/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2013 Bert Vermeulen <bert@biot.com>
 *
 * 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/>.
 */

#include <string.h>
#include "protocol.h"

/* Length of expected payload for each token. */
static int token_payloads[][2] = {
	{ TOKEN_WEIGHT_TIME_FAST, 0 },
	{ TOKEN_WEIGHT_TIME_SLOW, 0 },
	{ TOKEN_HOLD_MAX, 0 },
	{ TOKEN_HOLD_MIN, 0 },
	{ TOKEN_TIME, 3 },
	{ TOKEN_MEAS_RANGE_OVER, 0 },
	{ TOKEN_MEAS_RANGE_UNDER, 0 },
	{ TOKEN_STORE_FULL, 0 },
	{ TOKEN_RECORDING_ON, 0 },
	{ TOKEN_MEAS_WAS_READOUT, 1 },
	{ TOKEN_MEAS_WAS_BARGRAPH, 0 },
	{ TOKEN_MEASUREMENT, 2 },
	{ TOKEN_HOLD_NONE, 0 },
	{ TOKEN_BATTERY_LOW, 0 },
	{ TOKEN_MEAS_RANGE_OK, 0 },
	{ TOKEN_STORE_OK, 0 },
	{ TOKEN_RECORDING_OFF, 0 },
	{ TOKEN_WEIGHT_FREQ_A, 1 },
	{ TOKEN_WEIGHT_FREQ_C, 1 },
	{ TOKEN_BATTERY_OK, 0 },
	{ TOKEN_MEAS_RANGE_30_80, 0 },
	{ TOKEN_MEAS_RANGE_30_130, 0 },
	{ TOKEN_MEAS_RANGE_50_100, 0 },
	{ TOKEN_MEAS_RANGE_80_130, 0 },
};

static int find_token_payload_len(unsigned char c)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(token_payloads); i++) {
		if (token_payloads[i][0] == c)
			return token_payloads[i][1];
	}

	return -1;
}

/* Process measurement or setting (0xa5 command). */
static void process_mset(const struct sr_dev_inst *sdi)
{
	struct dev_context *devc;
	struct sr_datafeed_packet packet;
	struct sr_datafeed_analog analog;
	GString *dbg;
	float fvalue;
	int i;

	devc = sdi->priv;
	if (sr_log_loglevel_get() >= SR_LOG_SPEW) {
		dbg = g_string_sized_new(128);
		g_string_printf(dbg, "got command 0x%.2x token 0x%.2x",
				devc->cmd, devc->token);
		if (devc->buf_len) {
			g_string_append_printf(dbg, " payload");
			for (i = 0; i < devc->buf_len; i++)
				g_string_append_printf(dbg, " %.2x", devc->buf[i]);
		}
		sr_spew("%s", dbg->str);
		g_string_free(dbg, TRUE);
	}

	switch(devc->token) {
	case TOKEN_WEIGHT_TIME_FAST:
		devc->cur_mqflags |= SR_MQFLAG_SPL_TIME_WEIGHT_F;
		devc->cur_mqflags &= ~SR_MQFLAG_SPL_TIME_WEIGHT_S;
		break;
	case TOKEN_WEIGHT_TIME_SLOW:
		devc->cur_mqflags |= SR_MQFLAG_SPL_TIME_WEIGHT_S;
		devc->cur_mqflags &= ~SR_MQFLAG_SPL_TIME_WEIGHT_F;
		break;
	case TOKEN_WEIGHT_FREQ_A:
		devc->cur_mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_A;
		devc->cur_mqflags &= ~SR_MQFLAG_SPL_FREQ_WEIGHT_C;
		break;
	case TOKEN_WEIGHT_FREQ_C:
		devc->cur_mqflags |= SR_MQFLAG_SPL_FREQ_WEIGHT_C;
		devc->cur_mqflags &= ~SR_MQFLAG_SPL_FREQ_WEIGHT_A;
		break;
	case TOKEN_HOLD_MAX:
		devc->cur_mqflags |= SR_MQFLAG_HOLD | SR_MQFLAG_MAX;
		devc->cur_mqflags &= ~SR_MQFLAG_MIN;
		break;
	case TOKEN_HOLD_MIN:
		devc->cur_mqflags |= SR_MQFLAG_HOLD | SR_MQFLAG_MIN;
		devc->cur_mqflags &= ~SR_MQFLAG_MAX;
		break;
	case TOKEN_HOLD_NONE:
		devc->cur_mqflags &= ~(SR_MQFLAG_MAX | SR_MQFLAG_MIN | SR_MQFLAG_HOLD);
		break;
	case TOKEN_MEASUREMENT:
		fvalue = ((devc->buf[0] & 0xf0) >> 4) * 100;
		fvalue += (devc->buf[0] & 0x0f) * 10;
		fvalue += ((devc->buf[1] & 0xf0) >> 4);
		fvalue += (devc->buf[1] & 0x0f) / 10.0;
		devc->last_spl = fvalue;
		break;
	case TOKEN_MEAS_WAS_READOUT:
	case TOKEN_MEAS_WAS_BARGRAPH:
		if (devc->cur_mqflags & (SR_MQFLAG_MAX | SR_MQFLAG_MIN)) {
			if (devc->token == TOKEN_MEAS_WAS_BARGRAPH) {
				/* The device still sends bargraph measurements even
				 * when in max/min hold mode. Suppress them here, unless
				 * they're readout values. This duplicates the behavior
				 * of the device display exactly. */
				break;
			}
		}
		memset(&analog, 0, sizeof(struct sr_datafeed_analog));
		analog.mq = SR_MQ_SOUND_PRESSURE_LEVEL;
		analog.mqflags = devc->cur_mqflags;
		analog.unit = SR_UNIT_DECIBEL_SPL;
		analog.probes = sdi->probes;
		analog.num_samples = 1;
		analog.data = &devc->last_spl;
		packet.type = SR_DF_ANALOG;
		packet.payload = &analog;
		sr_session_send(devc->cb_data, &packet);

		devc->num_samples++;
		if (devc->limit_samples && devc->num_samples >= devc->limit_samples)
			sdi->driver->dev_acquisition_stop((struct sr_dev_inst *)sdi,
					devc->cb_data);
		break;
	case TOKEN_TIME:
	case TOKEN_STORE_OK:
	case TOKEN_STORE_FULL:
	case TOKEN_RECORDING_ON:
	case TOKEN_RECORDING_OFF:
	case TOKEN_BATTERY_OK:
	case TOKEN_BATTERY_LOW:
	case TOKEN_MEAS_RANGE_OK:
	case TOKEN_MEAS_RANGE_OVER:
	case TOKEN_MEAS_RANGE_UNDER:
	case TOKEN_MEAS_RANGE_30_80:
	case TOKEN_MEAS_RANGE_30_130:
	case TOKEN_MEAS_RANGE_50_100:
	case TOKEN_MEAS_RANGE_80_130:
		/* Not useful, or not expressable in sigrok. */
		break;
	}

}

static void process_byte(const struct sr_dev_inst *sdi, const unsigned char c)
{
	struct dev_context *devc;
	gint64 cur_time;
	int len;

	if (!(devc = sdi->priv))
		return;

	if (c == 0xff) {
		/* Device is in hold mode */
		devc->cur_mqflags |= SR_MQFLAG_HOLD;

		if (devc->hold_last_sent == 0) {
			/* First hold notification. */
			devc->hold_last_sent = g_get_monotonic_time();
			/* When the device leaves hold mode, it starts from scratch. */
			devc->state = ST_INIT;
		} else {
			cur_time = g_get_monotonic_time();
			if (cur_time - devc->hold_last_sent > HOLD_REPEAT_INTERVAL) {
				/* Force the last measurement out again. */
				devc->cmd = 0xa5;
				devc->token = TOKEN_MEAS_WAS_READOUT;
				process_mset(sdi);
				devc->hold_last_sent = cur_time;
			}
		}

		return;
	}
	devc->cur_mqflags &= ~SR_MQFLAG_HOLD;
	devc->hold_last_sent = 0;

	if (devc->state == ST_INIT) {
		if (c == 0xa5) {
			devc->cmd = c;
			devc->token = 0x00;
			devc->state = ST_GET_TOKEN;
		} else if (c == 0xbb) {
			devc->cmd = c;
			devc->buf_len = 0;
			devc->state = ST_GET_LOG;
		}
	} else if (devc->state == ST_GET_TOKEN) {
		devc->token = c;
		devc->buf_len = 0;
		len = find_token_payload_len(devc->token);
		if (len == -1 || len > 0) {
			devc->buf_len = 0;
			devc->state = ST_GET_DATA;
		} else {
			process_mset(sdi);
			devc->state = ST_INIT;
		}
	} else if (devc->state == ST_GET_DATA) {
		len = find_token_payload_len(devc->token);
		if (len == -1) {
			/* We don't know this token. */
			sr_dbg("Unknown 0xa5 token 0x%.2x", devc->token);
			if (c == 0xa5 || c == 0xbb) {
				/* Looks like a new command however. */
				process_mset(sdi);
				devc->state = ST_INIT;
			} else {
				devc->buf[devc->buf_len++] = c;
				if (devc->buf_len > BUF_SIZE) {
					/* Shouldn't happen, ignore. */
					devc->state = ST_INIT;
				}
			}
		} else {
			devc->buf[devc->buf_len++] = c;
			if (devc->buf_len == len) {
				process_mset(sdi);
				devc->state = ST_INIT;
			} else if (devc->buf_len > BUF_SIZE) {
				/* Shouldn't happen, ignore. */
				devc->state = ST_INIT;
			}
		}
	} else if (devc->state == ST_GET_LOG) {
	}

}

SR_PRIV int cem_dt_885x_receive_data(int fd, int revents, void *cb_data)
{
	const struct sr_dev_inst *sdi;
	struct sr_serial_dev_inst *serial;
	unsigned char c;

	(void)fd;

	if (!(sdi = cb_data))
		return TRUE;

	serial = sdi->conn;
	if (revents == G_IO_IN) {
		if (serial_read(serial, &c, 1) != 1)
			return TRUE;
		process_byte(sdi, c);
	}

	return TRUE;
}