/*
GanttProject is an opensource project management tool.
Copyright (C) 2004-2011 GanttProject team

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package biz.ganttproject.core.time;

import java.util.Date;

/**
 * @author bard
 */
public class TimeUnitFunctionOfDateImpl extends TimeUnitDateFrameableImpl implements TimeUnitFunctionOfDate {
  private final DateFrameable myDirectFrameable;

  public TimeUnitFunctionOfDateImpl(String name, TimeUnitGraph graph, TimeUnit directAtomUnit, DateFrameable framer) {
    super(name, graph, directAtomUnit, framer);
    myDirectFrameable = directAtomUnit;
  }

  @Override
  public TimeUnit createTimeUnit(Date date) {
    // TODO Only works if myBaseDate is not a TimeUnitFunctiongOfDateImpl!
    // (Quarter -> Month -> Day fails!)
    return new ParameterizedTimeUnitImpl(date);
  }

  @Override
  public int getAtomCount(TimeUnit atomUnit) {
    throw new UnsupportedOperationException(
        "This time unit is function of date. Use method createTimeUnit() to create a parameterized instance.");
  }

  private class ParameterizedTimeUnitImpl implements TimeUnit {
    private final Date myRightDate;

    private final Date myLeftDate;

    private int myAtomCount = -1;

    public ParameterizedTimeUnitImpl(Date myBaseDate) {
      this.myRightDate = TimeUnitFunctionOfDateImpl.this.adjustRight(myBaseDate);
      this.myLeftDate = TimeUnitFunctionOfDateImpl.this.adjustLeft(myBaseDate);
    }

    @Override
    public String getName() {
      return TimeUnitFunctionOfDateImpl.this.getName();
    }

    @Override
    public boolean isConstructedFrom(TimeUnit unit) {
      return TimeUnitFunctionOfDateImpl.this.isConstructedFrom(unit);
    }

    @Override
    public int getAtomCount(TimeUnit atomUnit) {
      if (atomUnit == TimeUnitFunctionOfDateImpl.this || atomUnit == this) {
        return 1;
      }
      int directAtomCount = getDirectAtomCount();
      return directAtomCount * getDirectAtomUnit().getAtomCount(atomUnit);
    }

    private int getDirectAtomCount() {
      if (myAtomCount == -1) {
        myAtomCount = 0;
        for (Date leftDate = TimeUnitFunctionOfDateImpl.this.myDirectFrameable.jumpLeft(myRightDate); leftDate.compareTo(myLeftDate) >= 0; myAtomCount++) {

          leftDate = TimeUnitFunctionOfDateImpl.this.myDirectFrameable.jumpLeft(leftDate);
        }
      }
      return myAtomCount;
    }

    @Override
    public TimeUnit getDirectAtomUnit() {
      return TimeUnitFunctionOfDateImpl.this.getDirectAtomUnit();
    }

    @Override
    public Date adjustRight(Date baseDate) {
      return TimeUnitFunctionOfDateImpl.this.adjustRight(baseDate);
    }

    @Override
    public Date adjustLeft(Date baseDate) {
      return TimeUnitFunctionOfDateImpl.this.adjustLeft(baseDate);
    }

    @Override
    public Date jumpLeft(Date baseDate) {
      return TimeUnitFunctionOfDateImpl.this.jumpLeft(baseDate);
    }

    @Override
    public boolean equals(Object o) {
      return TimeUnitFunctionOfDateImpl.this.equals(o);
    }

    @Override
    public int hashCode() {
      return super.hashCode();
    }

  }
}