/*
 * (c) 2011 Siegen, Germany by Nils Faerber <nils.faerber@kernelconcepts.de>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <termios.h>
#include <ctype.h>

#include "metawatch.h"
#include "metawatch_protocol.h"
#include "crc16ccitt.h"


#ifdef DEBUG
const char *mw_screen_mode_names[] = {
	"idle screen",
	"application screen",
	"notification screen",
	"scroll"
};

const char *mw_status_string[] = {
	"Reserved",
	"Mode Change",
	"Display Timeout"
};
#endif


#define MW_FRAME_DELAY		0x00

void dump_frame(unsigned char *frame, int len)
{
	int i;

	for (i=0; i<len; i++)
		fprintf(stderr, "0x%02x ", frame[i]);
	fprintf(stderr, "\n");
}


int mw_send_frame(int mw_fd, unsigned char msg_type, unsigned char options, unsigned char *data, unsigned char len)
{
	unsigned short crc;
	unsigned char frame[64];
	int tlen = len + 6; /* payload + 6 bytes frameing */
	int ret;

	memset(frame, 0, 64);
	frame[0] = MW_SOF;
	frame[1] = len + 6;
	frame[2] = msg_type;
	frame[3] = options;
	if (data != NULL && len > 0)
		memcpy(frame+4, data, len);

	crc = crc16ccitt(frame, len+4);
	*(unsigned short *)(frame+len+4) = crc;

#ifdef DEBUG
	dump_frame(frame, tlen);
#endif

	while (((ret = write(mw_fd, frame, tlen)) >= 0) && (tlen > 0))
		tlen -= ret;

	if (MW_FRAME_DELAY)
		usleep(MW_FRAME_DELAY);

	if (tlen == 0 && ret >= 0)
		return 0;
	else
		return ret;
}


/* ----------------------------------------------------------------------
 * Host to watch commands
 * ---------------------------------------------------------------------- */


void mw_set_rtc(int mw_fd, unsigned char clk1224, unsigned char date_fmt)
{
	time_t mtime;
	struct tm mtm;
	unsigned short year;
	unsigned char data[32];

	mtime = time(NULL);
	localtime_r(&mtime, &mtm);

	year = mtm.tm_year + 1900;  
	data[0] = (year & 0x0f00) >> 8;
	data[1] = (year & 0x00ff);
	data[2] = mtm.tm_mon + 1;
	data[3] = mtm.tm_mday;
	data[4] = mtm.tm_wday;
	data[5] = mtm.tm_hour;
	data[6] = mtm.tm_min;
	data[7] = mtm.tm_sec;
	data[8] = clk1224;
	data[9] = date_fmt;

	mw_send_frame(mw_fd, MW_SET_REAL_TIME_CLOCK, 0, data, 10);
}

void mw_set_vibrate_mode(int mw_fd, unsigned char enable, unsigned short on_time, unsigned short off_time, unsigned char cycles)
{
	unsigned char mdata[7];

	mdata[0] = enable;
	*(unsigned short *)(mdata+1) = on_time; /* miliseconds */
	*(unsigned short *)(mdata+3) = off_time; /* miliseconds */
	mdata[5] = cycles;
	mw_send_frame(mw_fd, MW_SET_VIBRATE_MODE, 0, mdata, 6);
}

void mw_configure_watch_mode(int mw_fd, unsigned char mode, unsigned char save, unsigned char timeout, unsigned char invert)
{
	unsigned char mdata[3];

	mdata[0] = timeout; /* seconds */
	mdata[1] = invert; /* 0=normal, 1=invert */
	mw_send_frame(mw_fd, MW_CONFIGURE_MODE, (mode & 0x0f) | ((save & 0x01) << 4), mdata, 2);
}

void mw_update_display(int mw_fd, unsigned char mode, unsigned char copy)
{
	mw_send_frame(mw_fd, MW_UPDATE_DISPLAY, (mode & 0x0f) | ((copy & 0x01) << 4), NULL, 0);
}

void mw_load_template(int mw_fd, unsigned char mode, unsigned char template_select)
{
	mw_send_frame(mw_fd, MW_LOAD_TEMPLATE, (mode & 0x0f), &template_select, 1);
}

/*
 * send line for screen-mode mode from *buffer to watch, starting at display row row_offset
 */
void mw_write_buffer(int mw_fd,
		unsigned char mode,
		unsigned char numlines,		/* number of lines, 0=two lines or 1=one line */
		unsigned char row_offset,	/* start at row_offset in display, e.g. lower part in idle @31 */
		unsigned char *buffer, int buflen)
{
	unsigned char mdata[32];

	buflen = 12 * (buflen / 12);	/* crop to 12 bytes */
	if ((numlines == 0 && buflen < 12) || (numlines == 1 && buflen < 24)) {
		fprintf(stderr, "mw_write_buffer: bufferlen does not match number of lines\n");
		return;
	};
	memset(mdata, 0, 32);
	mdata[0] = row_offset;
	memcpy((mdata+1), buffer, 12);
	if (numlines == 0) {
		mdata[13] = row_offset+1;
		memcpy((mdata+14), (buffer+12), 12);
	};
	mw_send_frame(mw_fd, MW_WRITE_BUFFER, (mode & 0x0f) | (((numlines & 0x01)<< 4) & 0x10), mdata, numlines ? 13 : 26);
}

/*
   Options:
	B0   : row select, 0 first row, 1 second row
	B1   : display select, 0 upper OLED, 1 lower OLED
	B2   : if 1 send an event upon completion
	B3..4: scroll type,
	B5..7: unused
   Scroll types:
   	B0: First buffer in a chain of scroll buffers
   	B1: Any buffer except first or last
   	B2: Last buffer of a chain
   	B3: reserved / unused
   Payload:
   	0: Start index col
   	1..: data
*/
void mw_write_oled_buffer(int mw_fd,
	unsigned char mode, /* idle or scroll */
	unsigned char oled, /* which OLED */
	unsigned char numcols,
	unsigned char col_index, /* starting index */
	unsigned char *buffer, int buflen)
{
	unsigned char mdata[32];
	int i;
	
	/* lower row first since display wil be updated after completion of upper row */
	if (buflen > 80) {
		for (i=80; i<buflen; i+=20) {
			mdata[0] = (i-80);
			memcpy((mdata+1), (buffer+i), 20);
			mw_send_frame(mw_fd, MW_WRITE_OLED_IDLE_DISPLAY_MSG, 0 | (oled ? 2 : 0), mdata, 21);
		}
	}
	for (i=0; i<80; i+=20) {
		mdata[0] = i;
		memcpy((mdata+1), (buffer+i), 20);
		mw_send_frame(mw_fd, MW_WRITE_OLED_IDLE_DISPLAY_MSG, 1 | (oled ? 2 : 0), mdata, 21);
	}
}

void mw_enable_button(int mw_fd,
		unsigned char mode,
		unsigned char button_index,
		unsigned char press_type,
		unsigned char callback_type,
		unsigned char callback_option)
{
	unsigned char mdata[32];

	memset(mdata, 0, 32);
	mdata[0] = mode;
	mdata[1] = button_index;
	mdata[2] = press_type;
	mdata[3] = callback_type;
	mdata[4] = callback_option;
	mw_send_frame(mw_fd, MW_ENABLE_BUTTON, 0, mdata, 5);
}

void mw_disable_button(int mw_fd,
		unsigned char mode,
		unsigned char button_index,
		unsigned char press_type)
{
	unsigned char mdata[32];

	memset(mdata, 0, 32);
	mdata[0] = mode;
	mdata[1] = button_index;
	mdata[2] = press_type;
	mw_send_frame(mw_fd, MW_ENABLE_BUTTON, 0, mdata, 3);
}

/* ----------------------------------------------------------------------
 * Watch responses, events or notifications
 * ---------------------------------------------------------------------- */


void mw_get_real_time_clock_response(int mw_fd, unsigned char *rtcrsp, int len)
{
	struct tm mtm;
	unsigned short year;
	unsigned char clk1224, date_fmt;

	if (len != 10) {
		fprintf(stderr, "get real time clock response length wrong %d != 10\n", len);
		return;
	}

	year = *(unsigned short *)rtcrsp;
	mtm.tm_year = year - 1900;
	mtm.tm_mon = rtcrsp[2] - 1;
	mtm.tm_mday = rtcrsp[3];
	mtm.tm_wday = rtcrsp[4];
	mtm.tm_hour = rtcrsp[5];
	mtm.tm_min = rtcrsp[6];
	mtm.tm_sec = rtcrsp[7];
	clk1224 = rtcrsp[8];
	date_fmt = rtcrsp[9];

	fprintf(stderr, "watch RTC is %s, clock format is %s, date format is %s\n", asctime(&mtm), clk1224 ? "24h" : "AM/PM", date_fmt ? "DD/MM" : "MM/DD");
}

void mw_get_battery_voltage_response(int mw_fd, unsigned char *batrsp, int len)
{
	unsigned short voltage = *(unsigned short *)batrsp;
	unsigned char power_good = batrsp[2];
	unsigned char bat_charging = batrsp[3];

	fprintf(stderr, "battery is at %dV, %s and %s\n", voltage, power_good ? "power is good" : "power fault", bat_charging ? "charging" : "not charging");
}

void mw_read_button_config_response(int mw_fd, unsigned char *btnrsp, int len)
{
	fprintf(stderr, "read button config response\n");
	fprintf(stderr, "screen mode      : 0x%02x\n", btnrsp[0]);
	fprintf(stderr, "button index     : 0x%02x\n", btnrsp[1]);
	fprintf(stderr, "mask table       : 0x%02x (", btnrsp[2]);
	fprintf(stderr, "%s ", (btnrsp[2] & 0x01) ? "Absolute, " : "");
	fprintf(stderr, "%s ", (btnrsp[2] & 0x02) ? "Press&Release, " : "");
	fprintf(stderr, "%s ", (btnrsp[2] & 0x04) ? "Press&Hold, " : "");
	fprintf(stderr, "%s ", (btnrsp[2] & 0x08) ? "Press&LongHold, " : "");
	fprintf(stderr, "%s ", (btnrsp[2] & 0x10) ? "Immediate" : "");
	fprintf(stderr, ")\n");
	fprintf(stderr, "callback msg type: 0x%02x\n", btnrsp[3]);
	fprintf(stderr, "callback msg opts: 0x%02d\n", btnrsp[4]);
}

void mw_read_light_sensor_response(int mw_fd, unsigned char *lightrsp, int len)
{
	unsigned char power_good = lightrsp[0];
	unsigned char bat_charging = lightrsp[1];
	unsigned short voltage = *(unsigned short *)(lightrsp+2);

	fprintf(stderr, "light sensor is at %d, power stat: %s and %s\n", voltage, power_good ? "power is good" : "power fault", bat_charging ? "charging" : "not charging");
}

void mw_status_change_event(int mw_fd, unsigned char option, unsigned char *statrsp, int len)
{
#ifdef DEBUG
	fprintf(stderr, "Status change event for mode %s: %s\n", mw_screen_mode_names[option&0x0f], mw_status_string[statrsp[0]]);	
#endif
}


/* ----------------------------------------------------------------------
 * Protocol handling
 * ---------------------------------------------------------------------- */


int decode_frame(int mw_fd, unsigned char *buf, int len)
{
	unsigned short crc;
	unsigned char msglen;
	unsigned char msgtype;
	unsigned char msgopt;
	unsigned char *msgdata;
	unsigned char msgdatalen;

	/* check frame */
	crc = *(unsigned short *)(buf+len-2);
	if (crc != crc16ccitt(buf, len-2)) {
		fprintf(stderr, "decode frame CRC error\n");
		return 1;
	}
#ifdef DEBUG
	 else
		fprintf(stderr, "decode frame CRC OK\n");
#endif
	if (buf[0] != MW_SOF) {
		fprintf(stderr, "decode frame SOF not found\n");
		return 1;
	}
#ifdef DEBUG
	 else
	fprintf(stderr, "decode frame found SOF\n");
#endif

	msglen = buf[1];
	msgtype = buf[2];
	msgopt = buf[3];
	msgdata = (buf+4);
	msgdatalen = msglen - 4 - 2;

	switch (msgtype) {
		case MW_GET_DEVICE_TYPE_RSP:
			fprintf(stderr, "Got device type ");
			switch(msgdata[0]) {
				case 0:
					fprintf(stderr, "Reserved\n");
					break;
				case 1:
					fprintf(stderr, "Ana-Digi\n");
					break;
				case 2:
					fprintf(stderr, "Digital\n");
					break;
				case 3:
					fprintf(stderr, "Development Board Digital\n");
					break;
				case 4:
					fprintf(stderr, "Development Board Ana-Digi\n");
					break;
				default:
					fprintf(stderr, "unknown %d\n", msgdata[0]);
					break;
			};
			break;
		case MW_GET_INFORMATION_STRING_RSP:
			msgdata[len-2] = 0;
			fprintf(stderr, "Got info string '%s'\n", msgdata);
			break;
		case MW_GET_REAL_TIME_CLOCK_RSP:
			mw_get_real_time_clock_response(mw_fd, msgdata, msgdatalen);
			break;
		case MW_READ_BATTERY_VOLTAGE_RSP:
			mw_get_battery_voltage_response(mw_fd, msgdata, msgdatalen);
			break;
		case MW_READ_LIGHT_SENSOR_RSP:
			mw_read_light_sensor_response(mw_fd, msgdata, msgdatalen);
			break;
		case MW_LOW_BATTERY_WARNING_MSG:
			fprintf(stderr, "Watch battery low, please connect charger\n");
			break;
		case MW_READ_BUTTON_CONFIG_RSP:
			mw_read_button_config_response(mw_fd, msgdata, msgdatalen);
			break;
		case MW_BUTTON_EVENT_MESSAGE:
			fprintf(stderr, "Button event message\n");
			break;
		case MW_LOW_BATTERY_BT_OFF_MSG:
			fprintf(stderr, "Watch battery extremely low - radio will turn off\n");
			break;
		case MW_STATUS_CHANGE_EVENT:
			mw_status_change_event(mw_fd, msgopt, msgdata, msgdatalen);
			break;
		default:
			fprintf(stderr, "Unkown msgtype 0x%02x\n", msgtype);
			break;
	};

	return 0;
}


/* ----------------------------------------------------------------------
 * Convenience functions not strictly part of the protocol
 * ---------------------------------------------------------------------- */

/* if flip=1 bits in each byte are inverted 7->1, 6->2, 5->3,...
   if invert=1 each byte is inverted
 */
void bmap_buffer_flipinvert(unsigned char flip, unsigned char invert, unsigned char *buf, int len)
{
	int i;
	unsigned char tmp;

	while (len--) {
		tmp = 0;
		if (flip) {
			for (i=0; i<8; i++)
				tmp |= ((*buf & (1<<i)) >> i) << (7-i);
			// fprintf(stderr, "0x%02x -> 0x%02x\n", *buf, tmp);
		} else
			tmp = *buf;
		*buf = invert ? ~tmp : tmp;
		buf++;
	}
}


void mw_send_bitmap(int mw_fd, unsigned char mode, int width, int height, int offset, unsigned char *bmapbuf, int buflen)
{
#ifdef DEBUG
	unsigned int i, x;
#endif
	unsigned int y, rowlength;
	unsigned char mw_buf[24];

	rowlength = (((width-1) / 8) + 1);
	if ((height + offset) > 96)
		height = 96 - offset;

#ifdef DEBUG
	fprintf(stderr, "row length = %d bytes\n", rowlength);
	fprintf(stderr, "bitmap resolution is %d x %d\n", width, height);
	fprintf(stderr, "\n");
	for (y=0; y<height; y++) {
		for (x=0; x<rowlength; x++) {
			for (i=0; i<8; i++)
				fprintf(stderr, "%c", (bmapbuf[(y*rowlength)+x] & (1<<(7-i))) ? '.' : ' ');
		}
		fprintf(stderr, "\n");
	}
	fprintf(stderr, "\n");
#endif

	for (y=0; y<height; y+=2) {
		memset(mw_buf, 0, 24);
		memcpy(mw_buf, (bmapbuf+(y*rowlength)), (rowlength > 12) ? 12 : rowlength);
		memcpy((mw_buf+12), (bmapbuf+((y+1)*rowlength)), (rowlength > 12) ? 12 : rowlength);
		mw_write_buffer(mw_fd, mode, 0, offset+y, mw_buf, 24);
	}
}