Demand.php

<?php

namespace KateMorley\Grid\State;

/** Represents details of demand. */
class Demand extends Map {
  public const DEMAND     = 'demand';
  public const FOSSILS    = 'fossils';
  public const RENEWABLES = 'renewables';
  public const OTHERS     = 'others';
  public const TRANSFERS  = 'transfers';

  public const KEYS = [
    self::DEMAND     => 'Demand',
    self::FOSSILS    => 'Fossil fuels',
    self::RENEWABLES => 'Renewables',
    self::OTHERS     => 'Other sources',
    self::TRANSFERS  => 'Transfers'
  ];

  private float $generation;

  /**
   * Constructs a new instance.
   *
   * @param Types     $types     Details of power generation by type
   * @param Transfers $transfers Details of transfers
   */
  public function __construct(Types $types, Transfers $transfers) {
    $fossils    = round($types->get(Types::FOSSILS), 1);
    $renewables = round($types->get(Types::RENEWABLES), 1);
    $others     = round($types->get(Types::OTHERS), 1);
    $transfers  = round($transfers->getTotal(), 1);

    $this->generation = $fossils + $renewables + $others;

    $this->map[self::DEMAND]     = $this->generation + $transfers;
    $this->map[self::FOSSILS]    = $fossils;
    $this->map[self::RENEWABLES] = $renewables;
    $this->map[self::OTHERS]     = $others;
    $this->map[self::TRANSFERS]  = $transfers;
  }

  /**
   * Returns the total power generation. This differs from calling getTotal() on
   * a Generation instance as return value is calculated from values that have
   * already been rounded, and hence is suitable for display in equations.
   */
  public function getGeneration(): float {
    return $this->generation;
  }
}