<?PHP

interface String_Interface
{
    public function toUpper();
    public function toLower();
    public function length();
    public function compareTo(String $string,
                              Boolean $casesensitive = NULL);
    public function trim(String $replace = NULL);
    public function trimStart(String $replace = NULL);
    public function trimEnd(String $replace = NULL);
    public function leftJoin(String $string,
                             String $separator = NULL);
    public function rightJoin(String $string,
                              String $separator = NULL);
    public function insert(Integer $start,
                           String $string);
    public function padLeft(Integer $chars,
                            String $string = NULL);
    public function padRight(Integer $chars,
                             String $string = NULL);
    public function contains(String $string,
                             Boolean $casesensitive = NULL);
    public function endsWith(String $string,
                             Boolean $casesensitive = NULL);
    public function startsWith(String $string,
                               Boolean $casesensitive = NULL);
    public function indexOf(String $string,
                            Boolean $casesensitive = NULL);
    public function lastIndexOf(String $string,
                                Boolean $casesensitive = NULL);
    public function replace(String $search,
                            String $replace = NULL);
    public function split(String $string = NULL);
    public function remove(Integer $start,
                           Integer $length = NULL);
}
class String
        extends Object
        implements String_Interface
{
    const Blank = '';
    public function equals(String $string) {
        return parent::_equals($string);
    }
    public function isUtf8() {
        $value = $this->get(); return new Boolean((bool) (utf8_encode(utf8_decode($value)) == $value));
    }
    public function isEmpty() {
        $value = $this->get(); return new Boolean((bool) empty($value));
    }
    public function isWhitespace() {
        $value = trim($this->get(),
                      ' '); return new Boolean((bool) empty($value));
    }
    public function length() {
        return new Integer(strlen($this->get()));
    }
    public function toUpper() {
        return $this->setCopy(strtoupper($this->get()));
    }
    public function toLower() {
        return $this->setCopy(strtolower($this->get()));
    }
    public function toBoolean() {
        return new Boolean((bool) $this->get());
    }
    public function set($value) {
        if(NULL === $value)
            throw new ArgumentNullException;
        if(!is_string($value))
            throw new DatatypeExpectedException(DatatypeExpectedException::ERROR_NOT_STRING);
        parent::set((string) $value);
        return $this;
    }
    public function compareTo(String $string,
                              Boolean $casesensitive = NULL) {
        return new Boolean(($casesensitive === NULL || $casesensitive->get() === FALSE)
                                ? ($this->get() === $string->get())
                                : ($this->getTemp()->toLower()->get() === $string->getTemp()->toLower()->get()));
    }
    public function trim(String $replace = NULL) {
        return $this->setCopy(($replace === NULL || TRUE === $replace->isEmpty())
                                ? trim($this->get())
                                : trim($this->get(),
                                       $replace->get()));
    }
    public function trimStart(String $replace = NULL) {
        return $this->setCopy(($replace === NULL || TRUE === $replace->isEmpty())
                                ? ltrim($this->get())
                                : ltrim($this->get(),
                                        $replace->get()));
    }
    public function trimEnd(String $replace = NULL) {
        return $this->setCopy(($replace === NULL || TRUE === $replace->isEmpty())
                                ? rtrim($this->get())
                                : rtrim($this->get(),
                                        $replace->get()));
    }
    public function leftJoin(String $string,
                             String $separator = NULL) {
        if(TRUE === $string->isEmpty()->get())
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_EMPTY_STRING);
        return $this->setCopy(($separator === NULL)
                                ? ($string->get().$this->get())
                                : ($string->get().$separator->get().$this->get()));
    }
    public function rightJoin(String $string,
                              String $separator = NULL) {
        if(TRUE === $string->isEmpty()->get())
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_EMPTY_STRING);
        return $this->setCopy(($separator === NULL)
                                ? ($this->get().$string->get())
                                : ($this->get().$separator->get().$string->get()));
    }
    public function insert(Integer $start,
                           String $string) {
        if(TRUE === $string->isEmpty()->get())
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_EMPTY_STRING);

        try
        {
            if($start->get() < 0)
                throw new ArgumentOutOfRangeException(ArgumentOutOfRangeException::ERROR_OUT_OF_STRING_INDEX);
        }
        catch(ArgumentOutOfRangeException $e)
        {
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_NOT_POSITIVE_INTEGER_OR_ZERO, $e);
        }

        $value = $this->get();
        return $this->setCopy(substr($value,
                                     0,
                                     $start->get()).$string->get().substr($value,
                                                                          $start->get(),
                                                                          $this->length()->get()));
    }
    /**
     * @todo str_pad is fuzzy. rewrite this
     */
    public function padLeft(Integer $chars,
                            String $string = NULL) {
        try
        {
            if($chars->get() < 0)
                throw new ArgumentOutOfRangeException(ArgumentOutOfRangeException::ERROR_OUT_OF_STRING_INDEX);
        }
        catch(ArgumentOutOfRangeException $e)
        {
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_NOT_POSITIVE_INTEGER_OR_ZERO, $e);
        }

        return $this->setCopy(($string === NULL || $string->isEmpty()->get() === TRUE)
                                ? (str_pad($this->get(),
                                           $chars->get(),
                                           ' ',
                                           STR_PAD_LEFT))
                                : (str_pad($this->get(),
                                           $chars->get(),
                                           $string->get(),
                                           STR_PAD_LEFT)));
    }
    /**
     * @todo str_pad is fuzzy. rewrite this
     */
    public function padRight(Integer $chars,
                             String $string = NULL) {
        try
        {
            if($chars->get() < 0)
                throw new ArgumentOutOfRangeException(ArgumentOutOfRangeException::ERROR_OUT_OF_STRING_INDEX);
        }
        catch(ArgumentOutOfRangeException $e)
        {
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_NOT_POSITIVE_INTEGER_OR_ZERO, $e);
        }

        return $this->setCopy(($string === NULL || $string->isEmpty()->get() === TRUE)
                                ? (str_pad($this->get(),
                                           $chars->get(),
                                           ' ',
                                           STR_PAD_RIGHT))
                                : (str_pad($this->get(),
                                           $chars->get(),
                                           $string->get(),
                                           STR_PAD_RIGHT)));
    }
    public function contains(String $string,
                             Boolean $casesensitive = NULL) {
        if(TRUE === $string->isEmpty()->get())
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_EMPTY_STRING);
        return new Boolean((bool) (($casesensitive === NULL || $casesensitive->get() === FALSE)
                                ? (preg_match('#'.$string->get().'#msie',
                                              $this->get()))
                                : (preg_match('#'.$string->get().'#mse',
                                              $this->get()))));
    }
    public function endsWith(String $string,
                             Boolean $casesensitive = NULL) {
        if(TRUE === $string->isEmpty()->get())
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_EMPTY_STRING);
        return new Boolean((bool) (($casesensitive === NULL || $casesensitive->get() === FALSE)
                                ? ($string->get() == substr($this->get(),
                                                            $this->length()->get() - $string->length()->get()))
                                : ($string->getTemp()->toLower()->get() == substr($this->getTemp()->toLower()->get(),
                                                                                  $this->length()->get() - $string->length()->get()))));
    }
    public function startsWith(String $string,
                               Boolean $casesensitive = NULL) {
        if(TRUE === $string->isEmpty()->get())
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_EMPTY_STRING);
        return new Boolean((bool) (($casesensitive === NULL || $casesensitive->get() === FALSE)
                                ? ($string->get() == substr($this->get(),
                                                            0,
                                                            $string->length()->get()))
                                : ($string->getTemp()->toLower()->get() == substr($this->getTemp()->toLower()->get(),
                                                                                  0,
                                                                                  $string->length()->get()))));
    }
    /**
     * @todo returns IntegerArray. how to map the results?
     */
    public function indexOf(String $string,
                            Boolean $casesensitive = NULL) {
        throw new ImplementationException(ImplementationException::ERROR_METHOD_NOT_IMPLEMENTED);
    }
    public function lastIndexOf(String $string,
                                Boolean $casesensitive = NULL) {
        if(TRUE === $string->isEmpty()->get())
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_EMPTY_STRING);

        $result = ($casesensitive === NULL || $casesensitive->get() === FALSE)
                ? (strrpos($this->get(),
                           $string->get()))
                : (strrpos($this->getTemp()->toLower()->get(),
                           $string->getTemp()->toLower()->get()));

        try
        {
            return new Integer($result);
        }
        catch(DatatypeExpectedException $e)
        {
            return new Boolean($result);
        }
    }
    public function replace(String $search,
                            String $replace = NULL) {
        if(TRUE === $search->isEmpty()->get())
            throw new ArgumentExpectedException(ArgumentExpectedException::ERROR_EMPTY_STRING);
        return $this->setCopy(($replace === NULL || $replace->isEmpty() === TRUE)
                                ? (str_replace($search->get(),
                                               '',
                                               $this->get()))
                                : (str_replace($search->get(),
                                               $replace->get(),
                                               $this->get())));
    }
    /**
     * @todo check split-pattern
     */
    public function split(String $string = NULL) {
        return new StringArray(($string === NULL || $string->isEmpty()->get() === TRUE)
                                ? (preg_split('/(?<!^)(?!$)/u',
                                              $this->get()))
                                : (explode($string->get(),
                                           $this->get())));
    }
    /**
     * @todo returns IntegerArray. how to map the results?
     */
    public function remove(Integer $start,
                           Integer $length = NULL) {
        throw new ImplementationException(ImplementationException::ERROR_METHOD_NOT_IMPLEMENTED);
    }
    public function __construct($value = self::Blank) {
        try
        {
            try
            {
                parent::__construct($value);
            }
            catch(DatatypeExpectedException $e)
            {
                throw new DatatypeExpectedException($e->getCode());
            }
            catch(ArgumentNullException $e)
            {
                throw new ArgumentNullException($e->getCode());
            }
        }
        catch(SystemException $e)
        {
            throw new ObjectHandlerException(ObjectHandlerException::ERROR_CAN_NOT_CREATE, $e);
        }
    }
}