/*
 * Copyright 2003-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package groovy.time;

import org.codehaus.groovy.runtime.DefaultGroovyMethods;

import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.ArrayList;

/**
 * Base class for date and time durations.
 * @see Duration
 * @author John Wilson tug@wilson.co.uk
 */
public abstract class BaseDuration {
    protected final int years;
    protected final int months;    
    protected final int days;
    protected final int hours;
    protected final int minutes;
    protected final int seconds;    
    protected final int millis;

    protected BaseDuration(final int years, final int months, final int days, final int hours, final int minutes, final int seconds, final int millis) {
        this.years = years;
        this.months = months;
        this.days = days;
        this.hours = hours;
        this.minutes = minutes;
        this.seconds = seconds;
        this.millis = millis;
    }

    protected BaseDuration(final int days, final int hours, final int minutes, final int seconds, final int millis) {
        this(0, 0, days, hours, minutes, seconds, millis);
    }
    
    public int getYears() {
        return this.years;
    }
    
    public int getMonths() {
        return this.months;
    }
    
    public int getDays() {
        return this.days;
    }
    
    public int getHours() {
        return this.hours;
    }
    
    public int getMinutes() {
        return this.minutes;
    }
    
    public int getSeconds() {
        return this.seconds;
    }
    
    public int getMillis() {
        return this.millis;
    }
    
    public Date plus(final Date date) {
    final Calendar cal = Calendar.getInstance();
    
        cal.setTime(date);
        cal.add(Calendar.YEAR, this.years);
        cal.add(Calendar.MONTH, this.months);
        cal.add(Calendar.DAY_OF_YEAR, this.days);
        cal.add(Calendar.HOUR_OF_DAY, this.hours);
        cal.add(Calendar.MINUTE, this.minutes);
        cal.add(Calendar.SECOND, this.seconds);
        cal.add(Calendar.MILLISECOND, this.millis);
        
        return cal.getTime();
    }

    public String toString() {
        List buffer = new ArrayList();

        if (this.years      != 0) buffer.add(this.years   + " years");
        if (this.months     != 0) buffer.add(this.months  + " months");
        if (this.days       != 0) buffer.add(this.days    + " days");
        if (this.hours      != 0) buffer.add(this.hours   + " hours");
        if (this.minutes    != 0) buffer.add(this.minutes + " minutes");

        if (this.seconds != 0 || this.millis != 0)
            buffer.add((seconds == 0 ? (millis < 0 ? "-0" : "0") : seconds) + "." + DefaultGroovyMethods.padLeft("" + Math.abs(millis), 3, "0")  + " seconds");

        if (buffer.size()!=0) {
            return DefaultGroovyMethods.join(buffer, ", ");
        } else {
            return "0";
        }
    }

    public abstract long toMilliseconds();
    
    public abstract Date getAgo();
    
    public abstract From getFrom();

    public abstract static class From {
        public abstract Date getNow();
        
        public Date getToday() {
            return getNow();
        }
    }
}