package holeg.model;

import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;

/**
 * Representative of a flexibility for a HolonElement.
 */
public class Flexibility {
  /*
   *  MODEL
   */
  /**
   * The Name of a Flexibility.
   */
  public String name;
  /**
   * How fast in TimeSteps the Flexibility can be activated.
   */
  public int speed;
  /**
   * How high the cost for a activation are.
   */
  public float cost;
  /**
   * SHould this Flexibility be Offered when is constrainList is fulfilled the flexibility can be
   * activated.
   */
  public boolean offered;
  /**
   * The List of Constrains the Flexibility
   */
  public List<Constrain> constrainList;
  /**
   * The owner of the Flexibility.
   */
  private transient HolonElement element;
  /**
   * The Duration in TimeSteps how long the Flexibility is activated.
   */
  private int duration;
  /** The Element this flexibility is assigned.*/
  /**
   * The Duration after a successful activation between the next possible activation.
   */
  private int cooldown;
  /*
   *  STATE
   */
  private transient FlexState state = FlexState.OFFERED;
  private transient int timeStep;
  private transient int activationTime = -1;
  private transient int durationEndTime = -1;
  private transient int coolDownEndTime = -1;

  public Flexibility(HolonElement element) {
    this(0, 0.f, 1, 0, false, element);
  }

  public Flexibility(int speed, float cost, int duration, int cooldown, boolean offered,
      HolonElement element) {
    this.speed = speed;
    this.cost = cost;
    setDuration(duration);
    setCooldown(cooldown);
    this.offered = offered;
    this.element = element;
    constrainList = new ArrayList<Constrain>();
  }

  public HolonElement getElement() {
    return element;
  }

  public void setElement(HolonElement element) {
    this.element = element;
  }

  public int getDuration() {
    return duration;
  }

  /**
   * Minimum duration is 1 TimeStep.
   */
  public void setDuration(int duration) {
    this.duration = Math.max(1, duration);
  }

  public int getCooldown() {
    return cooldown;
  }

  /**
   * No negative cooldown TimeSteps.
   */
  public void setCooldown(int cooldown) {
    this.cooldown = Math.max(0, cooldown);
  }

  /**
   * returns the total energy Amount accumulated over the TimeSteps.
   */
  public float magnitude() {
    return ((float) duration) * element.getEnergy();
  }

  public float energyReleased() {
    return
        (constrainList.stream().map(Constrain::getName).anyMatch(name -> name.equals("onConstrain"))
            ? -1.0f : 1.0f) * element.getEnergy();
  }

  public boolean isPositive() {
    return energyReleased() >= 0;
  }

  public boolean isNegative() {
    return energyReleased() < 0;
  }

  public int getSpeed() {
    return speed;
  }

  public void setSpeed(int speed) {
    this.speed = speed;
  }

  @Override
  public String toString() {
    return "Flexibility: " + name + " from [HolonElement: " + element.getName() + "]";
  }

  void calculateState(int timestep) {
    this.timeStep = timestep;
    state = revalidateState();
  }

  public boolean order() {
    if (canOrder()) {
      state = FlexState.IN_USE;
      durationEndTime = timeStep + this.getDuration();
      coolDownEndTime = durationEndTime + this.getCooldown();
      activationTime = timeStep;
      return true;
    }
    return false;
  }

  public boolean cancel() {
    if (activationTime == timeStep) {
      reset();
      return true;
    }
    return false;
  }

  void reset() {
    durationEndTime = -1;
    coolDownEndTime = -1;
    state = revalidateState();
  }

  public boolean canActivate() {
    return remainingTimeTillActivation() == 0;
  }

  public boolean canOrder() {
    boolean flexIsOffered = state.equals(FlexState.OFFERED);
    return flexIsOffered && !element.isFlexActive();
  }

  public FlexState getState() {
    return state;
  }

  public int remainingTimeTillActivation() {
    return Math.max(0, coolDownEndTime - timeStep);
  }

  public int remainingDuration() {
    return Math.max(0, durationEndTime - timeStep);
  }

  /**
   * Checks if all assigned constrains are fulfilled. When no constrains assigned returns true.
   */
  private boolean fulfillsConstrains() {
    return constrainList.stream().map(Constrain::getConstrainFunction).reduce(Predicate::and)
        .orElse(f -> true).test(this);
  }

  private FlexState revalidateState() {
    if (canActivate()) {
      if (!this.fulfillsConstrains() || element.isFlexActive()) {
        return FlexState.UNAVAILABLE;
      } else if (this.offered) {
        return FlexState.OFFERED;
      }
      return FlexState.NOT_OFFERED;
    } else if (remainingDuration() == 0) {
      return FlexState.ON_COOLDOWN;
    } else {
      return FlexState.IN_USE;
    }
  }

  public enum FlexState {
    IN_USE, ON_COOLDOWN, OFFERED, NOT_OFFERED, UNAVAILABLE
  }


}