/*
 *    classic.c
 *
 *	  This file is part of WiiC, written by:
 *		Gabriele Randelli
 *		Email: randelli@dis.uniroma1.it
 *
 *    Copyright 2010
 *		
 *	  This file is based on Wiiuse, written By:
 *		Michael Laforest	< para >
 *		Email: < thepara (--AT--) g m a i l [--DOT--] com >
 *
 *	  Copyright 2006-2007
 *
 *    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 3 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, see <http://www.gnu.org/licenses/>.
 *
 *	  $Header$
 */

/**
 *	@file
 *	@brief Classic controller expansion device.
 */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include "definitions.h"
#include "wiic_internal.h"
#include "dynamics.h"
#include "events.h"
#include "classic.h"

static void classic_ctrl_pressed_buttons(struct classic_ctrl_t* cc, short now);

/**
 *	@brief Handle the handshake data from the classic controller.
 *
 *	@param cc		A pointer to a classic_ctrl_t structure.
 *	@param data		The data read in from the device.
 *	@param len		The length of the data block, in bytes.
 *
 *	@return	Returns 1 if handshake was successful, 0 if not.
 */
int classic_ctrl_handshake(struct wiimote_t* wm, struct classic_ctrl_t* cc, byte* data, unsigned short len) {
	int i;
	int offset = 0;

	cc->btns = 0;
	cc->btns_held = 0;
	cc->btns_released = 0;
	cc->r_shoulder = 0;
	cc->l_shoulder = 0;

	/* decrypt data */
	for (i = 0; i < len; ++i)
		data[i] = (data[i] ^ 0x17) + 0x17;

	if (data[offset] == 0xFF) {
		/*
		 *	Sometimes the data returned here is not correct.
		 *	This might happen because the wiimote is lagging
		 *	behind our initialization sequence.
		 *	To fix this just request the handshake again.
		 *
		 *	Other times it's just the first 16 bytes are 0xFF,
		 *	but since the next 16 bytes are the same, just use
		 *	those.
		 */
		if (data[offset + 16] == 0xFF) {
			/* get the calibration data */
			byte* handshake_buf = malloc(EXP_HANDSHAKE_LEN * sizeof(byte));

			WIIC_DEBUG("Classic controller handshake appears invalid, trying again.");
			wiic_read_data_cb(wm, handshake_expansion, handshake_buf, WM_EXP_MEM_CALIBR, EXP_HANDSHAKE_LEN);

			return 0;
		} else
			offset += 16;
	}


	/* joystick stuff */
	cc->ljs.max.x = data[0 + offset] / 4;
	cc->ljs.min.x = data[1 + offset] / 4;
	cc->ljs.center.x = data[2 + offset] / 4;
	cc->ljs.max.y = data[3 + offset] / 4;
	cc->ljs.min.y = data[4 + offset] / 4;
	cc->ljs.center.y = data[5 + offset] / 4;

	cc->rjs.max.x = data[6 + offset] / 8;
	cc->rjs.min.x = data[7 + offset] / 8;
	cc->rjs.center.x = data[8 + offset] / 8;
	cc->rjs.max.y = data[9 + offset] / 8;
	cc->rjs.min.y = data[10 + offset] / 8;
	cc->rjs.center.y = data[11 + offset] / 8;

	/* handshake done */
	wm->exp.type = EXP_CLASSIC;

	return 1;
}


/**
 *	@brief The classic controller disconnected.
 *
 *	@param cc		A pointer to a classic_ctrl_t structure.
 */
void classic_ctrl_disconnected(struct classic_ctrl_t* cc) {
	memset(cc, 0, sizeof(struct classic_ctrl_t));
}



/**
 *	@brief Handle classic controller event.
 *
 *	@param cc		A pointer to a classic_ctrl_t structure.
 *	@param msg		The message specified in the event packet.
 */
void classic_ctrl_event(struct classic_ctrl_t* cc, byte* msg) {
	int i, lx, ly, rx, ry;
	byte l, r;

	/* decrypt data */
	for (i = 0; i < 6; ++i)
		msg[i] = (msg[i] ^ 0x17) + 0x17;

	classic_ctrl_pressed_buttons(cc, BIG_ENDIAN_SHORT(*(short*)(msg + 4)));

	/* left/right buttons */
	l = (((msg[2] & 0x60) >> 2) | ((msg[3] & 0xE0) >> 5));
	r = (msg[3] & 0x1F);

	/*
	 *	TODO - LR range hardcoded from 0x00 to 0x1F.
	 *	This is probably in the calibration somewhere.
	 */
	cc->r_shoulder = ((float)r / 0x1F);
	cc->l_shoulder = ((float)l / 0x1F);

	/* calculate joystick orientation */
	lx = (msg[0] & 0x3F);
	ly = (msg[1] & 0x3F);
	rx = ((msg[0] & 0xC0) >> 3) | ((msg[1] & 0xC0) >> 5) | ((msg[2] & 0x80) >> 7);
	ry = (msg[2] & 0x1F);

	calc_joystick_state(&cc->ljs, lx, ly);
	calc_joystick_state(&cc->rjs, rx, ry);
}


/**
 *	@brief Find what buttons are pressed.
 *
 *	@param cc		A pointer to a classic_ctrl_t structure.
 *	@param msg		The message byte specified in the event packet.
 */
static void classic_ctrl_pressed_buttons(struct classic_ctrl_t* cc, short now) {
	/* message is inverted (0 is active, 1 is inactive) */
	now = ~now & CLASSIC_CTRL_BUTTON_ALL;

	/* pressed now & were pressed, then held */
	cc->btns_held = (now & cc->btns);

	/* were pressed or were held & not pressed now, then released */
	cc->btns_released = ((cc->btns | cc->btns_held) & ~now);

	/* buttons pressed now */
	cc->btns = now;
}