text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2014 The Bitcoin developers
  // Copyright (c) 2017-2018 The PIVX developers
  // Copyright (c) 2018 The Escrow developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "script.h"
  #include "tinyformat.h"
  #include "utilstrencodings.h"
  
  namespace {
  inline std::string ValueString(const std::vector<unsigned char>& vch)
  {
      if (vch.size() <= 4)
          return strprintf("%d", CScriptNum(vch, false).getint());
      else
          return HexStr(vch);
  }
  } // anon namespace
  
  using namespace std;
  
  const char* GetOpName(opcodetype opcode)
  {
      switch (opcode)
      {
      // push value
      case OP_0                      : return "0";
      case OP_PUSHDATA1              : return "OP_PUSHDATA1";
      case OP_PUSHDATA2              : return "OP_PUSHDATA2";
      case OP_PUSHDATA4              : return "OP_PUSHDATA4";
      case OP_1NEGATE                : return "-1";
      case OP_RESERVED               : return "OP_RESERVED";
      case OP_1                      : return "1";
      case OP_2                      : return "2";
      case OP_3                      : return "3";
      case OP_4                      : return "4";
      case OP_5                      : return "5";
      case OP_6                      : return "6";
      case OP_7                      : return "7";
      case OP_8                      : return "8";
      case OP_9                      : return "9";
      case OP_10                     : return "10";
      case OP_11                     : return "11";
      case OP_12                     : return "12";
      case OP_13                     : return "13";
      case OP_14                     : return "14";
      case OP_15                     : return "15";
      case OP_16                     : return "16";
  
      // control
      case OP_NOP                    : return "OP_NOP";
      case OP_VER                    : return "OP_VER";
      case OP_IF                     : return "OP_IF";
      case OP_NOTIF                  : return "OP_NOTIF";
      case OP_VERIF                  : return "OP_VERIF";
      case OP_VERNOTIF               : return "OP_VERNOTIF";
      case OP_ELSE                   : return "OP_ELSE";
      case OP_ENDIF                  : return "OP_ENDIF";
      case OP_VERIFY                 : return "OP_VERIFY";
      case OP_RETURN                 : return "OP_RETURN";
  
      // stack ops
      case OP_TOALTSTACK             : return "OP_TOALTSTACK";
      case OP_FROMALTSTACK           : return "OP_FROMALTSTACK";
      case OP_2DROP                  : return "OP_2DROP";
      case OP_2DUP                   : return "OP_2DUP";
      case OP_3DUP                   : return "OP_3DUP";
      case OP_2OVER                  : return "OP_2OVER";
      case OP_2ROT                   : return "OP_2ROT";
      case OP_2SWAP                  : return "OP_2SWAP";
      case OP_IFDUP                  : return "OP_IFDUP";
      case OP_DEPTH                  : return "OP_DEPTH";
      case OP_DROP                   : return "OP_DROP";
      case OP_DUP                    : return "OP_DUP";
      case OP_NIP                    : return "OP_NIP";
      case OP_OVER                   : return "OP_OVER";
      case OP_PICK                   : return "OP_PICK";
      case OP_ROLL                   : return "OP_ROLL";
      case OP_ROT                    : return "OP_ROT";
      case OP_SWAP                   : return "OP_SWAP";
      case OP_TUCK                   : return "OP_TUCK";
  
      // splice ops
      case OP_CAT                    : return "OP_CAT";
      case OP_SUBSTR                 : return "OP_SUBSTR";
      case OP_LEFT                   : return "OP_LEFT";
      case OP_RIGHT                  : return "OP_RIGHT";
      case OP_SIZE                   : return "OP_SIZE";
  
      // bit logic
      case OP_INVERT                 : return "OP_INVERT";
      case OP_AND                    : return "OP_AND";
      case OP_OR                     : return "OP_OR";
      case OP_XOR                    : return "OP_XOR";
      case OP_EQUAL                  : return "OP_EQUAL";
      case OP_EQUALVERIFY            : return "OP_EQUALVERIFY";
      case OP_RESERVED1              : return "OP_RESERVED1";
      case OP_RESERVED2              : return "OP_RESERVED2";
  
      // numeric
      case OP_1ADD                   : return "OP_1ADD";
      case OP_1SUB                   : return "OP_1SUB";
      case OP_2MUL                   : return "OP_2MUL";
      case OP_2DIV                   : return "OP_2DIV";
      case OP_NEGATE                 : return "OP_NEGATE";
      case OP_ABS                    : return "OP_ABS";
      case OP_NOT                    : return "OP_NOT";
      case OP_0NOTEQUAL              : return "OP_0NOTEQUAL";
      case OP_ADD                    : return "OP_ADD";
      case OP_SUB                    : return "OP_SUB";
      case OP_MUL                    : return "OP_MUL";
      case OP_DIV                    : return "OP_DIV";
      case OP_MOD                    : return "OP_MOD";
      case OP_LSHIFT                 : return "OP_LSHIFT";
      case OP_RSHIFT                 : return "OP_RSHIFT";
      case OP_BOOLAND                : return "OP_BOOLAND";
      case OP_BOOLOR                 : return "OP_BOOLOR";
      case OP_NUMEQUAL               : return "OP_NUMEQUAL";
      case OP_NUMEQUALVERIFY         : return "OP_NUMEQUALVERIFY";
      case OP_NUMNOTEQUAL            : return "OP_NUMNOTEQUAL";
      case OP_LESSTHAN               : return "OP_LESSTHAN";
      case OP_GREATERTHAN            : return "OP_GREATERTHAN";
      case OP_LESSTHANOREQUAL        : return "OP_LESSTHANOREQUAL";
      case OP_GREATERTHANOREQUAL     : return "OP_GREATERTHANOREQUAL";
      case OP_MIN                    : return "OP_MIN";
      case OP_MAX                    : return "OP_MAX";
      case OP_WITHIN                 : return "OP_WITHIN";
  
      // crypto
      case OP_RIPEMD160              : return "OP_RIPEMD160";
      case OP_SHA1                   : return "OP_SHA1";
      case OP_SHA256                 : return "OP_SHA256";
      case OP_HASH160                : return "OP_HASH160";
      case OP_HASH256                : return "OP_HASH256";
      case OP_CODESEPARATOR          : return "OP_CODESEPARATOR";
      case OP_CHECKSIG               : return "OP_CHECKSIG";
      case OP_CHECKSIGVERIFY         : return "OP_CHECKSIGVERIFY";
      case OP_CHECKMULTISIG          : return "OP_CHECKMULTISIG";
      case OP_CHECKMULTISIGVERIFY    : return "OP_CHECKMULTISIGVERIFY";
  
      // expanson
      case OP_NOP1                   : return "OP_NOP1";
      case OP_NOP2                   : return "OP_NOP2";
      case OP_NOP3                   : return "OP_NOP3";
      case OP_NOP4                   : return "OP_NOP4";
      case OP_NOP5                   : return "OP_NOP5";
      case OP_NOP6                   : return "OP_NOP6";
      case OP_NOP7                   : return "OP_NOP7";
      case OP_NOP8                   : return "OP_NOP8";
      case OP_NOP9                   : return "OP_NOP9";
      case OP_NOP10                  : return "OP_NOP10";
  
      // zerocoin
      case OP_ZEROCOINMINT           : return "OP_ZEROCOINMINT";
      case OP_ZEROCOINSPEND          : return "OP_ZEROCOINSPEND";
  
      case OP_INVALIDOPCODE          : return "OP_INVALIDOPCODE";
  
      // Note:
      //  The template matching params OP_SMALLINTEGER/etc are defined in opcodetype enum
      //  as kind of implementation hack, they are *NOT* real opcodes.  If found in real
      //  Script, just let the default: case deal with them.
  
      default:
          return "OP_UNKNOWN";
      }
  }
  
  unsigned int CScript::GetSigOpCount(bool fAccurate) const
  {
      unsigned int n = 0;
      const_iterator pc = begin();
      opcodetype lastOpcode = OP_INVALIDOPCODE;
      while (pc < end())
      {
          opcodetype opcode;
          if (!GetOp(pc, opcode))
              break;
          if (opcode == OP_CHECKSIG || opcode == OP_CHECKSIGVERIFY)
              n++;
          else if (opcode == OP_CHECKMULTISIG || opcode == OP_CHECKMULTISIGVERIFY)
          {
              if (fAccurate && lastOpcode >= OP_1 && lastOpcode <= OP_16)
                  n += DecodeOP_N(lastOpcode);
              else
                  n += 20;
          }
          lastOpcode = opcode;
      }
      return n;
  }
  
  unsigned int CScript::GetSigOpCount(const CScript& scriptSig) const
  {
      if (!IsPayToScriptHash())
          return GetSigOpCount(true);
  
      // This is a pay-to-script-hash scriptPubKey;
      // get the last item that the scriptSig
      // pushes onto the stack:
      const_iterator pc = scriptSig.begin();
      vector<unsigned char> data;
      while (pc < scriptSig.end())
      {
          opcodetype opcode;
          if (!scriptSig.GetOp(pc, opcode, data))
              return 0;
          if (opcode > OP_16)
              return 0;
      }
  
      /// ... and return its opcount:
      CScript subscript(data.begin(), data.end());
      return subscript.GetSigOpCount(true);
  }
  
  bool CScript::IsNormalPaymentScript() const
  {
      if(this->size() != 25) return false;
  
      std::string str;
      opcodetype opcode;
      const_iterator pc = begin();
      int i = 0;
      while (pc < end())
      {
          GetOp(pc, opcode);
  
          if(     i == 0 && opcode != OP_DUP) return false;
          else if(i == 1 && opcode != OP_HASH160) return false;
          else if(i == 3 && opcode != OP_EQUALVERIFY) return false;
          else if(i == 4 && opcode != OP_CHECKSIG) return false;
          else if(i == 5) return false;
  
          i++;
      }
  
      return true;
  }
  
  bool CScript::IsPayToScriptHash() const
  {
      // Extra-fast test for pay-to-script-hash CScripts:
      return (this->size() == 23 &&
              this->at(0) == OP_HASH160 &&
              this->at(1) == 0x14 &&
              this->at(22) == OP_EQUAL);
  }
  
  bool CScript::IsZerocoinMint() const
  {
      //fast test for Zerocoin Mint CScripts
      return (this->size() > 0 &&
          this->at(0) == OP_ZEROCOINMINT);
  }
  
  bool CScript::IsZerocoinSpend() const
  {
      if (this->empty())
          return false;
  
      return (this->at(0) == OP_ZEROCOINSPEND);
  }
  
  bool CScript::IsPushOnly(const_iterator pc) const
  {
      while (pc < end())
      {
          opcodetype opcode;
          if (!GetOp(pc, opcode))
              return false;
          // Note that IsPushOnly() *does* consider OP_RESERVED to be a
          // push-type opcode, however execution of OP_RESERVED fails, so
          // it's not relevant to P2SH/BIP62 as the scriptSig would fail prior to
          // the P2SH special validation code being executed.
          if (opcode > OP_16)
              return false;
      }
      return true;
  }
  
  bool CScript::IsPushOnly() const
  {
      return this->IsPushOnly(begin());
  }
  
  std::string CScript::ToString() const
  {
      std::string str;
      opcodetype opcode;
      std::vector<unsigned char> vch;
      const_iterator pc = begin();
      while (pc < end())
      {
          if (!str.empty())
              str += " ";
          if (!GetOp(pc, opcode, vch))
          {
              str += "[error]";
              return str;
          }
          if (0 <= opcode && opcode <= OP_PUSHDATA4) {
              str += ValueString(vch);
          } else {
              str += GetOpName(opcode);
              if (opcode == OP_ZEROCOINSPEND) {
                  //Zerocoinspend has no further op codes.
                  break;
              }
          }
  
      }
      return str;
  }
  