<?php
/**
 * Validation rules.
 *
 * @package    Kohana
 * @category   Security
 * @author     Kohana Team
 * @copyright  (c) Kohana Team
 * @license    https://koseven.ga/LICENSE.md
 */
class Kohana_Valid {

	/**
	 * Checks if a field is not empty.
	 *
	 * @return  boolean
	 */
	public static function not_empty($value)
	{
		if (is_object($value) AND $value instanceof ArrayObject)
		{
			// Get the array from the ArrayObject
			$value = $value->getArrayCopy();
		}

		// Value cannot be NULL, FALSE, '', or an empty array
		return ! in_array($value, [NULL, FALSE, '', []], TRUE);
	}

	/**
	 * Checks a field against a regular expression.
	 *
	 * @param   string  $value      value
	 * @param   string  $expression regular expression to match (including delimiters)
	 * @return  boolean
	 */
	public static function regex($value, $expression)
	{
		return (bool) preg_match($expression, (string) $value);
	}

	/**
	 * Checks that a field is long enough.
	 *
	 * @param   string  $value  value
	 * @param   integer $length minimum length required
	 * @return  boolean
	 */
	public static function min_length($value, $length)
	{
		return UTF8::strlen($value) >= $length;
	}

	/**
	 * Checks that a field is short enough.
	 *
	 * @param   string  $value  value
	 * @param   integer $length maximum length required
	 * @return  boolean
	 */
	public static function max_length($value, $length)
	{
		return UTF8::strlen($value) <= $length;
	}

	/**
	 * Checks that a field is exactly the right length.
	 *
	 * @param   string          $value  value
	 * @param   integer|array   $length exact length required, or array of valid lengths
	 * @return  boolean
	 */
	public static function exact_length($value, $length)
	{
		if (is_array($length))
		{
			foreach ($length as $strlen)
			{
				if (UTF8::strlen($value) === $strlen)
					return TRUE;
			}
			return FALSE;
		}

		return UTF8::strlen($value) === $length;
	}

	/**
	 * Checks that a field is exactly the value required.
	 *
	 * @param   string  $value      value
	 * @param   string  $required   required value
	 * @return  boolean
	 */
	public static function equals($value, $required)
	{
		return ($value === $required);
	}

    /**
     * Validates e-mail address
     * @link  http://www.iamcal.com/publish/articles/php/parsing_email/
     * @link  http://www.w3.org/Protocols/rfc822/
     * 
     * @param  string  $email   e-mail address
     * @param  bool    $strict  strict e-mail checking
     * @return boolean
     */
    public static function email($email, $strict = FALSE)
    {
       	if ($strict)
	{
		return filter_var(filter_var($email, FILTER_SANITIZE_EMAIL), FILTER_VALIDATE_EMAIL) !== FALSE;
	}
	else
	{
		return filter_var($email, FILTER_VALIDATE_EMAIL) !== FALSE;
	}
    }

	/**
	 * Validate the domain of an email address by checking if the domain has a
	 * valid MX record.
	 *
	 * @link  http://php.net/checkdnsrr  not added to Windows until PHP 5.3.0
	 *
	 * @param   string  $email  email address
	 * @return  boolean
	 */
	public static function email_domain($email)
	{
		if ( ! Valid::not_empty($email))
			return FALSE; // Empty fields cause issues with checkdnsrr()

		// Check if the email domain has a valid MX record
		return (bool) checkdnsrr(preg_replace('/^[^@]++@/', '', $email), 'MX');
	}

	/**
	 * Validate a URL.
	 *
	 * @param   string  $url    URL
	 * @return  boolean
	 */
	public static function url($url)
	{
		// Based on http://www.apps.ietf.org/rfc/rfc1738.html#sec-5
		if ( ! preg_match(
			'~^

			# scheme
			[-a-z0-9+.]++://

			# username:password (optional)
			(?:
				    [-a-z0-9$_.+!*\'(),;?&=%]++   # username
				(?::[-a-z0-9$_.+!*\'(),;?&=%]++)? # password (optional)
				@
			)?

			(?:
				# ip address
				\d{1,3}+(?:\.\d{1,3}+){3}+

				| # or

				# hostname (captured)
				(
					     (?!-)[-a-z0-9]{1,63}+(?<!-)
					(?:\.(?!-)[-a-z0-9]{1,63}+(?<!-)){0,126}+
				)
			)

			# port (optional)
			(?::\d{1,5}+)?

			# path (optional)
			(?:/.*)?

			$~iDx', $url, $matches))
			return FALSE;

		// We matched an IP address
		if ( ! isset($matches[1]))
			return TRUE;

		// Check maximum length of the whole hostname
		// http://en.wikipedia.org/wiki/Domain_name#cite_note-0
		if (strlen($matches[1]) > 253)
			return FALSE;

		// An extra check for the top level domain
		// It must start with a letter
		$tld = ltrim(substr($matches[1], (int) strrpos($matches[1], '.')), '.');
		return ctype_alpha($tld[0]);
	}

	/**
	 * Validate an IP.
	 *
	 * @param   string  $ip             IP address
	 * @param   boolean $allow_private  allow private IP networks
	 * @return  boolean
	 */
	public static function ip($ip, $allow_private = TRUE)
	{
		// Do not allow reserved addresses
		$flags = FILTER_FLAG_NO_RES_RANGE;

		if ($allow_private === FALSE)
		{
			// Do not allow private or reserved addresses
			$flags = $flags | FILTER_FLAG_NO_PRIV_RANGE;
		}

		return (bool) filter_var($ip, FILTER_VALIDATE_IP, $flags);
	}

	/**
	 * Validates a credit card number, with a Luhn check if possible.
	 *
	 * @param   integer         $number credit card number
	 * @param   string|array    $type   card type, or an array of card types
	 * @return  boolean
	 * @uses    Valid::luhn
	 */
	public static function credit_card($number, $type = NULL)
	{
		// Remove all non-digit characters from the number
		if (($number = preg_replace('/\D+/', '', $number)) === '')
			return FALSE;

		if ($type == NULL)
		{
			// Use the default type
			$type = 'default';
		}
		elseif (is_array($type))
		{
			foreach ($type as $t)
			{
				// Test each type for validity
				if (Valid::credit_card($number, $t))
					return TRUE;
			}

			return FALSE;
		}

		$cards = Kohana::$config->load('credit_cards');

		// Check card type
		$type = strtolower($type);

		if ( ! isset($cards[$type]))
			return FALSE;

		// Check card number length
		$length = strlen($number);

		// Validate the card length by the card type
		if ( ! in_array($length, preg_split('/\D+/', $cards[$type]['length'])))
			return FALSE;

		// Check card number prefix
		if ( ! preg_match('/^'.$cards[$type]['prefix'].'/', $number))
			return FALSE;

		// No Luhn check required
		if ($cards[$type]['luhn'] == FALSE)
			return TRUE;

		return Valid::luhn($number);
	}

	/**
	 * Validate a number against the [Luhn](http://en.wikipedia.org/wiki/Luhn_algorithm)
	 * (mod10) formula.
	 *
	 * @param   string  $number number to check
	 * @return  boolean
	 */
	public static function luhn($number)
	{
		// Force the value to be a string as this method uses string functions.
		// Converting to an integer may pass PHP_INT_MAX and result in an error!
		$number = (string) $number;

		if ( ! ctype_digit($number))
		{
			// Luhn can only be used on numbers!
			return FALSE;
		}

		// Check number length
		$length = strlen($number);

		// Checksum of the card number
		$checksum = 0;

		for ($i = $length - 1; $i >= 0; $i -= 2)
		{
			// Add up every 2nd digit, starting from the right
			$checksum += substr($number, $i, 1);
		}

		for ($i = $length - 2; $i >= 0; $i -= 2)
		{
			// Add up every 2nd digit doubled, starting from the right
			$double = substr($number, $i, 1) * 2;

			// Subtract 9 from the double where value is greater than 10
			$checksum += ($double >= 10) ? ($double - 9) : $double;
		}

		// If the checksum is a multiple of 10, the number is valid
		return ($checksum % 10 === 0);
	}

	/**
	 * Checks if a phone number is valid.
	 *
	 * @param   string  $number     phone number to check
	 * @param   array   $lengths
	 * @return  boolean
	 */
	public static function phone($number, $lengths = NULL)
	{
		if ( ! is_array($lengths))
		{
			$lengths = [7,10,11];
		}

		// Remove all non-digit characters from the number
		$number = preg_replace('/\D+/', '', $number);

		// Check if the number is within range
		return in_array(strlen($number), $lengths);
	}

	/**
	 * Tests if a string is a valid date string.
	 *
	 * @param   string  $str    date to check
	 * @return  boolean
	 */
	public static function date($str)
	{
		return (strtotime($str) !== FALSE);
	}

	/**
	 * Checks whether a string consists of alphabetical characters only.
	 *
	 * @param   string  $str    input string
	 * @param   boolean $utf8   trigger UTF-8 compatibility
	 * @return  boolean
	 */
	public static function alpha($str, $utf8 = FALSE)
	{
		$str = (string) $str;

		if ($utf8 === TRUE)
		{
			return (bool) preg_match('/^\pL++$/uD', $str);
		}
		else
		{
			return ctype_alpha($str);
		}
	}

	/**
	 * Checks whether a string consists of alphabetical characters and numbers only.
	 *
	 * @param   string  $str    input string
	 * @param   boolean $utf8   trigger UTF-8 compatibility
	 * @return  boolean
	 */
	public static function alpha_numeric($str, $utf8 = FALSE)
	{
		if ($utf8 === TRUE)
		{
			return (bool) preg_match('/^[\pL\pN]++$/uD', $str);
		}
		else
		{
			return ctype_alnum($str);
		}
	}

	/**
	 * Checks whether a string consists of alphabetical characters, numbers, underscores and dashes only.
	 *
	 * @param   string  $str    input string
	 * @param   boolean $utf8   trigger UTF-8 compatibility
	 * @return  boolean
	 */
	public static function alpha_dash($str, $utf8 = FALSE)
	{
		if ($utf8 === TRUE)
		{
			$regex = '/^[-\pL\pN_]++$/uD';
		}
		else
		{
			$regex = '/^[-a-z0-9_]++$/iD';
		}

		return (bool) preg_match($regex, $str);
	}

	/**
	 * Checks whether a string consists of digits only (no dots or dashes).
	 *
	 * @param   string  $str    input string
	 * @param   boolean $utf8   trigger UTF-8 compatibility
	 * @return  boolean
	 */
	public static function digit($str, $utf8 = FALSE)
	{
		if ($utf8 === TRUE)
		{
			return (bool) preg_match('/^\pN++$/uD', $str);
		}
		else
		{
			return (is_int($str) AND $str >= 0) OR ctype_digit($str);
		}
	}

	/**
	 * Checks whether a string is a valid number (negative and decimal numbers allowed).
	 *
	 * Uses {@link http://www.php.net/manual/en/function.localeconv.php locale conversion}
	 * to allow decimal point to be locale specific (when used in PHP version < 8.0)
	 * {@link https://php.watch/versions/8.0/float-to-string-locale-independent more info}
	 *
	 * @param   string  $str    input string
	 * @return  boolean
	 */
	public static function numeric($str)
	{
		if (version_compare(phpversion(), '8.0.0', '<')) {
			// Get the decimal point for the current locale
			list($decimal) = array_values(localeconv());
		} else {
			// Since PHP 8 the decimal separator is locale independent
			$decimal = '.';
		}

		// A lookahead is used to make sure the string contains at least one digit (before or after the decimal point)
		return (bool) preg_match('/^-?+(?=.*[0-9])[0-9]*+'.preg_quote($decimal).'?+[0-9]*+$/D', (string) $str);
	}

	/**
	 * Tests if a number is within a range.
	 *
	 * @param   string  $number number to check
	 * @param   integer $min    minimum value
	 * @param   integer $max    maximum value
	 * @param   integer $step   increment size
	 * @return  boolean
	 */
	public static function range($number, $min, $max, $step = NULL)
	{
		if ($number < $min OR $number > $max)
		{
			// Number is outside of range
			return FALSE;
		}

		if ( ! $step)
		{
			// Default to steps of 1
			$step = 1;
		}

		// Check step requirements
		return (($number - $min) % $step === 0);
	}

	/**
	 * Checks if a string is a proper decimal format. Optionally, a specific
	 * number of digits can be checked too.
	 *
	 * @param   string  $str    number to check
	 * @param   integer $places number of decimal places
	 * @param   integer $digits number of digits
	 * @return  boolean
	 */
	public static function decimal($str, $places = 2, $digits = NULL)
	{
		if ($digits > 0)
		{
			// Specific number of digits
			$digits = '{'.( (int) $digits).'}';
		}
		else
		{
			// Any number of digits
			$digits = '+';
		}

		// Get the decimal point for the current locale
		list($decimal) = array_values(localeconv());

		return (bool) preg_match('/^[+-]?[0-9]'.$digits.preg_quote($decimal).'[0-9]{'.( (int) $places).'}$/D', $str);
	}

	/**
	 * Checks if a string is a proper hexadecimal HTML color value. The validation
	 * is quite flexible as it does not require an initial "#" and also allows for
	 * the short notation using only three instead of six hexadecimal characters.
	 *
	 * @param   string  $str    input string
	 * @return  boolean
	 */
	public static function color($str)
	{
		return (bool) preg_match('/^#?+[0-9a-f]{3}(?:[0-9a-f]{3})?$/iD', $str);
	}

	/**
	 * Checks if a field matches the value of another field.
	 *
	 * @param   array   $array  array of values
	 * @param   string  $field  field name
	 * @param   string  $match  field name to match
	 * @return  boolean
	 */
	public static function matches($array, $field, $match)
	{
		return ($array[$field] === $array[$match]);
	}

}