Weekend.java

package org.drip.analytics.eventday;

/*
 * -*- mode: java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 */

/*!
 * Copyright (C) 2020 Lakshmi Krishnamurthy
 * Copyright (C) 2019 Lakshmi Krishnamurthy
 * Copyright (C) 2018 Lakshmi Krishnamurthy
 * Copyright (C) 2017 Lakshmi Krishnamurthy
 * Copyright (C) 2016 Lakshmi Krishnamurthy
 * Copyright (C) 2015 Lakshmi Krishnamurthy
 * Copyright (C) 2014 Lakshmi Krishnamurthy
 * Copyright (C) 2013 Lakshmi Krishnamurthy
 * Copyright (C) 2012 Lakshmi Krishnamurthy
 * Copyright (C) 2011 Lakshmi Krishnamurthy
 * 
 *  This file is part of DROP, an open-source library targeting analytics/risk, transaction cost analytics,
 *      asset liability management analytics, capital, exposure, and margin analytics, valuation adjustment
 *      analytics, and portfolio construction analytics within and across fixed income, credit, commodity,
 *      equity, FX, and structured products. It also includes auxiliary libraries for algorithm support,
 *      numerical analysis, numerical optimization, spline builder, model validation, statistical learning,
 *      and computational support.
 *  
 *      https://lakshmidrip.github.io/DROP/
 *  
 *  DROP is composed of three modules:
 *  
 *  - DROP Product Core - https://lakshmidrip.github.io/DROP-Product-Core/
 *  - DROP Portfolio Core - https://lakshmidrip.github.io/DROP-Portfolio-Core/
 *  - DROP Computational Core - https://lakshmidrip.github.io/DROP-Computational-Core/
 * 
 *  DROP Product Core implements libraries for the following:
 *  - Fixed Income Analytics
 *  - Loan Analytics
 *  - Transaction Cost Analytics
 * 
 *  DROP Portfolio Core implements libraries for the following:
 *  - Asset Allocation Analytics
 *  - Asset Liability Management Analytics
 *  - Capital Estimation Analytics
 *  - Exposure Analytics
 *  - Margin Analytics
 *  - XVA Analytics
 * 
 *  DROP Computational Core implements libraries for the following:
 *  - Algorithm Support
 *  - Computation Support
 *  - Function Analysis
 *  - Model Validation
 *  - Numerical Analysis
 *  - Numerical Optimizer
 *  - Spline Builder
 *  - Statistical Learning
 * 
 *  Documentation for DROP is Spread Over:
 * 
 *  - Main                     => https://lakshmidrip.github.io/DROP/
 *  - Wiki                     => https://github.com/lakshmiDRIP/DROP/wiki
 *  - GitHub                   => https://github.com/lakshmiDRIP/DROP
 *  - Repo Layout Taxonomy     => https://github.com/lakshmiDRIP/DROP/blob/master/Taxonomy.md
 *  - Javadoc                  => https://lakshmidrip.github.io/DROP/Javadoc/index.html
 *  - Technical Specifications => https://github.com/lakshmiDRIP/DROP/tree/master/Docs/Internal
 *  - Release Versions         => https://lakshmidrip.github.io/DROP/version.html
 *  - Community Credits        => https://lakshmidrip.github.io/DROP/credits.html
 *  - Issues Catalog           => https://github.com/lakshmiDRIP/DROP/issues
 *  - JUnit                    => https://lakshmidrip.github.io/DROP/junit/index.html
 *  - Jacoco                   => https://lakshmidrip.github.io/DROP/jacoco/index.html
 * 
 *  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.
 */

/**
 * <i>Weekend</i> holds the left and the right weekend days. It provides functionality to retrieve them,
 * check if the given day is a weekend, and serialize/de-serialize weekend days.
 *
 *  <br><br>
 *  <ul>
 *      <li><b>Module </b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/ProductCore.md">Product Core Module</a></li>
 *      <li><b>Library</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/FixedIncomeAnalyticsLibrary.md">Fixed Income Analytics</a></li>
 *      <li><b>Project</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/analytics/README.md">Date, Cash Flow, and Cash Flow Period Measure Generation Utilities</a></li>
 *      <li><b>Package</b> = <a href = "https://github.com/lakshmiDRIP/DROP/tree/master/src/main/java/org/drip/analytics/eventday/README.md">Fixed, Variable, and Custom Holiday Creation</a></li>
 *  </ul>
 *
 * @author Lakshmi Krishnamurthy
 */

public class Weekend {
    private int[] _aiDay = null;

    /**
     * Create a Weekend Instance with SATURDAY and SUNDAY
     * 
     * @return Weekend object
     */

    public static final Weekend StandardWeekend()
    {
        try {
            return new Weekend (new int[] {org.drip.analytics.date.DateUtil.SUNDAY,
                org.drip.analytics.date.DateUtil.SATURDAY});
        } catch (java.lang.Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * Create the weekend instance object from the array of the weekend days
     * 
     * @param aiDay Array of the weekend days
     * 
     * @throws java.lang.Exception Thrown if cannot properly de-serialize Weekend
     */

    public Weekend (
        final int[] aiDay)
        throws java.lang.Exception
    {
        if (null == aiDay) throw new java.lang.Exception ("Weekend ctr: Invalid Inputs");

        int iNumWeekendDays = aiDay.length;;

        if (0 == iNumWeekendDays) throw new java.lang.Exception ("Weekend ctr: Invalid Inputs");

        _aiDay = new int[iNumWeekendDays];

        for (int i = 0; i < iNumWeekendDays; ++i)
            _aiDay[i] = aiDay[i];
    }

    /**
     * Retrieve the weekend days
     * 
     * @return Array of the weekend days
     */

    public int[] days()
    {
        return _aiDay;
    }

    /**
     * Is the given date a left weekend day
     * 
     * @param iDate Date
     * 
     * @return True (Left weekend day)
     */

    public boolean isLeftWeekend (
        final int iDate)
    {
        if (null == _aiDay || 0 == _aiDay.length) return false;

        if (_aiDay[0] == (iDate % 7)) return true;

        return false;
    }

    /**
     * Is the given date a right weekend day
     * 
     * @param dblDate Date
     * 
     * @return True (Right weekend day)
     */

    public boolean isRightWeekend (
        final double dblDate)
    {
        if (null == _aiDay || 1 >= _aiDay.length) return false;

        if (_aiDay[1] == (dblDate % 7)) return true;

        return false;
    }

    /**
     * Is the given date a weekend day
     * 
     * @param iDate Date
     * 
     * @return True (Weekend day)
     */

    public boolean isWeekend (
        final int iDate)
    {
        return isLeftWeekend (iDate) || isRightWeekend (iDate);
    }
}