#include <debugio.h>
#include <memory.h>
#include <stdio.h>

uint8* VideoPtr = (uint8*) 0xb8000;

Point ConsoleCursor = {0, 0};
UPoint ConsoleSize = {80, 25};

uint8 ConsoleDefaultColor = CONSOLE_DEFAULT_COLOR;

/**************************************
 *  Basic console operations *
 **************************************/
void ConsoleClear()
{
	uint32 temp;

	for (temp = 0; temp < ConsoleSize.X * ConsoleSize.Y; temp++)
	{
		VideoPtr[2 * temp] = 0;
		VideoPtr[2 * temp + 1] = ConsoleDefaultColor;
	}
	
	ConsoleCursor.X = ConsoleCursor.Y = 0;
	ConsoleCursorUpdateHardware();
}

void ConsoleScroll (uint32 lines)
{
	// Sanity check, don't scroll too much
	if (lines > ConsoleSize.Y) lines = ConsoleSize.Y;

	uint32 x, y;
	for (y = 0; y < ConsoleSize.Y - lines; y++)
		for (x = 0; x < 2*ConsoleSize.X; x++)
			VideoPtr[y * ConsoleSize.X * 2 + x] = VideoPtr[(y+lines)*ConsoleSize.X*2 + x];

	for (y = ConsoleSize.Y - lines; y < ConsoleSize.Y; y++)
		for (x = 0; x < ConsoleSize.X; x++)
		{
			VideoPtr[2 * (y * ConsoleSize.X + x)] = 0;
			VideoPtr[2 * (y * ConsoleSize.X + x) + 1] = ConsoleDefaultColor;
		}
	
	ConsoleCursor.Y -= lines;
}


/**************************************
 *  Cursor position *
 **************************************/
Point ConsoleGetCursor()
{
	return ConsoleCursor;
}

extern void ConsoleSetCursor(Point p)
{
	ConsoleCursor = p;
}

void ConsoleCursorIncreasePos (int32 delta)
{
	// Increase X, Y positions
	ConsoleCursor.Y += delta / ConsoleSize.X;
	ConsoleCursor.X += delta % ConsoleSize.X;

	// Next line if X > Screen width
	while (ConsoleCursor.X >= (int32)ConsoleSize.X)
	{
		ConsoleCursor.Y++;
		ConsoleCursor.X -= ConsoleSize.X;
	}

	// Previous line if X < 0
	while (ConsoleCursor.X < 0)
	{
		ConsoleCursor.Y--;
		ConsoleCursor.X += ConsoleSize.X;
	}

	// Scroll if Y > Screen height
	if (ConsoleCursor.Y >= (int32)ConsoleSize.Y)
		ConsoleScroll(1);
}

void ConsoleCursorNewline()
{
	ConsoleCursor.X = 0;

	if (++ConsoleCursor.Y >= (int32)ConsoleSize.Y)
		ConsoleScroll(1);
}

void ConsoleCursorUpdateHardware()
{
	uint16 temp = (uint16) (ConsoleCursor.Y * ConsoleSize.X + ConsoleCursor.X);
	uint16* port = (uint16*) 0x463 ;

	outportb(*port, 14);
	outportb(*port + 1, (temp >> 8) & 0xff);
	outportb(*port, 15);
	outportb(*port + 1, temp & 0xff);
}

uint8 Color (uint8 back, uint8 fore)
{
	return ((back<<4) | fore);
}

void ConsoleSetDefaultColor(uint8 color)
{
	ConsoleDefaultColor = color;
}

uint8 ConsoleGetDefaultColor ()
{
	return ConsoleDefaultColor;
}

UPoint ConsoleGetSize()
{
	return ConsoleSize;
}

void ConsoleCursorGoto(Point p)
{
	if (p.X >= 0 && p.X < (int32)ConsoleSize.X) ConsoleCursor.X = p.X;
	if (p.Y >= 0 && p.Y < (int32)ConsoleSize.Y) ConsoleCursor.Y = p.Y;
}