text: // Copyright (c) 2009-2017 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 <core_io.h>
  
  #include <base58.h>
  #include <consensus/consensus.h>
  #include <consensus/validation.h>
  #include <script/script.h>
  #include <script/standard.h>
  #include <serialize.h>
  #include <streams.h>
  #include <univalue.h>
  #include <util.h>
  #include <utilmoneystr.h>
  #include <utilstrencodings.h>
  
  UniValue ValueFromAmount(const CAmount& amount)
  {
      bool sign = amount < 0;
      int64_t n_abs = (sign ? -amount : amount);
      int64_t quotient = n_abs / COIN;
      int64_t remainder = n_abs % COIN;
      return UniValue(UniValue::VNUM,
              strprintf("%s%d.%08d", sign ? "-" : "", quotient, remainder));
  }
  
  std::string FormatScript(const CScript& script)
  {
      std::string ret;
      CScript::const_iterator it = script.begin();
      opcodetype op;
      while (it != script.end()) {
          CScript::const_iterator it2 = it;
          std::vector<unsigned char> vch;
          if (script.GetOp2(it, op, &vch)) {
              if (op == OP_0) {
                  ret += "0 ";
                  continue;
              } else if ((op >= OP_1 && op <= OP_16) || op == OP_1NEGATE) {
                  ret += strprintf("%i ", op - OP_1NEGATE - 1);
                  continue;
              } else if (op >= OP_NOP && op <= OP_NOP10) {
                  std::string str(GetOpName(op));
                  if (str.substr(0, 3) == std::string("OP_")) {
                      ret += str.substr(3, std::string::npos) + " ";
                      continue;
                  }
              }
              if (vch.size() > 0) {
                  ret += strprintf("0x%x 0x%x ", HexStr(it2, it - vch.size()), HexStr(it - vch.size(), it));
              } else {
                  ret += strprintf("0x%x ", HexStr(it2, it));
              }
              continue;
          }
          ret += strprintf("0x%x ", HexStr(it2, script.end()));
          break;
      }
      return ret.substr(0, ret.size() - 1);
  }
  
  const std::map<unsigned char, std::string> mapSigHashTypes = {
      {static_cast<unsigned char>(SIGHASH_ALL), std::string("ALL")},
      {static_cast<unsigned char>(SIGHASH_ALL|SIGHASH_ANYONECANPAY), std::string("ALL|ANYONECANPAY")},
      {static_cast<unsigned char>(SIGHASH_NONE), std::string("NONE")},
      {static_cast<unsigned char>(SIGHASH_NONE|SIGHASH_ANYONECANPAY), std::string("NONE|ANYONECANPAY")},
      {static_cast<unsigned char>(SIGHASH_SINGLE), std::string("SINGLE")},
      {static_cast<unsigned char>(SIGHASH_SINGLE|SIGHASH_ANYONECANPAY), std::string("SINGLE|ANYONECANPAY")},
  };
  
  /**
   * Create the assembly string representation of a CScript object.
   * @param[in] script    CScript object to convert into the asm string representation.
   * @param[in] fAttemptSighashDecode    Whether to attempt to decode sighash types on data within the script that matches the format
   *                                     of a signature. Only pass true for scripts you believe could contain signatures. For example,
   *                                     pass false, or omit the this argument (defaults to false), for scriptPubKeys.
   */
  std::string ScriptToAsmStr(const CScript& script, const bool fAttemptSighashDecode)
  {
      std::string str;
      opcodetype opcode;
      std::vector<unsigned char> vch;
      CScript::const_iterator pc = script.begin();
      while (pc < script.end()) {
          if (!str.empty()) {
              str += " ";
          }
          if (!script.GetOp(pc, opcode, vch)) {
              str += "[error]";
              return str;
          }
          if (0 <= opcode && opcode <= OP_PUSHDATA4) {
              if (vch.size() <= static_cast<std::vector<unsigned char>::size_type>(4)) {
                  str += strprintf("%d", CScriptNum(vch, false).getint());
              } else {
                  // the IsUnspendable check makes sure not to try to decode OP_RETURN data that may match the format of a signature
                  if (fAttemptSighashDecode && !script.IsUnspendable()) {
                      std::string strSigHashDecode;
                      // goal: only attempt to decode a defined sighash type from data that looks like a signature within a scriptSig.
                      // this won't decode correctly formatted public keys in Pubkey or Multisig scripts due to
                      // the restrictions on the pubkey formats (see IsCompressedOrUncompressedPubKey) being incongruous with the
                      // checks in CheckSignatureEncoding.
                      if (CheckSignatureEncoding(vch, SCRIPT_VERIFY_STRICTENC, nullptr)) {
                          const unsigned char chSigHashType = vch.back();
                          if (mapSigHashTypes.count(chSigHashType)) {
                              strSigHashDecode = "[" + mapSigHashTypes.find(chSigHashType)->second + "]";
                              vch.pop_back(); // remove the sighash type byte. it will be replaced by the decode.
                          }
                      }
                      str += HexStr(vch) + strSigHashDecode;
                  } else {
                      str += HexStr(vch);
                  }
              }
          } else {
              str += GetOpName(opcode);
          }
      }
      return str;
  }
  
  std::string EncodeHexTx(const CTransaction& tx, const int serializeFlags)
  {
      CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION | serializeFlags);
      ssTx << tx;
      return HexStr(ssTx.begin(), ssTx.end());
  }
  
  void ScriptPubKeyToUniv(const CScript& scriptPubKey,
                          UniValue& out, bool fIncludeHex)
  {
      txnouttype type;
      std::vector<CTxDestination> addresses;
      int nRequired;
  
      out.pushKV("asm", ScriptToAsmStr(scriptPubKey));
      if (fIncludeHex)
          out.pushKV("hex", HexStr(scriptPubKey.begin(), scriptPubKey.end()));
  
      if (!ExtractDestinations(scriptPubKey, type, addresses, nRequired)) {
          out.pushKV("type", GetTxnOutputType(type));
          return;
      }
  
      out.pushKV("reqSigs", nRequired);
      out.pushKV("type", GetTxnOutputType(type));
  
      UniValue a(UniValue::VARR);
      for (const CTxDestination& addr : addresses) {
          a.push_back(EncodeDestination(addr));
      }
      out.pushKV("addresses", a);
  }
  
  void TxToUniv(const CTransaction& tx, const uint256& hashBlock, UniValue& entry, bool include_hex, int serialize_flags)
  {
      entry.pushKV("txid", tx.GetHash().GetHex());
      entry.pushKV("hash", tx.GetWitnessHash().GetHex());
      entry.pushKV("version", tx.nVersion);
      entry.pushKV("size", (int)::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION));
      entry.pushKV("vsize", (GetTransactionWeight(tx) + WITNESS_SCALE_FACTOR - 1) / WITNESS_SCALE_FACTOR);
      entry.pushKV("time", (int64_t)tx.nTime);
      entry.pushKV("locktime", (int64_t)tx.nLockTime);
  
      UniValue vin(UniValue::VARR);
      for (unsigned int i = 0; i < tx.vin.size(); i++) {
          const CTxIn& txin = tx.vin[i];
          UniValue in(UniValue::VOBJ);
          if (tx.IsCoinBase())
              in.pushKV("coinbase", HexStr(txin.scriptSig.begin(), txin.scriptSig.end()));
          else {
              in.pushKV("txid", txin.prevout.hash.GetHex());
              in.pushKV("vout", (int64_t)txin.prevout.n);
              UniValue o(UniValue::VOBJ);
              o.pushKV("asm", ScriptToAsmStr(txin.scriptSig, true));
              o.pushKV("hex", HexStr(txin.scriptSig.begin(), txin.scriptSig.end()));
              in.pushKV("scriptSig", o);
              if (!tx.vin[i].scriptWitness.IsNull()) {
                  UniValue txinwitness(UniValue::VARR);
                  for (const auto& item : tx.vin[i].scriptWitness.stack) {
                      txinwitness.push_back(HexStr(item.begin(), item.end()));
                  }
                  in.pushKV("txinwitness", txinwitness);
              }
          }
          in.pushKV("sequence", (int64_t)txin.nSequence);
          vin.push_back(in);
      }
      entry.pushKV("vin", vin);
  
      UniValue vout(UniValue::VARR);
      for (unsigned int i = 0; i < tx.vout.size(); i++) {
          const CTxOut& txout = tx.vout[i];
  
          UniValue out(UniValue::VOBJ);
  
          out.pushKV("value", ValueFromAmount(txout.nValue));
          out.pushKV("n", (int64_t)i);
  
          UniValue o(UniValue::VOBJ);
          ScriptPubKeyToUniv(txout.scriptPubKey, o, true);
          out.pushKV("scriptPubKey", o);
          vout.push_back(out);
      }
      entry.pushKV("vout", vout);
  
      if (!hashBlock.IsNull())
          entry.pushKV("blockhash", hashBlock.GetHex());
  
      if (include_hex) {
          entry.pushKV("hex", EncodeHexTx(tx, serialize_flags)); // the hex-encoded transaction. used the name "hex" to be consistent with the verbose output of "getrawtransaction".
      }
  }
  