const { describe, it } = require('mocha')
const assert = require('assert')
const bitcoin = require('../../')
const regtestUtils = require('./_regtest')
const regtest = regtestUtils.network

// See bottom of file for some helper functions used to make the payment objects needed.

describe('bitcoinjs-lib (transactions with psbt)', () => {
  it('can create a 1-to-1 Transaction', () => {
    const alice = bitcoin.ECPair.fromWIF('L2uPYXe17xSTqbCjZvL2DsyXPCbXspvcu5mHLDYUgzdUbZGSKrSr')
    const psbt = new bitcoin.Psbt()
    psbt.setVersion(2) // These are defaults. This line is not needed.
    psbt.setLocktime(0) // These are defaults. This line is not needed.
    psbt.addInput({
      // if hash is string, txid, if hash is Buffer, is reversed compared to txid
      hash: '7d067b4a697a09d2c3cff7d4d9506c9955e93bff41bf82d439da7d030382bc3e',
      index: 0,
      sequence: 0xffffffff, // These are defaults. This line is not needed.

      // non-segwit inputs now require passing the whole previous tx as Buffer
      nonWitnessUtxo: Buffer.from(
        '0200000001f9f34e95b9d5c8abcd20fc5bd4a825d1517be62f0f775e5f36da944d9' +
        '452e550000000006b483045022100c86e9a111afc90f64b4904bd609e9eaed80d48' +
        'ca17c162b1aca0a788ac3526f002207bb79b60d4fc6526329bf18a77135dc566020' +
        '9e761da46e1c2f1152ec013215801210211755115eabf846720f5cb18f248666fec' +
        '631e5e1e66009ce3710ceea5b1ad13ffffffff01' +
        // value in satoshis (Int64LE) = 0x015f90 = 90000
        '905f010000000000' +
        // scriptPubkey length
        '19' +
        // scriptPubkey
        '76a9148bbc95d2709c71607c60ee3f097c1217482f518d88ac' +
        // locktime
        '00000000',
        'hex',
      ),

      // // If this input was segwit, instead of nonWitnessUtxo, you would add
      // // a witnessUtxo as follows. The scriptPubkey and the value only are needed.
      // witnessUtxo: {
      //   script: Buffer.from(
      //     '76a9148bbc95d2709c71607c60ee3f097c1217482f518d88ac',
      //     'hex',
      //   ),
      //   value: 90000,
      // },

      // Not featured here: redeemScript. A Buffer of the redeemScript
    })
    psbt.addOutput({
      address: '1KRMKfeZcmosxALVYESdPNez1AP1mEtywp',
      value: 80000
    })
    psbt.signInput(0, alice)
    psbt.validateSignatures(0)
    psbt.finalizeAllInputs()
    assert.strictEqual(
      psbt.extractTransaction().toHex(),
      '02000000013ebc8203037dda39d482bf41ff3be955996c50d9d4f7cfc3d2097a694a7' +
      'b067d000000006b483045022100931b6db94aed25d5486884d83fc37160f37f3368c0' +
      'd7f48c757112abefec983802205fda64cff98c849577026eb2ce916a50ea70626a766' +
      '9f8596dd89b720a26b4d501210365db9da3f8a260078a7e8f8b708a1161468fb2323f' +
      'fda5ec16b261ec1056f455ffffffff0180380100000000001976a914ca0d36044e0dc' +
      '08a22724efa6f6a07b0ec4c79aa88ac00000000',
    )
  })

  it('can create (and broadcast via 3PBP) a typical Transaction', async () => {
    // these are { payment: Payment; keys: ECPair[] }
    const alice1 = createPayment('p2pkh')
    const alice2 = createPayment('p2pkh')

    // give Alice 2 unspent outputs
    const inputData1 = await getInputData(5e4, alice1.payment, false, 'noredeem')
    const inputData2 = await getInputData(7e4, alice2.payment, false, 'noredeem')
    {
      const {
        hash, // string of txid or Buffer of tx hash. (txid and hash are reverse order)
        index, // the output index of the txo you are spending
        nonWitnessUtxo, // the full previous transaction as a Buffer
      } = inputData1
      assert.deepStrictEqual({ hash, index, nonWitnessUtxo }, inputData1)
    }

    // network is only needed if you pass an address to addOutput
    // using script (Buffer of scriptPubkey) instead will avoid needed network.
    const psbt = new bitcoin.Psbt({ network: regtest })
      .addInput(inputData1) // alice1 unspent
      .addInput(inputData2) // alice2 unspent
      .addOutput({
        address: 'mwCwTceJvYV27KXBc3NJZys6CjsgsoeHmf',
        value: 8e4
      }) // the actual "spend"
      .addOutput({
        address: alice2.payment.address, // OR script, which is a Buffer.
        value: 1e4
      }) // Alice's change
    // (in)(5e4 + 7e4) - (out)(8e4 + 1e4) = (fee)3e4 = 30000, this is the miner fee

    // Let's show a new feature with PSBT.
    // We can have multiple signers sign in parrallel and combine them.
    // (this is not necessary, but a nice feature)

    // encode to send out to the signers
    const psbtBaseText = psbt.toBase64()

    // each signer imports
    const signer1 = bitcoin.Psbt.fromBase64(psbtBaseText)
    const signer2 = bitcoin.Psbt.fromBase64(psbtBaseText)

    // Alice signs each input with the respective private keys
    // signInput and signInputAsync are better
    // (They take the input index explicitly as the first arg)
    signer1.sign(alice1.keys[0])
    signer2.sign(alice2.keys[0])

    // If your signer object's sign method returns a promise, use the following
    // await signer2.signAsync(alice2.keys[0])

    // encode to send back to combiner (signer 1 and 2 are not near each other)
    const s1text = signer1.toBase64()
    const s2text = signer2.toBase64()

    const final1 = bitcoin.Psbt.fromBase64(s1text)
    const final2 = bitcoin.Psbt.fromBase64(s2text)

    // final1.combine(final2) would give the exact same result
    psbt.combine(final1, final2)

    // Finalizer wants to check all signatures are valid before finalizing.
    // If the finalizer wants to check for specific pubkeys, the second arg
    // can be passed. See the first multisig example below.
    assert.strictEqual(psbt.validateSignatures(0), true)
    assert.strictEqual(psbt.validateSignatures(1), true)

    // This step it new. Since we separate the signing operation and
    // the creation of the scriptSig and witness stack, we are able to
    psbt.finalizeAllInputs()
    // it returns an array of the success of each input, also a result attribute
    // which is true if all array items are true.

    // build and broadcast our RegTest network
    await regtestUtils.broadcast(psbt.extractTransaction().toHex())
    // to build and broadcast to the actual Bitcoin network, see https://github.com/bitcoinjs/bitcoinjs-lib/issues/839
  })

  it('can create (and broadcast via 3PBP) a Transaction with an OP_RETURN output', async () => {
    const alice1 = createPayment('p2pkh')
    const inputData1 = await getInputData(2e5, alice1.payment, false, 'noredeem')

    const data = Buffer.from('bitcoinjs-lib', 'utf8')
    const embed = bitcoin.payments.embed({ data: [data] })

    const psbt = new bitcoin.Psbt({ network: regtest })
      .addInput(inputData1)
      .addOutput({
        script: embed.output,
        value: 1000
      })
      .addOutput({
        address: regtestUtils.RANDOM_ADDRESS,
        value: 1e5
      })
      .signInput(0, alice1.keys[0])

    assert.strictEqual(psbt.validateSignatures(0), true)
    psbt.finalizeAllInputs()

    // build and broadcast to the RegTest network
    await regtestUtils.broadcast(psbt.extractTransaction().toHex())
  })

  it('can create (and broadcast via 3PBP) a Transaction, w/ a P2SH(P2MS(2 of 4)) (multisig) input', async () => {
    const multisig = createPayment('p2sh-p2ms(2 of 4)')
    const inputData1 = await getInputData(2e4, multisig.payment, false, 'p2sh')
    {
      const {
        hash,
        index,
        nonWitnessUtxo,
        redeemScript, // NEW: P2SH needs to give redeemScript when adding an input.
      } = inputData1
      assert.deepStrictEqual({ hash, index, nonWitnessUtxo, redeemScript }, inputData1)
    }

    const psbt = new bitcoin.Psbt({ network: regtest })
      .addInput(inputData1)
      .addOutput({
        address: regtestUtils.RANDOM_ADDRESS,
        value: 1e4
      })
      .signInput(0, multisig.keys[0])
      .signInput(0, multisig.keys[2])

    assert.strictEqual(psbt.validateSignatures(0), true)
    assert.strictEqual(psbt.validateSignatures(0, multisig.keys[0].publicKey), true)
    assert.throws(() => {
      psbt.validateSignatures(0, multisig.keys[3].publicKey)
    }, new RegExp('No signatures for this pubkey'))
    psbt.finalizeAllInputs()

    const tx = psbt.extractTransaction()

    // build and broadcast to the Bitcoin RegTest network
    await regtestUtils.broadcast(tx.toHex())

    await regtestUtils.verify({
      txId: tx.getId(),
      address: regtestUtils.RANDOM_ADDRESS,
      vout: 0,
      value: 1e4
    })
  })

  it('can create (and broadcast via 3PBP) a Transaction, w/ a P2SH(P2WPKH) input', async () => {
    const p2sh = createPayment('p2sh-p2wpkh')
    const inputData = await getInputData(5e4, p2sh.payment, true, 'p2sh')
    {
      const {
        hash,
        index,
        witnessUtxo, // NEW: this is an object of the output being spent { script: Buffer; value: Satoshis; }
        redeemScript,
      } = inputData
      assert.deepStrictEqual({ hash, index, witnessUtxo, redeemScript }, inputData)
    }

    const psbt = new bitcoin.Psbt({ network: regtest })
      .addInput(inputData)
      .addOutput({
        address: regtestUtils.RANDOM_ADDRESS,
        value: 2e4
      })
      .signInput(0, p2sh.keys[0])

    assert.strictEqual(psbt.validateSignatures(0), true)
    psbt.finalizeAllInputs()

    const tx = psbt.extractTransaction()

    // build and broadcast to the Bitcoin RegTest network
    await regtestUtils.broadcast(tx.toHex())

    await regtestUtils.verify({
      txId: tx.getId(),
      address: regtestUtils.RANDOM_ADDRESS,
      vout: 0,
      value: 2e4
    })
  })

  it('can create (and broadcast via 3PBP) a Transaction, w/ a P2WPKH input', async () => {

    // the only thing that changes is you don't give a redeemscript for input data

    const p2wpkh = createPayment('p2wpkh')
    const inputData = await getInputData(5e4, p2wpkh.payment, true, 'noredeem')
    {
      const {
        hash,
        index,
        witnessUtxo,
      } = inputData
      assert.deepStrictEqual({ hash, index, witnessUtxo }, inputData)
    }

    const psbt = new bitcoin.Psbt({ network: regtest })
      .addInput(inputData)
      .addOutput({
        address: regtestUtils.RANDOM_ADDRESS,
        value: 2e4
      })
      .signInput(0, p2wpkh.keys[0])

    assert.strictEqual(psbt.validateSignatures(0), true)
    psbt.finalizeAllInputs()

    const tx = psbt.extractTransaction()

    // build and broadcast to the Bitcoin RegTest network
    await regtestUtils.broadcast(tx.toHex())

    await regtestUtils.verify({
      txId: tx.getId(),
      address: regtestUtils.RANDOM_ADDRESS,
      vout: 0,
      value: 2e4
    })
  })

  it('can create (and broadcast via 3PBP) a Transaction, w/ a P2WSH(P2PK) input', async () => {
    const p2wsh = createPayment('p2wsh-p2pk')
    const inputData = await getInputData(5e4, p2wsh.payment, true, 'p2wsh')
    {
      const {
        hash,
        index,
        witnessUtxo,
        witnessScript, // NEW: A Buffer of the witnessScript
      } = inputData
      assert.deepStrictEqual({ hash, index, witnessUtxo, witnessScript }, inputData)
    }

    const psbt = new bitcoin.Psbt({ network: regtest })
      .addInput(inputData)
      .addOutput({
        address: regtestUtils.RANDOM_ADDRESS,
        value: 2e4
      })
      .signInput(0, p2wsh.keys[0])

    assert.strictEqual(psbt.validateSignatures(0), true)
    psbt.finalizeAllInputs()

    const tx = psbt.extractTransaction()

    // build and broadcast to the Bitcoin RegTest network
    await regtestUtils.broadcast(tx.toHex())

    await regtestUtils.verify({
      txId: tx.getId(),
      address: regtestUtils.RANDOM_ADDRESS,
      vout: 0,
      value: 2e4
    })
  })

  it('can create (and broadcast via 3PBP) a Transaction, w/ a P2SH(P2WSH(P2MS(3 of 4))) (SegWit multisig) input', async () => {
    const p2sh = createPayment('p2sh-p2wsh-p2ms(3 of 4)')
    const inputData = await getInputData(5e4, p2sh.payment, true, 'p2sh-p2wsh')
    {
      const {
        hash,
        index,
        witnessUtxo,
        redeemScript,
        witnessScript,
      } = inputData
      assert.deepStrictEqual({ hash, index, witnessUtxo, redeemScript, witnessScript }, inputData)
    }

    const psbt = new bitcoin.Psbt({ network: regtest })
      .addInput(inputData)
      .addOutput({
        address: regtestUtils.RANDOM_ADDRESS,
        value: 2e4
      })
      .signInput(0, p2sh.keys[0])
      .signInput(0, p2sh.keys[2])
      .signInput(0, p2sh.keys[3])

    assert.strictEqual(psbt.validateSignatures(0), true)
    assert.strictEqual(psbt.validateSignatures(0, p2sh.keys[3].publicKey), true)
    assert.throws(() => {
      psbt.validateSignatures(0, p2sh.keys[1].publicKey)
    }, new RegExp('No signatures for this pubkey'))
    psbt.finalizeAllInputs()

    const tx = psbt.extractTransaction()

    // build and broadcast to the Bitcoin RegTest network
    await regtestUtils.broadcast(tx.toHex())

    await regtestUtils.verify({
      txId: tx.getId(),
      address: regtestUtils.RANDOM_ADDRESS,
      vout: 0,
      value: 2e4
    })
  })
})

function createPayment(_type, network) {
  network = network || regtest
  const splitType = _type.split('-').reverse();
  const isMultisig = splitType[0].slice(0, 4) === 'p2ms';
  const keys = [];
  let m;
  if (isMultisig) {
    const match = splitType[0].match(/^p2ms\((\d+) of (\d+)\)$/)
    m = parseInt(match[1])
    let n = parseInt(match[2])
    while (n > 1) {
      keys.push(bitcoin.ECPair.makeRandom({ network }));
      n--
    }
  }
  keys.push(bitcoin.ECPair.makeRandom({ network }));

  let payment;
  splitType.forEach(type => {
    if (type.slice(0, 4) === 'p2ms') {
      payment = bitcoin.payments.p2ms({
        m,
        pubkeys: keys.map(key => key.publicKey).sort(),
        network,
      });
    } else if (['p2sh', 'p2wsh'].indexOf(type) > -1) {
      payment = bitcoin.payments[type]({
        redeem: payment,
        network,
      });
    } else {
      payment = bitcoin.payments[type]({
        pubkey: keys[0].publicKey,
        network,
      });
    }
  });

  return {
    payment,
    keys,
  };
}

function getWitnessUtxo(out) {
  delete out.address;
  out.script = Buffer.from(out.script, 'hex');
  return out;
}

async function getInputData(amount, payment, isSegwit, redeemType) {
  const unspent = await regtestUtils.faucetComplex(payment.output, amount);
  const utx = await regtestUtils.fetch(unspent.txId);
  // for non segwit inputs, you must pass the full transaction buffer
  const nonWitnessUtxo = Buffer.from(utx.txHex, 'hex');
  // for segwit inputs, you only need the output script and value as an object.
  const witnessUtxo = getWitnessUtxo(utx.outs[unspent.vout]);
  const mixin = isSegwit ? { witnessUtxo } : { nonWitnessUtxo };
  const mixin2 = {};
  switch (redeemType) {
    case 'p2sh':
      mixin2.redeemScript = payment.redeem.output;
      break;
    case 'p2wsh':
      mixin2.witnessScript = payment.redeem.output;
      break;
    case 'p2sh-p2wsh':
      mixin2.witnessScript = payment.redeem.redeem.output;
      mixin2.redeemScript = payment.redeem.output;
      break;
  }
  return {
    hash: unspent.txId,
    index: unspent.vout,
    ...mixin,
    ...mixin2,
  };
}