<?php

namespace Leenooks;

use Carbon\Carbon as CarbonBase;

/**
 * This overrides the default Carbon\Carbon class so that we can enable
 * additional Date functions, like Half Years
 */

class Carbon extends CarbonBase
{
    const MONTHS_PER_HALF = 6;

    public function __get($name)
    {
       switch ($name) {
            case 'half':
                return (int) ceil($this->month / static::MONTHS_PER_HALF);

           case 'quarter_string':
               return sprintf('%dQ%d',$this->year,$this->quarter);

            default:
                return parent::__get($name);
       }
    }

    public function addHalf(): self
    {
        return $this->addHalves(1);
    }

    public function addHalves(int $unit): self
    {
        return $this->addQuarters(2*$unit);
    }

    public function subHalf(): self
    {
        return $this->subHalves(1);
    }

    public function subHalves(int $unit): self
    {
        return $this->subQuarters(2*$unit);
    }

    /**
     * Modify to the first occurrence of a given day of the week
     * in the current quarter. If no dayOfWeek is provided, modify to the
     * first day of the current quarter.  Use the supplied constants
     * to indicate the desired dayOfWeek, ex. static::MONDAY.
     *
     * @param int|null $dayOfWeek
     *
     * @return static
     */
    public function startOfHalf($dayOfWeek = null)
    {
        return $this->setDate($this->year, $this->half * static::MONTHS_PER_HALF - 5, 1)->firstOfMonth($dayOfWeek);
    }

    /**
     * Modify to the last occurrence of a given day of the week
     * in the current quarter. If no dayOfWeek is provided, modify to the
     * last day of the current quarter.  Use the supplied constants
     * to indicate the desired dayOfWeek, ex. static::MONDAY.
     *
     * @param int|null $dayOfWeek
     *
     * @return static
     */
    public function endOfHalf($dayOfWeek = null)
    {
        return $this->setDate($this->year, $this->half * static::MONTHS_PER_HALF, 1)->lastOfMonth($dayOfWeek);
    }
}