text: // Copyright (c) 2016-2019 Duality Blockchain Solutions Developers
  // Copyright (c) 2014-2017 The Dash Core Developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "governance-validators.h"
  
  #include "base58.h"
  #include "timedata.h"
  #include "tinyformat.h"
  #include "utilstrencodings.h"
  
  #include <algorithm>
  
  const size_t MAX_DATA_SIZE = 512;
  const size_t MAX_NAME_SIZE = 40;
  
  CProposalValidator::CProposalValidator(const std::string& strHexData) : objJSON(UniValue::VOBJ),
                                                                          fJSONValid(false),
                                                                          strErrorMessages()
  {
      if (!strHexData.empty()) {
          ParseStrHexData(strHexData);
      }
  }
  
  void CProposalValidator::ParseStrHexData(const std::string& strHexData)
  {
      std::vector<unsigned char> v = ParseHex(strHexData);
      if (v.size() > MAX_DATA_SIZE) {
          strErrorMessages = strprintf("data exceeds %lu characters;", MAX_DATA_SIZE);
          return;
      }
      ParseJSONData(std::string(v.begin(), v.end()));
  }
  
  bool CProposalValidator::Validate(bool fCheckExpiration)
  {
      if (!fJSONValid) {
          strErrorMessages += "JSON parsing error;";
          return false;
      }
      if (!ValidateName()) {
          strErrorMessages += "Invalid name;";
          return false;
      }
      if (!ValidateStartEndEpoch(fCheckExpiration)) {
          strErrorMessages += "Invalid start:end range;";
          return false;
      }
      if (!ValidatePaymentAmount()) {
          strErrorMessages += "Invalid payment amount;";
          return false;
      }
      if (!ValidatePaymentAddress()) {
          strErrorMessages += "Invalid payment address;";
          return false;
      }
      if (!ValidateURL()) {
          strErrorMessages += "Invalid URL;";
          return false;
      }
      return true;
  }
  
  bool CProposalValidator::ValidateName()
  {
      std::string strName;
      if (!GetDataValue("name", strName)) {
          strErrorMessages += "name field not found;";
          return false;
      }
  
      if (strName.size() > MAX_NAME_SIZE) {
          strErrorMessages += strprintf("name exceeds %lu characters;", MAX_NAME_SIZE);
          return false;
      }
  
      static const std::string strAllowedChars = "-_abcdefghijklmnopqrstuvwxyz0123456789";
  
      std::transform(strName.begin(), strName.end(), strName.begin(), ::tolower);
  
      if (strName.find_first_not_of(strAllowedChars) != std::string::npos) {
          strErrorMessages += "name contains invalid characters;";
          return false;
      }
  
      return true;
  }
  
  bool CProposalValidator::ValidateStartEndEpoch(bool fCheckExpiration)
  {
      int64_t nStartEpoch = 0;
      int64_t nEndEpoch = 0;
  
      if (!GetDataValue("start_epoch", nStartEpoch)) {
          strErrorMessages += "start_epoch field not found;";
          return false;
      }
  
      if (!GetDataValue("end_epoch", nEndEpoch)) {
          strErrorMessages += "end_epoch field not found;";
          return false;
      }
  
      if (nEndEpoch <= nStartEpoch) {
          strErrorMessages += "end_epoch <= start_epoch;";
          return false;
      }
  
      if (fCheckExpiration && nEndEpoch <= GetAdjustedTime()) {
          strErrorMessages += "expired;";
          return false;
      }
  
      return true;
  }
  
  bool CProposalValidator::ValidatePaymentAmount()
  {
      double dValue = 0.0;
  
      if (!GetDataValue("payment_amount", dValue)) {
          strErrorMessages += "payment_amount field not found;";
          return false;
      }
  
      if (dValue <= 0.0) {
          strErrorMessages += "payment_amount is negative;";
          return false;
      }
  
      // TODO: Should check for an amount which exceeds the budget but this is
      // currently difficult because start and end epochs are defined in terms of
      // clock time instead of block height.
  
      return true;
  }
  
  bool CProposalValidator::ValidatePaymentAddress()
  {
      std::string strPaymentAddress;
  
      if (!GetDataValue("payment_address", strPaymentAddress)) {
          strErrorMessages += "payment_address field not found;";
          return false;
      }
  
      if (std::find_if(strPaymentAddress.begin(), strPaymentAddress.end(), ::isspace) != strPaymentAddress.end()) {
          strErrorMessages += "payment_address can't have whitespaces;";
          return false;
      }
  
      CDynamicAddress address(strPaymentAddress);
      if (!address.IsValid()) {
          strErrorMessages += "payment_address is invalid;";
          return false;
      }
  
      if (address.IsScript()) {
          strErrorMessages += "script addresses are not supported;";
          return false;
      }
  
      return true;
  }
  
  bool CProposalValidator::ValidateURL()
  {
      std::string strURL;
      if (!GetDataValue("url", strURL)) {
          strErrorMessages += "url field not found;";
          return false;
      }
  
      if (std::find_if(strURL.begin(), strURL.end(), ::isspace) != strURL.end()) {
          strErrorMessages += "url can't have whitespaces;";
          return false;
      }
  
      if (strURL.size() < 4U) {
          strErrorMessages += "url too short;";
          return false;
      }
  
      if (!CheckURL(strURL)) {
          strErrorMessages += "url invalid;";
          return false;
      }
  
      return true;
  }
  
  void CProposalValidator::ParseJSONData(const std::string& strJSONData)
  {
      fJSONValid = false;
  
      if (strJSONData.empty()) {
          return;
      }
  
      try {
          UniValue obj(UniValue::VOBJ);
  
          obj.read(strJSONData);
  
          if (obj.isObject()) {
              objJSON = obj;
          } else {
              std::vector<UniValue> arr1 = obj.getValues();
              std::vector<UniValue> arr2 = arr1.at(0).getValues();
              objJSON = arr2.at(1);
          }
  
          fJSONValid = true;
      } catch (std::exception& e) {
          strErrorMessages += std::string(e.what()) + std::string(";");
      } catch (...) {
          strErrorMessages += "Unknown exception;";
      }
  }
  
  bool CProposalValidator::GetDataValue(const std::string& strKey, std::string& strValueRet)
  {
      bool fOK = false;
      try {
          strValueRet = objJSON[strKey].get_str();
          fOK = true;
      } catch (std::exception& e) {
          strErrorMessages += std::string(e.what()) + std::string(";");
      } catch (...) {
          strErrorMessages += "Unknown exception;";
      }
      return fOK;
  }
  
  bool CProposalValidator::GetDataValue(const std::string& strKey, int64_t& nValueRet)
  {
      bool fOK = false;
      try {
          const UniValue uValue = objJSON[strKey];
          switch (uValue.getType()) {
          case UniValue::VNUM:
              nValueRet = uValue.get_int64();
              fOK = true;
              break;
          default:
              break;
          }
      } catch (std::exception& e) {
          strErrorMessages += std::string(e.what()) + std::string(";");
      } catch (...) {
          strErrorMessages += "Unknown exception;";
      }
      return fOK;
  }
  
  bool CProposalValidator::GetDataValue(const std::string& strKey, double& dValueRet)
  {
      bool fOK = false;
      try {
          const UniValue uValue = objJSON[strKey];
          switch (uValue.getType()) {
          case UniValue::VNUM:
              dValueRet = uValue.get_real();
              fOK = true;
              break;
          default:
              break;
          }
      } catch (std::exception& e) {
          strErrorMessages += std::string(e.what()) + std::string(";");
      } catch (...) {
          strErrorMessages += "Unknown exception;";
      }
      return fOK;
  }
  
  /*
    The purpose of this function is to replicate the behavior of the
    Python urlparse function used by sentinel (urlparse.py).  This function
    should return false whenever urlparse raises an exception and true
    otherwise.
   */
  bool CProposalValidator::CheckURL(const std::string& strURLIn)
  {
      std::string strRest(strURLIn);
      std::string::size_type nPos = strRest.find(':');
  
      if (nPos != std::string::npos) {
          //std::string strSchema = strRest.substr(0,nPos);
  
          if (nPos < strRest.size()) {
              strRest = strRest.substr(nPos + 1);
          } else {
              strRest = "";
          }
      }
  
      // Process netloc
      if ((strRest.size() > 2) && (strRest.substr(0, 2) == "//")) {
          static const std::string strNetlocDelimiters = "/?#";
  
          strRest = strRest.substr(2);
  
          std::string::size_type nPos2 = strRest.find_first_of(strNetlocDelimiters);
  
          std::string strNetloc = strRest.substr(0, nPos2);
  
          if ((strNetloc.find('[') != std::string::npos) && (strNetloc.find(']') == std::string::npos)) {
              return false;
          }
  
          if ((strNetloc.find(']') != std::string::npos) && (strNetloc.find('[') == std::string::npos)) {
              return false;
          }
      }
  
      return true;
  }