text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2013 The BitcoinUnlimited developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #ifndef BITCOIN_CHAIN_PARAMS_H
  #define BITCOIN_CHAIN_PARAMS_H
  
  #include "bignum.h"
  #include "uint256.h"
  #include "util.h"
  
  #include <vector>
  
  using namespace std;
  
  #define MESSAGE_START_SIZE 4
  typedef unsigned char MessageStartChars[MESSAGE_START_SIZE];
  
  class CAddress;
  class CBlock;
  
  struct CDNSSeedData {
      string name, host;
      CDNSSeedData(const string &strName, const string &strHost) : name(strName), host(strHost) {}
  };
  
  /**
   * CChainParams defines various tweakable parameters of a given instance of the
   * BitcoinUnlimited system. There are three: the main network on which people trade goods
   * and services, the public test network which gets reset from time to time and
   * a regression test mode which is intended for private networks only. It has
   * minimal difficulty to ensure that blocks can be found instantly.
   */
  class CChainParams
  {
  public:
      enum Network {
          MAIN,
          TESTNET,
          REGTEST,
      };
  
      enum Base58Type {
          PUBKEY_ADDRESS,
          SCRIPT_ADDRESS,
          SECRET_KEY,
          EXT_PUBLIC_KEY,
          EXT_SECRET_KEY,
  
          MAX_BASE58_TYPES
      };
  
      const uint256& HashGenesisBlock() const { return hashGenesisBlock; }
      const MessageStartChars& MessageStart() const { return pchMessageStart; }
      const vector<unsigned char>& AlertKey() const { return vAlertPubKey; }
      int GetDefaultPort() const { return nDefaultPort; }
      const CBigNum& ProofOfWorkLimit() const { return bnProofOfWorkLimit; }
      int SubsidyHalvingInterval() const { return nSubsidyHalvingInterval; }
      virtual const CBlock& GenesisBlock() const = 0;
      virtual bool RequireRPCPassword() const { return true; }
      const string& DataDir() const { return strDataDir; }
      virtual Network NetworkID() const = 0;
      const vector<CDNSSeedData>& DNSSeeds() const { return vSeeds; }
      const std::vector<unsigned char> &Base58Prefix(Base58Type type) const { return base58Prefixes[type]; }
      virtual const vector<CAddress>& FixedSeeds() const = 0;
      int RPCPort() const { return nRPCPort; }
  protected:
      CChainParams() {};
  
      uint256 hashGenesisBlock;
      MessageStartChars pchMessageStart;
      // Raw pub key bytes for the broadcast alert signing key.
      vector<unsigned char> vAlertPubKey;
      int nDefaultPort;
      int nRPCPort;
      CBigNum bnProofOfWorkLimit;
      int nSubsidyHalvingInterval;
      string strDataDir;
      vector<CDNSSeedData> vSeeds;
      std::vector<unsigned char> base58Prefixes[MAX_BASE58_TYPES];
  };
  
  /**
   * Return the currently selected parameters. This won't change after app startup
   * outside of the unit tests.
   */
  const CChainParams &Params();
  
  /** Sets the params returned by Params() to those for the given network. */
  void SelectParams(CChainParams::Network network);
  
  /**
   * Looks for -regtest or -testnet and then calls SelectParams as appropriate.
   * Returns false if an invalid combination is given.
   */
  bool SelectParamsFromCommandLine();
  
  inline bool TestNet() {
      // Note: it's deliberate that this returns "false" for regression test mode.
      return Params().NetworkID() == CChainParams::TESTNET;
  }
  
  inline bool RegTest() {
      return Params().NetworkID() == CChainParams::REGTEST;
  }
  
  #endif
  