import EtudeError from "../error/EtudeError";
import Exceptional from "../util/Exceptional";
import MathUtil from "../util/MathUtil";

export default class Dynamic {
  public static MINIMUM_VELOCITY = 0;
  public static MAXIMUM_VELOCITY = 127;

  public static size = 0;
  private static _values = [];

  public static PIANISSISSIMO = new Dynamic(16);
  public static PIANISSIMO = new Dynamic(32);
  public static PIANO = new Dynamic(48);
  public static MEZZO_PIANO = new Dynamic(64);
  public static MEZZO_FORTE = new Dynamic(80);
  public static FORTE = new Dynamic(96);
  public static FORTISSIMO = new Dynamic(112);
  public static FORTISSISSIMO = new Dynamic(127);

  private constructor(private velocity: number) {
    ++Dynamic.size;
    Dynamic._values.push(this);

    this.velocity = MathUtil.clamp(Dynamic.MINIMUM_VELOCITY, Dynamic.MAXIMUM_VELOCITY, velocity);
  }

  public static values(): Dynamic[] {
    return Dynamic._values.slice();
  }

  public ordinal(): number {
    return Dynamic._values.indexOf(this);
  }

  public static valueOf(dynamicString: string): Dynamic {
    const dynamic = Dynamic[dynamicString];
    if (dynamic instanceof Dynamic) {
      return dynamic;
    }
    throw EtudeError.forInvalid(Dynamic, dynamicString);
  }

  public crescendo(amount: number): Dynamic {
    return new Dynamic(this.velocity + amount);
  }

  public diminuendo(amount: number): Dynamic {
    return new Dynamic(this.velocity - amount);
  }

  public static fromString(dynamicString: string): Exceptional<Dynamic> {
    return Exceptional
      .ofNullable(dynamicString)
      .map(s => s.trim())
      .filter(s => !s.isEmpty())
      .flatMap(s => {
        let dynamic: Dynamic;
        switch(s){
          case "ppp": dynamic = Dynamic.PIANISSISSIMO; break;
          case "pp": dynamic = Dynamic.PIANISSIMO; break;
          case "p": dynamic = Dynamic.PIANO; break;
          case "mp": dynamic = Dynamic.MEZZO_PIANO; break;
          case "mf": dynamic = Dynamic.MEZZO_FORTE; break;
          case "f": dynamic = Dynamic.FORTE; break;
          case "ff": dynamic = Dynamic.FORTISSIMO; break;
          case "fff": dynamic = Dynamic.FORTISSISSIMO; break;
          default: dynamic = null;
        }
        return Exceptional.ofNullable(dynamic);
      });
  }

  public toString(): string {
    return this.velocity.toString();
  }

  public getVelocity(): number {
    return this.velocity;
  }
}