//------------------------------------------------------------------------------
/*
    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.
*/
//==============================================================================

#include <BeastConfig.h>
#include <ripple/app/paths/AccountCurrencies.h>
#include <ripple/app/paths/RippleCalc.h>
#include <ripple/app/paths/PathRequest.h>
#include <ripple/app/paths/PathRequests.h>
#include <ripple/app/main/Application.h>
#include <ripple/app/misc/NetworkOPs.h>
#include <ripple/basics/Log.h>
#include <ripple/core/Config.h>
#include <ripple/core/LoadFeeTrack.h>
#include <ripple/net/RPCErr.h>
#include <ripple/protocol/ErrorCodes.h>
#include <ripple/protocol/UintTypes.h>
#include <beast/module/core/text/LexicalCast.h>
#include <boost/optional.hpp>
#include <tuple>

namespace ripple {

PathRequest::PathRequest (
    Application& app,
    const std::shared_ptr<InfoSub>& subscriber,
    int id,
    PathRequests& owner,
    beast::Journal journal)
        : app_ (app)
        , m_journal (journal)
        , mOwner (owner)
        , wpSubscriber (subscriber)
        , jvStatus (Json::objectValue)
        , mLastIndex (0)
        , mInProgress (false)
        , iLastLevel (0)
        , bLastSuccess (false)
        , iIdentifier (id)
{
    if (m_journal.debug)
        m_journal.debug << iIdentifier << " created";
    ptCreated = boost::posix_time::microsec_clock::universal_time ();
}

PathRequest::PathRequest (
    Application& app,
    std::function <void(void)> const& completion,
    int id,
    PathRequests& owner,
    beast::Journal journal)
        : app_ (app)
        , m_journal (journal)
        , mOwner (owner)
        , fCompletion (completion)
        , jvStatus (Json::objectValue)
        , mLastIndex (0)
        , mInProgress (false)
        , iLastLevel (0)
        , bLastSuccess (false)
        , iIdentifier (id)
{
    if (m_journal.debug)
        m_journal.debug << iIdentifier << " created";
    ptCreated = boost::posix_time::microsec_clock::universal_time ();
}

static std::string const get_milli_diff (
    boost::posix_time::ptime const& after,
    boost::posix_time::ptime
    const& before)
{
    return beast::lexicalCastThrow <std::string> (
        static_cast <unsigned> ((after - before).total_milliseconds()));
}

static std::string const get_milli_diff (boost::posix_time::ptime const& before)
{
    return get_milli_diff(
        boost::posix_time::microsec_clock::universal_time(), before);
}

PathRequest::~PathRequest()
{
    std::string fast, full;
    if (!ptQuickReply.is_not_a_date_time())
    {
        fast = " fast:";
        fast += get_milli_diff (ptQuickReply, ptCreated);
        fast += "ms";
    }
    if (!ptFullReply.is_not_a_date_time())
    {
        full = " full:";
        full += get_milli_diff (ptFullReply, ptCreated);
        full += "ms";
    }
    if (m_journal.info)
        m_journal.info << iIdentifier << " complete:" << fast << full <<
        " total:" << get_milli_diff(ptCreated) << "ms";
}

bool PathRequest::isNew ()
{
    ScopedLockType sl (mIndexLock);

    // does this path request still need its first full path
    return mLastIndex == 0;
}

bool PathRequest::needsUpdate (bool newOnly, LedgerIndex index)
{
    ScopedLockType sl (mIndexLock);

    if (mInProgress)
    {
        // Another thread is handling this
        return false;
    }

    if (newOnly && (mLastIndex != 0))
    {
        // Only handling new requests, this isn't new
        return false;
    }

    if (mLastIndex >= index)
    {
        return false;
    }

    mInProgress = true;
    return true;
}

bool PathRequest::hasCompletion ()
{
    return bool (fCompletion);
}

void PathRequest::updateComplete ()
{
    ScopedLockType sl (mIndexLock);

    assert (mInProgress);
    mInProgress = false;

    if (fCompletion)
    {
        fCompletion();
        fCompletion = std::function<void (void)>();
    }
}

bool PathRequest::isValid (RippleLineCache::ref crCache)
{
    ScopedLockType sl (mLock);
    if (! raSrcAccount || ! raDstAccount)
        return false;

    if (! convert_all_ && (saSendMax || saDstAmount <= zero))
    {
        // If send max specified, dst amt must be -1.
        jvStatus = rpcError(rpcDST_AMT_MALFORMED);
        return false;
    }

    if (! crCache->getLedger()->exists(
        keylet::account(*raSrcAccount)))
    {
        // Source account does not exist.
        jvStatus = rpcError (rpcSRC_ACT_NOT_FOUND);
        return false;
    }

    auto const& lrLedger = crCache->getLedger();
    auto const sleDest = crCache->getLedger()->read(
        keylet::account(*raDstAccount));

    Json::Value& jvDestCur =
        (jvStatus[jss::destination_currencies] = Json::arrayValue);

    if (! sleDest)
    {
        jvDestCur.append (Json::Value (systemCurrencyCode()));
        if (! saDstAmount.native ())
        {
            // Only XRP can be send to a non-existent account.
            jvStatus = rpcError (rpcACT_NOT_FOUND);
            return false;
        }

        if (! convert_all_ && saDstAmount <
            STAmount (lrLedger->fees().accountReserve (0)))
        {
            // Payment must meet reserve.
            jvStatus = rpcError (rpcDST_AMT_MALFORMED);
            return false;
        }
    }
    else
    {
        bool const disallowXRP (
            sleDest->getFlags() & lsfDisallowXRP);

        auto usDestCurrID = accountDestCurrencies (
                *raDstAccount, crCache, ! disallowXRP);

        for (auto const& currency : usDestCurrID)
            jvDestCur.append (to_string (currency));
        jvStatus[jss::destination_tag] =
            (sleDest->getFlags() & lsfRequireDestTag);
    }

    jvStatus[jss::ledger_hash] = to_string (lrLedger->info().hash);
    jvStatus[jss::ledger_index] = lrLedger->seq();
    return true;
}

Json::Value PathRequest::doCreate (
    RippleLineCache::ref& cache,
    Json::Value const& value,
    bool& valid)
{
    Json::Value status;

    if (parseJson (value) != PFR_PJ_INVALID)
    {
        valid = isValid (cache);
        status = valid ? doUpdate(cache, true) : jvStatus;
    }
    else
    {
        valid = false;
        status = jvStatus;
    }

    if (m_journal.debug)
    {
        if (valid)
        {
            m_journal.debug << iIdentifier
                            << " valid: " << toBase58(*raSrcAccount);
            m_journal.debug << iIdentifier
                            << " Deliver: " << saDstAmount.getFullText ();
        }
        else
        {
            m_journal.debug << iIdentifier << " invalid";
        }
    }

    return status;
}

int PathRequest::parseJson (Json::Value const& jvParams)
{
    if (! jvParams.isMember(jss::source_account))
    {
        jvStatus = rpcError(rpcSRC_ACT_MISSING);
        return PFR_PJ_INVALID;
    }

    if (! jvParams.isMember(jss::destination_account))
    {
        jvStatus = rpcError(rpcDST_ACT_MISSING);
        return PFR_PJ_INVALID;
    }

    if (! jvParams.isMember(jss::destination_amount))
    {
        jvStatus = rpcError(rpcDST_AMT_MISSING);
        return PFR_PJ_INVALID;
    }

    raSrcAccount = parseBase58<AccountID>(
        jvParams[jss::source_account].asString());
    if (! raSrcAccount)
    {
        jvStatus = rpcError (rpcSRC_ACT_MALFORMED);
        return PFR_PJ_INVALID;
    }

    raDstAccount = parseBase58<AccountID>(
        jvParams[jss::destination_account].asString());
    if (! raDstAccount)
    {
        jvStatus = rpcError (rpcDST_ACT_MALFORMED);
        return PFR_PJ_INVALID;
    }

    if (! amountFromJsonNoThrow (
        saDstAmount, jvParams[jss::destination_amount]))
    {
        jvStatus = rpcError (rpcDST_AMT_MALFORMED);
        return PFR_PJ_INVALID;
    }

    convert_all_ =
        saDstAmount == STAmount(saDstAmount.issue(), 1u, 0, true);

    if ((saDstAmount.getCurrency ().isZero () &&
            saDstAmount.getIssuer ().isNonZero ()) ||
        (saDstAmount.getCurrency () == badCurrency ()) ||
        (! convert_all_ && saDstAmount <= zero))
    {
        jvStatus = rpcError (rpcDST_AMT_MALFORMED);
        return PFR_PJ_INVALID;
    }

    if (jvParams.isMember(jss::send_max))
    {
        // Send_max requires destination amount to be -1.
        if (! convert_all_)
        {
            jvStatus = rpcError(rpcDST_AMT_MALFORMED);
            return PFR_PJ_INVALID;
        }

        saSendMax.emplace();
        if (! amountFromJsonNoThrow(
            *saSendMax, jvParams[jss::send_max]) ||
            (saSendMax->getCurrency().isZero() &&
                saSendMax->getIssuer().isNonZero()) ||
            (saSendMax->getCurrency() == badCurrency()) ||
            (*saSendMax <= zero &&
                *saSendMax != STAmount(saSendMax->issue(), 1u, 0, true)))
        {
            jvStatus = rpcError(rpcSENDMAX_MALFORMED);
            return PFR_PJ_INVALID;
        }
    }

    if (jvParams.isMember (jss::source_currencies))
    {
        Json::Value const& jvSrcCur = jvParams[jss::source_currencies];

        if (!jvSrcCur.isArray ())
        {
            jvStatus = rpcError (rpcSRC_CUR_MALFORMED);
            return PFR_PJ_INVALID;
        }

        sciSourceCurrencies.clear ();

        for (unsigned i = 0; i < jvSrcCur.size (); ++i)
        {
            Json::Value const& jvCur = jvSrcCur[i];
            Currency uCur;
            AccountID uIss;

            if (! jvCur.isObject() ||
                ! jvCur.isMember (jss::currency) ||
                ! to_currency (uCur, jvCur[jss::currency].asString ()))
            {
                jvStatus = rpcError (rpcSRC_CUR_MALFORMED);
                return PFR_PJ_INVALID;
            }

            if (jvCur.isMember (jss::issuer) &&
                !to_issuer (uIss, jvCur[jss::issuer].asString ()))
            {
                jvStatus = rpcError (rpcSRC_ISR_MALFORMED);
            }

            if (uCur.isZero () && uIss.isNonZero ())
            {
                jvStatus = rpcError (rpcSRC_CUR_MALFORMED);
                return PFR_PJ_INVALID;
            }

            if (uCur.isNonZero() && uIss.isZero())
                uIss = *raSrcAccount;

            if (saSendMax)
            {
                // If the currencies don't match, ignore the source currency.
                if (uCur == saSendMax->getCurrency())
                {
                    // If neither is the source and they are not equal, then the
                    // source issuer is illegal.
                    if (uIss != *raSrcAccount &&
                        saSendMax->getIssuer() != *raSrcAccount &&
                        uIss != saSendMax->getIssuer())
                    {
                        jvStatus = rpcError (rpcSRC_ISR_MALFORMED);
                        return PFR_PJ_INVALID;
                    }

                    // If both are the source, use the source.
                    // Otherwise, use the one that's not the source.
                    if (uIss != *raSrcAccount)
                        sciSourceCurrencies.insert({uCur, uIss});
                    else if (saSendMax->getIssuer() != *raSrcAccount)
                        sciSourceCurrencies.insert({uCur, saSendMax->getIssuer()});
                    else
                        sciSourceCurrencies.insert({uCur, *raSrcAccount});
                }
            }
            else
            {
                sciSourceCurrencies.insert({uCur, uIss});
            }
        }
    }

    if (jvParams.isMember ("id"))
        jvId = jvParams["id"];

    return PFR_PJ_NOCHANGE;
}

Json::Value PathRequest::doClose (Json::Value const&)
{
    m_journal.debug << iIdentifier << " closed";
    ScopedLockType sl (mLock);
    jvStatus[jss::closed] = true;
    return jvStatus;
}

Json::Value PathRequest::doStatus (Json::Value const&)
{
    ScopedLockType sl (mLock);
    jvStatus[jss::status] = jss::success;
    return jvStatus;
}

void PathRequest::resetLevel (int l)
{
    if (iLastLevel > l)
        iLastLevel = l;
}

bool
PathRequest::findPaths (
    RippleLineCache::ref cache,
        FindPaths& fp, Issue const& issue,
            Json::Value& jvArray)
{
    STPath fullLiquidityPath;
    auto result = fp.findPathsForIssue(issue,
        mContext[issue], fullLiquidityPath, app_);
    if (! result)
    {
        m_journal.debug << iIdentifier << " No paths found";
        return false;
    }
    mContext[issue] = *result;

    boost::optional<PaymentSandbox> sandbox;
    sandbox.emplace(&*cache->getLedger(), tapNONE);

    auto& sourceAccount = ! isXRP(issue.account)
        ? issue.account
        : isXRP(issue.currency)
        ? xrpAccount()
        : *raSrcAccount;

    STAmount saMaxAmount = saSendMax.value_or(
        STAmount({issue.currency, sourceAccount}, 1u, 0, true));

    m_journal.debug << iIdentifier
        << " Paths found, calling rippleCalc";

    path::RippleCalc::Input rcInput;
    if (convert_all_)
        rcInput.partialPaymentAllowed = true;

    auto rc = path::RippleCalc::rippleCalculate(
        *sandbox, saMaxAmount,
        convert_all_ ? STAmount(saDstAmount.issue(), STAmount::cMaxValue,
            STAmount::cMaxOffset) : saDstAmount,
        *raDstAccount, *raSrcAccount, *result, &rcInput);

    if (! convert_all_ &&
        ! fullLiquidityPath.empty() &&
        (rc.result() == terNO_LINE || rc.result() == tecPATH_PARTIAL))
    {
        m_journal.debug << iIdentifier
            << " Trying with an extra path element";
        result->push_back(fullLiquidityPath);
        sandbox.emplace(&*cache->getLedger(), tapNONE);

        rc = path::RippleCalc::rippleCalculate(
            *sandbox, saMaxAmount, saDstAmount,
                *raDstAccount, *raSrcAccount, *result);
        if (rc.result() != tesSUCCESS)
        {
            m_journal.warning << iIdentifier
                << " Failed with covering path "
                << transHuman(rc.result());
        }
        else
        {
            m_journal.debug << iIdentifier
                << " Extra path element gives "
                << transHuman(rc.result());
        }
    }

    if (rc.result () == tesSUCCESS)
    {
        Json::Value jvEntry (Json::objectValue);
        rc.actualAmountIn.setIssuer (sourceAccount);
        jvEntry[jss::source_amount] = rc.actualAmountIn.getJson (0);
        jvEntry[jss::paths_computed] = result->getJson(0);

        if (convert_all_)
            jvEntry[jss::destination_amount] = rc.actualAmountOut.getJson(0);

        if (hasCompletion ())
        {
            // Old ripple_path_find API requires this
            jvEntry[jss::paths_canonical] = Json::arrayValue;
        }

        jvArray.append (jvEntry);
        return true;
    }

    m_journal.debug << iIdentifier << " rippleCalc returns "
        << transHuman (rc.result ());
    return false;
}

Json::Value PathRequest::doUpdate (RippleLineCache::ref cache, bool fast)
{
    m_journal.debug << iIdentifier << " update " << (fast ? "fast" : "normal");

    ScopedLockType sl (mLock);

    if (!isValid (cache))
        return jvStatus;
    jvStatus = Json::objectValue;

    auto sourceCurrencies = sciSourceCurrencies;

    if (sourceCurrencies.empty ())
    {
        auto usCurrencies =
                accountSourceCurrencies (*raSrcAccount, cache, true);
        bool sameAccount = *raSrcAccount == *raDstAccount;
        for (auto const& c: usCurrencies)
        {
            if (!sameAccount || (c != saDstAmount.getCurrency ()))
            {
                if (c.isZero ())
                    sourceCurrencies.insert ({c, xrpAccount()});
                else
                    sourceCurrencies.insert ({c, *raSrcAccount});
            }
        }
    }

    if (hasCompletion ())
    {
        // Old ripple_path_find API gives destination_currencies
        auto& destCurrencies = (jvStatus[jss::destination_currencies] = Json::arrayValue);
        auto usCurrencies = accountDestCurrencies (*raDstAccount, cache, true);
        for (auto const& c : usCurrencies)
            destCurrencies.append (to_string (c));
    }

    jvStatus[jss::source_account] = app_.accountIDCache().toBase58(*raSrcAccount);
    jvStatus[jss::destination_account] = app_.accountIDCache().toBase58(*raDstAccount);
    jvStatus[jss::destination_amount] = saDstAmount.getJson (0);
    jvStatus[jss::full_reply] = ! fast;

    if (jvId)
        jvStatus["id"] = jvId;

    int iLevel = iLastLevel;
    bool loaded = app_.getFeeTrack().isLoadedLocal();

    if (iLevel == 0)
    {
        // first pass
        if (loaded || fast)
            iLevel = app_.config().PATH_SEARCH_FAST;
        else
            iLevel = app_.config().PATH_SEARCH;
    }
    else if ((iLevel == app_.config().PATH_SEARCH_FAST) && !fast)
    {
        // leaving fast pathfinding
        iLevel = app_.config().PATH_SEARCH;
        if (loaded && (iLevel > app_.config().PATH_SEARCH_FAST))
            --iLevel;
    }
    else if (bLastSuccess)
    {
        // decrement, if possible
        if (iLevel > app_.config().PATH_SEARCH ||
            (loaded && (iLevel > app_.config().PATH_SEARCH_FAST)))
            --iLevel;
    }
    else
    {
        // adjust as needed
        if (!loaded && (iLevel < app_.config().PATH_SEARCH_MAX))
            ++iLevel;
        if (loaded && (iLevel > app_.config().PATH_SEARCH_FAST))
            --iLevel;
    }

    m_journal.debug << iIdentifier << " processing at level " << iLevel;

    bool found = false;
    Json::Value jvArray = Json::arrayValue;
    FindPaths fp (
        cache,
        *raSrcAccount,
        *raDstAccount,
        convert_all_ ? STAmount(saDstAmount.issue(), STAmount::cMaxValue,
            STAmount::cMaxOffset) : saDstAmount,
        saSendMax,
        iLevel,
        4);  // iMaxPaths
    for (auto const& i: sourceCurrencies)
    {
        JLOG(m_journal.debug)
            << iIdentifier
            << " Trying to find paths: "
            << STAmount(i, 1).getFullText();
        if (findPaths(cache, fp, i, jvArray))
            found = true;
    }

    iLastLevel = iLevel;
    bLastSuccess = found;

    if (fast && ptQuickReply.is_not_a_date_time())
    {
        ptQuickReply = boost::posix_time::microsec_clock::universal_time();
        mOwner.reportFast ((ptQuickReply-ptCreated).total_milliseconds());
    }
    else if (!fast && ptFullReply.is_not_a_date_time())
    {
        ptFullReply = boost::posix_time::microsec_clock::universal_time();
        mOwner.reportFull ((ptFullReply-ptCreated).total_milliseconds());
    }

    jvStatus[jss::alternatives] = jvArray;
    return jvStatus;
}

InfoSub::pointer PathRequest::getSubscriber ()
{
    return wpSubscriber.lock ();
}

} // ripple