vat_id)) {
-			$vat_id = sprintf('%010d', $vat_id);
-		} else {
-			throw new InvalidArgumentException('VatId can either be a string, int or null.');
-		}
-
-		if ($vat_id !== '') {
-			if (preg_match('/^\d{10}$/', $vat_id) !== 1) {
-				throw new InvalidArgumentException("Invalid VAT ID set. Must be contain 10 chars, digits only. '{$vat_id}' provided.");
-			}
-		}
-
-		if ($this->recipient_type === self::TYPE_COMPANY && $vat_id === '') {
-			throw new RuntimeException('Company recipient must have VAT ID set.');
-		}
-
-		return $vat_id;
-	}
-
-	/** @var string Recipient bank account number (26 digits), mandatory */
-	protected $bank_account = '';
-
-	/**
-	 * Sets mandatory recipient routing bank account number. Account number must contain 26 digits.
-	 * Digits can be grouped and separated by spaces however all spaces will be removed.
-	 *
-	 * @param string $account Recipient bank account number (26 digits)
-	 *
-	 * @return $this
-	 */
-	public function bankAccount($account)
-	{
-		$this->bank_account = $this->validateBankAccount($account);
-
-		return $this;
-	}
-
-	/**
-	 * @param string $account
-	 *
-	 * @return string
-	 *
-	 * @throws \InvalidArgumentException
-	 */
-	protected function validateBankAccount($account)
-	{
-		if (!is_string($account)) {
-			throw new InvalidArgumentException('Bank account number must be a string.');
-		}
-		$account = str_replace(' ', '', $account);
-
-		if (preg_match('/^\d{26}$/', $account) !== 1) {
-			throw new InvalidArgumentException("Bank account number must be 26 chars long, digits only. '{$account}' provided.");
-		}
-
-		return $account;
-	}
-
-	/** @var string 20 chars max, recipient name, mandatory */
-	protected $recipient_name = '';
-
-	/** @var int */
-	const NAME_MAX_LEN = 20;
-
-	/**
-	 * Sets recipient name. Up to 20 chars (longer strings are allowed and will be trimmed).
-	 *
-	 * @param string $name recipient name
-	 *
-	 * @return $this
-	 */
-	public function name($name)
-	{
-		$this->recipient_name = $this->validateName($name);
-
-		return $this;
-	}
-
-	/**
-	 * @param string $name
-	 *
-	 * @return string
-	 *
-	 * @throws \InvalidArgumentException
-	 * @throws \RuntimeException
-	 */
-	protected function validateName($name)
-	{
-		if (!is_string($name)) {
-			throw new InvalidArgumentException('Recipient name must be a string.');
-		}
-
-		if ($this->strict_mode && mb_strlen($name) > self::NAME_MAX_LEN) {
-			throw new InvalidArgumentException(sprintf('Recipient name must not exceed %d chars.', self::NAME_MAX_LEN));
-		}
-
-		$name = mb_substr($name, 0, self::NAME_MAX_LEN);
-
-		if ($name === '') {
-			throw new RuntimeException('Recipient name cannot be empty.');
-		}
-
-		return $name;
-	}
-
-	/** @var string 2 chars, country code (i.e. 'PL'), optional, letters */
-	protected $country_code = '';
-
-	/**
-	 * @param string|null $country_code 2 chars, country code (i.e. 'PL'), optional, letters
-	 *
-	 * @return $this
-	 *
-	 * @throws \InvalidArgumentException
-	 */
-	public function country($country_code)
-	{
-		if ($country_code === null) {
-			$country_code = '';
-		}
-
-		if (!is_string($country_code)) {
-			throw new InvalidArgumentException('Country code must be a string.');
-		}
-
-		$country_code = mb_strtoupper($country_code);
-		if ($country_code !== '') {
-			if (preg_match('/^[A-Z]{2}$/', $country_code) !== 1) {
-				throw new InvalidArgumentException("Country code must be a 2 character long, letters only. '{$country_code}' provided.");
-			}
-		}
-
-		$this->country_code = strtoupper($country_code);
-
-		return $this;
-	}
-
-	/** @var string */
-	protected $payment_title = '';
-
-	/** @var int */
-	const TITLE_MAX_LEN = 32;
-
-	/**
-	 * @param string $title 32 chars, payment title, mandatory, letters+digits
-	 *
-	 * @return $this
-	 */
-	public function title($title)
-	{
-		$this->payment_title = $this->validateTitle($title);
-
-		return $this;
-	}
-
-	/**
-	 * @param string $title
-	 *
-	 * @return string
-	 *
-	 * @throws \InvalidArgumentException
-	 */
-	protected function validateTitle($title)
-	{
-		if (!is_string($title)) {
-			throw new InvalidArgumentException('Payment title must be a string.');
-		}
-
-		if ($this->strict_mode && mb_strlen($title) > self::TITLE_MAX_LEN) {
-			throw new InvalidArgumentException(sprintf('Payment title must not exceed %d chars.', self::TITLE_MAX_LEN));
-		}
-
-		if ($title === '') {
-			throw new RuntimeException('Payment title cannot be empty.');
-		}
-
-		return mb_substr(trim($title), 0, self::TITLE_MAX_LEN);
-	}
-
-	/** @var int|null */
-	protected $amount = null;
-
-	/**
-	 * @param float|int $amount 6 chars, amount in Polish grosz, digits, mandatory
-	 *
-	 * @return $this
-	 */
-	public function amount($amount)
-	{
-		$this->amount = $this->validateAmount($amount);
-
-		return $this;
-	}
-
-	/**
-	 * @param float|int $amount
-	 *
-	 * @return int
-	 *
-	 * @throws \OutOfRangeException
-	 * @throws \InvalidArgumentException
-	 * @throws \RuntimeException
-	 */
-	protected function validateAmount($amount)
-	{
-		if ($amount === null) {
-			throw new RuntimeException('Amount not specified.');
-		}
-
-		if (is_float($amount)) {
-			$amount = (int)($amount * 100);
-		} elseif (!is_int($amount)) {
-			throw new InvalidArgumentException('Amount must be either float or int');
-		}
-
-		if ($amount < 0) {
-			throw new OutOfRangeException('Amount cannot be negative.');
-		}
-
-		if ($amount > 999999) {
-			throw new OutOfRangeException('Amount representation cannot exceed 6 digits. Current value: {$amount}');
-		}
-
-		return $amount;
-	}
-
-	/** @var string */
-	protected $reserved1 = '';
-
-	/** @var int */
-	const RESERVED1_MAX_LEN = 20;
-
-	/**
-	 * @param string|null $id 20 chars, reserved i.e. for payment reference id, optional, digits (but we use letters+digits as some banks do too)
-	 *
-	 * @return $this
-	 *
-	 * @throws \InvalidArgumentException
-	 */
-	public function reserved1($id)
-	{
-		if ($id === null) {
-			$id = '';
-		}
-
-		if (!is_string($id)) {
-			throw new InvalidArgumentException('Reserved1/RefId value must be a string.');
-		}
-
-		if (mb_strlen($id) > self::RESERVED1_MAX_LEN) {
-			throw new InvalidArgumentException(sprintf('Maksymalna długość wartości Reserved1/RefId to %d znaków.', self::RESERVED1_MAX_LEN));
-		}
-
-		$this->reserved1 = $id;
-
-		return $this;
-	}
-
-	/**
-	 * Alias for reserved1()
-	 *
-	 * @param string|null $id
-	 *
-	 * @return $this
-	 */
-	public function refId($id)
-	{
-		return $this->reserved1($id);
-	}
-
-	/** @var string */
-	protected $reserved2 = '';
-
-	/** @var int */
-	const RESERVED2_MAX_LEN = 12;
-
-	/**
-	 * 12 chars, reserved i.e. for Invobill reference id, optional, digits (but we allow letters+digits as some banks do too)
-	 *
-	 * @param string|null $id
-	 *
-	 * @return $this
-	 *
-	 * @throws \InvalidArgumentException
-	 */
-	public function reserved2($id)
-	{
-		if ($id === null) {
-			$id = '';
-		}
-
-		if (!is_string($id)) {
-			throw new InvalidArgumentException('Reserved2/Invobill value must be a string.');
-		}
-
-		if (mb_strlen($id) > self::RESERVED2_MAX_LEN) {
-			throw new InvalidArgumentException(sprintf('Maksymalna długość wartości Reserved2/Invobill to %d znaków.', self::RESERVED2_MAX_LEN));
-		}
-
-		$this->reserved2 = $id;
-
-		return $this;
-	}
-
-	/**
-	 * Alias for reserved2()
-	 *
-	 * @param string|null $id
-	 *
-	 * @return $this
-	 */
-	public function invobill($id)
-	{
-		return $this->reserved2($id);
-	}
-
-	/** @var string */
-	protected $reserved3 = '';
-
-	/** @var int */
-	const RESERVED3_MAX_LEN = 24;
-
-	/**
-	 * 24 chars, reserved, optional, letters+digits
-	 *
-	 * @param string|null $id
-	 *
-	 * @return $this
-	 *
-	 * @throws \InvalidArgumentException
-	 */
-	public function reserved3($id)
-	{
-		if ($id === null) {
-			$id = '';
-		}
-
-		if (!is_string($id)) {
-			throw new InvalidArgumentException('Reserved3 value must be a string.');
-		}
-
-		if (mb_strlen($id) > self::RESERVED3_MAX_LEN) {
-			throw new InvalidArgumentException(sprintf('Maksymalna długość wartości Reserved3 to %d znaków.', self::RESERVED3_MAX_LEN));
-		}
-
-		$this->reserved3 = $id;
-
-		return $this;
-	}
-
-	/**
-	 * @return string
-	 *
-	 * @throws \RuntimeException
-	 */
-	public function build()
-	{
-		// validate
-		$this->validateBankAccount($this->bank_account);
-		$this->validateName($this->recipient_name);
-		$this->validateVatId($this->vat_id);
-		$this->validateTitle($this->payment_title);
-		$this->validateAmount($this->amount);
-
-		// build
-		$fields = [
-			$this->vat_id,
-			$this->country_code,
-			$this->bank_account,
-			sprintf('%06d', $this->amount),
-			$this->recipient_name,
-			$this->payment_title,
-			$this->reserved1,
-			$this->reserved2,
-			$this->reserved3,
-		];
-
-		$result = implode($this->separator, $fields);
-		if (mb_strlen($result) > self::MAX_LEN) {
-			throw new RuntimeException(
-				sprintf('Oops, this should not happen! Result string is %d chars long (max allowed %d). Please report this!', mb_strlen($result), self::MAX_LEN));
-		}
-
-		return $result;
-	}
+    /** @var int */
+    const TYPE_COMPANY = 1;
+
+    /** @var int */
+    const TYPE_PERSON = 2;
+
+    /** @var string */
+    protected $separator = '|';
+
+    /** @var int Maks. allowed length of result string */
+    const MAX_LEN = 160;
+
+
+    /**
+     * Builder constructor.
+     *
+     * @param int  $recipient_type
+     * @param bool $strict_mode
+     */
+    public function __construct($recipient_type = self::TYPE_PERSON, $strict_mode = false)
+    {
+        if ($recipient_type !== self::TYPE_COMPANY && $recipient_type !== self::TYPE_PERSON) {
+            throw new RuntimeException('Invalid recipient type specified.');
+        }
+
+        $this->recipient_type = $recipient_type;
+        $this->strictMode($strict_mode);
+    }
+
+    /** @var bool */
+    protected $strict_mode = false;
+
+    /**
+     * Controls strict mode. When mode is disabled (default) some methods may trim down string arguments
+     * exceeding max allowed length. With strict mode on, such case would throw InvalidArgumentException.
+     *
+     * @param bool $mode Set to @true to enable strict mode, @false (default) otherwise.
+     */
+    public function strictMode($mode)
+    {
+        if (!is_bool($mode)) {
+            throw new InvalidArgumentException('Mode argument must be a boolean.');
+        }
+
+        $this->strict_mode = (bool)$mode;
+    }
+
+    /** @var int */
+    protected $recipient_type = self::TYPE_PERSON;
+
+    /** @var string VAT ID (10 chars). required for TYPE_COMPANY (VAT ID), optional otherwise, digits */
+    protected $vat_id = '';
+
+    /**
+     * Sets recipient Vat ID
+     *
+     * @param string|int|null $vat_id
+     *
+     * @return $this
+     */
+    public function vatId($vat_id)
+    {
+        $this->vat_id = $this->validateVatId($vat_id);
+
+        return $this;
+    }
+
+    /**
+     * @param string|int|null $vat_id
+     *
+     * @return string
+     *
+     * @throws \InvalidArgumentException
+     * @throws \RuntimeException
+     */
+    protected function validateVatId($vat_id)
+    {
+        if (is_string($vat_id)) {
+            $vat_id = trim(str_replace('-', '', $vat_id));
+        } elseif ($vat_id === null) {
+            $vat_id = '';
+        } elseif (is_int($vat_id)) {
+            $vat_id = sprintf('%010d', $vat_id);
+        } else {
+            throw new InvalidArgumentException('VatId can either be a string, int or null.');
+        }
+
+        if ($vat_id !== '') {
+            if (preg_match('/^\d{10}$/', $vat_id) !== 1) {
+                throw new InvalidArgumentException("Invalid VAT ID set. Must be contain 10 chars, digits only. '{$vat_id}' provided.");
+            }
+        }
+
+        if ($this->recipient_type === self::TYPE_COMPANY && $vat_id === '') {
+            throw new RuntimeException('Company recipient must have VAT ID set.');
+        }
+
+        return $vat_id;
+    }
+
+    /** @var string Recipient bank account number (26 digits), mandatory */
+    protected $bank_account = '';
+
+    /**
+     * Sets mandatory recipient routing bank account number. Account number must contain 26 digits.
+     * Digits can be grouped and separated by spaces however all spaces will be removed.
+     *
+     * @param string $account Recipient bank account number (26 digits)
+     *
+     * @return $this
+     */
+    public function bankAccount($account)
+    {
+        $this->bank_account = $this->validateBankAccount($account);
+
+        return $this;
+    }
+
+    /**
+     * @param string $account
+     *
+     * @return string
+     *
+     * @throws \InvalidArgumentException
+     */
+    protected function validateBankAccount($account)
+    {
+        if (!is_string($account)) {
+            throw new InvalidArgumentException('Bank account number must be a string.');
+        }
+        $account = str_replace(' ', '', $account);
+
+        if (preg_match('/^\d{26}$/', $account) !== 1) {
+            throw new InvalidArgumentException("Bank account number must be 26 chars long, digits only. '{$account}' provided.");
+        }
+
+        return $account;
+    }
+
+    /** @var string 20 chars max, recipient name, mandatory */
+    protected $recipient_name = '';
+
+    /** @var int */
+    const NAME_MAX_LEN = 20;
+
+    /**
+     * Sets recipient name. Up to 20 chars (longer strings are allowed and will be trimmed).
+     *
+     * @param string $name recipient name
+     *
+     * @return $this
+     */
+    public function name($name)
+    {
+        $this->recipient_name = $this->validateName($name);
+
+        return $this;
+    }
+
+    /**
+     * @param string $name
+     *
+     * @return string
+     *
+     * @throws \InvalidArgumentException
+     * @throws \RuntimeException
+     */
+    protected function validateName($name)
+    {
+        if (!is_string($name)) {
+            throw new InvalidArgumentException('Recipient name must be a string.');
+        }
+
+        if ($this->strict_mode && mb_strlen($name) > self::NAME_MAX_LEN) {
+            throw new InvalidArgumentException(sprintf('Recipient name must not exceed %d chars.', self::NAME_MAX_LEN));
+        }
+
+        $name = mb_substr($name, 0, self::NAME_MAX_LEN);
+
+        if ($name === '') {
+            throw new RuntimeException('Recipient name cannot be empty.');
+        }
+
+        return $name;
+    }
+
+    /** @var string 2 chars, country code (i.e. 'PL'), optional, letters */
+    protected $country_code = '';
+
+    /**
+     * @param string|null $country_code 2 chars, country code (i.e. 'PL'), optional, letters
+     *
+     * @return $this
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function country($country_code)
+    {
+        if ($country_code === null) {
+            $country_code = '';
+        }
+
+        if (!is_string($country_code)) {
+            throw new InvalidArgumentException('Country code must be a string.');
+        }
+
+        $country_code = mb_strtoupper($country_code);
+        if ($country_code !== '') {
+            if (preg_match('/^[A-Z]{2}$/', $country_code) !== 1) {
+                throw new InvalidArgumentException("Country code must be a 2 character long, letters only. '{$country_code}' provided.");
+            }
+        }
+
+        $this->country_code = strtoupper($country_code);
+
+        return $this;
+    }
+
+    /** @var string */
+    protected $payment_title = '';
+
+    /** @var int */
+    const TITLE_MAX_LEN = 32;
+
+    /**
+     * @param string $title 32 chars, payment title, mandatory, letters+digits
+     *
+     * @return $this
+     */
+    public function title($title)
+    {
+        $this->payment_title = $this->validateTitle($title);
+
+        return $this;
+    }
+
+    /**
+     * @param string $title
+     *
+     * @return string
+     *
+     * @throws \InvalidArgumentException
+     */
+    protected function validateTitle($title)
+    {
+        if (!is_string($title)) {
+            throw new InvalidArgumentException('Payment title must be a string.');
+        }
+
+        if ($this->strict_mode && mb_strlen($title) > self::TITLE_MAX_LEN) {
+            throw new InvalidArgumentException(sprintf('Payment title must not exceed %d chars.', self::TITLE_MAX_LEN));
+        }
+
+        if ($title === '') {
+            throw new RuntimeException('Payment title cannot be empty.');
+        }
+
+        return mb_substr(trim($title), 0, self::TITLE_MAX_LEN);
+    }
+
+    /** @var int|null */
+    protected $amount = null;
+
+    /**
+     * @param float|int $amount 6 chars, amount in Polish grosz, digits, mandatory
+     *
+     * @return $this
+     */
+    public function amount($amount)
+    {
+        $this->amount = $this->validateAmount($amount);
+
+        return $this;
+    }
+
+    /**
+     * @param float|int $amount
+     *
+     * @return int
+     *
+     * @throws \OutOfRangeException
+     * @throws \InvalidArgumentException
+     * @throws \RuntimeException
+     */
+    protected function validateAmount($amount)
+    {
+        if ($amount === null) {
+            throw new RuntimeException('Amount not specified.');
+        }
+
+        if (is_float($amount)) {
+            $amount = (int)($amount * 100);
+        } elseif (!is_int($amount)) {
+            throw new InvalidArgumentException('Amount must be either float or int');
+        }
+
+        if ($amount < 0) {
+            throw new OutOfRangeException('Amount cannot be negative.');
+        }
+
+        if ($amount > 999999) {
+            throw new OutOfRangeException('Amount representation cannot exceed 6 digits. Current value: {$amount}');
+        }
+
+        return $amount;
+    }
+
+    /** @var string */
+    protected $reserved1 = '';
+
+    /** @var int */
+    const RESERVED1_MAX_LEN = 20;
+
+    /**
+     * @param string|null $id 20 chars, reserved i.e. for payment reference id, optional, digits (but we use letters+digits as some banks do too)
+     *
+     * @return $this
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function reserved1($id)
+    {
+        if ($id === null) {
+            $id = '';
+        }
+
+        if (!is_string($id)) {
+            throw new InvalidArgumentException('Reserved1/RefId value must be a string.');
+        }
+
+        if (mb_strlen($id) > self::RESERVED1_MAX_LEN) {
+            throw new InvalidArgumentException(sprintf('Maksymalna długość wartości Reserved1/RefId to %d znaków.', self::RESERVED1_MAX_LEN));
+        }
+
+        $this->reserved1 = $id;
+
+        return $this;
+    }
+
+    /**
+     * Alias for reserved1()
+     *
+     * @param string|null $id
+     *
+     * @return $this
+     */
+    public function refId($id)
+    {
+        return $this->reserved1($id);
+    }
+
+    /** @var string */
+    protected $reserved2 = '';
+
+    /** @var int */
+    const RESERVED2_MAX_LEN = 12;
+
+    /**
+     * 12 chars, reserved i.e. for Invobill reference id, optional, digits (but we allow letters+digits as some banks do too)
+     *
+     * @param string|null $id
+     *
+     * @return $this
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function reserved2($id)
+    {
+        if ($id === null) {
+            $id = '';
+        }
+
+        if (!is_string($id)) {
+            throw new InvalidArgumentException('Reserved2/Invobill value must be a string.');
+        }
+
+        if (mb_strlen($id) > self::RESERVED2_MAX_LEN) {
+            throw new InvalidArgumentException(sprintf('Maksymalna długość wartości Reserved2/Invobill to %d znaków.', self::RESERVED2_MAX_LEN));
+        }
+
+        $this->reserved2 = $id;
+
+        return $this;
+    }
+
+    /**
+     * Alias for reserved2()
+     *
+     * @param string|null $id
+     *
+     * @return $this
+     */
+    public function invobill($id)
+    {
+        return $this->reserved2($id);
+    }
+
+    /** @var string */
+    protected $reserved3 = '';
+
+    /** @var int */
+    const RESERVED3_MAX_LEN = 24;
+
+    /**
+     * 24 chars, reserved, optional, letters+digits
+     *
+     * @param string|null $id
+     *
+     * @return $this
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function reserved3($id)
+    {
+        if ($id === null) {
+            $id = '';
+        }
+
+        if (!is_string($id)) {
+            throw new InvalidArgumentException('Reserved3 value must be a string.');
+        }
+
+        if (mb_strlen($id) > self::RESERVED3_MAX_LEN) {
+            throw new InvalidArgumentException(sprintf('Maksymalna długość wartości Reserved3 to %d znaków.', self::RESERVED3_MAX_LEN));
+        }
+
+        $this->reserved3 = $id;
+
+        return $this;
+    }
+
+    /**
+     * @return string
+     *
+     * @throws \RuntimeException
+     */
+    public function build()
+    {
+        // validate
+        $this->validateBankAccount($this->bank_account);
+        $this->validateName($this->recipient_name);
+        $this->validateVatId($this->vat_id);
+        $this->validateTitle($this->payment_title);
+        $this->validateAmount($this->amount);
+
+        // build
+        $fields = [
+            $this->vat_id,
+            $this->country_code,
+            $this->bank_account,
+            sprintf('%06d', $this->amount),
+            $this->recipient_name,
+            $this->payment_title,
+            $this->reserved1,
+            $this->reserved2,
+            $this->reserved3,
+        ];
+
+        $result = implode($this->separator, $fields);
+        if (mb_strlen($result) > self::MAX_LEN) {
+            throw new RuntimeException(
+                sprintf('Oops, this should not happen! Result string is %d chars long (max allowed %d). Please report this!', mb_strlen($result), self::MAX_LEN));
+        }
+
+        return $result;
+    }
 }