// vconsole.c
// Author: Josh Holtrop
// Date: 08/02/04
// Modified: 08/16/04

#include "char/vconsole.h"
#include "hos_defines.h"
#include "fs/devices.h"
#include "mm/vmm.h"
#include "lang/asmfuncs.h"
#include "display.h"
#include "functions.h"

vconsole_t *vconsoles[VCONSOLE_MAX];	// pointer to virtual console structs
extern int display_activeConsole;	// display subsystem active virtual console number 
char	ansi2vgaAttr[8] = {0, 4, 2, 6, 1, 5, 3, 7};

void	vconsole_put_char(minor_t id, int c);
void	vconsole_update_cursor(minor_t id, u16_t position);
void	vconsole_update_attribute(minor_t id);
void	vconsole_refresh(minor_t id);

// initialization routine for vconsoles module
int	vconsole_init(major_t major)
{
	dev_driver_t *vconsole_driver;
	if (( vconsole_driver = New(dev_driver_t) ))
	{
		vconsole_driver->char_write = vconsole_char_write;
		devices_register_major('c', major, vconsole_driver);
		return 0;
	}
	return -1;
}

// routine to create a new virtual console object
minor_t	vconsole_new(int width, int height)
{
	int i;
	for (i = 1; i < VCONSOLE_MAX; i++)
	{
		if ( (!vconsoles[i]) && ( vconsoles[i] = kcalloc(1, sizeof(vconsole_t))))  //New(vconsole_t) ) )
		{
			if (( vconsoles[i]->buffer = kmalloc(width * height * 2) ))
			{
				vconsoles[i]->width = width;
				vconsoles[i]->height = height;
				vconsoles[i]->attribute = vconsoles[i]->foreground = 0x07;
				memsetw(vconsoles[i]->buffer, 0x0720, width * height);
				// register the device as /dev/console%d
				return i;
			}
			else
			{
				kfree(vconsoles[i]);
				return 0;
			}
		}
	}
	return 0;
}


// called by display subsystem to draw a virtual console to the screen
int	vconsole_draw(minor_t id)
{
	if (vconsoles[id])
		return display_console_draw(id, vconsoles[id]->cursorPosition, vconsoles[id]->buffer);
	return -1;
}


// called by character device interface when a character is written to device w/ minor #id
int	vconsole_char_write(minor_t id, int c)
{
	if (!vconsoles[id])
		return -1;
	int cursorY = vconsoles[id]->cursorPosition / vconsoles[id]->width;
	int cursorX = vconsoles[id]->cursorPosition % vconsoles[id]->width;
	int evalEscapePosition = 0;
	switch (vconsoles[id]->escapeLevel)
	{
	case 2:
		if (c >= '0' && c <= '9')	// c is part of an escape value
		{
			vconsoles[id]->escapeValue[vconsoles[id]->escapePosition] *= 10;
			vconsoles[id]->escapeValue[vconsoles[id]->escapePosition] += c - '0';
			return 0;
		}
		else if (c == ';')
		{
			if (vconsoles[id]->escapePosition < 7)
				vconsoles[id]->escapePosition++;
			return 0;
		}
		switch (c)
		{
			case 'A':	// move cursor up n rows
				cursorY -= vconsoles[id]->escapeValue[0];
				if (cursorY < 0)
					cursorY = 0;
				vconsole_update_cursor(id, cursorY * vconsoles[id]->width + cursorX);
				break;
			case 'B':	// move cursor down n rows
				cursorY += vconsoles[id]->escapeValue[0];
				if (cursorY >= vconsoles[id]->height)
					cursorY = vconsoles[id]->height - 1;
				vconsole_update_cursor(id, cursorY * vconsoles[id]->width + cursorX);
				break;
			case 'C':	// move cursor left n columns
				cursorX -= vconsoles[id]->escapeValue[0];
				if (cursorX < 0)
					cursorX = 0;
				vconsole_update_cursor(id, cursorY * vconsoles[id]->width + cursorX);
				break;
			case 'D':	// move cursor right n columns
				cursorX += vconsoles[id]->escapeValue[0];
				if (cursorX >= vconsoles[id]->width)
					cursorX = vconsoles[id]->width - 1;
				vconsole_update_cursor(id, cursorY * vconsoles[id]->width + cursorX);
				break;
			case 'H':
			case 'f':	// move cursor to position (x,y) upper left is (1,1)
				cursorX = vconsoles[id]->escapeValue[0] - 1;
				cursorY = vconsoles[id]->escapeValue[1] - 1;
				if (cursorY < 0)
					cursorY = 0;
				if (cursorY >= vconsoles[id]->height)
					cursorY = vconsoles[id]->height - 1;
				if (cursorX < 0)
					cursorX = 0;
				if (cursorX >= vconsoles[id]->width)
					cursorX = vconsoles[id]->width - 1;
				vconsole_update_cursor(id, cursorY * vconsoles[id]->width + cursorX);
				break;
			case 'J':	// clear screen, home cursor
				memsetw(vconsoles[id]->buffer, 0x0720, vconsoles[id]->width * vconsoles[id]->height);
				vconsole_draw(id);
				vconsole_update_cursor(id, 0);
				break;
			case 'K':	// erase line from cursor position (including char. under cursor) to end of line
				memsetw(vconsoles[id]->buffer + vconsoles[id]->cursorPosition, 0x0720, vconsoles[id]->width - cursorX);
				vconsole_draw(id);
				break;
			case 's':	// push cursor position on an internal stack
				if (vconsoles[id]->cursorStackPosition < 16)
				  vconsoles[id]->cursorStack[vconsoles[id]->cursorStackPosition++] = vconsoles[id]->cursorPosition;
				break;
			case 'u':	// pop cursor position from stack
			  if (vconsoles[id]->cursorStackPosition > 0)
			    {
			      vconsole_update_cursor(id, vconsoles[id]->cursorStack[--vconsoles[id]->cursorStackPosition]);
			      
			    }
				break;
			case 'm':	// set text attributes
				for (evalEscapePosition = 0; evalEscapePosition <= vconsoles[id]->escapePosition; evalEscapePosition++)
				{
					switch (vconsoles[id]->escapeValue[evalEscapePosition])
					{
					case 0:
						vconsoles[id]->foreground = 0x07;
						vconsoles[id]->background = 0x00;
						vconsoles[id]->concealed = 0;
						vconsoles[id]->reverse = 0;
						vconsoles[id]->blink = 0;
						vconsoles[id]->bold = 0;
						vconsole_update_attribute(id);
						break;
					case 1:
						vconsoles[id]->bold = 1;
						vconsole_update_attribute(id);
						break;
					case 5:
						vconsoles[id]->blink = 1;
						vconsole_update_attribute(id);
						break;
					case 7:
						vconsoles[id]->reverse = 1;
						vconsole_update_attribute(id);
						break;
					case 30:
					case 31:
					case 32:
					case 33:
					case 34:
					case 35:
					case 36:
					case 37:
						vconsoles[id]->foreground = ansi2vgaAttr[vconsoles[id]->escapeValue[evalEscapePosition] - 30];
						vconsole_update_attribute(id);
						break;
					case 40:
					case 41:
					case 42:
					case 43:
					case 44:
					case 45:
					case 46:
					case 47:
						vconsoles[id]->background = ansi2vgaAttr[vconsoles[id]->escapeValue[evalEscapePosition] - 40];
						vconsole_update_attribute(id);
						break;
					}
				}
				vconsoles[id]->escapePosition = 0;
				break;
		}
		memsetd(vconsoles[id]->escapeValue, 0, 8);
		vconsoles[id]->escapePosition = 0;
		vconsoles[id]->escapeLevel = 0;
		return 0;
	case 1:
		if (c == '[')
			vconsoles[id]->escapeLevel = 2;
			break;
		vconsoles[id]->escapeLevel = 0;
		return 0;	// invalid escape sequence
	default:
		if (c == '\e')
		{
			vconsoles[id]->escapeLevel = 1;
			return 0;
		}
		vconsole_put_char(id, c);
	}
	return 0;
}


// write the character to the virtual console
void	vconsole_put_char(minor_t id, int c)
{
	if (!vconsoles[id]->concealed)
	{
		switch (c)
		{
		case '\t':
			if (vconsoles[id]->cursorPosition % 8)
				vconsole_update_cursor(id, vconsoles[id]->cursorPosition + (8 - (vconsoles[id]->cursorPosition % 8)));
			else
				vconsole_update_cursor(id, vconsoles[id]->cursorPosition + 8);
			break;
		case '\n':
			if (vconsoles[id]->cursorPosition % (vconsoles[id]->width))
				vconsole_update_cursor(id, vconsoles[id]->cursorPosition + (vconsoles[id]->width - (vconsoles[id]->cursorPosition % vconsoles[id]->width)));
			else
				vconsole_update_cursor(id, vconsoles[id]->cursorPosition + vconsoles[id]->width);
			break;
		default:
			vconsoles[id]->buffer[vconsoles[id]->cursorPosition] = c | (vconsoles[id]->attribute << 8);
			if (id == display_activeConsole)
				display_console_put_char(id, c | (vconsoles[id]->attribute << 8), vconsoles[id]->cursorPosition);
			vconsole_update_cursor(id, vconsoles[id]->cursorPosition + 1);
		}
	}
}

void	vconsole_update_cursor(minor_t id, u16_t position)
{
	vconsoles[id]->cursorPosition = position;
	if (position >= (vconsoles[id]->width * vconsoles[id]->height))	// time to scroll console
	{
	  int i;
	  for (i = 0; i < vconsoles[id]->cursorStackPosition; i++)
	    {
	      vconsoles[id]->cursorStack[i] -= vconsoles[id]->width;
	      if (vconsoles[id]->cursorStack[i] < 0)
		vconsoles[id]->cursorStack[i] = 0;
	    }
		vconsoles[id]->cursorPosition -= vconsoles[id]->width;
		memcpyw(vconsoles[id]->buffer, vconsoles[id]->buffer + vconsoles[id]->width, vconsoles[id]->width * (vconsoles[id]->height - 1));
		memsetw(vconsoles[id]->buffer + (vconsoles[id]->width * (vconsoles[id]->height - 1)), 0x0720, vconsoles[id]->width);
		if (display_activeConsole == id)
		{
			vconsole_draw(id);
			return;
		}
	}
	if (display_activeConsole == id)
		display_console_update_cursor(id, position);
}

void	vconsole_update_attribute(minor_t id)
{
	if (vconsoles[id]->reverse)
	{
		vconsoles[id]->attribute =
			vconsoles[id]->blink << 7 |
			vconsoles[id]->foreground << 4 |
			vconsoles[id]->bold << 3 |
			vconsoles[id]->background;
	}
	else
	{
		vconsoles[id]->attribute =
			vconsoles[id]->blink << 7 |
			vconsoles[id]->background << 4 |
			vconsoles[id]->bold << 3 |
			vconsoles[id]->foreground;
	}
}