// Copyright (c) 2019-2020 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <coins.h>
#include <script/signingprovider.h>
#include <test/util/transaction_utils.h>

CMutableTransaction BuildCreditingTransaction(const CScript& scriptPubKey, int nValue)
{
    CMutableTransaction txCredit;
    txCredit.version = 1;
    txCredit.nLockTime = 0;
    txCredit.vin.resize(1);
    txCredit.vout.resize(1);
    txCredit.vin[0].prevout.SetNull();
    txCredit.vin[0].scriptSig = CScript() << CScriptNum(0) << CScriptNum(0);
    txCredit.vin[0].nSequence = CTxIn::SEQUENCE_FINAL;
    txCredit.vout[0].scriptPubKey = scriptPubKey;
    txCredit.vout[0].nValue = nValue;

    return txCredit;
}

CMutableTransaction BuildSpendingTransaction(const CScript& scriptSig, const CScriptWitness& scriptWitness, const CTransaction& txCredit)
{
    CMutableTransaction txSpend;
    txSpend.version = 1;
    txSpend.nLockTime = 0;
    txSpend.vin.resize(1);
    txSpend.vout.resize(1);
    txSpend.vin[0].scriptWitness = scriptWitness;
    txSpend.vin[0].prevout.hash = txCredit.GetHash();
    txSpend.vin[0].prevout.n = 0;
    txSpend.vin[0].scriptSig = scriptSig;
    txSpend.vin[0].nSequence = CTxIn::SEQUENCE_FINAL;
    txSpend.vout[0].scriptPubKey = CScript();
    txSpend.vout[0].nValue = txCredit.vout[0].nValue;

    return txSpend;
}

std::vector<CMutableTransaction> SetupDummyInputs(FillableSigningProvider& keystoreRet, CCoinsViewCache& coinsRet, const std::array<CAmount,4>& nValues)
{
    std::vector<CMutableTransaction> dummyTransactions;
    dummyTransactions.resize(2);

    // Add some keys to the keystore:
    CKey key[4];
    for (int i = 0; i < 4; i++) {
        key[i].MakeNewKey(i % 2);
        keystoreRet.AddKey(key[i]);
    }

    // Create some dummy input transactions
    dummyTransactions[0].vout.resize(2);
    dummyTransactions[0].vout[0].nValue = nValues[0];
    dummyTransactions[0].vout[0].scriptPubKey << ToByteVector(key[0].GetPubKey()) << OP_CHECKSIG;
    dummyTransactions[0].vout[1].nValue = nValues[1];
    dummyTransactions[0].vout[1].scriptPubKey << ToByteVector(key[1].GetPubKey()) << OP_CHECKSIG;
    AddCoins(coinsRet, CTransaction(dummyTransactions[0]), 0);

    dummyTransactions[1].vout.resize(2);
    dummyTransactions[1].vout[0].nValue = nValues[2];
    dummyTransactions[1].vout[0].scriptPubKey = GetScriptForDestination(PKHash(key[2].GetPubKey()));
    dummyTransactions[1].vout[1].nValue = nValues[3];
    dummyTransactions[1].vout[1].scriptPubKey = GetScriptForDestination(PKHash(key[3].GetPubKey()));
    AddCoins(coinsRet, CTransaction(dummyTransactions[1]), 0);

    return dummyTransactions;
}
