/*  SliMP3 emulator - an emulator for the SliMP3 network MP3 player.
    Copyright (C) 2001 Jacob Potter

    This program 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 2 of the License, or
    (at your option) any later version.

    This program 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 this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
    USA.
*/

#include <stdio.h>

char line1[41], line2[41];
int xpos, ypos;			/* xpos is 0 - 39, ypos is 0 or 1. */

int movemode, cursdisp;

#define MODE_INC 1
#define MODE_DEC -1

#define MODE_CURSOR 4
#define MODE_DISPLAY 5

/*
Clear display	-	-	-	COMPLETE
Go to home position	-	-	COMPLETE
Mode: decrement address, shift cursor	COMPLETE
Mode: decrement address, shift display	COMPLETE
Mode: increment address, shift cursor	COMPLETE
Mode: increment address, shift display	COMPLETE
Display off	-	-	-	TODO
Display on, with cursor	-	-	TODO
Display on, with blinking	-	TODO
Display on, cursor and blinking	-	TODO
Move cursor left	-	-	COMPLETE
Move cursor right	-	-	COMPLETE
Shift display left	-	-	TODO
Shift display right	-	-	TODO
Set 8-bit mode	-	-	-	TODO
Set 4-bit mode	-	-	-	TODO
*/


void parseMessage(char *buffer, int blen) {
	int i, c;
	char commandByte;

	for (i=0; i < blen; i += 2) {
		if (buffer[i] == 0) {

			/* Wait for (buffer[i+1]) ms. */
		
		} else if (buffer[i] == 2) {
			commandByte = buffer[i+1];

			if (commandByte == 1) {
				/* Clear display */
				for (i = 0; i < 40; i++) line1[i] = ' ';
				for (i = 0; i < 40; i++) line2[i] = ' ';
				line1[40] = 0; line2[40] = 0;
				xpos = 0; ypos = 0;
			} else if ((commandByte & 254) == 2) {
				/* Go to home position. */
				xpos = 0; ypos = 0;
			} else if (commandByte == 4) {
				/* Mode: decrement address, shift cursor */
				movemode = MODE_DEC;
				cursdisp = MODE_CURSOR;
			} else if (commandByte == 5) {
				/* Mode: decrement address, shift display */
				movemode = MODE_DEC;
				cursdisp = MODE_DISPLAY;
			} else if (commandByte == 6) {
				/* Mode: increment address, shift cursor */
				movemode = MODE_INC;
				cursdisp = MODE_CURSOR;
			} else if (commandByte == 7) {
				/* Mode: increment address, shift display */
				movemode = MODE_INC;
				cursdisp = MODE_DISPLAY;
			} else if ((commandByte & 252) == 8) {
				/* Display off */
			} else if (commandByte == 14) {
				/* Display on, with cursor */
			} else if (commandByte == 13) {
				/* Display on, with blinking */
			} else if (commandByte == 15) {
				/* Display on, cursor and blinking */
			} else if ((commandByte & 252) == 16) {
				/* Move cursor left */
				xpos--;
				if (xpos < 0) {
					if (ypos == 0) xpos = 0;
					else { xpos = 39; ypos--; }
				}
			} else if ((commandByte & 252) == 20) {
				/* Move cursor right */
				xpos++;
				if (xpos > 39) {
					xpos = 0;
					if (ypos == 0) ypos = 1;
				} 
			} else if ((commandByte & 252) == 24) {
				/* Shift display left */
			} else if ((commandByte & 252) == 28) {
				/* Shift display right */
			} else if ((commandByte & 240) == 48) {
				/* Set 8-bit mode */
			} else if ((commandByte & 240) == 32) {
				/* Set 4-bit mode */
			} else if (commandByte & 128) {
				c = ((unsigned char)commandByte) & 127;
				if (c < 40) {
					xpos = c;
					ypos = 0;
				} else if ((c > 63) && (c < 104)) {
					xpos = (c - 64);
					ypos = 1;
				} else {
					printf("Bad address %u!\n", c);
				}
			} else {
				c = (unsigned char)buffer[i+1];
				printf("-- Unknown VFD command %u --\n", (unsigned)c);
				/* Whoa! Unknown command! */
			}
		} else if (buffer[i] == 3) {
			/* Put buffer[i+1] in to the display RAM and shift accordingly. */
			if (!ypos) line1[xpos] = buffer[i+1];
			else	   line2[xpos] = buffer[i+1];
			xpos += movemode;
			if (cursdisp == MODE_CURSOR) {
				if (xpos < 0) {
					if (ypos == 1)	xpos = 39;
					else		xpos = 0;
					ypos = 0;
				} else if (xpos > 39) {
					if (ypos == 0)	xpos = 0;
					else		xpos = 39;
					ypos = 1;
				}
			} else {

				/* I don't know what to do here... */

			}
		} else {
			c = (unsigned char)buffer[i+1];
			printf("-- Unknown VFD mode %u --\n", (unsigned)c);
		}
	}
	printf(" ,--------------------------------------.\n");
	printf("|%s|\n", line1);
	printf("|%s|\n", line2);
	printf(" `--------------------------------------'\n");
}


void initDisplay() {
	char dispClear[2] = { 2, 1 };

	parseMessage(dispClear, 2);

	movemode = 1;
	cursdisp = MODE_CURSOR;
}