#include "WString.h"


/* atoi: convert s to an integer
 *
 * Here's the easy way:
 * int atoi(char *s){return (int)strtoul(s, NULL, 10);}
 * But I'll behave...
 */
int atoi(char *s)
{
    int n, sign;

    while (isspace(*s))
        s++;
    sign = (*s == '+' || *s == '-') ? ((*s++ == '+') ? 1 : -1) : 1;
    for (n = 0; isdigit(*s); s++)
        n = (n * 10) + (*s - '0');  /* note to language lawyers --
                                     * the digits are in consecutive
                                     * order in the character set
                                     * C90 5.2.1
                                     */
    return sign * n;
}

/* Shamelessly copied from my 4-12 answer

itoa() is non-standard, but defined on p.64 as having this prototype:

void itoa(int n, char s[])

Instead of this, I thought I'd use a different prototype (one I got from

the library manual of one of my compilers) since it includes all of the
above:

char *itoa(int value, char *digits, int base);

Description:  The itoa() function converts an integer value into an
ASCII string of digits.  The base argument specifies the number base for

the conversion.  The base must be a value in the range [2..36], where 2
is binary, 8 is octal, 10 is decimal, and 16 is hexadecimal.  The buffer

pointed to by digits must be large enough to hold the ASCII string of
digits plus a terminating null character.  The maximum amount of buffer
space used is the precision of an int in bits + 2 (one for the sign and
one for the terminating null).

Returns:  digits, or NULL if error.

*/

char *utoa(unsigned value, char *digits, int base)
{
    char *s, *p;

    s = "0123456789abcdefghijklmnopqrstuvwxyz"; /* don't care if s is in

                                                 * read-only memory
                                                 */
    if (base == 0)
        base = 10;
    if (digits == NULL || base < 2 || base > 36)
        return NULL;
    if (value < (unsigned) base) {
        digits[0] = s[value];
        digits[1] = '\0';
    } else {
        for (p = utoa(value / ((unsigned)base), digits, base);
             *p;
             p++);
        utoa( value % ((unsigned)base), p, base);
    }
    return digits;
}

char *itoa(int value, char *digits, int base)
{
    char *d;
    unsigned u; /* assume unsigned is big enough to hold all the
                 * unsigned values -x could possibly be -- don't
                 * know how well this assumption holds on the
                 * DeathStation 9000, so beware of nasal demons
                 */

    d = digits;
    if (base == 0)
        base = 10;
    if (digits == NULL || base < 2 || base > 36)
        return NULL;
    if (value < 0) {
        *d++ = '-';
        u = -((unsigned)value);
    } else
        u = value;
    utoa(u, d, base);
    return digits;
}


/*********************************************/
/*  Constructors                             */
/*********************************************/

String::String(const char *cstr)
{
	init();
	if (cstr) copy(cstr, strlen(cstr));
}

String::String(const String &value)
{
	init();
	*this = value;
}

String::String(char c)
{
	init();
	char buf[2];
	buf[0] = c;
	buf[1] = 0;
	*this = buf;
}

String::String(unsigned char value, unsigned char base)
{
	init();
	char buf[9];
	utoa(value, buf, base);
	*this = buf;
}

String::String(int value, unsigned char base)
{
	init();
	char buf[18];
	itoa(value, buf, base);
	*this = buf;
}

String::String(unsigned int value, unsigned char base)
{
	init();
	char buf[17];
	utoa(value, buf, base);
	*this = buf;
}


String::~String()
{
	free(buffer);
}

/*********************************************/
/*  Memory Management                        */
/*********************************************/

inline void String::init(void)
{
	buffer = NULL;
	capacity = 0;
	len = 0;
	flags = 0;
}

void String::invalidate(void)
{
	if (buffer) free(buffer);
	buffer = NULL;
	capacity = len = 0;
}

unsigned char String::reserve(unsigned int size)
{
	if (buffer && capacity >= size) return 1;
	if (changeBuffer(size)) {
		if (len == 0) buffer[0] = 0;
		return 1;
	}
	return 0;
}

unsigned char String::changeBuffer(unsigned int maxStrLen)
{
	char *newbuffer = (char *)realloc(buffer, maxStrLen + 1);
	if (newbuffer) {
		buffer = newbuffer;
		capacity = maxStrLen;
		return 1;
	}
	return 0;
}

/*********************************************/
/*  Copy and Move                            */
/*********************************************/

String & String::copy(const char *cstr, unsigned int length)
{
	if (!reserve(length)) {
		invalidate();
		return *this;
	}
	len = length;
	strcpy(buffer, cstr);
	return *this;
}

String & String::operator = (const String &rhs)
{
	if (this == &rhs) return *this;
	
	if (rhs.buffer) copy(rhs.buffer, rhs.len);
	else invalidate();
	
	return *this;
}

String & String::operator = (const char *cstr)
{
	if (cstr) copy(cstr, strlen(cstr));
	else invalidate();
	
	return *this;
}

/*********************************************/
/*  concat                                   */
/*********************************************/

unsigned char String::concat(const String &s)
{
	return concat(s.buffer, s.len);
}

unsigned char String::concat(const char *cstr, unsigned int length)
{
	unsigned int newlen = len + length;
	if (!cstr) return 0;
	if (length == 0) return 1;
	if (!reserve(newlen)) return 0;
	strcpy(buffer + len, cstr);
	len = newlen;
	return 1;
}

unsigned char String::concat(const char *cstr)
{
	if (!cstr) return 0;
	return concat(cstr, strlen(cstr));
}

unsigned char String::concat(char c)
{
	char buf[2];
	buf[0] = c;
	buf[1] = 0;
	return concat(buf, 1);
}

unsigned char String::concat(unsigned char num)
{
	char buf[4];
	itoa(num, buf, 10);
	return concat(buf, strlen(buf));
}

unsigned char String::concat(int num)
{
	char buf[7];
	itoa(num, buf, 10);
	return concat(buf, strlen(buf));
}

unsigned char String::concat(unsigned int num)
{
	char buf[6];
	utoa(num, buf, 10);
	return concat(buf, strlen(buf));
}

/*********************************************/
/*  Comparison                               */
/*********************************************/

int String::compareTo(const String &s) const
{
	if (!buffer || !s.buffer) {
		if (s.buffer && s.len > 0) return 0 - *(unsigned char *)s.buffer;
		if (buffer && len > 0) return *(unsigned char *)buffer;
		return 0;
	}
	return strcmp(buffer, s.buffer);
}

unsigned char String::equals(const String &s2) const
{
	return (len == s2.len && compareTo(s2) == 0);
}

unsigned char String::equals(const char *cstr) const
{
	if (len == 0) return (cstr == NULL || *cstr == 0);
	if (cstr == NULL) return buffer[0] == 0;
	return strcmp(buffer, cstr) == 0;
}

unsigned char String::operator<(const String &rhs) const
{
	return compareTo(rhs) < 0;
}

unsigned char String::operator>(const String &rhs) const
{
	return compareTo(rhs) > 0;
}

unsigned char String::operator<=(const String &rhs) const
{
	return compareTo(rhs) <= 0;
}

unsigned char String::operator>=(const String &rhs) const
{
	return compareTo(rhs) >= 0;
}

unsigned char String::equalsIgnoreCase( const String &s2 ) const
{
	if (this == &s2) return 1;
	if (len != s2.len) return 0;
	if (len == 0) return 1;
	const char *p1 = buffer;
	const char *p2 = s2.buffer;
	while (*p1) {
		if (tolower(*p1++) != tolower(*p2++)) return 0;
	} 
	return 1;
}

unsigned char String::startsWith( const String &s2 ) const
{
	if (len < s2.len) return 0;
	return startsWith(s2, 0);
}

unsigned char String::startsWith( const String &s2, unsigned int offset ) const
{
	if (offset > len - s2.len || !buffer || !s2.buffer) return 0;
	return strncmp( &buffer[offset], s2.buffer, s2.len ) == 0;
}

unsigned char String::endsWith( const String &s2 ) const
{
	if ( len < s2.len || !buffer || !s2.buffer) return 0;
	return strcmp(&buffer[len - s2.len], s2.buffer) == 0;
}

/*********************************************/
/*  Character Access                         */
/*********************************************/

char String::charAt(unsigned int loc) const
{
	return operator[](loc);
}

void String::setCharAt(unsigned int loc, char c) 
{
	if (loc < len) buffer[loc] = c;
}

char & String::operator[](unsigned int index)
{
	static char dummy_writable_char;
	if (index >= len || !buffer) {
		dummy_writable_char = 0;
		return dummy_writable_char;
	}
	return buffer[index];
}

char String::operator[]( unsigned int index ) const
{
	if (index >= len || !buffer) return 0;
	return buffer[index];
}

void String::getBytes(unsigned char *buf, unsigned int bufsize, unsigned int index) const
{
	if (!bufsize || !buf) return;
	if (index >= len) {
		buf[0] = 0;
		return;
	}
	unsigned int n = bufsize - 1;
	if (n > len - index) n = len - index;
	strncpy((char *)buf, buffer + index, n);
	buf[n] = 0;
}

/*********************************************/
/*  Search                                   */
/*********************************************/

int String::indexOf(char c) const
{
	return indexOf(c, 0);
}

int String::indexOf( char ch, unsigned int fromIndex ) const
{
	if (fromIndex >= len) return -1;
	const char* temp = strchr(buffer + fromIndex, ch);
	if (temp == NULL) return -1;
	return temp - buffer;
}

int String::indexOf(const String &s2) const
{
	return indexOf(s2, 0);
}

int String::indexOf(const String &s2, unsigned int fromIndex) const
{
	if (fromIndex >= len) return -1;
	const char *found = strstr(buffer + fromIndex, s2.buffer);
	if (found == NULL) return -1;
	return found - buffer;
}

int String::lastIndexOf( char theChar ) const
{
	return lastIndexOf(theChar, len - 1);
}

int String::lastIndexOf(char ch, unsigned int fromIndex) const
{
	if (fromIndex >= len) return -1;
	char tempchar = buffer[fromIndex + 1];
	buffer[fromIndex + 1] = '\0';
	char* temp = strrchr( buffer, ch );
	buffer[fromIndex + 1] = tempchar;
	if (temp == NULL) return -1;
	return temp - buffer;
}

int String::lastIndexOf(const String &s2) const
{
	return lastIndexOf(s2, len - s2.len);
}

int String::lastIndexOf(const String &s2, unsigned int fromIndex) const
{
  	if (s2.len == 0 || len == 0 || s2.len > len) return -1;
	if (fromIndex >= len) fromIndex = len - 1;
	int found = -1;
	for (char *p = buffer; p <= buffer + fromIndex; p++) {
		p = strstr(p, s2.buffer);
		if (!p) break;
		if ((unsigned int)(p - buffer) <= fromIndex) found = p - buffer;
	}
	return found;
}

String String::substring( unsigned int left ) const
{
	return substring(left, len);
}

String String::substring(unsigned int left, unsigned int right) const
{
	if (left > right) {
		unsigned int temp = right;
		right = left;
		left = temp;
	}
	String out;
	if (left > len) return out;
	if (right > len) right = len;
	char temp = buffer[right];  // save the replaced character
	buffer[right] = '\0';	
	out = buffer + left;  // pointer arithmetic
	buffer[right] = temp;  //restore character
	return out;
}

/*********************************************/
/*  Modification                             */
/*********************************************/

void String::replace(char find, char replace)
{
	if (!buffer) return;
	for (char *p = buffer; *p; p++) {
		if (*p == find) *p = replace;
	}
}

void String::replace(const String& find, const String& replace)
{
	if (len == 0 || find.len == 0) return;
	int diff = replace.len - find.len;
	char *readFrom = buffer;
	char *foundAt;
	if (diff == 0) {
		while ((foundAt = strstr(readFrom, find.buffer)) != NULL) {
			memcpy(foundAt, replace.buffer, replace.len);
			readFrom = foundAt + replace.len;
		}
	} else if (diff < 0) {
		char *writeTo = buffer;
		while ((foundAt = strstr(readFrom, find.buffer)) != NULL) {
			unsigned int n = foundAt - readFrom;
			memcpy(writeTo, readFrom, n);
			writeTo += n;
			memcpy(writeTo, replace.buffer, replace.len);
			writeTo += replace.len;
			readFrom = foundAt + find.len;
			len += diff;
		}
		strcpy(writeTo, readFrom);
	} else {
		unsigned int size = len; // compute size needed for result
		while ((foundAt = strstr(readFrom, find.buffer)) != NULL) {
			readFrom = foundAt + find.len;
			size += diff;
		}
		if (size == len) return;
		if (size > capacity && !changeBuffer(size)) return; // XXX: tell user!
		int index = len - 1;
		while (index >= 0 && (index = lastIndexOf(find, index)) >= 0) {
			readFrom = buffer + index + find.len;
			memmove(readFrom + diff, readFrom, len - (readFrom - buffer));
			len += diff;
			buffer[len] = 0;
			memcpy(buffer + index, replace.buffer, replace.len);
			index--;
		}
	}
}

void String::toLowerCase(void)
{
	if (!buffer) return;
	for (char *p = buffer; *p; p++) {
		*p = tolower(*p);
	}
}

void String::toUpperCase(void)
{
	if (!buffer) return;
	for (char *p = buffer; *p; p++) {
		*p = toupper(*p);
	}
}

void String::trim(void)
{
	if (!buffer || len == 0) return;
	char *begin = buffer;
	while (isspace(*begin)) begin++;
	char *end = buffer + len - 1;
	while (isspace(*end) && end >= begin) end--;
	len = end + 1 - begin;
	if (begin > buffer) memcpy(buffer, begin, len);
	buffer[len] = 0;
}

/*********************************************/
/*  Parsing / Conversion                     */
/*********************************************/

long String::toInt(void) const
{
	if (buffer) return atol(buffer);
	return 0;
}