// Copyright (c) 2009-2012 The Bitcoin developers

// Distributed under the MIT/X11 software license, see the accompanying

// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <boost/assign/list_of.hpp> // for 'map_list_of()'

#include <boost/foreach.hpp>

#include "checkpoints.h"

#include "txdb.h"

#include "main.h"

#include "uint256.h"

static const int nCheckpointSpan = 500;

namespace Checkpoints

{

typedef std::map<int, uint256> MapCheckpoints;

//

// What makes a good checkpoint block?

// + Is surrounded by blocks with reasonable timestamps

// (no blocks before with a timestamp after, none after with

// timestamp before)

// + Contains no strange transactions

//

static MapCheckpoints mapCheckpoints =

boost::assign::map_list_of

( 0, uint256("0x00001123368370feb0997f471423e4445be205b9947e7053c762886317274d2a") )

( 2, uint256("0x2a95c98075c4ca1ae23f4bdc207be423efb64f347bd7ad7f0568bab5a2ea7f4f") ) // Premine

( 100, uint256("0x58c23d68b43a670f11bc5993c4194347779bde93b1e856ce2d2ec99ca3a0952c") )

( 1000, uint256("0x4d41cbcf542ef60c8e9acd8229684bf1bbbbfab062c56122dd1a30a2331f45c4") )

( 142050, uint256("0xf8825a74a619639003719cf0874f6efd200e978ff6645cd1ea61ba006d982750") )

;

// TestNet has no checkpoints

static MapCheckpoints mapCheckpointsTestnet;

// RegTest has no checkpoints

static MapCheckpoints mapCheckpointsRegTest;

bool CheckHardened(int nHeight, const uint256& hash)

{

MapCheckpoints& checkpoints = (TestNet() ? mapCheckpointsTestnet :IsRegTest() ? mapCheckpointsRegTest : mapCheckpoints);

MapCheckpoints::const_iterator i = checkpoints.find(nHeight);

if (i == checkpoints.end()) return true;

return hash == i->second;

}

int GetTotalBlocksEstimate()

{

MapCheckpoints& checkpoints = (TestNet() ? mapCheckpointsTestnet : mapCheckpoints);

if (checkpoints.empty())

return 0;

return checkpoints.rbegin()->first;

}

CBlockIndex* GetLastCheckpoint(const std::map<uint256, CBlockIndex*>& mapBlockIndex)

{

MapCheckpoints& checkpoints = (TestNet() ? mapCheckpointsTestnet : mapCheckpoints);

BOOST_REVERSE_FOREACH(const MapCheckpoints::value_type& i, checkpoints)

{

const uint256& hash = i.second;

std::map<uint256, CBlockIndex*>::const_iterator t = mapBlockIndex.find(hash);

if (t != mapBlockIndex.end())

return t->second;

}

return NULL;

}

// Automatically select a suitable sync-checkpoint

const CBlockIndex* AutoSelectSyncCheckpoint()

{

const CBlockIndex *pindex = pindexBest;

// Search backward for a block within max span and maturity window

while (pindex->pprev && pindex->nHeight + nCheckpointSpan > pindexBest->nHeight)

pindex = pindex->pprev;

return pindex;

}

// Check against synchronized checkpoint

bool CheckSync(int nHeight)

{

const CBlockIndex* pindexSync = AutoSelectSyncCheckpoint();

if (nHeight <= pindexSync->nHeight)

return false;

return true;

}

}