@vbyte/btc-dev/src/lib/tx/create.ts

Batteries-included toolset for plebian bitcoin development

import { Assert }            from '@vbyte/micro-lib'
import { COINBASE, DEFAULT } from '@/const.js'

import {
  normalize_prevout,
  normalize_sequence,
  normalize_value
} from './util.js'

import {
  assert_tx_template,
  assert_vin_template,
  assert_vout_template
} from './validate.js'

import type {
  TxData,
  TxInput,
  TxOutput,
  TxTemplate,
  TxSpendInput,
  TxCoinbaseInput,
  TxOutputTemplate,
  TxVirtualInput,
  TxInputTemplate
} from '@/types/index.js'

export function create_coinbase_input (
  config : TxInputTemplate
) : TxCoinbaseInput {
  assert_vin_template(config)
  Assert.exists(config.coinbase, 'coinbase is required')
  const txid       = COINBASE.TXID
  const vout       = COINBASE.VOUT
  const coinbase   = config.coinbase
  const witness    = config.witness ?? []
  const sequence   = normalize_sequence(config.sequence)
  return { coinbase, prevout: null, script_sig: null, sequence, witness, txid, vout }
}

export function create_virtual_input (
  config : TxInputTemplate
) : TxVirtualInput {
  assert_vin_template(config)
  Assert.is_empty(config.coinbase, 'coinbase is not allowed')
  Assert.is_empty(config.prevout,  'prevout is not allowed')
  const { txid, vout, script_sig = null, witness = [] } = config
  const sequence = normalize_sequence(config.sequence)
  return { txid, vout, coinbase: null, prevout: null, script_sig, sequence, witness }
}

export function create_spend_input (
  config : TxInputTemplate
) : TxSpendInput {
  assert_vin_template(config)
  Assert.exists(config.prevout, 'prevout is required')
  const { txid, vout, script_sig = null, witness = [] } = config
  const prevout    = normalize_prevout(config.prevout)
  const sequence   = normalize_sequence(config.sequence)
  return { txid, vout, coinbase: null, prevout, script_sig, sequence, witness }
}

export function create_tx_input (
  config : TxInputTemplate
) : TxInput {
  if (config.coinbase) return create_coinbase_input(config)
  if (config.prevout)  return create_spend_input(config)
  return create_virtual_input(config)
}

export function create_tx_output (
  config : TxOutputTemplate
) : TxOutput {
  assert_vout_template(config)
  const script_pk = config.script_pk
  const value     = normalize_value(config.value)
  return { script_pk, value }
}

export function create_tx (
  config? : Partial<TxTemplate>
) : TxData {
  assert_tx_template(config)
  const { vin = [], vout = [] } = config ?? { vin: [], vout: [] }
  const locktime = config.locktime ?? DEFAULT.LOCKTIME
  const version  = config.version  ?? DEFAULT.VERSION
  const inputs   = vin.map(txin   => create_tx_input(txin))
  const outputs  = vout.map(txout => create_tx_output(txout))
  return { locktime, vin : inputs, vout : outputs, version }
}