/**
 * Copyright (C) 2021 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 sevenUnitsGUI;

import java.util.List;
import java.util.function.Function;
import java.util.function.Predicate;

import sevenUnits.unit.UnitDatabase;
import sevenUnits.unit.UnitPrefix;
import sevenUnits.utils.UncertainDouble;

/**
 * An object that handles interactions between the view and the backend code
 * 
 * @author Adrien Hopkins
 * @since 2021-12-15
 */
public final class Presenter {
	/**
	 * The view that this presenter communicates with
	 */
	private final View view;
	
	/**
	 * The database that this presenter communicates with (effectively the model)
	 */
	private final UnitDatabase database;
	
	// ====== SETTINGS ======
	
	/**
	 * The rule used for parsing input numbers. Any number-string inputted into
	 * this program will be parsed using this method.
	 */
	private Function<String, UncertainDouble> numberParsingRule;
	
	/**
	 * The rule used for displaying the results of unit conversions. The result
	 * of unit conversions will be put into this function, and the resulting
	 * string will be used in the output.
	 */
	private Function<UncertainDouble, String> numberDisplayRule;
	
	/**
	 * A predicate that determines whether or not a certain combination of
	 * prefixes is allowed. If it returns false, a combination of prefixes will
	 * not be allowed. Prefixes are put in the list from right to left.
	 */
	private Predicate<List<UnitPrefix>> prefixRepetitionRule;
	
	/**
	 * If this is true, views that show units as a list will have metric units
	 * removed from the From unit list and imperial/USC units removed from the To
	 * unit list.
	 */
	private boolean oneWayConversion;
	
	/**
	 * If this is false, duplicate units will be removed from the unit view in
	 * views that show units as a list to choose from.
	 */
	private boolean showDuplicateUnits;
	
	/**
	 * Creates a Presenter
	 * 
	 * @param view the view that this presenter communicates with
	 * @since 2021-12-15
	 */
	public Presenter(View view) {
		this.view = view;
		this.database = new UnitDatabase();
	}
	
	/**
	 * Sets the dimension of the view's From and To units.
	 * 
	 * @throws UnsupportedOperationException if the view does not support
	 *                                       unit-based conversion (does not
	 *                                       implement
	 *                                       {@link UnitConversionView})
	 * @since 2021-12-15
	 */
	public void applyDimensionFilter() {}
	
	/**
	 * Gets settings from the view and applies them to both view and presenter.
	 * 
	 * @since 2021-12-15
	 */
	public void applySettings() {}
	
	/**
	 * Converts from the view's input expression to its output expression.
	 * Displays an error message if any of the required fields are invalid.
	 * 
	 * @throws UnsupportedOperationException if the view does not support
	 *                                       expression-based conversion (does
	 *                                       not implement
	 *                                       {@link ExpressionConversionView})
	 * @since 2021-12-15
	 */
	public void convertExpressions() {}
	
	/**
	 * Converts from the view's input unit to its output unit. Displays an error
	 * message if any of the required fields are invalid.
	 * 
	 * @throws UnsupportedOperationException if the view does not support
	 *                                       unit-based conversion (does not
	 *                                       implement
	 *                                       {@link UnitConversionView})
	 * @since 2021-12-15
	 */
	public void convertUnits() {}
	
	/**
	 * Loads settings from the user's settings file and applies them to the view.
	 * 
	 * @since 2021-12-15
	 */
	public void loadSettings() {}
	
	/**
	 * Gets user settings from the view then saves them to the user's settings
	 * file.
	 * 
	 * @since 2021-12-15
	 */
	public void saveSettings() {}
}