/*
 * libdivecomputer
 *
 * Copyright (C) 2012 Jef Driesen
 *
 * 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 2.1 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., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301 USA
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>

#ifdef _MSC_VER
#define snprintf _snprintf
#endif

#include <libdivecomputer/units.h>

#include "shearwater_predator.h"
#include "shearwater_petrel.h"
#include "shearwater_common.h"
#include "context-private.h"
#include "parser-private.h"
#include "array.h"

#define ISINSTANCE(parser)	( \
	dc_parser_isinstance((parser), &shearwater_predator_parser_vtable) || \
	dc_parser_isinstance((parser), &shearwater_petrel_parser_vtable))

#define SZ_BLOCK   0x80
#define SZ_SAMPLE_PREDATOR  0x10
#define SZ_SAMPLE_PETREL    0x20

#define GASSWITCH     0x01
#define PPO2_EXTERNAL 0x02
#define SETPOINT_HIGH 0x04
#define SC            0x08
#define OC            0x10

#define METRIC   0
#define IMPERIAL 1

#define NGASMIXES 10
#define MAXSTRINGS 32

typedef struct shearwater_predator_parser_t shearwater_predator_parser_t;

struct shearwater_predator_parser_t {
	dc_parser_t base;
	unsigned int model;
	unsigned int samplesize;
	// Cached fields.
	unsigned int cached;
	unsigned int headersize;
	unsigned int footersize;
	unsigned int ngasmixes;
	unsigned int oxygen[NGASMIXES];
	unsigned int helium[NGASMIXES];
	double calibration[3];
	unsigned int serial;
	dc_divemode_t mode;
	unsigned char logversion;

	/* String fields */
	dc_field_string_t strings[MAXSTRINGS];
};

static dc_status_t shearwater_predator_parser_set_data (dc_parser_t *abstract, const unsigned char *data, unsigned int size);
static dc_status_t shearwater_predator_parser_get_datetime (dc_parser_t *abstract, dc_datetime_t *datetime);
static dc_status_t shearwater_predator_parser_get_field (dc_parser_t *abstract, dc_field_type_t type, unsigned int flags, void *value);
static dc_status_t shearwater_predator_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_t callback, void *userdata);

static const dc_parser_vtable_t shearwater_predator_parser_vtable = {
	sizeof(shearwater_predator_parser_t),
	DC_FAMILY_SHEARWATER_PREDATOR,
	shearwater_predator_parser_set_data, /* set_data */
	shearwater_predator_parser_get_datetime, /* datetime */
	shearwater_predator_parser_get_field, /* fields */
	shearwater_predator_parser_samples_foreach, /* samples_foreach */
	NULL /* destroy */
};

static const dc_parser_vtable_t shearwater_petrel_parser_vtable = {
	sizeof(shearwater_predator_parser_t),
	DC_FAMILY_SHEARWATER_PETREL,
	shearwater_predator_parser_set_data, /* set_data */
	shearwater_predator_parser_get_datetime, /* datetime */
	shearwater_predator_parser_get_field, /* fields */
	shearwater_predator_parser_samples_foreach, /* samples_foreach */
	NULL /* destroy */
};


static unsigned int
shearwater_predator_find_gasmix (shearwater_predator_parser_t *parser, unsigned int o2, unsigned int he)
{
	unsigned int i = 0;
	while (i < parser->ngasmixes) {
		if (o2 == parser->oxygen[i] && he == parser->helium[i])
			break;
		i++;
	}

	return i;
}


dc_status_t
shearwater_common_parser_create (dc_parser_t **out, dc_context_t *context, unsigned int model, unsigned int serial)
{
	shearwater_predator_parser_t *parser = NULL;
	const dc_parser_vtable_t *vtable = NULL;
	unsigned int samplesize = 0;

	if (out == NULL)
		return DC_STATUS_INVALIDARGS;

	if (model != PREDATOR) {
		vtable = &shearwater_petrel_parser_vtable;
		samplesize = SZ_SAMPLE_PETREL;
	} else {
		vtable = &shearwater_predator_parser_vtable;
		samplesize = SZ_SAMPLE_PREDATOR;
	}

	// Allocate memory.
	parser = (shearwater_predator_parser_t *) dc_parser_allocate (context, vtable);
	if (parser == NULL) {
		ERROR (context, "Failed to allocate memory.");
		return DC_STATUS_NOMEMORY;
	}

	// Set the default values.
	parser->model = model;
	parser->samplesize = samplesize;
	parser->serial = serial;

	// Set the default values.
	parser->cached = 0;
	parser->headersize = 0;
	parser->footersize = 0;
	parser->ngasmixes = 0;
	for (unsigned int i = 0; i < NGASMIXES; ++i) {
		parser->oxygen[i] = 0;
		parser->helium[i] = 0;
	}
	parser->mode = DC_DIVEMODE_OC;

	*out = (dc_parser_t *) parser;

	return DC_STATUS_SUCCESS;
}


static dc_status_t
shearwater_predator_parser_set_data (dc_parser_t *abstract, const unsigned char *data, unsigned int size)
{
	shearwater_predator_parser_t *parser = (shearwater_predator_parser_t *) abstract;

	// Reset the cache.
	parser->cached = 0;
	parser->headersize = 0;
	parser->footersize = 0;
	parser->ngasmixes = 0;
	for (unsigned int i = 0; i < NGASMIXES; ++i) {
		parser->oxygen[i] = 0;
		parser->helium[i] = 0;
	}
	parser->mode = DC_DIVEMODE_OC;

	return DC_STATUS_SUCCESS;
}


static dc_status_t
shearwater_predator_parser_get_datetime (dc_parser_t *abstract, dc_datetime_t *datetime)
{
	const unsigned char *data = abstract->data;
	unsigned int size = abstract->size;

	if (size < 2 * SZ_BLOCK)
		return DC_STATUS_DATAFORMAT;

	unsigned int ticks = array_uint32_be (data + 12);

	if (!dc_datetime_gmtime (datetime, ticks))
		return DC_STATUS_DATAFORMAT;

	return DC_STATUS_SUCCESS;
}

/*
 * These string cache interfaces should be some generic
 * library rather than copied for all the dive computers.
 *
 * This is just copied from the EON Steel code.
 */
static void
add_string(shearwater_predator_parser_t *parser, const char *desc, const char *value)
{
	int i;

	for (i = 0; i < MAXSTRINGS; i++) {
		dc_field_string_t *str = parser->strings+i;
		if (str->desc)
			continue;
		str->desc = desc;
		str->value = strdup(value);
		break;
	}
}

static void
add_string_fmt(shearwater_predator_parser_t *parser, const char *desc, const char *fmt, ...)
{
	char buffer[256];
	va_list ap;

	/*
	 * We ignore the return value from vsnprintf, and we
	 * always NUL-terminate the destination buffer ourselves.
	 *
	 * That way we don't have to worry about random bad legacy
	 * implementations.
	 */
	va_start(ap, fmt);
	buffer[sizeof(buffer)-1] = 0;
	(void) vsnprintf(buffer, sizeof(buffer)-1, fmt, ap);
	va_end(ap);

	return add_string(parser, desc, buffer);
}

// The Battery state is a big-endian word:
//
//  ffff = not paired / no comms for 90 s
//  fffe = no comms for 30 s
//
// Otherwise:
//   - top four bits are battery state (0 - normal, 1 - critical, 2 - warning)
//   - bottom 12 bits are pressure in 2 psi increments (0..8k psi)
//
// This returns the state as a bitmask (so you can see all states it had
// during the dive). Note that we currently do not report pairing and
// communication lapses. Todo?
static unsigned int
battery_state(const unsigned char *data)
{
	unsigned int pressure = array_uint16_be(data);
	unsigned int state;

	if ((pressure & 0xFFF0) == 0xFFF0)
		return 0;
	state = pressure >> 12;
	if (state > 2)
		return 0;
	return 1u << state;
}

// Show the battery state
//
// NOTE! Right now it only shows the most serious bit
// but the code is set up so that we could perhaps
// indicate that the battery is on the edge (ie it
// reported both "normal" _and_ "warning" during the
// dive - maybe that would be a "starting to warn")
//
// We could also report unpaired and comm errors.
static void
add_battery_info(shearwater_predator_parser_t *parser, const char *desc, unsigned int state)
{
	if (state >= 1 && state <= 7) {
		static const char *states[8] = {
			"",		// 000 - No state bits, not used
			"normal",	// 001 - only normal
			"critical",	// 010 - only critical
			"critical",	// 011 - both normal and critical
			"warning",	// 100 - only warning
			"warning",	// 101 - normal and warning
			"critical",	// 110 - warning and critical
			"critical",	// 111 - normal, warning and critical
		};
		add_string(parser, desc, states[state]);
	}
}

static void
add_deco_model(shearwater_predator_parser_t *parser, const unsigned char *data)
{
	switch	(data[67]) {
	case 0:
		add_string_fmt(parser, "Deco model", "GF %u/%u", data[4], data[5]);
		break;
	case 1:
		add_string_fmt(parser, "Deco model", "VPM-B +%u", data[68]);
		break;
	case 2:
		add_string_fmt(parser, "Deco model", "VPM-B/GFS +%u %u%%", data[68], data[85]);
		break;
	default:
		add_string_fmt(parser, "Deco model", "Unknown model %d", data[67]);
	}
}

static void
add_battery_type(shearwater_predator_parser_t *parser, const unsigned char *data)
{
	if (parser->logversion < 7)
		return;

	switch (data[120]) {
	case 1:
		add_string(parser, "Battery type", "1.5V Alkaline");
		break;
	case 2:
		add_string(parser, "Battery type", "1.5V Lithium");
		break;
	case 3:
		add_string(parser, "Battery type", "1.2V NiMH");
		break;
	case 4:
		add_string(parser, "Battery type", "3.6V Saft");
		break;
	case 5:
		add_string(parser, "Battery type", "3.7V Li-Ion");
		break;
	default:
		add_string_fmt(parser, "Battery type", "unknown type %d", data[120]);
		break;
	}
}

static dc_status_t
shearwater_predator_parser_cache (shearwater_predator_parser_t *parser)
{
	dc_parser_t *abstract = (dc_parser_t *) parser;
	const unsigned char *data = parser->base.data;
	unsigned int size = parser->base.size;

	if (parser->cached) {
		return DC_STATUS_SUCCESS;
	}

	unsigned int headersize = SZ_BLOCK;
	unsigned int footersize = SZ_BLOCK;
	if (size < headersize + footersize) {
		ERROR (abstract->context, "Invalid data length.");
		return DC_STATUS_DATAFORMAT;
	}

	// Log versions before 6 weren't reliably stored in the data, but
	// 6 is also the oldest version that we assume in our code
	parser->logversion = 6;
	if (data[127] > 6)
		parser->logversion = data[127];
	INFO(abstract->context, "Shearwater log version %u\n", parser->logversion);

	memset(parser->strings, 0, sizeof(parser->strings));

	// Adjust the footersize for the final block.
	if (parser->model > PREDATOR || array_uint16_be (data + size - footersize) == 0xFFFD) {
		footersize += SZ_BLOCK;
		if (size < headersize + footersize) {
			ERROR (abstract->context, "Invalid data length.");
			return DC_STATUS_DATAFORMAT;
		}
	}

	// Default dive mode.
	dc_divemode_t mode = DC_DIVEMODE_OC;

	// Get the gas mixes.
	unsigned int ngasmixes = 0;
	unsigned int oxygen[NGASMIXES] = {0};
	unsigned int helium[NGASMIXES] = {0};
	unsigned int o2_previous = 0, he_previous = 0;

	// Transmitter battery levels
	unsigned int t1_battery = 0, t2_battery = 0;

	unsigned int offset = headersize;
	unsigned int length = size - footersize;
	while (offset < length) {
		// Ignore empty samples.
		if (array_isequal (data + offset, parser->samplesize, 0x00)) {
			offset += parser->samplesize;
			continue;
		}

		// Status flags.
		unsigned int status = data[offset + 11];
		if ((status & OC) == 0) {
			mode = DC_DIVEMODE_CC;
		}

		// Gaschange.
		unsigned int o2 = data[offset + 7];
		unsigned int he = data[offset + 8];
		if (o2 != o2_previous || he != he_previous) {
			// Find the gasmix in the list.
			unsigned int idx = 0;
			while (idx < ngasmixes) {
				if (o2 == oxygen[idx] && he == helium[idx])
					break;
				idx++;
			}

			// Add it to list if not found.
			if (idx >= ngasmixes) {
				if (idx >= NGASMIXES) {
					ERROR (abstract->context, "Maximum number of gas mixes reached.");
					return DC_STATUS_NOMEMORY;
				}
				oxygen[idx] = o2;
				helium[idx] = he;
				ngasmixes = idx + 1;
			}

			o2_previous = o2;
			he_previous = he;
		}

		// Transmitter battery levels
		if (parser->logversion >= 7) {
			// T1 at offset 27, T2 at offset 19
			t1_battery |= battery_state(data + offset + 27);
			t2_battery |= battery_state(data + offset + 19);
		}

		offset += parser->samplesize;
	}

	// Cache sensor calibration for later use
	parser->calibration[0] = array_uint16_be(data + 87) / 100000.0;
	parser->calibration[1] = array_uint16_be(data + 89) / 100000.0;
	parser->calibration[2] = array_uint16_be(data + 91) / 100000.0;
	// The Predator expects the mV output of the cells to be within 30mV
	// to 70mV in 100% O2 at 1 atmosphere.
	// If the calibration value is scaled with a factor 2.2, then the
	// sensors lines up and matches the average.
	if (parser->model == PREDATOR) {
		for (size_t i = 0; i < 3; ++i) {
			parser->calibration[i] *= 2.2;
		}
	}

	// Cache the data for later use.
	parser->headersize = headersize;
	parser->footersize = footersize;
	parser->ngasmixes = ngasmixes;
	for (unsigned int i = 0; i < ngasmixes; ++i) {
		parser->oxygen[i] = oxygen[i];
		parser->helium[i] = helium[i];
	}
	parser->mode = mode;
	add_string_fmt(parser, "Serial", "%08x", parser->serial);
	add_string_fmt(parser, "FW Version", "%2x", data[19]);
	add_deco_model(parser, data);
	add_battery_type(parser, data);
	add_string_fmt(parser, "Battery at end", "%.1f V", data[9] / 10.0);
	add_battery_info(parser, "T1 battery", t1_battery);
	add_battery_info(parser, "T2 battery", t2_battery);
	parser->cached = 1;

	return DC_STATUS_SUCCESS;
}

static dc_status_t
shearwater_predator_parser_get_field (dc_parser_t *abstract, dc_field_type_t type, unsigned int flags, void *value)
{
	shearwater_predator_parser_t *parser = (shearwater_predator_parser_t *) abstract;

	const unsigned char *data = abstract->data;
	unsigned int size = abstract->size;

	// Cache the parser data.
	dc_status_t rc = shearwater_predator_parser_cache (parser);
	if (rc != DC_STATUS_SUCCESS)
		return rc;

	// Get the offset to the footer record.
	unsigned int footer = size - parser->footersize;

	// Get the unit system.
	unsigned int units = data[8];

	dc_gasmix_t *gasmix = (dc_gasmix_t *) value;
	dc_salinity_t *water = (dc_salinity_t *) value;
	dc_field_string_t *string = (dc_field_string_t *) value;
	unsigned int density = 0;

	if (value) {
		switch (type) {
		case DC_FIELD_DIVETIME:
			*((unsigned int *) value) = array_uint16_be (data + footer + 6) * 60;
			break;
		case DC_FIELD_MAXDEPTH:
			if (units == IMPERIAL)
				*((double *) value) = array_uint16_be (data + footer + 4) * FEET;
			else
				*((double *) value) = array_uint16_be (data + footer + 4);
			break;
		case DC_FIELD_GASMIX_COUNT:
			*((unsigned int *) value) = parser->ngasmixes;
			break;
		case DC_FIELD_GASMIX:
			gasmix->oxygen = parser->oxygen[flags] / 100.0;
			gasmix->helium = parser->helium[flags] / 100.0;
			gasmix->nitrogen = 1.0 - gasmix->oxygen - gasmix->helium;
			break;
		case DC_FIELD_SALINITY:
			density = array_uint16_be (data + 83);
			if (density == 1000)
				water->type = DC_WATER_FRESH;
			else
				water->type = DC_WATER_SALT;
			water->density = density;
			break;
		case DC_FIELD_ATMOSPHERIC:
			*((double *) value) = array_uint16_be (data + 47) / 1000.0;
			break;
		case DC_FIELD_DIVEMODE:
			*((dc_divemode_t *) value) = parser->mode;
			break;
		case DC_FIELD_STRING:
			if (flags < MAXSTRINGS) {
				dc_field_string_t *p = parser->strings + flags;
				if (p->desc) {
					*string = *p;
					break;
				}
			}
			return DC_STATUS_UNSUPPORTED;
		default:
			return DC_STATUS_UNSUPPORTED;
		}
	}

	return DC_STATUS_SUCCESS;
}


static dc_status_t
shearwater_predator_parser_samples_foreach (dc_parser_t *abstract, dc_sample_callback_t callback, void *userdata)
{
	shearwater_predator_parser_t *parser = (shearwater_predator_parser_t *) abstract;

	const unsigned char *data = abstract->data;
	unsigned int size = abstract->size;

	// Cache the parser data.
	dc_status_t rc = shearwater_predator_parser_cache (parser);
	if (rc != DC_STATUS_SUCCESS)
		return rc;

	// Get the unit system.
	unsigned int units = data[8];

	// Previous gas mix.
	unsigned int o2_previous = 0, he_previous = 0;

	unsigned int time = 0;
	unsigned int offset = parser->headersize;
	unsigned int length = size - parser->footersize;

	while (offset < length) {
		dc_sample_value_t sample = {0};

		// Ignore empty samples.
		if (array_isequal (data + offset, parser->samplesize, 0x00)) {
			offset += parser->samplesize;
			continue;
		}

		// Time (seconds).
		time += 10;
		sample.time = time;
		if (callback) callback (DC_SAMPLE_TIME, sample, userdata);

		// Depth (1/10 m or ft).
		unsigned int depth = array_uint16_be (data + offset);
		if (units == IMPERIAL)
			sample.depth = depth * FEET / 10.0;
		else
			sample.depth = depth / 10.0;
		if (callback) callback (DC_SAMPLE_DEPTH, sample, userdata);

		// Temperature (°C or °F).
		int temperature = (signed char) data[offset + 13];
		if (temperature < 0) {
			// Fix negative temperatures.
			temperature += 102;
			if (temperature > 0) {
				temperature = 0;
			}
		}
		if (units == IMPERIAL)
			sample.temperature = (temperature - 32.0) * (5.0 / 9.0);
		else
			sample.temperature = temperature;
		if (callback) callback (DC_SAMPLE_TEMPERATURE, sample, userdata);

		// Status flags.
		unsigned int status = data[offset + 11];

		if ((status & OC) == 0) {
			// PPO2
#ifdef SENSOR_AVERAGE
			sample.ppo2 = data[offset + 6] / 100.0;
			if (callback) callback (DC_SAMPLE_PPO2, sample, userdata);
#else
			if ((status & PPO2_EXTERNAL) == 0) {
				sample.ppo2 = data[offset + 12] * parser->calibration[0];
				if (callback && (data[86] & 0x01)) callback (DC_SAMPLE_PPO2, sample, userdata);

				sample.ppo2 = data[offset + 14] * parser->calibration[1];
				if (callback && (data[86] & 0x02)) callback (DC_SAMPLE_PPO2, sample, userdata);

				sample.ppo2 = data[offset + 15] * parser->calibration[2];
				if (callback && (data[86] & 0x04)) callback (DC_SAMPLE_PPO2, sample, userdata);
			}
#endif

			// Setpoint
			if (parser->model > PREDATOR) {
				sample.setpoint = data[offset + 18] / 100.0;
			} else {
				if (status & SETPOINT_HIGH) {
					sample.setpoint = data[18] / 100.0;
				} else {
					sample.setpoint = data[17] / 100.0;
				}
			}
			if (callback) callback (DC_SAMPLE_SETPOINT, sample, userdata);
		}

		// CNS
		if (parser->model > PREDATOR) {
			sample.cns = data[offset + 22] / 100.0;
			if (callback) callback (DC_SAMPLE_CNS, sample, userdata);
		}

		// Gaschange.
		unsigned int o2 = data[offset + 7];
		unsigned int he = data[offset + 8];
		if (o2 != o2_previous || he != he_previous) {
			unsigned int idx = shearwater_predator_find_gasmix (parser, o2, he);
			if (idx >= parser->ngasmixes) {
				ERROR (abstract->context, "Invalid gas mix.");
				return DC_STATUS_DATAFORMAT;
			}

			sample.gasmix = idx;
			if (callback) callback (DC_SAMPLE_GASMIX, sample, userdata);
			o2_previous = o2;
			he_previous = he;
		}

		// Deco stop / NDL.
		unsigned int decostop = array_uint16_be (data + offset + 2);
		if (decostop) {
			sample.deco.type = DC_DECO_DECOSTOP;
			if (units == IMPERIAL)
				sample.deco.depth = decostop * FEET;
			else
				sample.deco.depth = decostop;
		} else {
			sample.deco.type = DC_DECO_NDL;
			sample.deco.depth = 0.0;
		}
		sample.deco.time = data[offset + 9] * 60;
		if (callback) callback (DC_SAMPLE_DECO, sample, userdata);

		// for logversion 7 and newer (introduced for Perdix AI)
		// detect tank pressure
		if (parser->logversion >= 7) {
			// Pressure (2 psi).
			// 0xFFFF is not paired / no coms for 90 seconds
			// 0xFFFE no coms for 30 seconds
			// top 4 bits battery level:
			// 0 - normal, 1 - critical, 2 - warning
			unsigned int pressure = array_uint16_be (data + offset + 27);
			if ((pressure & 0xFFF0) != 0xFFF0) {
				pressure &= 0x0FFF;
				sample.pressure.tank = 0;
				sample.pressure.value = pressure * 2 * PSI / BAR;
				if (callback) callback (DC_SAMPLE_PRESSURE, sample, userdata);
			}
			pressure = array_uint16_be (data + offset + 19);
			if ((pressure & 0xFFF0) != 0xFFF0) {
				pressure &= 0x0FFF;
				sample.pressure.tank = 1;
				sample.pressure.value = pressure * 2 * PSI / BAR;
				if (callback) callback (DC_SAMPLE_PRESSURE, sample, userdata);
			}
			// Gas time remaining in minutes
			if (data[offset + 21] < 0xFBu) {
				sample.rbt = data[offset + 21];
				if (callback) callback (DC_SAMPLE_RBT, sample, userdata);
			}
		}

		offset += parser->samplesize;
	}
	return DC_STATUS_SUCCESS;
}