class Eth::Key

def address
  Util.public_key_to_address public_bytes
end

def initialize(priv: nil)
  # Creates a new, randomized libsecp256k1 context.
  ctx = Secp256k1::Context.new context_randomization_bytes: SecureRandom.random_bytes(32)
  # Creates a new random key pair (public, private).
  key = ctx.generate_key_pair
  unless priv.nil?
    # Converts hex private keys to binary strings.
    priv = Util.hex_to_bin priv if Util.is_hex? priv
    # Creates a keypair from existing private key data.
    key = ctx.key_pair_from_private_key priv
  end
  # Sets the attributes.
  @private_key = key.private_key
  @public_key = key.public_key
end

def personal_sign(message, chain_id = nil)
  prefixed_message = Signature.prefix_message message
  hashed_message = Util.keccak256 prefixed_message
  sign hashed_message, chain_id
end

def private_bytes
  @private_key.data
end

def private_hex
  Util.bin_to_hex @private_key.data
end

def public_bytes
  @public_key.uncompressed
end

def public_bytes_compressed
  @public_key.compressed
end

def public_hex
  Util.bin_to_hex @public_key.uncompressed
end

def public_hex_compressed
  Util.bin_to_hex @public_key.compressed
end

def sign(blob, chain_id = nil)
  context = Secp256k1::Context.new
  compact, recovery_id = context.sign_recoverable(@private_key, blob).compact
  signature = compact.bytes
  v = Chain.to_v recovery_id, chain_id
  is_leading_zero = true
  [v].pack("N").unpack("C*").each do |byte|
    is_leading_zero = false if byte > 0 and is_leading_zero
    signature.append byte unless is_leading_zero and byte === 0
  end
  Util.bin_to_hex signature.pack "c*"
end

def sign_typed_data(typed_data, chain_id = nil)
  hash_to_sign = Eip712.hash typed_data
  sign hash_to_sign, chain_id
end