// Used to convert between satoshi and bitcoin.
const ConversionFactor = 100000000;

export default class Amount {
  // Holds the actual amount in satoshis
  private readonly _satoshis: number;

  private constructor(satoshis: number) {
    this._satoshis = satoshis;
    this.toJSON = Amount.prototype.toJSON;
    this.GetSatoshiAmount = Amount.prototype.GetSatoshiAmount;
  }

  // Create an Amount object using bitcoin unit.
  public static FromBitcoin(bitcoin: number) {
    return new Amount(bitcoin * ConversionFactor);
  }

  // Create an Amount object using satoshi unit.
  public static FromSatoshis(satoshis: number) {
    return new Amount(satoshis);
  }

  // Get the amount value in bitcoin.
  public GetBitcoinAmount() {
    return this._satoshis / ConversionFactor;
  }

  // Get the amount value in satoshi.
  public GetSatoshiAmount() {
    return this._satoshis;
  }

  // Return a new Amount object with value increased by the given amount of
  // satoshi.
  public AddSatoshis(satoshis: number) {
    return new Amount(this._satoshis + satoshis);
  }

  // Return a new Amount object with value increased by the given amount of
  // bitcoin.
  public AddBitcoins(bitcoins: number) {
    return new Amount(this._satoshis + bitcoins * ConversionFactor);
  }

  // Return a new Amount object with value increased by the given amount.
  public AddAmount(amount: Amount) {
    return new Amount(this._satoshis + amount._satoshis);
  }

  // Returns the difference between the amount of satoshi in this object and
  // the amount of satoshi of the given object.
  public CompareWith(amount: Amount) {
    return new Amount(this._satoshis - amount._satoshis);
  }

  toJSON(): AmountJSON {
    return Object.assign({}, this, {
      _satoshis: this._satoshis,
    });
  }

  static fromJSON(json: AmountJSON): Amount {
    if (!json) {
      return Amount.FromSatoshis(0);
    }
    const amount = Object.create(Amount.prototype);
    return Object.assign(amount, json, {
      _satoshis: json._satoshis,
      GetSatoshiAmount: Amount.prototype.GetSatoshiAmount,
    });
  }

  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  static reviver(key: string, value: any): any {
    return key === '' ? Amount.fromJSON(value) : value;
  }
}

export interface AmountJSON {
  _satoshis: number;
}