//------------------------------------------------------------------------------
/*
    This file is part of rippled: https://github.com/ripple/rippled
    Copyright (c) 2012, 2013 Ripple Labs Inc.

    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================


typedef std::pair<uint256, InboundLedger::pointer> u256_acq_pair;

InboundLedgers::InboundLedgers (Stoppable& parent)
    : Stoppable ("InboundLedgers", parent)
    , mLock (this, "InboundLedger", __FILE__, __LINE__)
    , mRecentFailures ("LedgerAcquireRecentFailures", 0, kReacquireIntervalSeconds)
{
}

InboundLedger::pointer InboundLedgers::findCreate (uint256 const& hash, uint32 seq, bool couldBeNew)
{
    assert (hash.isNonZero ());
    InboundLedger::pointer ret;

    {
        ScopedLockType sl (mLock, __FILE__, __LINE__);

        if (! isStopping ())
        {
            boost::unordered_map<uint256, InboundLedger::pointer>::iterator it = mLedgers.find (hash);
            if (it != mLedgers.end ())
            {
                ret = it->second;
                // FIXME: Should set the sequence if it's not set
            }
            else
            {
                ret = boost::make_shared<InboundLedger> (hash, seq);
                assert (ret);
                mLedgers.insert (std::make_pair (hash, ret));
                ret->init (sl, couldBeNew);
            }
        }
    }

    return ret;
}

InboundLedger::pointer InboundLedgers::find (uint256 const& hash)
{
    assert (hash.isNonZero ());

    InboundLedger::pointer ret;

    {
        ScopedLockType sl (mLock, __FILE__, __LINE__);

        boost::unordered_map<uint256, InboundLedger::pointer>::iterator it = mLedgers.find (hash);
        if (it != mLedgers.end ())
        {
            ret = it->second;
        }
    }

    return ret;
}

bool InboundLedgers::hasLedger (LedgerHash const& hash)
{
    assert (hash.isNonZero ());

    ScopedLockType sl (mLock, __FILE__, __LINE__);
    return mLedgers.find (hash) != mLedgers.end ();
}

void InboundLedgers::dropLedger (LedgerHash const& hash)
{
    assert (hash.isNonZero ());

    ScopedLockType sl (mLock, __FILE__, __LINE__);
    mLedgers.erase (hash);

}

bool InboundLedgers::awaitLedgerData (LedgerHash const& ledgerHash)
{
    InboundLedger::pointer ledger = find (ledgerHash);

    if (!ledger)
        return false;

    ledger->awaitData ();
    return true;
}

/*
This gets called when
    "We got some data from an inbound ledger"

inboundLedgerTrigger:
  "What do we do with this partial data?"
  Figures out what to do with the responses to our requests for information.

*/
// means "We got some data from an inbound ledger"
void InboundLedgers::gotLedgerData (Job&, LedgerHash hash,
        boost::shared_ptr<protocol::TMLedgerData> packet_ptr, boost::weak_ptr<Peer> wPeer)
{
    protocol::TMLedgerData& packet = *packet_ptr;
    Peer::pointer peer = wPeer.lock ();

    WriteLog (lsTRACE, InboundLedger) << "Got data (" << packet.nodes ().size () << ") for acquiring ledger: " << hash;

    InboundLedger::pointer ledger = find (hash);

    if (!ledger)
    {
        WriteLog (lsTRACE, InboundLedger) << "Got data for ledger we're not acquiring";

        if (peer)
            peer->applyLoadCharge (LT_InvalidRequest);

        return;
    }

    ledger->noAwaitData ();

    if (!peer)
        return;

    if (packet.type () == protocol::liBASE)
    {
        if (packet.nodes_size () < 1)
        {
            WriteLog (lsWARNING, InboundLedger) << "Got empty base data";
            peer->applyLoadCharge (LT_InvalidRequest);
            return;
        }

        if (!ledger->takeBase (packet.nodes (0).nodedata ()))
        {
            WriteLog (lsWARNING, InboundLedger) << "Got invalid base data";
            peer->applyLoadCharge (LT_InvalidRequest);
            return;
        }

        SHAMapAddNode san = SHAMapAddNode::useful ();

        if ((packet.nodes ().size () > 1) && !ledger->takeAsRootNode (strCopy (packet.nodes (1).nodedata ()), san))
        {
            WriteLog (lsWARNING, InboundLedger) << "Included ASbase invalid";
        }

        if ((packet.nodes ().size () > 2) && !ledger->takeTxRootNode (strCopy (packet.nodes (2).nodedata ()), san))
        {
            WriteLog (lsWARNING, InboundLedger) << "Included TXbase invalid";
        }

        if (!san.isInvalid ())
        {
            ledger->progress ();
            ledger->trigger (peer);
        }
        else
            WriteLog (lsDEBUG, InboundLedger) << "Peer sends invalid base data";

        return;
    }

    if ((packet.type () == protocol::liTX_NODE) || (packet.type () == protocol::liAS_NODE))
    {
        std::list<SHAMapNode> nodeIDs;
        std::list< Blob > nodeData;

        if (packet.nodes ().size () <= 0)
        {
            WriteLog (lsINFO, InboundLedger) << "Got response with no nodes";
            peer->applyLoadCharge (LT_InvalidRequest);
            return;
        }

        for (int i = 0; i < packet.nodes ().size (); ++i)
        {
            const protocol::TMLedgerNode& node = packet.nodes (i);

            if (!node.has_nodeid () || !node.has_nodedata ())
            {
                WriteLog (lsWARNING, InboundLedger) << "Got bad node";
                peer->applyLoadCharge (LT_InvalidRequest);
                return;
            }

            nodeIDs.push_back (SHAMapNode (node.nodeid ().data (), node.nodeid ().size ()));
            nodeData.push_back (Blob (node.nodedata ().begin (), node.nodedata ().end ()));
        }

        SHAMapAddNode ret;

        if (packet.type () == protocol::liTX_NODE)
            ledger->takeTxNode (nodeIDs, nodeData, ret);
        else
            ledger->takeAsNode (nodeIDs, nodeData, ret);

        if (!ret.isInvalid ())
        {
            ledger->progress ();
            ledger->trigger (peer);
        }
        else
            WriteLog (lsDEBUG, InboundLedger) << "Peer sends invalid node data";

        return;
    }

    WriteLog (lsWARNING, InboundLedger) << "Not sure what ledger data we got";
    peer->applyLoadCharge (LT_InvalidRequest);
}

void InboundLedgers::sweep ()
{
    mRecentFailures.sweep ();

    int const now = UptimeTimer::getInstance ().getElapsedSeconds ();

    // Make a list of things to sweep, while holding the lock
    std::vector <MapType::mapped_type> stuffToSweep;
    std::size_t total;
    {
        ScopedLockType sl (mLock, __FILE__, __LINE__);
        MapType::iterator it (mLedgers.begin ());
        total = mLedgers.size ();
        stuffToSweep.reserve (total);

        while (it != mLedgers.end ())
        {
            if (it->second->getLastAction () > now)
            {
                it->second->touch ();
                ++it;
            }
            else if ((it->second->getLastAction () + 60) < now)
            {
                stuffToSweep.push_back (it->second);
                // shouldn't cause the actual final delete
                // since we are holding a reference in the vector.
                it = mLedgers.erase (it);
            }
            else
            {
                ++it;
            }
        }
    }

    WriteLog (lsDEBUG, InboundLedger) <<
        "Sweeped " << stuffToSweep.size () <<
        " out of " << total << " inbound ledgers.";
}

int InboundLedgers::getFetchCount (int& timeoutCount)
{
    timeoutCount = 0;
    int ret = 0;

    std::vector<u256_acq_pair> inboundLedgers;

    {
        ScopedLockType sl (mLock, __FILE__, __LINE__);

        inboundLedgers.reserve(mLedgers.size());
        BOOST_FOREACH (const u256_acq_pair & it, mLedgers)
        {
            inboundLedgers.push_back(it);
        }
    }

    BOOST_FOREACH (const u256_acq_pair & it, inboundLedgers)
    {
        if (it.second->isActive ())
        {
            ++ret;
            timeoutCount += it.second->getTimeouts ();
        }
    }
    return ret;
}

void InboundLedgers::gotFetchPack (Job&)
{
    std::vector<InboundLedger::pointer> acquires;
    {
        ScopedLockType sl (mLock, __FILE__, __LINE__);

        acquires.reserve (mLedgers.size ());
        BOOST_FOREACH (const u256_acq_pair & it, mLedgers)
        {
            assert (it.second);
            acquires.push_back (it.second);
        }
    }

    BOOST_FOREACH (const InboundLedger::pointer & acquire, acquires)
    {
        acquire->checkLocal ();
    }
}

void InboundLedgers::clearFailures ()
{
    ScopedLockType sl (mLock, __FILE__, __LINE__);

    mRecentFailures.clear();
    mLedgers.clear();
}

Json::Value InboundLedgers::getInfo()
{
    Json::Value ret(Json::objectValue);

    std::vector<u256_acq_pair> acquires;
    {
        ScopedLockType sl (mLock, __FILE__, __LINE__);

        acquires.reserve (mLedgers.size ());
        BOOST_FOREACH (const u256_acq_pair & it, mLedgers)
        {
            assert (it.second);
            acquires.push_back (it);
        }
    }

    BOOST_FOREACH (const u256_acq_pair& it, acquires)
    {
        uint32 seq = it.second->getSeq();
        if (seq > 1)
            ret[lexicalCastThrow <std::string>(seq)] = it.second->getJson(0);
        else
            ret[it.first.GetHex()] = it.second->getJson(0);
    }

    return ret;
}

void InboundLedgers::onStop ()
{
    ScopedLockType lock (mLock, __FILE__, __LINE__);

    mLedgers.clear();
    mRecentFailures.clear();

    stopped();
}