/*
 * This file is part of LibrePlan
 *
 * Copyright (C) 2009-2010 Fundación para o Fomento da Calidade Industrial e
 *                         Desenvolvemento Tecnolóxico de Galicia
 * Copyright (C) 2010-2011 Igalia, S.L.
 *
 * 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 <http://www.gnu.org/licenses/>.
 */

package org.zkoss.ganttz.timetracker.zoom;

import java.math.BigDecimal;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.Iterator;

import org.joda.time.DateTime;
import org.joda.time.LocalDate;
import org.joda.time.Months;

/**
 * Zoom level for months and years and weeks in the second level.
 *
 * @author Óscar González Fernández <ogonzalez@igalia.com>
 * @author Lorenzo Tilve Álvaro <ltilve@igalia.com>
 */
public class DetailFourTimeTrackerState extends TimeTrackerState {

    private static final int NUMBER_OF_WEEKS_MINIMUM = 40;

    private static final int SECOND_LEVEL_SIZE = 56;

    DetailFourTimeTrackerState(
            IDetailItemModifier firstLevelModifier, IDetailItemModifier secondLevelModifier) {

        super(firstLevelModifier, secondLevelModifier);
    }

    public final double pixelPerDay() {
        return SECOND_LEVEL_SIZE / (double) 7;
    }

    public final double daysPerPixel() {
        return (double) 7 / SECOND_LEVEL_SIZE;
    }

    @Override
    protected IDetailItemCreator getDetailItemCreatorFirstLevel() {
        return dateTime -> new DetailItem(
                getSizeMonth(dateTime), dateTime.toString("MMMM,YYYY"), dateTime, dateTime.plusMonths(1));
    }

    @Override
    protected IDetailItemCreator getDetailItemCreatorSecondLevel() {
        return dateTime ->  {
            int daysUntilFirstDayNextWeek = getDaysUntilFirstDayNextWeek(dateTime.toLocalDate());
            int sizeWeek = BigDecimal.valueOf(pixelPerDay() * daysUntilFirstDayNextWeek).intValue();

            return new DetailItem(
                    sizeWeek,
                    Integer.toString(dateTime.getWeekOfWeekyear()),
                    dateTime,
                    dateTime.plusDays(daysUntilFirstDayNextWeek));
        };
    }

    @Override
    protected LocalDate round(LocalDate date, boolean down) {
        if (date.getDayOfMonth() == 1) {
            return date;
        }

        return down ? date.withDayOfMonth(1) : date.plusMonths(1).withDayOfMonth(1);
    }

    @Override
    protected Period getMinimumPeriod() {
        return PeriodType.WEEKS.amount(NUMBER_OF_WEEKS_MINIMUM);
    }

    @Override
    protected ZoomLevel getZoomLevel() {
        return ZoomLevel.DETAIL_THREE;
    }

    @Override
    public int getSecondLevelSize() {
        return SECOND_LEVEL_SIZE;
    }

    private int getSizeMonth(DateTime dateTime) {
        Calendar cal =
                new GregorianCalendar(dateTime.getYear(), dateTime.getMonthOfYear() - 1, dateTime.getDayOfMonth());

        // Get the number of days in that month
        int days = cal.getActualMaximum(Calendar.DAY_OF_MONTH);

        return BigDecimal.valueOf(pixelPerDay() * days).intValue();
    }

    @Override
    protected Iterator<LocalDate> getPeriodsFirstLevelGenerator(LocalDate start) {
        return new LazyGenerator<LocalDate>(start) {
            @Override
            protected LocalDate next(LocalDate last) {
                return last.plus(Months.ONE);
            }
        };
    }

    @Override
    protected Iterator<LocalDate> getPeriodsSecondLevelGenerator(LocalDate start) {
        return new LazyGenerator<LocalDate>(start) {
            @Override
            protected LocalDate next(LocalDate last) {
                return last.getDayOfWeek() != 1 ? last.plusDays(getDaysUntilFirstDayNextWeek(last)) : last.plusWeeks(1);
            }
        };
    }

    private int getDaysUntilFirstDayNextWeek(LocalDate date) {
        return 8 - date.getDayOfWeek();
    }
}