// drep =
//   [ 0, addr_keyhash
//   // 1, scripthash
//   // 2  ; always abstain
//   // 3  ; always no confidence
//   ]
export type RawDRep = [0, Buffer] | [1, Buffer] | [2] | [3];

export class DRep {
  type!: string;
  keyHash!: Buffer;
  scriptHash!: Buffer;
  static fromCborObject(obj: RawDRep): DRep {
    throw new Error("Method 'fromCborObject' must be implemented in derived classes");
  }
}

export class KeyDRep extends DRep {
  declare keyHash: Buffer;
  constructor(keyHash: Buffer) {
    super();
    this.keyHash = keyHash;
    this.type = "keyDRep";
  }
  static override fromCborObject(obj: RawDRep): KeyDRep {
    if (obj[0] == 0) {
      return new KeyDRep(obj[1]);
    } else throw new Error("Invalid CBOR type for KeyDRep");
  }
}

export class ScriptDRep extends DRep {
  declare scriptHash: Buffer;
  constructor(scriptHash: Buffer) {
    super();
    this.scriptHash = scriptHash;
    this.type = "scriptDRep";
  }
  static override fromCborObject(obj: RawDRep): ScriptDRep {
    if (obj[0] == 1) {
      return new ScriptDRep(obj[1]);
    } else throw new Error("Invalid CBOR type for ScriptDRep");
  }
}

export class AbstainDRep extends DRep {
  constructor() {
    super();
    this.type = "abstainDRep";
  }
  static override fromCborObject(obj: RawDRep): AbstainDRep {
    if (obj[0] == 2) {
      return new AbstainDRep();
    } else throw new Error("Invalid CBOR type for AbstainDRep");
  }
}

export class NoConfidenceDRep extends DRep {
  constructor() {
    super();
    this.type = "noConfidenceDRep";
  }
  static override fromCborObject(obj: RawDRep): NoConfidenceDRep {
    if (obj[0] == 3) {
      return new NoConfidenceDRep();
    } else throw new Error("Invalid CBOR type for NoConfidenceDRep");
  }
}

DRep.fromCborObject = function (obj: RawDRep): DRep {
  switch (obj[0]) {
    case 0:
      return KeyDRep.fromCborObject(obj);
    case 1:
      return ScriptDRep.fromCborObject(obj);
    case 2:
      return AbstainDRep.fromCborObject(obj);
    case 3:
      return NoConfidenceDRep.fromCborObject(obj);
    default:
      throw new Error("Unknown DRep type");
  }
};