// String.cpp

#include <new>
#include <string.h>

#include "String.h"

/*!
        \class String
        \brief A very simple string class.
*/

// constructor
String::String()
        : fLength(0),
          fString(NULL)
{
}

// copy constructor
String::String(const String &string)
        : fLength(0),
          fString(NULL)
{
        *this = string;
}

// constructor
String::String(const char *string, int32 length)
        : fLength(0),
          fString(NULL)
{
        SetTo(string, length);
}

// destructor
String::~String()
{
        Unset();
}

// SetTo
bool
String::SetTo(const char *string, int32 maxLength)
{
        if (string) {
                if (maxLength > 0)
                        maxLength = strnlen(string, maxLength);
                else if (maxLength < 0)
                        maxLength = strlen(string);
        }
        return _SetTo(string, maxLength);
}

// Unset
void
String::Unset()
{
        if (fString) {
                delete[] fString;
                fString = NULL;
        }
        fLength = 0;
}

// Truncate
void
String::Truncate(int32 newLength)
{
        if (newLength < 0)
                newLength = 0;
        if (newLength < fLength) {
                char *string = fString;
                fString = NULL;
                if (!_SetTo(string, newLength)) {
                        fString = string;
                        fLength = newLength;
                        fString[fLength] = '\0';
                } else
                        delete[] string;
        }
}

// GetString
const char *
String::GetString() const
{
        if (fString)
                return fString;
        return "";
}

// =
String &
String::operator=(const String &string)
{
        if (&string != this)
                _SetTo(string.fString, string.fLength);
        return *this;
}

// ==
bool
String::operator==(const String &string) const
{
        return (fLength == string.fLength
                        && (fLength == 0 || !strcmp(fString, string.fString)));
}

// _SetTo
bool
String::_SetTo(const char *string, int32 length)
{
        bool result = true;
        Unset();
        if (string && length > 0) {
                fString = new(std::nothrow) char[length + 1];
                if (fString) {
                        memcpy(fString, string, length);
                        fString[length] = '\0';
                        fLength = length;
                } else
                        result = false;
        }
        return result;
}