text: // Copyright (c) 2010 Satoshi Nakamoto
  // Copyright (c) 2009-2014 The Bitcoin developers
  // Copyright (c) 2014-2015 The Eve developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "checkpoints.h"
  #include "main.h"
  #include "rpcserver.h"
  #include "sync.h"
  #include "util.h"
  
  #include <stdint.h>
  
  #include "json/json_spirit_value.h"
  
  using namespace json_spirit;
  using namespace std;
  
  extern void TxToJSON(const CTransaction& tx, const uint256 hashBlock, Object& entry);
  void ScriptPubKeyToJSON(const CScript& scriptPubKey, Object& out, bool fIncludeHex);
  
  double GetDifficulty(const CBlockIndex* blockindex)
  {
      // Floating point number that is a multiple of the minimum difficulty,
      // minimum difficulty = 1.0.
      if (blockindex == NULL)
      {
          if (chainActive.Tip() == NULL)
              return 1.0;
          else
              blockindex = chainActive.Tip();
      }
  
      int nShift = (blockindex->nBits >> 24) & 0xff;
  
      double dDiff =
          (double)0x0000ffff / (double)(blockindex->nBits & 0x00ffffff);
  
      while (nShift < 29)
      {
          dDiff *= 256.0;
          nShift++;
      }
      while (nShift > 29)
      {
          dDiff /= 256.0;
          nShift--;
      }
  
      return dDiff;
  }
  
  
  Object blockToJSON(const CBlock& block, const CBlockIndex* blockindex, bool txDetails = false)
  {
      Object result;
      result.push_back(Pair("hash", block.GetHash().GetHex()));
      int confirmations = -1;
      // Only report confirmations if the block is on the main chain
      if (chainActive.Contains(blockindex))
          confirmations = chainActive.Height() - blockindex->nHeight + 1;
      result.push_back(Pair("confirmations", confirmations));
      result.push_back(Pair("size", (int)::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION)));
      result.push_back(Pair("height", blockindex->nHeight));
      result.push_back(Pair("version", block.nVersion));
      result.push_back(Pair("merkleroot", block.hashMerkleRoot.GetHex()));
      Array txs;
      BOOST_FOREACH(const CTransaction&tx, block.vtx)
      {
          if(txDetails)
          {
              Object objTx;
              TxToJSON(tx, uint256(0), objTx);
              txs.push_back(objTx);
          }
          else
              txs.push_back(tx.GetHash().GetHex());
      }
      result.push_back(Pair("tx", txs));
      result.push_back(Pair("time", block.GetBlockTime()));
      result.push_back(Pair("nonce", (uint64_t)block.nNonce));
      result.push_back(Pair("bits", strprintf("%08x", block.nBits)));
      result.push_back(Pair("difficulty", GetDifficulty(blockindex)));
      result.push_back(Pair("chainwork", blockindex->nChainWork.GetHex()));
  
      if (blockindex->pprev)
          result.push_back(Pair("previousblockhash", blockindex->pprev->GetBlockHash().GetHex()));
      CBlockIndex *pnext = chainActive.Next(blockindex);
      if (pnext)
          result.push_back(Pair("nextblockhash", pnext->GetBlockHash().GetHex()));
      return result;
  }
  
  
  Object blockHeaderToJSON(const CBlock& block, const CBlockIndex* blockindex)
  {
      Object result;
      result.push_back(Pair("version", block.nVersion));
      if (blockindex->pprev)
          result.push_back(Pair("previousblockhash", blockindex->pprev->GetBlockHash().GetHex()));
      result.push_back(Pair("merkleroot", block.hashMerkleRoot.GetHex()));
      result.push_back(Pair("time", block.GetBlockTime()));
      result.push_back(Pair("bits", strprintf("%08x", block.nBits)));
      result.push_back(Pair("nonce", (uint64_t)block.nNonce));
      return result;
  }
  
  
  Value getblockcount(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 0)
          throw runtime_error(
              "getblockcount\n"
              "\nReturns the number of blocks in the longest block chain.\n"
              "\nResult:\n"
              "n    (numeric) The current block count\n"
              "\nExamples:\n"
              + HelpExampleCli("getblockcount", "")
              + HelpExampleRpc("getblockcount", "")
          );
  
      return chainActive.Height();
  }
  
  Value getbestblockhash(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 0)
          throw runtime_error(
              "getbestblockhash\n"
              "\nReturns the hash of the best (tip) block in the longest block chain.\n"
              "\nResult\n"
              "\"hex\"      (string) the block hash hex encoded\n"
              "\nExamples\n"
              + HelpExampleCli("getbestblockhash", "")
              + HelpExampleRpc("getbestblockhash", "")
          );
  
      return chainActive.Tip()->GetBlockHash().GetHex();
  }
  
  Value getdifficulty(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 0)
          throw runtime_error(
              "getdifficulty\n"
              "\nReturns the proof-of-work difficulty as a multiple of the minimum difficulty.\n"
              "\nResult:\n"
              "n.nnn       (numeric) the proof-of-work difficulty as a multiple of the minimum difficulty.\n"
              "\nExamples:\n"
              + HelpExampleCli("getdifficulty", "")
              + HelpExampleRpc("getdifficulty", "")
          );
  
      return GetDifficulty();
  }
  
  
  Value getrawmempool(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() > 1)
          throw runtime_error(
              "getrawmempool ( verbose )\n"
              "\nReturns all transaction ids in memory pool as a json array of string transaction ids.\n"
              "\nArguments:\n"
              "1. verbose           (boolean, optional, default=false) true for a json object, false for array of transaction ids\n"
              "\nResult: (for verbose = false):\n"
              "[                     (json array of string)\n"
              "  \"transactionid\"     (string) The transaction id\n"
              "  ,...\n"
              "]\n"
              "\nResult: (for verbose = true):\n"
              "{                           (json object)\n"
              "  \"transactionid\" : {       (json object)\n"
              "    \"size\" : n,             (numeric) transaction size in bytes\n"
              "    \"fee\" : n,              (numeric) transaction fee in eves\n"
              "    \"time\" : n,             (numeric) local time transaction entered pool in seconds since 1 Jan 1970 GMT\n"
              "    \"height\" : n,           (numeric) block height when transaction entered pool\n"
              "    \"startingpriority\" : n, (numeric) priority when transaction entered pool\n"
              "    \"currentpriority\" : n,  (numeric) transaction priority now\n"
              "    \"depends\" : [           (array) unconfirmed transactions used as inputs for this transaction\n"
              "        \"transactionid\",    (string) parent transaction id\n"
              "       ... ]\n"
              "  }, ...\n"
              "]\n"
              "\nExamples\n"
              + HelpExampleCli("getrawmempool", "true")
              + HelpExampleRpc("getrawmempool", "true")
          );
  
      bool fVerbose = false;
      if (params.size() > 0)
          fVerbose = params[0].get_bool();
  
      if (fVerbose)
      {
          LOCK(mempool.cs);
          Object o;
          BOOST_FOREACH(const PAIRTYPE(uint256, CTxMemPoolEntry)& entry, mempool.mapTx)
          {
              const uint256& hash = entry.first;
              const CTxMemPoolEntry& e = entry.second;
              Object info;
              info.push_back(Pair("size", (int)e.GetTxSize()));
              info.push_back(Pair("fee", ValueFromAmount(e.GetFee())));
              info.push_back(Pair("time", e.GetTime()));
              info.push_back(Pair("height", (int)e.GetHeight()));
              info.push_back(Pair("startingpriority", e.GetPriority(e.GetHeight())));
              info.push_back(Pair("currentpriority", e.GetPriority(chainActive.Height())));
              const CTransaction& tx = e.GetTx();
              set<string> setDepends;
              BOOST_FOREACH(const CTxIn& txin, tx.vin)
              {
                  if (mempool.exists(txin.prevout.hash))
                      setDepends.insert(txin.prevout.hash.ToString());
              }
              Array depends(setDepends.begin(), setDepends.end());
              info.push_back(Pair("depends", depends));
              o.push_back(Pair(hash.ToString(), info));
          }
          return o;
      }
      else
      {
          vector<uint256> vtxid;
          mempool.queryHashes(vtxid);
  
          Array a;
          BOOST_FOREACH(const uint256& hash, vtxid)
              a.push_back(hash.ToString());
  
          return a;
      }
  }
  
  Value getblockhash(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 1)
          throw runtime_error(
              "getblockhash index\n"
              "\nReturns hash of block in best-block-chain at index provided.\n"
              "\nArguments:\n"
              "1. index         (numeric, required) The block index\n"
              "\nResult:\n"
              "\"hash\"         (string) The block hash\n"
              "\nExamples:\n"
              + HelpExampleCli("getblockhash", "1000")
              + HelpExampleRpc("getblockhash", "1000")
          );
  
      int nHeight = params[0].get_int();
      if (nHeight < 0 || nHeight > chainActive.Height())
          throw JSONRPCError(RPC_INVALID_PARAMETER, "Block height out of range");
  
      CBlockIndex* pblockindex = chainActive[nHeight];
      return pblockindex->GetBlockHash().GetHex();
  }
  
  Value getblock(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() < 1 || params.size() > 2)
          throw runtime_error(
              "getblock \"hash\" ( verbose )\n"
              "\nIf verbose is false, returns a string that is serialized, hex-encoded data for block 'hash'.\n"
              "If verbose is true, returns an Object with information about block <hash>.\n"
              "\nArguments:\n"
              "1. \"hash\"          (string, required) The block hash\n"
              "2. verbose           (boolean, optional, default=true) true for a json object, false for the hex encoded data\n"
              "\nResult (for verbose = true):\n"
              "{\n"
              "  \"hash\" : \"hash\",     (string) the block hash (same as provided)\n"
              "  \"confirmations\" : n,   (numeric) The number of confirmations, or -1 if the block is not on the main chain\n"
              "  \"size\" : n,            (numeric) The block size\n"
              "  \"height\" : n,          (numeric) The block height or index\n"
              "  \"version\" : n,         (numeric) The block version\n"
              "  \"merkleroot\" : \"xxxx\", (string) The merkle root\n"
              "  \"tx\" : [               (array of string) The transaction ids\n"
              "     \"transactionid\"     (string) The transaction id\n"
              "     ,...\n"
              "  ],\n"
              "  \"time\" : ttt,          (numeric) The block time in seconds since epoch (Jan 1 1970 GMT)\n"
              "  \"nonce\" : n,           (numeric) The nonce\n"
              "  \"bits\" : \"1d00ffff\", (string) The bits\n"
              "  \"difficulty\" : x.xxx,  (numeric) The difficulty\n"
              "  \"previousblockhash\" : \"hash\",  (string) The hash of the previous block\n"
              "  \"nextblockhash\" : \"hash\"       (string) The hash of the next block\n"
              "}\n"
              "\nResult (for verbose=false):\n"
              "\"data\"             (string) A string that is serialized, hex-encoded data for block 'hash'.\n"
              "\nExamples:\n"
              + HelpExampleCli("getblock", "\"00000000000fd08c2fb661d2fcb0d49abb3a91e5f27082ce64feed3b4dede2e2\"")
              + HelpExampleRpc("getblock", "\"00000000000fd08c2fb661d2fcb0d49abb3a91e5f27082ce64feed3b4dede2e2\"")
          );
  
      std::string strHash = params[0].get_str();
      uint256 hash(strHash);
  
      bool fVerbose = true;
      if (params.size() > 1)
          fVerbose = params[1].get_bool();
  
      if (mapBlockIndex.count(hash) == 0)
          throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
  
      CBlock block;
      CBlockIndex* pblockindex = mapBlockIndex[hash];
  
      if(!ReadBlockFromDisk(block, pblockindex))
          throw JSONRPCError(RPC_INTERNAL_ERROR, "Can't read block from disk");
  
      if (!fVerbose)
      {
          CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION);
          ssBlock << block;
          std::string strHex = HexStr(ssBlock.begin(), ssBlock.end());
          return strHex;
      }
  
      return blockToJSON(block, pblockindex);
  }
  
  Value getblockheader(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() < 1 || params.size() > 2)
          throw runtime_error(
                  "getblockheader \"hash\" ( verbose )\n"
                  "\nIf verbose is false, returns a string that is serialized, hex-encoded data for block 'hash' header.\n"
                  "If verbose is true, returns an Object with information about block <hash> header.\n"
                  "\nArguments:\n"
                  "1. \"hash\"          (string, required) The block hash\n"
                  "2. verbose           (boolean, optional, default=true) true for a json object, false for the hex encoded data\n"
                  "\nResult (for verbose = true):\n"
                  "{\n"
                  "  \"version\" : n,         (numeric) The block version\n"
                  "  \"previousblockhash\" : \"hash\",  (string) The hash of the previous block\n"
                  "  \"merkleroot\" : \"xxxx\", (string) The merkle root\n"
                  "  \"time\" : ttt,          (numeric) The block time in seconds since epoch (Jan 1 1970 GMT)\n"
                  "  \"bits\" : \"1d00ffff\", (string) The bits\n"
                  "  \"nonce\" : n,           (numeric) The nonce\n"
                  "}\n"
                  "\nResult (for verbose=false):\n"
                  "\"data\"             (string) A string that is serialized, hex-encoded data for block 'hash' header.\n"
                  "\nExamples:\n"
                  + HelpExampleCli("getblockheader", "\"00000000000fd08c2fb661d2fcb0d49abb3a91e5f27082ce64feed3b4dede2e2\"")
                  + HelpExampleRpc("getblockheader", "\"00000000000fd08c2fb661d2fcb0d49abb3a91e5f27082ce64feed3b4dede2e2\"")
                  );
  
      std::string strHash = params[0].get_str();
      uint256 hash(strHash);
  
      bool fVerbose = true;
      if (params.size() > 1)
          fVerbose = params[1].get_bool();
  
      if (mapBlockIndex.count(hash) == 0)
          throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
  
      CBlock block;
      CBlockIndex* pblockindex = mapBlockIndex[hash];
  
      if(!ReadBlockFromDisk(block, pblockindex))
          throw JSONRPCError(RPC_INTERNAL_ERROR, "Can't read block from disk");
  
      if (!fVerbose)
      {
          CDataStream ssBlock(SER_NETWORK, PROTOCOL_VERSION);
          ssBlock << block.GetBlockHeader();
          std::string strHex = HexStr(ssBlock.begin(), ssBlock.end());
          return strHex;
      }
  
      return blockHeaderToJSON(block, pblockindex);
  }
  
  Value gettxoutsetinfo(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 0)
          throw runtime_error(
              "gettxoutsetinfo\n"
              "\nReturns statistics about the unspent transaction output set.\n"
              "Note this call may take some time.\n"
              "\nResult:\n"
              "{\n"
              "  \"height\":n,     (numeric) The current block height (index)\n"
              "  \"bestblock\": \"hex\",   (string) the best block hash hex\n"
              "  \"transactions\": n,      (numeric) The number of transactions\n"
              "  \"txouts\": n,            (numeric) The number of output transactions\n"
              "  \"bytes_serialized\": n,  (numeric) The serialized size\n"
              "  \"hash_serialized\": \"hash\",   (string) The serialized hash\n"
              "  \"total_amount\": x.xxx          (numeric) The total amount\n"
              "}\n"
              "\nExamples:\n"
              + HelpExampleCli("gettxoutsetinfo", "")
              + HelpExampleRpc("gettxoutsetinfo", "")
          );
  
      Object ret;
  
      CCoinsStats stats;
      FlushStateToDisk();
      if (pcoinsTip->GetStats(stats)) {
          ret.push_back(Pair("height", (int64_t)stats.nHeight));
          ret.push_back(Pair("bestblock", stats.hashBlock.GetHex()));
          ret.push_back(Pair("transactions", (int64_t)stats.nTransactions));
          ret.push_back(Pair("txouts", (int64_t)stats.nTransactionOutputs));
          ret.push_back(Pair("bytes_serialized", (int64_t)stats.nSerializedSize));
          ret.push_back(Pair("hash_serialized", stats.hashSerialized.GetHex()));
          ret.push_back(Pair("total_amount", ValueFromAmount(stats.nTotalAmount)));
      }
      return ret;
  }
  
  Value gettxout(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() < 2 || params.size() > 3)
          throw runtime_error(
              "gettxout \"txid\" n ( includemempool )\n"
              "\nReturns details about an unspent transaction output.\n"
              "\nArguments:\n"
              "1. \"txid\"       (string, required) The transaction id\n"
              "2. n              (numeric, required) vout value\n"
              "3. includemempool  (boolean, optional) Whether to included the mem pool\n"
              "\nResult:\n"
              "{\n"
              "  \"bestblock\" : \"hash\",    (string) the block hash\n"
              "  \"confirmations\" : n,       (numeric) The number of confirmations\n"
              "  \"value\" : x.xxx,           (numeric) The transaction value in btc\n"
              "  \"scriptPubKey\" : {         (json object)\n"
              "     \"asm\" : \"code\",       (string) \n"
              "     \"hex\" : \"hex\",        (string) \n"
              "     \"reqSigs\" : n,          (numeric) Number of required signatures\n"
              "     \"type\" : \"pubkeyhash\", (string) The type, eg pubkeyhash\n"
              "     \"addresses\" : [          (array of string) array of eve addresses\n"
              "        \"eveaddress\"     (string) eve address\n"
              "        ,...\n"
              "     ]\n"
              "  },\n"
              "  \"version\" : n,            (numeric) The version\n"
              "  \"coinbase\" : true|false   (boolean) Coinbase or not\n"
              "}\n"
  
              "\nExamples:\n"
              "\nGet unspent transactions\n"
              + HelpExampleCli("listunspent", "") +
              "\nView the details\n"
              + HelpExampleCli("gettxout", "\"txid\" 1") +
              "\nAs a json rpc call\n"
              + HelpExampleRpc("gettxout", "\"txid\", 1")
          );
  
      Object ret;
  
      std::string strHash = params[0].get_str();
      uint256 hash(strHash);
      int n = params[1].get_int();
      bool fMempool = true;
      if (params.size() > 2)
          fMempool = params[2].get_bool();
  
      CCoins coins;
      if (fMempool) {
          LOCK(mempool.cs);
          CCoinsViewMemPool view(pcoinsTip, mempool);
          if (!view.GetCoins(hash, coins))
              return Value::null;
          mempool.pruneSpent(hash, coins); // TODO: this should be done by the CCoinsViewMemPool
      } else {
          if (!pcoinsTip->GetCoins(hash, coins))
              return Value::null;
      }
      if (n<0 || (unsigned int)n>=coins.vout.size() || coins.vout[n].IsNull())
          return Value::null;
  
      BlockMap::iterator it = mapBlockIndex.find(pcoinsTip->GetBestBlock());
      CBlockIndex *pindex = it->second;
      ret.push_back(Pair("bestblock", pindex->GetBlockHash().GetHex()));
      if ((unsigned int)coins.nHeight == MEMPOOL_HEIGHT)
          ret.push_back(Pair("confirmations", 0));
      else
          ret.push_back(Pair("confirmations", pindex->nHeight - coins.nHeight + 1));
      ret.push_back(Pair("value", ValueFromAmount(coins.vout[n].nValue)));
      Object o;
      ScriptPubKeyToJSON(coins.vout[n].scriptPubKey, o, true);
      ret.push_back(Pair("scriptPubKey", o));
      ret.push_back(Pair("version", coins.nVersion));
      ret.push_back(Pair("coinbase", coins.fCoinBase));
  
      return ret;
  }
  
  Value verifychain(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() > 2)
          throw runtime_error(
              "verifychain ( checklevel numblocks )\n"
              "\nVerifies blockchain database.\n"
              "\nArguments:\n"
              "1. checklevel   (numeric, optional, 0-4, default=3) How thorough the block verification is.\n"
              "2. numblocks    (numeric, optional, default=288, 0=all) The number of blocks to check.\n"
              "\nResult:\n"
              "true|false       (boolean) Verified or not\n"
              "\nExamples:\n"
              + HelpExampleCli("verifychain", "")
              + HelpExampleRpc("verifychain", "")
          );
  
      int nCheckLevel = GetArg("-checklevel", 3);
      int nCheckDepth = GetArg("-checkblocks", 288);
      if (params.size() > 0)
          nCheckLevel = params[0].get_int();
      if (params.size() > 1)
          nCheckDepth = params[1].get_int();
  
      return CVerifyDB().VerifyDB(pcoinsTip, nCheckLevel, nCheckDepth);
  }
  
  Value getblockchaininfo(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 0)
          throw runtime_error(
              "getblockchaininfo\n"
              "Returns an object containing various state info regarding block chain processing.\n"
              "\nResult:\n"
              "{\n"
              "  \"chain\": \"xxxx\",        (string) current network name as defined in BIP70 (main, test, regtest)\n"
              "  \"blocks\": xxxxxx,         (numeric) the current number of blocks processed in the server\n"
              "  \"headers\": xxxxxx,        (numeric) the current number of headers we have validated\n"
              "  \"bestblockhash\": \"...\", (string) the hash of the currently best block\n"
              "  \"difficulty\": xxxxxx,     (numeric) the current difficulty\n"
              "  \"verificationprogress\": xxxx, (numeric) estimate of verification progress [0..1]\n"
              "  \"chainwork\": \"xxxx\"     (string) total amount of work in active chain, in hexadecimal\n"
              "}\n"
              "\nExamples:\n"
              + HelpExampleCli("getblockchaininfo", "")
              + HelpExampleRpc("getblockchaininfo", "")
          );
  
      Object obj;
      obj.push_back(Pair("chain",                 Params().NetworkIDString()));
      obj.push_back(Pair("blocks",                (int)chainActive.Height()));
      obj.push_back(Pair("headers",               pindexBestHeader ? pindexBestHeader->nHeight : -1));
      obj.push_back(Pair("bestblockhash",         chainActive.Tip()->GetBlockHash().GetHex()));
      obj.push_back(Pair("difficulty",            (double)GetDifficulty()));
      obj.push_back(Pair("verificationprogress",  Checkpoints::GuessVerificationProgress(chainActive.Tip())));
      obj.push_back(Pair("chainwork",             chainActive.Tip()->nChainWork.GetHex()));
      return obj;
  }
  
  /** Comparison function for sorting the getchaintips heads.  */
  struct CompareBlocksByHeight
  {
      bool operator()(const CBlockIndex* a, const CBlockIndex* b) const
      {
          /* Make sure that unequal blocks with the same height do not compare
             equal. Use the pointers themselves to make a distinction. */
  
          if (a->nHeight != b->nHeight)
            return (a->nHeight > b->nHeight);
  
          return a < b;
      }
  };
  
  Value getchaintips(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 0)
          throw runtime_error(
              "getchaintips\n"
              "Return information about all known tips in the block tree,"
              " including the main chain as well as orphaned branches.\n"
              "\nResult:\n"
              "[\n"
              "  {\n"
              "    \"height\": xxxx,         (numeric) height of the chain tip\n"
              "    \"hash\": \"xxxx\",         (string) block hash of the tip\n"
              "    \"branchlen\": 0          (numeric) zero for main chain\n"
              "    \"status\": \"active\"      (string) \"active\" for the main chain\n"
              "  },\n"
              "  {\n"
              "    \"height\": xxxx,\n"
              "    \"hash\": \"xxxx\",\n"
              "    \"branchlen\": 1          (numeric) length of branch connecting the tip to the main chain\n"
              "    \"status\": \"xxxx\"        (string) status of the chain (active, valid-fork, valid-headers, headers-only, invalid)\n"
              "  }\n"
              "]\n"
              "Possible values for status:\n"
              "1.  \"invalid\"               This branch contains at least one invalid block\n"
              "2.  \"headers-only\"          Not all blocks for this branch are available, but the headers are valid\n"
              "3.  \"valid-headers\"         All blocks are available for this branch, but they were never fully validated\n"
              "4.  \"valid-fork\"            This branch is not part of the active chain, but is fully validated\n"
              "5.  \"active\"                This is the tip of the active main chain, which is certainly valid\n"
              "\nExamples:\n"
              + HelpExampleCli("getchaintips", "")
              + HelpExampleRpc("getchaintips", "")
          );
  
      /* Build up a list of chain tips.  We start with the list of all
         known blocks, and successively remove blocks that appear as pprev
         of another block.  */
      std::set<const CBlockIndex*, CompareBlocksByHeight> setTips;
      BOOST_FOREACH(const PAIRTYPE(const uint256, CBlockIndex*)& item, mapBlockIndex)
          setTips.insert(item.second);
      BOOST_FOREACH(const PAIRTYPE(const uint256, CBlockIndex*)& item, mapBlockIndex)
      {
          const CBlockIndex* pprev = item.second->pprev;
          if (pprev)
              setTips.erase(pprev);
      }
  
      // Always report the currently active tip.
      setTips.insert(chainActive.Tip());
  
      /* Construct the output array.  */
      Array res;
      BOOST_FOREACH(const CBlockIndex* block, setTips)
      {
          Object obj;
          obj.push_back(Pair("height", block->nHeight));
          obj.push_back(Pair("hash", block->phashBlock->GetHex()));
  
          const int branchLen = block->nHeight - chainActive.FindFork(block)->nHeight;
          obj.push_back(Pair("branchlen", branchLen));
  
          string status;
          if (chainActive.Contains(block)) {
              // This block is part of the currently active chain.
              status = "active";
          } else if (block->nStatus & BLOCK_FAILED_MASK) {
              // This block or one of its ancestors is invalid.
              status = "invalid";
          } else if (block->nChainTx == 0) {
              // This block cannot be connected because full block data for it or one of its parents is missing.
              status = "headers-only";
          } else if (block->IsValid(BLOCK_VALID_SCRIPTS)) {
              // This block is fully validated, but no longer part of the active chain. It was probably the active block once, but was reorganized.
              status = "valid-fork";
          } else if (block->IsValid(BLOCK_VALID_TREE)) {
              // The headers for this block are valid, but it has not been validated. It was probably never part of the most-work chain.
              status = "valid-headers";
          } else {
              // No clue.
              status = "unknown";
          }
          obj.push_back(Pair("status", status));
  
          res.push_back(obj);
      }
  
      return res;
  }
  
  Value getmempoolinfo(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 0)
          throw runtime_error(
              "getmempoolinfo\n"
              "\nReturns details on the active state of the TX memory pool.\n"
              "\nResult:\n"
              "{\n"
              "  \"size\": xxxxx                (numeric) Current tx count\n"
              "  \"bytes\": xxxxx               (numeric) Sum of all tx sizes\n"
              "}\n"
              "\nExamples:\n"
              + HelpExampleCli("getmempoolinfo", "")
              + HelpExampleRpc("getmempoolinfo", "")
          );
  
      Object ret;
      ret.push_back(Pair("size", (int64_t) mempool.size()));
      ret.push_back(Pair("bytes", (int64_t) mempool.GetTotalTxSize()));
  
      return ret;
  }
  
  Value invalidateblock(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 1)
          throw runtime_error(
              "invalidateblock \"hash\"\n"
              "\nPermanently marks a block as invalid, as if it violated a consensus rule.\n"
              "\nArguments:\n"
              "1. hash   (string, required) the hash of the block to mark as invalid\n"
              "\nResult:\n"
              "\nExamples:\n"
              + HelpExampleCli("invalidateblock", "\"blockhash\"")
              + HelpExampleRpc("invalidateblock", "\"blockhash\"")
          );
  
      std::string strHash = params[0].get_str();
      uint256 hash(strHash);
      CValidationState state;
  
      {
          LOCK(cs_main);
          if (mapBlockIndex.count(hash) == 0)
              throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
  
          CBlockIndex* pblockindex = mapBlockIndex[hash];
          InvalidateBlock(state, pblockindex);
      }
  
      if (state.IsValid()) {
          ActivateBestChain(state);
      }
  
      if (!state.IsValid()) {
          throw JSONRPCError(RPC_DATABASE_ERROR, state.GetRejectReason());
      }
  
      return Value::null;
  }
  
  Value reconsiderblock(const Array& params, bool fHelp)
  {
      if (fHelp || params.size() != 1)
          throw runtime_error(
              "reconsiderblock \"hash\"\n"
              "\nRemoves invalidity status of a block and its descendants, reconsider them for activation.\n"
              "This can be used to undo the effects of invalidateblock.\n"
              "\nArguments:\n"
              "1. hash   (string, required) the hash of the block to reconsider\n"
              "\nResult:\n"
              "\nExamples:\n"
              + HelpExampleCli("reconsiderblock", "\"blockhash\"")
              + HelpExampleRpc("reconsiderblock", "\"blockhash\"")
          );
  
      std::string strHash = params[0].get_str();
      uint256 hash(strHash);
      CValidationState state;
  
      {
          LOCK(cs_main);
          if (mapBlockIndex.count(hash) == 0)
              throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
  
          CBlockIndex* pblockindex = mapBlockIndex[hash];
          ReconsiderBlock(state, pblockindex);
      }
  
      if (state.IsValid()) {
          ActivateBestChain(state);
      }
  
      if (!state.IsValid()) {
          throw JSONRPCError(RPC_DATABASE_ERROR, state.GetRejectReason());
      }
  
      return Value::null;
  }
  