defmodule BitcoinLib.Transaction.Spec do
@moduledoc """
A simplified version of a %BitcoinLib.Transaction that can be filled with human readable formats
"""
defstruct version: 2, inputs: [], outputs: [], locktime: 2_404_140
alias BitcoinLib.Key.PrivateKey
alias BitcoinLib.Script
alias BitcoinLib.Transaction
alias BitcoinLib.Transaction.Spec
@doc """
Adds a human readable input into a transaction spec
## Examples
iex> %BitcoinLib.Transaction.Spec{}
...> |> BitcoinLib.Transaction.Spec.add_input!(
...> txid: "6925062befcf8aafae78de879fec2535ec016e251c19b1c0792993258a6fda26",
...> vout: 1,
...> redeem_script: "76a914c39658833d83f2299416e697af2fb95a998853d388ac"
...> )
%BitcoinLib.Transaction.Spec{
inputs: [
%BitcoinLib.Transaction.Spec.Input{
txid: "6925062befcf8aafae78de879fec2535ec016e251c19b1c0792993258a6fda26",
vout: 1,
redeem_script: [
%BitcoinLib.Script.Opcodes.Stack.Dup{},
%BitcoinLib.Script.Opcodes.Crypto.Hash160{},
%BitcoinLib.Script.Opcodes.Data{value: <<0xc39658833d83f2299416e697af2fb95a998853d3::160>>},
%BitcoinLib.Script.Opcodes.BitwiseLogic.EqualVerify{},
%BitcoinLib.Script.Opcodes.Crypto.CheckSig{script: <<0x76a914c39658833d83f2299416e697af2fb95a998853d388ac::200>>}
]
}
],
outputs: []
}
"""
@spec add_input!(%Spec{}, binary() | list()) :: %Spec{}
def add_input!(
%Spec{} = spec,
txid: txid,
vout: vout,
redeem_script: redeem_script
)
when is_binary(redeem_script) do
{:ok, parsed_redeem_script} =
redeem_script
|> Binary.from_hex()
|> Script.parse()
Spec.add_input!(spec,
txid: txid,
vout: vout,
redeem_script: parsed_redeem_script
)
end
def add_input!(%Spec{inputs: inputs} = spec,
txid: txid,
vout: vout,
redeem_script: redeem_script
)
when is_list(redeem_script) do
input_spec = %Spec.Input{
txid: txid,
vout: vout,
redeem_script: redeem_script
}
%{spec | inputs: [input_spec | inputs]}
end
@doc """
Adds a human readable output into a transaction spec
## Examples
iex> p2pkh_script = BitcoinLib.Script.Types.P2pkh.create(<<0xad6a62e2d23d1c060897cd0cc79c42dad715e4c7::160>>)
...> amount = 1000
...> transaction_spec = %BitcoinLib.Transaction.Spec{}
...> transaction_spec
...> |> BitcoinLib.Transaction.Spec.add_output(p2pkh_script, amount)
%BitcoinLib.Transaction.Spec{
inputs: [],
outputs: [%BitcoinLib.Transaction.Spec.Output{
script_pub_key: [
%BitcoinLib.Script.Opcodes.Stack.Dup{},
%BitcoinLib.Script.Opcodes.Crypto.Hash160{},
%BitcoinLib.Script.Opcodes.Data{value: <<0xad6a62e2d23d1c060897cd0cc79c42dad715e4c7::160>>},
%BitcoinLib.Script.Opcodes.BitwiseLogic.EqualVerify{},
%BitcoinLib.Script.Opcodes.Crypto.CheckSig{script: <<0x76a914ad6a62e2d23d1c060897cd0cc79c42dad715e4c788ac::200>>}
],
value: 1000
}
]
}
"""
@spec add_output(%Spec{}, binary() | list(), integer()) :: %Spec{}
def add_output(%Spec{} = spec, script_pub_key, value)
when is_binary(script_pub_key) do
parsed_script = script_pub_key |> Binary.from_hex() |> Script.parse!()
Spec.add_output(spec, parsed_script, value)
end
def add_output(%Spec{outputs: outputs} = spec, script_pub_key, value)
when is_list(script_pub_key) do
output_spec = %Spec.Output{script_pub_key: script_pub_key, value: value}
%{spec | outputs: [output_spec | outputs]}
end
@doc """
Create a transaction from a spec
## Examples
iex> %BitcoinLib.Transaction.Spec{
...> inputs: [
...> %BitcoinLib.Transaction.Spec.Input{
...> txid: "6925062befcf8aafae78de879fec2535ec016e251c19b1c0792993258a6fda26",
...> vout: 1,
...> redeem_script: "76a914c39658833d83f2299416e697af2fb95a998853d388ac"
...> }
...> ],
...> outputs: [%BitcoinLib.Transaction.Spec.Output{
...> script_pub_key: [
...> %BitcoinLib.Script.Opcodes.Stack.Dup{},
...> %BitcoinLib.Script.Opcodes.Crypto.Hash160{},
...> %BitcoinLib.Script.Opcodes.Data{value: <<0xad6a62e2d23d1c060897cd0cc79c42dad715e4c7::160>>},
...> %BitcoinLib.Script.Opcodes.BitwiseLogic.EqualVerify{},
...> %BitcoinLib.Script.Opcodes.Crypto.CheckSig{}
...> ],
...> value: 1000
...> }
...> ]
...> }
...> |> BitcoinLib.Transaction.Spec.to_transaction()
%BitcoinLib.Transaction{
version: 2,
id: "346330ef042212b04fabfdf91ce17f0c615a7458f159d4892d5e8385dbb742ce",
inputs: [
%BitcoinLib.Transaction.Input{
txid: "6925062befcf8aafae78de879fec2535ec016e251c19b1c0792993258a6fda26",
vout: 1,
script_sig: "76a914c39658833d83f2299416e697af2fb95a998853d388ac",
sequence: 4294967293
}
],
outputs: [
%BitcoinLib.Transaction.Output{
value: 1000,
script_pub_key: [
%BitcoinLib.Script.Opcodes.Stack.Dup{},
%BitcoinLib.Script.Opcodes.Crypto.Hash160{},
%BitcoinLib.Script.Opcodes.Data{value: <<0xad6a62e2d23d1c060897cd0cc79c42dad715e4c7::160>>},
%BitcoinLib.Script.Opcodes.BitwiseLogic.EqualVerify{},
%BitcoinLib.Script.Opcodes.Crypto.CheckSig{}
]
}
],
locktime: 2404140,
witness: []
}
"""
@spec to_transaction(%Spec{}) :: %Transaction{}
def to_transaction(%Spec{
version: version,
outputs: spec_outputs,
inputs: spec_inputs,
locktime: locktime
}) do
transaction = %Transaction{
version: version,
locktime: locktime,
outputs: Enum.map(spec_outputs, &Spec.Output.to_transaction_output/1),
inputs: Enum.map(spec_inputs, &Spec.Input.to_transaction_input/1)
}
transaction
|> Transaction.add_id()
end
@doc """
With the help of a privat key, transforms a transaction into a signed binary that can be sent
on the network so funds can be spent
## Examples
iex> private_key = BitcoinLib.Key.PrivateKey.from_seed_phrase(
...> "rally celery split order almost twenty ignore record legend learn chaos decade"
...> )
...>%BitcoinLib.Transaction.Spec{
...> inputs: [
...> %BitcoinLib.Transaction.Spec.Input{
...> txid: "6925062befcf8aafae78de879fec2535ec016e251c19b1c0792993258a6fda26",
...> vout: 1,
...> redeem_script: "76a914c39658833d83f2299416e697af2fb95a998853d388ac"
...> }
...> ],
...> outputs: [%BitcoinLib.Transaction.Spec.Output{
...> script_pub_key: [
...> %BitcoinLib.Script.Opcodes.Stack.Dup{},
...> %BitcoinLib.Script.Opcodes.Crypto.Hash160{},
...> %BitcoinLib.Script.Opcodes.Data{value: <<0xad6a62e2d23d1c060897cd0cc79c42dad715e4c7::160>>},
...> %BitcoinLib.Script.Opcodes.BitwiseLogic.EqualVerify{},
...> %BitcoinLib.Script.Opcodes.Crypto.CheckSig{}
...> ],
...> value: 1000
...> }
...> ]
...>}
...> |> BitcoinLib.Transaction.Spec.sign_and_encode(private_key)
"020000000126da6f8a25932979c0b1191c256e01ec3525ec9f87de78aeaf8acfef2b062569010000006b483045022100fdb5f58ab2dd24aeea72c0f832abde538e176f4474b3fe62a9c6e7e8a1a79e92022049565926bb564b996a19c6c3abd1dfbf35f9432ea7aadb10976dacee97d2e10c012102702ded1cca9816fa1a94787ffc6f3ace62cd3b63164f76d227d0935a33ee48c3fdffffff01e8030000000000001976a914ad6a62e2d23d1c060897cd0cc79c42dad715e4c788ac2caf2400"
"""
@spec sign_and_encode(%Spec{}, %PrivateKey{}) :: binary()
def sign_and_encode(spec, %PrivateKey{} = private_key) do
spec
|> to_transaction
|> Transaction.sign_and_encode(private_key)
end
end
