interface SignatureOptions {
  segwitType?: 'p2wpkh' | 'p2sh(p2wpkh)';
  extraEntropy?: Buffer;
}

export interface Signer {
  // param hash: 32 byte Buffer containing the digest of the message
  // param extraEntropy (optional): the 32 byte Buffer of the "extra data" part of RFC6979 nonces
  // returns object
  //   attribute signature: 64 byte Buffer, first 32 R value, last 32 S value of ECDSA signature
  //   attribute recovery: Number (integer) from 0 to 3 (inclusive), also known as recid, used for pubkey recovery
  sign(hash: Buffer, extraEntropy?: Buffer): { signature: Buffer; recovery: number; };
}

export interface SignerAsync {
  // Same as Signer, but return is wrapped in a Promise
  sign(hash: Buffer, extraEntropy?: Buffer): Promise<{ signature: Buffer; recovery: number; }>;
}

export function magicHash(
  message: string | Buffer,
  messagePrefix?: string
): Buffer;

// sign function is overloaded
export function sign(
  message: string | Buffer,
  privateKey: Buffer | Signer,
  compressed?: boolean,
  sigOptions?: SignatureOptions
): Buffer;
export function sign(
  message: string | Buffer,
  privateKey: Buffer | Signer,
  compressed?: boolean,
  messagePrefix?: string,
  sigOptions?: SignatureOptions
): Buffer;

// signAsync function is overloaded
export function signAsync(
  message: string | Buffer,
  privateKey: Buffer | SignerAsync | Signer,
  compressed?: boolean,
  sigOptions?: SignatureOptions
): Promise<Buffer>;
export function signAsync(
  message: string | Buffer,
  privateKey: Buffer | SignerAsync | Signer,
  compressed?: boolean,
  messagePrefix?: string,
  sigOptions?: SignatureOptions
): Promise<Buffer>;

export function verify(
  message: string | Buffer,
  address: string,
  signature: string | Buffer,
  messagePrefix?: string,
  checkSegwitAlways?: boolean
): boolean;