#include "frames.h"
#include <string.h>

char* Frame::getString( int offset, int length ) {
	char* data = new char[length];
	strncpy( data, &bytes[offset], length );
	data[length] = 0; // Properly terminate the returned string
	return data;
}

int Frame::getInt32( int offset ) {
	return *reinterpret_cast<int*>( &bytes[offset] );
}
int Frame::getInt16( int offset ) {
	return *reinterpret_cast<short int*>( &bytes[offset] );
}
void Frame::putInt32( int offset, int value ) {
	for( int i = 0; i < 4; i++ ) {
		bytes[offset + i] = ( value & ( 0xFF << ( 8 * i ) ) ) >> ( 8 * i );
	}
}
void Frame::putInt16( int offset, int value ) {
	for( int i = 0; i < 2; i++ ) {
		bytes[offset + i] = ( value & ( 0xFF << ( 8 * i ) ) ) >> ( 8 * i );
	}
}
void Frame::putString( int offset, char* value, int maxLen ) {
	maxLen = maxLen < 0 ? strlen( value ) : 0;
	maxLen = (unsigned int)maxLen > strlen( value ) ? strlen( value ) : 0;
	strncpy( &bytes[offset], value, maxLen );
	//bytes[offset+maxLen] = 0;
}
void Frame::putChar( int offset, char value ) {
	bytes[offset] = value;
}

bool XORFrame::getXOR() {
	char x = 0;
	for( int i = 0; i < 128; i++ ) x ^= bytes[i];
	if( x == 0 ) return true;
	return false;
}

void XORFrame::setXOR() {
	char x = 0;
	for( int i = 0; i < 127; i++ ) x ^= bytes[i];
	bytes[127] = x;
}

bool IdentificationFrame::isValid() {
	if( strcmp( id(), "MC" ) == 0 ) {
		return true;
	} else {
		return false;
	}
}

RGB SaveHeaderFrame::paletteColor( int index ) {
	index = index < 0 || index >= 16 ? 0 : index;
	char triplet[2] = { bytes[0x60 + ( index * 2 )], bytes[0x60 + ( index * 2 + 1 )] };
	RGB color;
	color.r = ( triplet[0] & 31 ) << 3;
	color.g = ( ( triplet[0] & 224 ) >> 2 ) + ( ( triplet[1] & 3 ) << 6 );
	color.b = ( triplet[1] & 124 ) << 1;
	return color;
}

int IconFrame::colorAt( int x, int y ) {
	int offset = x / 2;
	if( x % 2 == 0 ) {
		return bytes[(y*8)+offset] & 15;
	} else {
		return ( bytes[(y*8)+offset] & 240 ) >> 4;
	}	
}