/**
 * Copyright (C) 2018 Adrien Hopkins
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
package org.unitConverter.unit;

import org.unitConverter.math.ObjectProduct;

/**
 * All of the units, prefixes and dimensions that are used by the SI, as well as some outside the SI.
 * 
 * <p>
 * This class does not include prefixed units. To obtain prefixed units, use {@link LinearUnit#withPrefix}:
 * 
 * <pre>
 * LinearUnit KILOMETRE = SI.METRE.withPrefix(SI.KILO);
 * </pre>
 * 
 * 
 * @author Adrien Hopkins
 * @since 2019-10-16
 */
public final class SI {
	/// dimensions used by SI units
	// base dimensions, as BaseDimensions
	public static final class BaseDimensions {
		public static final BaseDimension LENGTH = BaseDimension.valueOf("Length", "L");
		public static final BaseDimension MASS = BaseDimension.valueOf("Mass", "M");
		public static final BaseDimension TIME = BaseDimension.valueOf("Time", "T");
		public static final BaseDimension ELECTRIC_CURRENT = BaseDimension.valueOf("Electric Current", "I");
		public static final BaseDimension TEMPERATURE = BaseDimension.valueOf("Temperature", "\u0398"); // theta symbol
		public static final BaseDimension QUANTITY = BaseDimension.valueOf("Quantity", "N");
		public static final BaseDimension LUMINOUS_INTENSITY = BaseDimension.valueOf("Luminous Intensity", "J");
		public static final BaseDimension INFORMATION = BaseDimension.valueOf("Information", "Info"); // non-SI
		public static final BaseDimension CURRENCY = BaseDimension.valueOf("Currency", "$$"); // non-SI

		// You may NOT get SI.BaseDimensions instances!
		private BaseDimensions() {
			throw new AssertionError();
		}
	}

	/// base units of the SI
	// suppressing warnings since these are the same object, but in a different form (class)
	@SuppressWarnings("hiding")
	public static final class BaseUnits {
		public static final BaseUnit METRE = BaseUnit.valueOf(BaseDimensions.LENGTH, "metre", "m");
		public static final BaseUnit KILOGRAM = BaseUnit.valueOf(BaseDimensions.MASS, "kilogram", "kg");
		public static final BaseUnit SECOND = BaseUnit.valueOf(BaseDimensions.TIME, "second", "s");
		public static final BaseUnit AMPERE = BaseUnit.valueOf(BaseDimensions.ELECTRIC_CURRENT, "ampere", "A");
		public static final BaseUnit KELVIN = BaseUnit.valueOf(BaseDimensions.TEMPERATURE, "kelvin", "K");
		public static final BaseUnit MOLE = BaseUnit.valueOf(BaseDimensions.QUANTITY, "mole", "mol");
		public static final BaseUnit CANDELA = BaseUnit.valueOf(BaseDimensions.LUMINOUS_INTENSITY, "candela", "cd");
		public static final BaseUnit BIT = BaseUnit.valueOf(BaseDimensions.INFORMATION, "bit", "b");
		public static final BaseUnit DOLLAR = BaseUnit.valueOf(BaseDimensions.CURRENCY, "dollar", "$");

		// You may NOT get SI.BaseUnits instances!
		private BaseUnits() {
			throw new AssertionError();
		}
	}

	/**
	 * Constants that relate to the SI or other systems.
	 * 
	 * @author Adrien Hopkins
	 * @since 2019-11-08
	 */
	public static final class Constants {
		public static final LinearUnit EARTH_GRAVITY = METRE.dividedBy(SECOND).dividedBy(SECOND).times(9.80665);
	}

	// dimensions used in the SI, as ObjectProducts
	public static final class Dimensions {
		public static final ObjectProduct<BaseDimension> EMPTY = ObjectProduct.empty();
		public static final ObjectProduct<BaseDimension> LENGTH = ObjectProduct.oneOf(BaseDimensions.LENGTH);
		public static final ObjectProduct<BaseDimension> MASS = ObjectProduct.oneOf(BaseDimensions.MASS);
		public static final ObjectProduct<BaseDimension> TIME = ObjectProduct.oneOf(BaseDimensions.TIME);
		public static final ObjectProduct<BaseDimension> ELECTRIC_CURRENT = ObjectProduct
				.oneOf(BaseDimensions.ELECTRIC_CURRENT);
		public static final ObjectProduct<BaseDimension> TEMPERATURE = ObjectProduct.oneOf(BaseDimensions.TEMPERATURE);
		public static final ObjectProduct<BaseDimension> QUANTITY = ObjectProduct.oneOf(BaseDimensions.QUANTITY);
		public static final ObjectProduct<BaseDimension> LUMINOUS_INTENSITY = ObjectProduct
				.oneOf(BaseDimensions.LUMINOUS_INTENSITY);
		public static final ObjectProduct<BaseDimension> INFORMATION = ObjectProduct.oneOf(BaseDimensions.INFORMATION);
		public static final ObjectProduct<BaseDimension> CURRENCY = ObjectProduct.oneOf(BaseDimensions.CURRENCY);
		// derived dimensions without named SI units
		public static final ObjectProduct<BaseDimension> AREA = LENGTH.times(LENGTH);

		public static final ObjectProduct<BaseDimension> VOLUME = AREA.times(LENGTH);
		public static final ObjectProduct<BaseDimension> VELOCITY = LENGTH.dividedBy(TIME);
		public static final ObjectProduct<BaseDimension> ACCELERATION = VELOCITY.dividedBy(TIME);
		public static final ObjectProduct<BaseDimension> WAVENUMBER = EMPTY.dividedBy(LENGTH);
		public static final ObjectProduct<BaseDimension> MASS_DENSITY = MASS.dividedBy(VOLUME);
		public static final ObjectProduct<BaseDimension> SURFACE_DENSITY = MASS.dividedBy(AREA);
		public static final ObjectProduct<BaseDimension> SPECIFIC_VOLUME = VOLUME.dividedBy(MASS);
		public static final ObjectProduct<BaseDimension> CURRENT_DENSITY = ELECTRIC_CURRENT.dividedBy(AREA);
		public static final ObjectProduct<BaseDimension> MAGNETIC_FIELD_STRENGTH = ELECTRIC_CURRENT.dividedBy(LENGTH);
		public static final ObjectProduct<BaseDimension> CONCENTRATION = QUANTITY.dividedBy(VOLUME);
		public static final ObjectProduct<BaseDimension> MASS_CONCENTRATION = CONCENTRATION.times(MASS);
		public static final ObjectProduct<BaseDimension> LUMINANCE = LUMINOUS_INTENSITY.dividedBy(AREA);
		public static final ObjectProduct<BaseDimension> REFRACTIVE_INDEX = VELOCITY.dividedBy(VELOCITY);
		public static final ObjectProduct<BaseDimension> REFLACTIVE_PERMEABILITY = EMPTY.times(EMPTY);
		public static final ObjectProduct<BaseDimension> ANGLE = LENGTH.dividedBy(LENGTH);
		public static final ObjectProduct<BaseDimension> SOLID_ANGLE = AREA.dividedBy(AREA);

		// derived dimensions with named SI units
		public static final ObjectProduct<BaseDimension> FREQUENCY = EMPTY.dividedBy(TIME);
		public static final ObjectProduct<BaseDimension> FORCE = MASS.times(ACCELERATION);
		public static final ObjectProduct<BaseDimension> ENERGY = FORCE.times(LENGTH);
		public static final ObjectProduct<BaseDimension> POWER = ENERGY.dividedBy(TIME);
		public static final ObjectProduct<BaseDimension> ELECTRIC_CHARGE = ELECTRIC_CURRENT.times(TIME);
		public static final ObjectProduct<BaseDimension> VOLTAGE = ENERGY.dividedBy(ELECTRIC_CHARGE);
		public static final ObjectProduct<BaseDimension> CAPACITANCE = ELECTRIC_CHARGE.dividedBy(VOLTAGE);
		public static final ObjectProduct<BaseDimension> ELECTRIC_RESISTANCE = VOLTAGE.dividedBy(ELECTRIC_CURRENT);
		public static final ObjectProduct<BaseDimension> ELECTRIC_CONDUCTANCE = ELECTRIC_CURRENT.dividedBy(VOLTAGE);
		public static final ObjectProduct<BaseDimension> MAGNETIC_FLUX = VOLTAGE.times(TIME);
		public static final ObjectProduct<BaseDimension> MAGNETIC_FLUX_DENSITY = MAGNETIC_FLUX.dividedBy(AREA);
		public static final ObjectProduct<BaseDimension> INDUCTANCE = MAGNETIC_FLUX.dividedBy(ELECTRIC_CURRENT);
		public static final ObjectProduct<BaseDimension> LUMINOUS_FLUX = LUMINOUS_INTENSITY.times(SOLID_ANGLE);
		public static final ObjectProduct<BaseDimension> ILLUMINANCE = LUMINOUS_FLUX.dividedBy(AREA);
		public static final ObjectProduct<BaseDimension> SPECIFIC_ENERGY = ENERGY.dividedBy(MASS);
		public static final ObjectProduct<BaseDimension> CATALYTIC_ACTIVITY = QUANTITY.dividedBy(TIME);

		// You may NOT get SI.Dimension instances!
		private Dimensions() {
			throw new AssertionError();
		}
	}

	/// The units of the SI
	public static final LinearUnit ONE = LinearUnit.valueOf(ObjectProduct.empty(), 1);
	public static final LinearUnit METRE = BaseUnits.METRE.asLinearUnit()
			.withName(NameSymbol.of("metre", "m", "meter"));
	public static final LinearUnit KILOGRAM = BaseUnits.KILOGRAM.asLinearUnit()
			.withName(NameSymbol.of("kilogram", "kg"));
	public static final LinearUnit SECOND = BaseUnits.SECOND.asLinearUnit()
			.withName(NameSymbol.of("second", "s", "sec"));
	public static final LinearUnit AMPERE = BaseUnits.AMPERE.asLinearUnit().withName(NameSymbol.of("ampere", "A"));
	public static final LinearUnit KELVIN = BaseUnits.KELVIN.asLinearUnit().withName(NameSymbol.of("kelvin", "K"));
	public static final LinearUnit MOLE = BaseUnits.MOLE.asLinearUnit().withName(NameSymbol.of("mole", "mol"));
	public static final LinearUnit CANDELA = BaseUnits.CANDELA.asLinearUnit().withName(NameSymbol.of("candela", "cd"));
	public static final LinearUnit BIT = BaseUnits.BIT.asLinearUnit().withName(NameSymbol.of("bit", "b"));
	public static final LinearUnit DOLLAR = BaseUnits.DOLLAR.asLinearUnit().withName(NameSymbol.of("dollar", "$"));

	// Non-base units
	public static final LinearUnit RADIAN = METRE.dividedBy(METRE);
	public static final LinearUnit STERADIAN = RADIAN.times(RADIAN);
	public static final LinearUnit HERTZ = ONE.dividedBy(SECOND); // for periodic phenomena
	public static final LinearUnit NEWTON = KILOGRAM.times(METRE).dividedBy(SECOND.times(SECOND));
	public static final LinearUnit PASCAL = NEWTON.dividedBy(METRE.times(METRE));
	public static final LinearUnit JOULE = NEWTON.times(METRE);
	public static final LinearUnit WATT = JOULE.dividedBy(SECOND);
	public static final LinearUnit COULOMB = AMPERE.times(SECOND);
	public static final LinearUnit VOLT = JOULE.dividedBy(COULOMB);
	public static final LinearUnit FARAD = COULOMB.dividedBy(VOLT);
	public static final LinearUnit OHM = VOLT.dividedBy(AMPERE);
	public static final LinearUnit SIEMENS = ONE.dividedBy(OHM);
	public static final LinearUnit WEBER = VOLT.times(SECOND);
	public static final LinearUnit TESLA = WEBER.dividedBy(METRE.times(METRE));
	public static final LinearUnit HENRY = WEBER.dividedBy(AMPERE);
	public static final LinearUnit LUMEN = CANDELA.times(STERADIAN);
	public static final LinearUnit LUX = LUMEN.dividedBy(METRE.times(METRE));
	public static final LinearUnit BEQUEREL = ONE.dividedBy(SECOND); // for activity referred to a nucleotide
	public static final LinearUnit GRAY = JOULE.dividedBy(KILOGRAM); // for absorbed dose
	public static final LinearUnit SIEVERT = JOULE.dividedBy(KILOGRAM); // for dose equivalent
	public static final LinearUnit KATAL = MOLE.dividedBy(SECOND);

	// common derived units included for convenience
	public static final LinearUnit GRAM = KILOGRAM.dividedBy(1000);
	public static final LinearUnit SQUARE_METRE = METRE.toExponent(2);
	public static final LinearUnit CUBIC_METRE = METRE.toExponent(3);
	public static final LinearUnit METRE_PER_SECOND = METRE.dividedBy(SECOND);

	// Non-SI units included for convenience
	public static final Unit CELSIUS = Unit.fromConversionFunctions(KELVIN.getBase(), tempK -> tempK - 273.15,
			tempC -> tempC + 273.15);
	public static final LinearUnit MINUTE = SECOND.times(60);
	public static final LinearUnit HOUR = MINUTE.times(60);
	public static final LinearUnit DAY = HOUR.times(60);
	public static final LinearUnit KILOMETRE_PER_HOUR = METRE.times(1000).dividedBy(HOUR);
	public static final LinearUnit DEGREE = RADIAN.times(360 / (2 * Math.PI));
	public static final LinearUnit ARCMINUTE = DEGREE.dividedBy(60);
	public static final LinearUnit ARCSECOND = ARCMINUTE.dividedBy(60);
	public static final LinearUnit ASTRONOMICAL_UNIT = METRE.times(149597870700.0);
	public static final LinearUnit PARSEC = ASTRONOMICAL_UNIT.times(ARCSECOND);
	public static final LinearUnit HECTARE = METRE.times(METRE).times(10000.0);
	public static final LinearUnit LITRE = METRE.times(METRE).times(METRE).dividedBy(1000.0);
	public static final LinearUnit TONNE = KILOGRAM.times(1000.0);
	public static final LinearUnit DALTON = KILOGRAM.times(1.660539040e-27); // approximate value
	public static final LinearUnit ELECTRONVOLT = JOULE.times(1.602176634e-19);
	public static final Unit NEPER = Unit.fromConversionFunctions(ONE.getBase(), pr -> 0.5 * Math.log(pr),
			Np -> Math.exp(2 * Np));
	public static final Unit BEL = Unit.fromConversionFunctions(ONE.getBase(), pr -> Math.log10(pr),
			dB -> Math.pow(10, dB));
	public static final Unit DECIBEL = Unit.fromConversionFunctions(ONE.getBase(), pr -> 10 * Math.log10(pr),
			dB -> Math.pow(10, dB / 10));

	/// The prefixes of the SI
	// expanding decimal prefixes
	public static final UnitPrefix KILO = UnitPrefix.valueOf(1e3);
	public static final UnitPrefix MEGA = UnitPrefix.valueOf(1e6);
	public static final UnitPrefix GIGA = UnitPrefix.valueOf(1e9);
	public static final UnitPrefix TERA = UnitPrefix.valueOf(1e12);
	public static final UnitPrefix PETA = UnitPrefix.valueOf(1e15);
	public static final UnitPrefix EXA = UnitPrefix.valueOf(1e18);
	public static final UnitPrefix ZETTA = UnitPrefix.valueOf(1e21);
	public static final UnitPrefix YOTTA = UnitPrefix.valueOf(1e24);

	// contracting decimal prefixes
	public static final UnitPrefix MILLI = UnitPrefix.valueOf(1e-3);
	public static final UnitPrefix MICRO = UnitPrefix.valueOf(1e-6);
	public static final UnitPrefix NANO = UnitPrefix.valueOf(1e-9);
	public static final UnitPrefix PICO = UnitPrefix.valueOf(1e-12);
	public static final UnitPrefix FEMTO = UnitPrefix.valueOf(1e-15);
	public static final UnitPrefix ATTO = UnitPrefix.valueOf(1e-18);
	public static final UnitPrefix ZEPTO = UnitPrefix.valueOf(1e-21);
	public static final UnitPrefix YOCTO = UnitPrefix.valueOf(1e-24);

	// prefixes that don't match the pattern of thousands
	public static final UnitPrefix DEKA = UnitPrefix.valueOf(1e1);
	public static final UnitPrefix HECTO = UnitPrefix.valueOf(1e2);
	public static final UnitPrefix DECI = UnitPrefix.valueOf(1e-1);
	public static final UnitPrefix CENTI = UnitPrefix.valueOf(1e-2);
	public static final UnitPrefix KIBI = UnitPrefix.valueOf(1024);
	public static final UnitPrefix MEBI = KIBI.times(1024);
	public static final UnitPrefix GIBI = MEBI.times(1024);
	public static final UnitPrefix TEBI = GIBI.times(1024);
	public static final UnitPrefix PEBI = TEBI.times(1024);
	public static final UnitPrefix EXBI = PEBI.times(1024);

	// You may NOT get SI instances!
	private SI() {
		throw new AssertionError();
	}
}