/* kernLdr_print.c - This file is a part of NutsOS
 *
 * NutsOS
 * Copyright (C) 2013  Free Software Foundation, Inc.
 *
 * NutsOS is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * NutsOS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with NutsOS; If not, see <http://www.gnu.org/licenses/>.
 *
 * Valentin Verdier <valentin.verdier03@gmail.com>
 */

#include "kernLdr.h"

#define DEFAULT_COLOR 0x0F

char color = (char) DEFAULT_COLOR;

void scrollup(int lines) {
	char* vid;
	char* offset;

	for(vid = (char*) VIDEO_ADDR; vid < (char*) VIDEO_END_OFFSET; vid += 2) {
		offset = (char*) (vid + lines * 160);

		if(offset < (char*) VIDEO_END_OFFSET) {
			vid[0] = offset[0];
			vid[1] = offset[1];
		} else {
			vid[0] = 0;
			vid[1] = color;
		}
	}

	pos_y -= lines;
	if(pos_y < 0) {
		pos_y = 0;
	}
}

void write_char(char c_ascii) {
	char* vid;
	vid = (char*) (VIDEO_ADDR + pos_y * 160 + pos_x * 2);

	switch(c_ascii) {
		case 0:
			break;

		case 8:
			vid[-2] = 0;
			vid[-1] = color;
			pos_x--;
			break;

		case 10: // Ligne suivante
			pos_x = 0;
			pos_y++;
			break;

		case 13: // Retour debut de ligne
			pos_x = 0;
			break;

		default:
			vid[0] = c_ascii;
			vid[1] = color;
			pos_x++;
			break;
	}

	if(pos_x > 79) {
		pos_x = 0;
		pos_y++;
	}
	if(pos_y > 24) {
		scrollup(1);
	}
	if(posX < 0) {
		posX = 79;
		posY--;
	}
	if(posY < 0) {
		posX = 0;
		posY = 0;
	}
	if(enable_cursor) {
		move_cursor(pos_x, pos_y);
	}
}

static void print_dec(unsigned int a, char color) {
	char str[11];
	int_to_str(a, str, 10);

	unsigned int i;
	for(i = 0; str[i] != 0; i++) {
		write_char(str[i]);
	}
}

static void print_hex(unsigned int a, char color) {
	char str[9];
	int_to_str(a, str, 16);

	unsigned int i;
	for(i = 0; str[i] != 0; i++) {
		write_char(str[i]);
	}
}

static void print_bin(unsigned int a, char color) {
	char str[33];
	int_to_str(a, str, 2);

	unsigned int i;
	for(i = 0; str[i] != 0; i++) {
		write_char(str[i]);
	}
}

void print(char *str, ...) {
	va_list arg;
	va_start(arg, str);

	while(str[0] != 0) {
		if(str[0] == '%') {
			if(str[1] == 'd') {
				print_dec(va_arg(arg, T_dword), color);
				str += 2;
			} else if(str[1] == 'x') {
				print_hex(va_arg(arg, T_dword), color);
				str += 2;
			} else if(str[1] == 'b') {
				print_bin(va_arg(arg, T_dword), color);
				str += 2;
			} else if(str[1] == 's') {
				print(va_arg(arg, char*), color);
				str += 2;
			} else if(str[1] == 'C') {
				
			} else {
				write_char(*str, color);
				str++;
			}
		} else {
			write_char(*str, color);
			str++;
		}
	}
	va_end(arg);
}

void clear() {
	char* vid;
	for(vid = (char*) VIDEO_ADDR; vid <= (char*) VIDEO_END_OFFSET; vid += 2) {
		vid[0] = 0;
		vid[1] = ;
	}
}

void show_cursor() {
	enable_cursor = 1;
	move_cursor(pos_x, pos_y);
}

void hide_cursor() {
	enable_cursor = 0;
	move_cursor(-1, -1);
}

void move_cursor(char x, char y) {
	T_word c_pos = (T_word) (y * 80 + x);

	_out(0x3D4, 0x0F);
	_out(0x3D5, (T_byte) cpos);
	_out(0x3D4, 0x0E);
	_out(0x3D5, (T_byte) (cpos >> 8));
}