/*
 * Copyright (c) 2003-2010 Hypertriton, Inc. <http://hypertriton.com/>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Unit conversions (taken from Agar-1.3.4).
 */

#include <cnc.h>
#include <string.h>
#include <stdio.h>
#include <math.h>

#define N_(x) (x)
#define _(x) (x)

const char *agUnitGroupNames[] = {
	N_("Identity"),
	N_("Length"),
	N_("Angle"),
	N_("Area"),
	N_("Volume"),
	N_("Velocity"),
	N_("Mass"),
	N_("Time"),
	N_("Electrical current"),
	N_("Temperature"),
	N_("Light"),
	N_("Power"),
	N_("Electromotive force"),
	N_("Electrical resistance"),
	N_("Capacitance"),
	N_("Inductance"),
	N_("Frequency"),
	N_("Pressure"),
	N_("Vacuum"),
	NULL
};
const cnc_unit_t *cnc_unit_groups[] = {
	cncIdentityUnit,
	cncLengthUnits,
	cncAngleUnits,
	cncAreaUnits,
	cncVolumeUnits,
	cncSpeedUnits,
	cncMassUnits,
	cncTimeUnits,
	cncCurrentUnits,
	cncTemperatureUnits,
	cncLightUnits,
	cncPowerUnits,
	cncEMFUnits,
	cncResistanceUnits,
	cncCapacitanceUnits,
	cncInductanceUnits,
	cncFrequencyUnits,
	cncPressureUnits,
	cncVacuumUnits,
};
const int cnc_unit_groups_count = sizeof(cnc_unit_groups) / sizeof(cnc_unit_groups[0]);

/*
 * Return the unit of specified key, searching in all groups.
 * If key=NULL, return the base unit.
 */
const cnc_unit_t *
cnc_find_unit_all(const char *key)
{
	int i;

	for (i = 0; i < cnc_unit_groups_count; i++) {
		const cnc_unit_t *group = cnc_unit_groups[i];
		const cnc_unit_t *unit;

		for (unit = &group[0]; unit->key != NULL; unit++) {
			if (key == NULL) {
				if (unit->divider == 1)
					return (unit);
			} else {
				if (strcmp(unit->key, key) == 0)
					return (unit);
			}
		}
	}
	cnc_set_error("No such unit: %s", key);
	return (NULL);
}

/*
 * Return the unit of specified key, searching in all groups.
 * If key=NULL, return the base unit.
 */
const cnc_unit_t *
cnc_find_unit(const char *key, const cnc_unit_t *group)
{
	const cnc_unit_t *unit;

	for (unit = &group[0]; unit->key != NULL; unit++) {
		if (key == NULL) {
			if (unit->divider == 1)
				return (unit);
		} else {
			if (strcmp(unit->key, key) == 0)
				return (unit);
		}
	}
	cnc_set_error("No such unit: %s", key);
	return (NULL);
}

/* Return the unit which yields the number with the least figures. */
const cnc_unit_t *
cnc_best_unit(const cnc_unit_t ugroup[], double n)
{
	const cnc_unit_t *unit, *bestunit = NULL;
	double smallest = HUGE_VAL;
	double diff;

	if (n == 0) {
		goto defunit;
	}
	for (unit = &ugroup[0]; unit->key != NULL; unit++) {
		if (n/unit->divider >= 1.0) {
			diff = fabs(n-unit->divider);
			if (diff < smallest) {
				smallest = diff;
				bestunit = unit;
			}
		}
	}
	if (bestunit == NULL) {
		goto defunit;
	}
	return (bestunit);
defunit:
	for (unit = &ugroup[0]; unit->key != NULL; unit++) {
		if (unit->divider == 1.0)
			break;
	}
	return (unit);
}

/* Format a number using the unit most suited to its magnitude. */
int
cnc_unit_format(double n, const cnc_unit_t ugroup[], char *buf, size_t len)
{
	const cnc_unit_t *ubest;

	ubest = cnc_best_unit(ugroup, n);
	return (snprintf(buf, len, "%.2f%s", cnc_base2unit(n, ubest),
	    ubest->abbr[0] != '\0' ? ubest->abbr : ubest->key));
}

/* Default unit (identity) */
const cnc_unit_t cncIdentityUnit[] = {
	{ "identity", "", "",	1.0, NULL },
	{ NULL,	NULL, NULL,	0, NULL }
};

/* Units of length/distance */
const cnc_unit_t cncLengthUnits[] = {
	{ "Ang", "\xc3\x85", N_("\xc3\x85ngstroms"), 1e-10,	NULL },
	{ "fm", "", N_("Femtometres"),		1e-15,		NULL },
	{ "pm", "", N_("Picometres"),		1e-12,		NULL },
	{ "nm", "", N_("Nanometres"),		1e-9,		NULL },
	{ "um", "\xc2\xb5", N_("Microns"),	1e-6,		NULL },
	{ "mil", "", N_("Mils"),		25e-6,		NULL },
	{ "mm", "", N_("Millimeters"),		1e-3,		NULL },
	{ "in", "", N_("Inches"),		0.0254,		NULL },
	{ "cm",	"", N_("Centimeters"),		1e-2,		NULL },
	{ "dm",	"", N_("Decimeters"),		0.1,		NULL },
	{ "ft",	"", N_("Feet"),			0.3048,		NULL },
	{ "yd", "", N_("Yards"),		0.9144,		NULL },
	{ "m", "", N_("Meters"),		1.0,		NULL },
	{ "km", "", N_("Kilometers"),		1000,		NULL },
	{ "mi", "", N_("Miles"),		1609.344,	NULL },
	{ NULL,	NULL, NULL,			0, NULL }
};

/* Units of angle */
const cnc_unit_t cncAngleUnits[] = {
	{ "rad", "", N_("Radians"),		1.0, NULL },
	{ "deg", "\xc2\xb0", N_("Degrees"),	0.01745329251994329577, NULL },
	{ "rev", "", N_("Revolutions"),		6.28318530717958647692, NULL },
	{ "grad", "", N_("Grads"),		0.01570796326794896619, NULL },
	{ "point", "", N_("Points"),		0.19634954084936207740, NULL },
	{ "brad", "", N_("Binary degrees"),	0.02454369260617025968, NULL },
	{ "HA", "", N_("Hour angle"),		0.26179938779914943654, NULL },
	{ NULL,	NULL, NULL,			0, NULL }
};

/* Units of area (SI derived) */
const cnc_unit_t cncAreaUnits[] = {
	{ "um^2", "\xc2\xb5\xc2\xb2", N_("Square micrometers"),	1e-6, NULL },
	{ "mm^2", "mm\xc2\xb2",	N_("Square millimeters"),	1e-3, NULL },
	{ "cm^2", "cm\xc2\xb2",	N_("Square centimeters"),	1e-2, NULL },
	{ "in^2", "in\xc2\xb2",	N_("Square inches"),		0.0254,	NULL },
	{ "ft^2", "ft\xc2\xb2",	N_("Square feet"),		0.3048,	NULL },
	{ "yd^2", "yd\xc2\xb2",	N_("Square yards"),		0.9144,	NULL },
	{ "m^2", "m\xc2\xb2",	N_("Square meters"),		1.0, NULL },
	{ "km^2", "km\xc2\xb2",	N_("Square kilometers"),	1000, NULL },
	{ "mi^2", "mi\xc2\xb2",	N_("Square miles"),		1609.35, NULL },
	{ NULL, NULL, NULL,					0, NULL }
};

/* Units of volume (SI derived) */
const cnc_unit_t cncVolumeUnits[] = {
	{ "um^3", "\xc2\xb5m\xc2\xb3", N_("Cubic micrometers"),	1e-6, NULL },
	{ "mm^3", "mm\xc2\xb3",	N_("Cubic millimeters"),	1e-3, NULL },
	{ "cm^3", "cm\xc2\xb3",	N_("Cubic centimeters"),	1e-2, NULL },
	{ "in^3", "in\xc2\xb3",	N_("Cubic inches"),		0.0254, NULL },
	{ "ft^3", "ft\xc2\xb3",	N_("Cubic feet"),		0.3048,	NULL },
	{ "yd^3", "yd\xc2\xb3",	N_("Cubic yards"),		0.9144, NULL },
	{ "m^3", "m\xc2\xb3", N_("Cubic meters"),		1.0, NULL },
	{ "km^3", "km\xc2\xb3",	N_("Cubic kilometers"),		1e3, NULL },
	{ "mi^3", "mi\xc2\xb3",	N_("Cubic miles"),		1609.35, NULL },
	{ NULL, NULL, NULL,					0, NULL }
};

/* Units of speed/velocity (SI derived) */
const cnc_unit_t cncSpeedUnits[] = {
	{ "um/s", "\xc2\xb5m/s", N_("Micrometers per second"),	1e-6, NULL },
	{ "mm/s", "", N_("Millimeters per second"),		1e-3, NULL },
	{ "cm/s", "", N_("Centimeters per second"),		1e-2, NULL },
	{ "in/s", "", N_("Inches per second"),			0.0254, NULL },
	{ "ft/s", "", N_("Feet per second"),			0.3048,	NULL },
	{ "yd/s", "", N_("Yards per second"),			0.9144,	NULL },
	{ "m/s", "", N_("Meters per second"),			1.0, NULL },
	{ "km/s", "", N_("Kilometers per second"),		1e3, NULL },
	{ "mi/s", "", N_("Miles per second"),			1609.35, NULL },
	{ NULL, NULL, NULL,					0, NULL }
};

/* Units of weight */
const cnc_unit_t cncMassUnits[] = {
	{ "ug", "\xc2\xb5g", N_("Micrograms"),	1e-6,			NULL },
	{ "mg", "", N_("Milligrams"),		1e-3,			NULL },
	{ "cg", "", N_("Centigrams"),		1e-2,			NULL },
	{ "dg", "", N_("Decigrams"),		1e-1,			NULL },
	{ "g", "", N_("Grams"),			1.0,			NULL },
	{ "oz", "", N_("Ounces [comm]"),	28.349,			NULL },
	{ "lb", "", N_("Pounds [comm]"),	453.59,			NULL },
	{ "kg", "", N_("Kilograms"),		1e3,			NULL },
	{ "t(s)", "", N_("Tons [short]"),	907200,			NULL },
	{ "t", "", N_("Tons [metric]"),		1e6,			NULL },
	{ "t(l)", "", N_("Tons [long]"),	1016064,		NULL },
	{ NULL, NULL, NULL,				0, NULL }
};

/* Units of time */
const cnc_unit_t cncTimeUnits[] = {
	{ "ns", "", N_("Nanoseconds"),			1e-9, NULL },
	{ "us", "\xc2\xb5s", N_("Microseconds"),	1e-6, NULL },
	{ "ms", "", N_("Milliseconds"),			1e-3, NULL },
	{ "sec", "", N_("Seconds"),			1.0, NULL },
	{ "min", "", N_("Minutes"),			60, NULL },
	{ "hr", "", N_("Hours"),			3600, NULL },
	{ "day", "", N_("Days"),			86400, NULL },
	{ "wk", "", N_("Weeks"),			604800,	NULL },
	{ "yr", "", N_("Years"),			31104000, NULL },
	{ NULL,	NULL, NULL,				0, NULL }
};

/* Units of electrical current */
const cnc_unit_t cncCurrentUnits[] = {
	{ "pA", "", N_("Picoamperes"),			1e-12, NULL },
	{ "nA", "", N_("Nanoamperes"),			1e-9, NULL },
	{ "uA", "\xc2\xb5\x41", N_("Microamperes"),	1e-6, NULL },
	{ "mA", "", N_("Milliamperes"),			1e-3, NULL },
	{ "A", "", N_("Amperes"),			1.0, NULL },
	{ "kA", "", N_("Kiloamperes"),			1e3, NULL },
	{ "MA", "", N_("Megaamperes"),			1e6, NULL },
	{ NULL, NULL, NULL,				0, NULL }
};

static double
cnc_conv_Fahrenheit(double n, int f2k)
{
	if (f2k) {
		return ((n+459.67) / 1.8);
	} else {
		return (1.8*n - 459.67);
	}
}

static double
cnc_conv_Celsius(double n, int c2k)
{
	if (c2k) {
		return (n+273.15);
	} else {
		return (n-273.15);
	}
}

const cnc_unit_t cncTemperatureUnits[] = {
	{ "degC", "\xc2\xb0\x43", N_("Degrees Celsius"),   0, cnc_conv_Celsius },
	{ "degF", "\xc2\xb0\x46", N_("Degrees Farenheit"), 0, cnc_conv_Fahrenheit},
	{ "uk", "\xc2\xb5k", "Microkelvins",			1e-6, NULL },
	{ "mk", "", "Millikelvins",				1e-3, NULL },
	{ "k", "", "Kelvins",					1.0, NULL },
	{ "kk",	"", "Kilokelvins",				1e3, NULL },
	{ "Mk",	"", N_("Megakelvins"),				1e6, NULL },
	{ NULL,	NULL, NULL,					0, NULL }
};

/* Units of light measurement */
const cnc_unit_t cncLightUnits[] = {
	{ "ucd", "\xc2\xb5\x63\x64", "Microcandelas",		1e-6, NULL },
	{ "mcd", "", "Millicandelas",				1e-3, NULL },
	{ "cd", "", "Candelas",					1.0, NULL },
	{ "kcd", "", "Kilocandelas",				1e3, NULL },
	{ "Mcd", "", N_("Megacandelas"),			1e6, NULL },
	{ NULL, NULL, NULL,					0, NULL }
};

/* Units of power */
const cnc_unit_t cncPowerUnits[] = {
	{ "uW", "\xc2\xb5W", "Microwatts",	1e-6, NULL },
	{ "mW", "", "Milliwatts",		1e-3, NULL },
	{ "BTU/h", "", "BTU/hr",		0.292875, NULL },
	{ "f-lb/s", "", N_("Foot-lbs/sec"),	1.355818, NULL },
	{ "W", "", "Watts",			1.0, NULL },
	{ "kC/m", "", "Kilocalories/min",	69.733, NULL },
	{ "HP", "", N_("Horsepower"),		746, NULL },
	{ "kW", "", "Kilowatts",		1e3, NULL },
	{ "kC/s", "", "Kilocalories/sec",	4183.98, NULL },
	{ "MW", "", N_("Megawatts"),		1e6, NULL },
	{ "GW", "", "Gigawatts",		1e9, NULL },
	{ NULL, NULL, NULL,			0, NULL }
};

/* Units of electromotive force */
const cnc_unit_t cncEMFUnits[] = {
	{ "uV", "\xc2\xb5V", "Microvolts",	1e-6, NULL },
	{ "mV", "", "Millivolts",		1e-3, NULL },
	{ "V", "", "Volts",			1.0, NULL },
	{ "kV", "", "Kilovolts",		1e3, NULL },
	{ "MV", "", N_("Megavolts"),		1e6, NULL },
	{ NULL, NULL, NULL,			0, NULL }
};

/* Units of electrical resistance */
const cnc_unit_t cncResistanceUnits[] = {
	{ "uohm", "\xc2\xb5\xce\xa9", "Microohms",	1e-6, NULL },
	{ "mohm", "m\xce\xa9", "Milliohms",		1e-3, NULL },
	{ "ohm", "\xce\xa9", "Ohms",			1.0, NULL },
	{ "kohm", "k\xce\xa9",	"Kilohms",		1e3, NULL },
	{ "Mohm", "M\xce\xa9", N_("Megaohms"),		1e6, NULL },
	{ NULL, NULL, NULL,				0, NULL }
};

/* Units of electrical capacitance */
const cnc_unit_t cncCapacitanceUnits[] = {
	{ "pF", "", "Picofarads",			1e-12, NULL },
	{ "nF", "", "Nanofarads",			1e-9, NULL },
	{ "uF", "\xc2\xb5\x46",	"Microfarads",		1e-6, NULL },
	{ "mF", "", "Millifarads",			1e-3, NULL },
	{ "F", "", "Farads",				1.0, NULL },
	{ "kF", "", "Kilofarads",			1e3, NULL },
	{ NULL,	NULL, NULL,				0, NULL }
};

/* Units of electrical inductance */
const cnc_unit_t cncInductanceUnits[] = {
	{ "uH", "\xc2\xb5\x48",	"Microhenries",		1e-6, NULL },
	{ "mH", "", "Millihenries",			1e-3, NULL },
	{ "H", "", "Henries",				1.0, NULL },
	{ "kH", "", "Kilohenries",			1e3, NULL },
	{ NULL, NULL, NULL,				0, NULL }
};

/* Units of frequency */
const cnc_unit_t cncFrequencyUnits[] = {
	{ "uHz", "\xc2\xb5Hz","Microhertz",	1e-6, NULL },
	{ "mHz", "", "Millihertz",		1e-3, NULL },
	{ "Hz", "", "Hertz",			1.0, NULL },
	{ "kHz", "", "Kilohertz",		1e3, NULL },
	{ "MHz", "", N_("Megahertz"),		1e6, NULL },
	{ "GHz", "", "Gigahertz",		1e9, NULL },
	{ NULL, NULL, NULL,			0, NULL }
};

/* Units of pressure and stress */
const cnc_unit_t cncPressureUnits[] = {
	{ "Pa",        "",                "Pascals",			1.0, NULL },
	{ "mbar",      "",                "Millibars",			1e2, NULL },
	{ "kPa",       "",                "Kilopascals",		1e3, NULL },
	{ "bar",       "",                "Bars",			1e5, NULL },
	{ "Kg-f/m^2",  "Kg-f/m\xc2\xb2",  N_("Kg-force per m\xc2\xb2"),	9.80665, NULL },
	{ "cm H2O",    "cm H\xc2\xb2O",   N_("Centimeters of water"),	98.0665, NULL },
	{ "in H2O",    "in H\xc2\xb2O",   N_("Inches of water"),	249.08891, NULL },
	{ "cm Hg",     "",                N_("Centimeters of mercury"),	1333.22, NULL },
	{ "Ft H2O",    "Ft H\xc2\xb2O",   N_("Feet of water"),   	2989.06692, NULL },
	{ "in Hg",     "",                N_("Inches of mercury"),      3386.388, NULL },
	{ "m H2O",     "m H\xc2\xb2O",    N_("Meters of water"),	9806.65, NULL },
	{ "Kips/in^2", "Kips/in\xc2\xb2", N_("Kips per in\xc2\xb2"),	6894760, NULL },
	{ "Atm",       "",                N_("Atmospheres"),		101325, NULL },
	{ NULL,	NULL, NULL, 0, NULL }
};

/* Units of vacuum pressure */
const cnc_unit_t cncVacuumUnits[] = {
	{ "ubar(V)",       "\xc2\xb5\x62\x61\x72", N_("Microbar"),            0.000750062, NULL },
	{ "Pa(V)",         "Pa",               N_("Pascals"),                 0.007500617, NULL },
	{ "N/m^2(V)",      "N/m\xc2\xb2",      N_("Newtons per m\xc2\xb2"),   0.007500617, NULL },
	{ "mtorr(V)",      "mtorr",            N_("Millitorr"),               0.001, NULL },
	{ "micron Hg(V)",  "micron Hg",        N_("Microns of Mercury"),      0.001, NULL },
	{ "mbar(V)",       "mbar",             N_("Millibar"),                0.75030012004802, NULL },
	{ "torr(V)",       "torr",             N_("Torr"),                    1.0, NULL },
	{ "mm Hg(V)",      "mm Hg",            N_("Millimeters of Mercury"),  1.0, NULL },
	{ "in H2O(V-4C)",  "in H\xc2\xb2O (4\xc2\xb0\x43)",  N_("Inches of Water (4\xc2\xb0\x43)"), 1.868268641, NULL },
	{ "in H2O(V-60F)", "in H\xc2\xb2O (60\xc2\xb0\x46)", N_("Inches of Water (60\xc2\xb0\x46)"), 1.866475993, NULL },
	{ "in Hg(V-32F)",  "in Hg (32\xc2\xb0\x46)", N_("Inches of Mercury (32\xc2\xb0\x46)"), 25.399938811, NULL },
	{ "in Hg(V-60F)",  "in Hg (60\xc2\xb0\x46)", N_("Inches of Mercury (60\xc2\xb0\x46)"), 25.328457932, NULL },
	{ "psi(V)",        "psi",              N_("Pounds per in\xc2\xb2"),   51.714932572, NULL },
	{ "at(V)",         "at",               N_("Atmospheres technical"),   735.559240069, NULL },
	{ "kg/cm^2(V)",    "kg/cm\xc2\xb2",    N_("Kilograms per cm\xc2\xb2"),735.56454579, NULL },
	{ "bar(V)",        "bar",              N_("Bar"),                     750.30012004, NULL },
	{ "dynes/cm^2(V)", "dynes/cm\xc2\xb2", N_("Dynes per cm\xc2\xb2"),    750.33012004, NULL },
	{ "Atm(V)",        "Atm",              N_("Standard atmospheres"),    760.0, NULL },
	{ NULL, NULL, NULL, 0.0, NULL }
};