/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 com.epam.dlab.configuration;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Map;
import java.util.TreeMap;

import org.apache.commons.lang3.StringUtils;

import com.epam.dlab.exceptions.ParseException;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.MoreObjects;
import com.google.common.base.MoreObjects.ToStringHelper;

/** Provides schedule time configuration.
 */
public class SchedulerConfiguration {
	
	/** User's schedule. */
	@JsonProperty
	private String schedule = "12, 13:30:23, 18:34, 08:50, 7:80";
	
	
	/** Return the schedule of user.
	 */
	public String getSchedule() {
		return schedule;
	}
	
	/** Set the schedule of user.
	 */
	public void setSchedule(String schedule) {
		this.schedule = schedule;
	}
	
	
	/** Schedule. */
	private Map<String, Calendar> realSchedule = new TreeMap<>();
	
	/** Build the schedule from user' schedule.
	 * @throws ParseException
	 */
	public void build() throws ParseException {
		SimpleDateFormat df = new SimpleDateFormat("HH:mm:ss");
		String [] unitArray = schedule.split(",");
		realSchedule.clear();
		for (int i = 0; i < unitArray.length; i++) {
			Calendar date = Calendar.getInstance();
			int [] time = getTime(unitArray[i]);
			try {
				df.parse(StringUtils.join(time, ':'));
			} catch (Exception e) {
				throw new ParseException("Cannot parse date " + unitArray[i] + ". " + e.getLocalizedMessage(), e);
			}
			date.clear();
			date.set(1, 1, 1, time[0], time[1], time[2]);
			realSchedule.put(df.format(date.getTime()), date);
		}
		adjustStartTime();
	}
	
	/** Return the schedule.
	 */
	public Map<String, Calendar> getRealSchedule() {
		return realSchedule;
	}
	
	/** Return time array of user' schedule time.
	 * @param time the time in format HH:mm:ss.
	 * @throws ParseException
	 */
	private int [] getTime(String time) throws ParseException {
		String [] timeString = time.trim().split(":");
		int [] timeInt = new int[3];
		
		for (int i = 0; i < timeInt.length; i++) {
			if (i < timeString.length) {
				try {
					timeInt[i] = Integer.parseInt(timeString[i]);
				} catch (Exception e) {
					throw new ParseException("Cannot parse date " + time + ". " + e.getLocalizedMessage(), e);
				}
			} else {
				timeInt[i] = 0;
			}
		}
		
		return timeInt;
	}

	/** Adjust the time in schedule for current time.
	 */
	public void adjustStartTime() {
		Calendar now = Calendar.getInstance();
		for(String key : realSchedule.keySet()) {
			Calendar time = realSchedule.get(key);
			if (time.before(now)) {
				time.set(now.get(Calendar.YEAR),
						now.get(Calendar.MONTH),
						now.get(Calendar.DAY_OF_MONTH),
						time.get(Calendar.HOUR_OF_DAY),
						time.get(Calendar.MINUTE),
						time.get(Calendar.SECOND));
				if (time.before(now)) {
					time.add(Calendar.DAY_OF_MONTH, 1);
				}
				realSchedule.put(key, time);
			}
		}
	}
	
	/** Return the key of the next start time from the schedule.
	 */
	public String getNextTimeKey() {
		long now = System.currentTimeMillis();
		String nextKey = null;
		long nextTime = -1;
		
		for(String key : realSchedule.keySet()) {
			long time = realSchedule.get(key).getTimeInMillis();
			if ((time >= now && time < nextTime) || nextTime == -1) {
				nextTime = time;
				nextKey = key;
			}
		}
		return nextKey;
	}
	
	/** Return the next start time from the schedule.
	 */
	public Calendar getNextTime() {
		String key = getNextTimeKey();
		return (key == null ? null : realSchedule.get(key));
	}
	
	/** Return the key of the near start time from the schedule to the current time.
	 */
	public String getNearTimeKey() {
		long now = System.currentTimeMillis();
		String nextKey = null;
		long nextTime = -1;
		
		for(String key : realSchedule.keySet()) {
			long time = Math.abs(now - realSchedule.get(key).getTimeInMillis());
			if (time < nextTime || nextTime == -1) {
				nextTime = time;
				nextKey = key;
			}
		}
		return nextKey;
	}
	
	/** Return the near start time from the schedule to the current time.
	 */
	public Calendar getNearTime() {
		String key = getNearTimeKey();
		return (key == null ? null : realSchedule.get(key));
	}
	
	/** Returns a string representation of the object.
	 * @param self the object to generate the string for (typically this), used only for its class name.
	 */
	public ToStringHelper toStringHelper(Object self) {
		SimpleDateFormat df = new SimpleDateFormat("dd.MM.yyyy HH:mm:ss");
		ToStringHelper helper = MoreObjects.toStringHelper(self);
		for(String key : realSchedule.keySet()) {
			Calendar time = realSchedule.get(key);
			helper.add(key, df.format(time.getTime()));
		}
    	return helper;
    }
    
    @Override
    public String toString() {
    	return toStringHelper(this)
    			.toString();
    }

	@Override
	public boolean equals(Object o) {
		if (this == o) return true;
		if (!(o instanceof SchedulerConfiguration)) return false;

		SchedulerConfiguration that = (SchedulerConfiguration) o;

		return getRealSchedule() != null ? getRealSchedule().keySet().equals(that.getRealSchedule().keySet())
				: that.getRealSchedule() == null;
	}

	@Override
	public int hashCode() {
		return getRealSchedule() != null ? getRealSchedule().keySet().hashCode() : 0;
	}
}