//------------------------------------------------------------------------------
/*
    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 <ripple/app/ledger/TransactionMaster.h>
#include <ripple/app/misc/NetworkOPs.h>
#include <ripple/app/misc/SHAMapStoreImp.h>
#include <ripple/beast/core/CurrentThreadName.h>
#include <ripple/core/ConfigSections.h>
#include <ripple/nodestore/impl/DatabaseRotatingImp.h>

#include <boost/algorithm/string/predicate.hpp>

namespace ripple {
void SHAMapStoreImp::SavedStateDB::init (BasicConfig const& config,
                                         std::string const& dbName)
{
    std::lock_guard lock (mutex_);

    open(session_, config, dbName);

    session_ << "PRAGMA synchronous=FULL;";

    session_ <<
        "CREATE TABLE IF NOT EXISTS DbState ("
        "  Key                    INTEGER PRIMARY KEY,"
        "  WritableDb             TEXT,"
        "  ArchiveDb              TEXT,"
        "  LastRotatedLedger      INTEGER"
        ");"
        ;

    session_ <<
        "CREATE TABLE IF NOT EXISTS CanDelete ("
        "  Key                    INTEGER PRIMARY KEY,"
        "  CanDeleteSeq           INTEGER"
        ");"
        ;

    std::int64_t count = 0;
    {
        boost::optional<std::int64_t> countO;
        session_ <<
                "SELECT COUNT(Key) FROM DbState WHERE Key = 1;"
                , soci::into (countO);
        if (!countO)
            Throw<std::runtime_error> ("Failed to fetch Key Count from DbState.");
        count = *countO;
    }

    if (!count)
    {
        session_ <<
                "INSERT INTO DbState VALUES (1, '', '', 0);";
    }


    {
        boost::optional<std::int64_t> countO;
        session_ <<
                "SELECT COUNT(Key) FROM CanDelete WHERE Key = 1;"
                , soci::into (countO);
        if (!countO)
            Throw<std::runtime_error> ("Failed to fetch Key Count from CanDelete.");
        count = *countO;
    }

    if (!count)
    {
        session_ <<
                "INSERT INTO CanDelete VALUES (1, 0);";
    }
}

LedgerIndex
SHAMapStoreImp::SavedStateDB::getCanDelete()
{
    LedgerIndex seq;
    std::lock_guard lock (mutex_);

    session_ <<
            "SELECT CanDeleteSeq FROM CanDelete WHERE Key = 1;"
            , soci::into (seq);
    ;

    return seq;
}

LedgerIndex
SHAMapStoreImp::SavedStateDB::setCanDelete (LedgerIndex canDelete)
{
    std::lock_guard lock (mutex_);

    session_ <<
            "UPDATE CanDelete SET CanDeleteSeq = :canDelete WHERE Key = 1;"
            , soci::use (canDelete)
            ;

    return canDelete;
}

SHAMapStoreImp::SavedState
SHAMapStoreImp::SavedStateDB::getState()
{
    SavedState state;

    std::lock_guard lock (mutex_);

    session_ <<
            "SELECT WritableDb, ArchiveDb, LastRotatedLedger"
            " FROM DbState WHERE Key = 1;"
            , soci::into (state.writableDb), soci::into (state.archiveDb)
            , soci::into (state.lastRotated)
            ;

    return state;
}

void
SHAMapStoreImp::SavedStateDB::setState (SavedState const& state)
{
    std::lock_guard lock (mutex_);
    session_ <<
            "UPDATE DbState"
            " SET WritableDb = :writableDb,"
            " ArchiveDb = :archiveDb,"
            " LastRotatedLedger = :lastRotated"
            " WHERE Key = 1;"
            , soci::use (state.writableDb)
            , soci::use (state.archiveDb)
            , soci::use (state.lastRotated)
            ;
}

void
SHAMapStoreImp::SavedStateDB::setLastRotated (LedgerIndex seq)
{
    std::lock_guard lock (mutex_);
    session_ <<
            "UPDATE DbState SET LastRotatedLedger = :seq"
            " WHERE Key = 1;"
            , soci::use (seq)
            ;
}

//------------------------------------------------------------------------------

SHAMapStoreImp::SHAMapStoreImp(
    Application& app,
    Stoppable& parent,
    NodeStore::Scheduler& scheduler,
    beast::Journal journal)
    : SHAMapStore (parent)
    , app_ (app)
    , scheduler_ (scheduler)
    , journal_ (journal)
    , working_(true)
    , canDelete_ (std::numeric_limits <LedgerIndex>::max())
{
    Config& config {app.config()};
    Section& section {config.section(ConfigSection::nodeDatabase())};
    if (section.empty())
    {
        Throw<std::runtime_error>(
            "Missing [" + ConfigSection::nodeDatabase() +
            "] entry in configuration file");

    }

    // RocksDB only. Use sensible defaults if no values specified.
    if (boost::iequals(
        get<std::string>(section, "type"), "RocksDB"))
    {
        if (!section.exists("cache_mb"))
        {
            section.set("cache_mb", std::to_string(
                config.getSize(siHashNodeDBCache)));
        }

        if (!section.exists("filter_bits") && (config.NODE_SIZE >= 2))
            section.set("filter_bits", "10");
    }

    get_if_exists(section, "delete_batch", deleteBatch_);
    get_if_exists(section, "backOff", backOff_);
    get_if_exists(section, "age_threshold", ageThreshold_);
    get_if_exists(section, "online_delete", deleteInterval_);

    if (deleteInterval_)
    {
        get_if_exists(section, "advisory_delete", advisoryDelete_);

        auto const minInterval = config.standalone() ?
            minimumDeletionIntervalSA_ : minimumDeletionInterval_;
        if (deleteInterval_ < minInterval)
        {
            Throw<std::runtime_error>("online_delete must be at least " +
                std::to_string (minInterval));
        }

        if (config.LEDGER_HISTORY > deleteInterval_)
        {
            Throw<std::runtime_error>(
                "online_delete must not be less than ledger_history (currently " +
                std::to_string (config.LEDGER_HISTORY) + ")");
        }

        state_db_.init(config, dbName_);
        dbPaths();
    }
}

std::unique_ptr <NodeStore::Database>
SHAMapStoreImp::makeNodeStore(std::string const& name, std::int32_t readThreads)
{
    // Anything which calls addJob must be a descendant of the JobQueue.
    // Therefore Database objects use the JobQueue as Stoppable parent.
    std::unique_ptr <NodeStore::Database> db;
    if (deleteInterval_)
    {
        SavedState state = state_db_.getState();
        auto writableBackend = makeBackendRotating(state.writableDb);
        auto archiveBackend = makeBackendRotating(state.archiveDb);
        if (! state.writableDb.size())
        {
            state.writableDb = writableBackend->getName();
            state.archiveDb = archiveBackend->getName();
            state_db_.setState (state);
        }

        // Create NodeStore with two backends to allow online deletion of data
        auto dbr = std::make_unique<NodeStore::DatabaseRotatingImp>(
            name,
            scheduler_,
            readThreads,
            app_.getJobQueue(),
            std::move(writableBackend),
            std::move(archiveBackend),
            app_.config().section(ConfigSection::nodeDatabase()),
            app_.logs().journal(nodeStoreName_));
        fdRequired_ += dbr->fdRequired();
        dbRotating_ = dbr.get();
        db.reset(dynamic_cast<NodeStore::Database*>(dbr.release()));
    }
    else
    {
        db = NodeStore::Manager::instance().make_Database(
            name,
            scheduler_,
            readThreads,
            app_.getJobQueue(),
            app_.config().section(ConfigSection::nodeDatabase()),
            app_.logs().journal(nodeStoreName_));
        fdRequired_ += db->fdRequired();
    }
    return db;
}

void
SHAMapStoreImp::onLedgerClosed(
    std::shared_ptr<Ledger const> const& ledger)
{
    {
        std::lock_guard lock (mutex_);
        newLedger_ = ledger;
        working_ = true;
    }
    cond_.notify_one();
}

void
SHAMapStoreImp::rendezvous() const
{
    if (!working_)
        return;

    std::unique_lock <std::mutex> lock(mutex_);
    rendezvous_.wait(lock, [&]
    {
        return !working_;
    });
}

int
SHAMapStoreImp::fdRequired() const
{
    return fdRequired_;
}

bool
SHAMapStoreImp::copyNode (std::uint64_t& nodeCount,
        SHAMapAbstractNode const& node)
{
    // Copy a single record from node to dbRotating_
    dbRotating_->fetch(node.getNodeHash().as_uint256(), node.getSeq());
    if (! (++nodeCount % checkHealthInterval_))
    {
        if (health())
            return false;
    }

    return true;
}

void
SHAMapStoreImp::run()
{
    beast::setCurrentThreadName ("SHAMapStore");
    LedgerIndex lastRotated = state_db_.getState().lastRotated;
    netOPs_ = &app_.getOPs();
    ledgerMaster_ = &app_.getLedgerMaster();
    fullBelowCache_ = &app_.family().fullbelow();
    treeNodeCache_ = &app_.family().treecache();
    transactionDb_ = &app_.getTxnDB();
    ledgerDb_ = &app_.getLedgerDB();

    if (advisoryDelete_)
        canDelete_ = state_db_.getCanDelete ();

    while (1)
    {
        healthy_ = true;
        std::shared_ptr<Ledger const> validatedLedger;

        {
            std::unique_lock <std::mutex> lock (mutex_);
            working_ = false;
            rendezvous_.notify_all();
            if (stop_)
            {
                stopped();
                return;
            }
            cond_.wait (lock);
            if (newLedger_)
            {
                validatedLedger = std::move(newLedger_);
            }
            else
                continue;
        }

        LedgerIndex validatedSeq = validatedLedger->info().seq;
        if (!lastRotated)
        {
            lastRotated = validatedSeq;
            state_db_.setLastRotated (lastRotated);
        }

        // will delete up to (not including) lastRotated)
        if (validatedSeq >= lastRotated + deleteInterval_
                && canDelete_ >= lastRotated - 1)
        {
            JLOG(journal_.debug()) << "rotating  validatedSeq " << validatedSeq
                    << " lastRotated " << lastRotated << " deleteInterval "
                    << deleteInterval_ << " canDelete_ " << canDelete_;

            switch (health())
            {
                case Health::stopping:
                    stopped();
                    return;
                case Health::unhealthy:
                    continue;
                case Health::ok:
                default:
                    ;
            }

            clearPrior (lastRotated);
            switch (health())
            {
                case Health::stopping:
                    stopped();
                    return;
                case Health::unhealthy:
                    continue;
                case Health::ok:
                default:
                    ;
            }

            std::uint64_t nodeCount = 0;
            validatedLedger->stateMap().snapShot (
                    false)->visitNodes (
                    std::bind (&SHAMapStoreImp::copyNode, this,
                    std::ref(nodeCount), std::placeholders::_1));
            JLOG(journal_.debug()) << "copied ledger " << validatedSeq
                    << " nodecount " << nodeCount;
            switch (health())
            {
                case Health::stopping:
                    stopped();
                    return;
                case Health::unhealthy:
                    continue;
                case Health::ok:
                default:
                    ;
            }

            freshenCaches();
            JLOG(journal_.debug()) << validatedSeq << " freshened caches";
            switch (health())
            {
                case Health::stopping:
                    stopped();
                    return;
                case Health::unhealthy:
                    continue;
                case Health::ok:
                default:
                    ;
            }

            auto newBackend = makeBackendRotating();
            JLOG(journal_.debug()) << validatedSeq << " new backend "
                    << newBackend->getName();

            clearCaches (validatedSeq);
            switch (health())
            {
                case Health::stopping:
                    stopped();
                    return;
                case Health::unhealthy:
                    continue;
                case Health::ok:
                default:
                    ;
            }

            std::string nextArchiveDir =
                dbRotating_->getWritableBackend()->getName();
            lastRotated = validatedSeq;
            std::unique_ptr<NodeStore::Backend> oldBackend;
            {
                std::lock_guard lock (dbRotating_->peekMutex());

                state_db_.setState (SavedState {newBackend->getName(),
                        nextArchiveDir, lastRotated});
                clearCaches (validatedSeq);
                oldBackend = dbRotating_->rotateBackends(
                    std::move(newBackend));
            }
            JLOG(journal_.debug()) << "finished rotation " << validatedSeq;

            oldBackend->setDeletePath();
        }
    }
}

void
SHAMapStoreImp::dbPaths()
{
    Section section {app_.config().section(ConfigSection::nodeDatabase())};
    boost::filesystem::path dbPath = get<std::string>(section, "path");

    if (boost::filesystem::exists (dbPath))
    {
        if (! boost::filesystem::is_directory (dbPath))
        {
            journal_.error() << "node db path must be a directory. "
                    << dbPath.string();
            Throw<std::runtime_error> (
                    "node db path must be a directory.");
        }
    }
    else
    {
        boost::filesystem::create_directories (dbPath);
    }

    SavedState state = state_db_.getState();

    {
        auto update = [&dbPath](std::string& sPath)
        {
            if (sPath.empty())
                return false;

            // Check if configured "path" matches stored directory path
            using namespace boost::filesystem;
            auto const stored {path(sPath)};
            if (stored.parent_path() == dbPath)
                return false;

            sPath = (dbPath / stored.filename()).string();
            return true;
        };

        if (update(state.writableDb))
        {
            update(state.archiveDb);
            state_db_.setState(state);
        }
    }

    bool writableDbExists = false;
    bool archiveDbExists = false;

    for (boost::filesystem::directory_iterator it (dbPath);
            it != boost::filesystem::directory_iterator(); ++it)
    {
        if (! state.writableDb.compare (it->path().string()))
            writableDbExists = true;
        else if (! state.archiveDb.compare (it->path().string()))
            archiveDbExists = true;
        else if (! dbPrefix_.compare (it->path().stem().string()))
            boost::filesystem::remove_all (it->path());
    }

    if ((!writableDbExists && state.writableDb.size()) ||
            (!archiveDbExists && state.archiveDb.size()) ||
            (writableDbExists != archiveDbExists) ||
            state.writableDb.empty() != state.archiveDb.empty())
    {
        boost::filesystem::path stateDbPathName =
            app_.config().legacy("database_path");
        stateDbPathName /= dbName_;
        stateDbPathName += "*";

        journal_.error() << "state db error:\n"
                << "  writableDbExists " << writableDbExists
                << " archiveDbExists " << archiveDbExists << '\n'
                << "  writableDb '" << state.writableDb
                << "' archiveDb '" << state.archiveDb << "\n\n"
                << "The existing data is in a corrupted state.\n"
                << "To resume operation, remove the files matching "
                << stateDbPathName.string()
                << " and contents of the directory "
                << get<std::string>(section, "path") << '\n'
                << "Optionally, you can move those files to another\n"
                << "location if you wish to analyze or back up the data.\n"
                << "However, there is no guarantee that the data in its\n"
                << "existing form is usable.";

        Throw<std::runtime_error> ("state db error");
    }
}

std::unique_ptr <NodeStore::Backend>
SHAMapStoreImp::makeBackendRotating (std::string path)
{
    Section section {app_.config().section(ConfigSection::nodeDatabase())};
    boost::filesystem::path newPath;

    if (path.size())
    {
        newPath = path;
    }
    else
    {
        boost::filesystem::path p = get<std::string>(section, "path");
        p /= dbPrefix_;
        p += ".%%%%";
        newPath = boost::filesystem::unique_path (p);
    }
    section.set("path", newPath.string());

    auto backend {NodeStore::Manager::instance().make_Backend(
        section, scheduler_, app_.logs().journal(nodeStoreName_))};
    backend->open();
    return backend;
}

bool
SHAMapStoreImp::clearSql (DatabaseCon& database,
        LedgerIndex lastRotated,
        std::string const& minQuery,
        std::string const& deleteQuery)
{
    LedgerIndex min = std::numeric_limits <LedgerIndex>::max();

    {
        auto db = database.checkoutDb ();
        boost::optional<std::uint64_t> m;
        *db << minQuery, soci::into(m);
        if (!m)
            return false;
        min = *m;
    }

    if(min > lastRotated || health() != Health::ok)
        return false;

    boost::format formattedDeleteQuery (deleteQuery);

    JLOG(journal_.debug()) <<
        "start: " << deleteQuery << " from " << min << " to " << lastRotated;
    while (min < lastRotated)
    {
        min = std::min(lastRotated, min + deleteBatch_);
        {
            auto db =  database.checkoutDb ();
            *db << boost::str (formattedDeleteQuery % min);
        }
        if (health())
            return true;
        if (min < lastRotated)
            std::this_thread::sleep_for (
                    std::chrono::milliseconds (backOff_));
    }
    JLOG(journal_.debug()) << "finished: " << deleteQuery;
    return true;
}

void
SHAMapStoreImp::clearCaches (LedgerIndex validatedSeq)
{
    ledgerMaster_->clearLedgerCachePrior (validatedSeq);
    fullBelowCache_->clear();
}

void
SHAMapStoreImp::freshenCaches()
{
    if (freshenCache (dbRotating_->getPositiveCache()))
        return;
    if (freshenCache (*treeNodeCache_))
        return;
    if (freshenCache (app_.getMasterTransaction().getCache()))
        return;
}

void
SHAMapStoreImp::clearPrior (LedgerIndex lastRotated)
{
    if (health())
        return;

    ledgerMaster_->clearPriorLedgers (lastRotated);
    if (health())
        return;

    clearSql (*ledgerDb_, lastRotated,
        "SELECT MIN(LedgerSeq) FROM Ledgers;",
        "DELETE FROM Ledgers WHERE LedgerSeq < %u;");
    if (health())
        return;

    clearSql (*transactionDb_, lastRotated,
        "SELECT MIN(LedgerSeq) FROM Transactions;",
        "DELETE FROM Transactions WHERE LedgerSeq < %u;");
    if (health())
        return;

    clearSql (*transactionDb_, lastRotated,
        "SELECT MIN(LedgerSeq) FROM AccountTransactions;",
        "DELETE FROM AccountTransactions WHERE LedgerSeq < %u;");
    if (health())
        return;
}

SHAMapStoreImp::Health
SHAMapStoreImp::health()
{
    {
        std::lock_guard lock (mutex_);
        if (stop_)
            return Health::stopping;
    }
    if (! netOPs_)
        return Health::ok;

    constexpr static std::chrono::seconds age_threshold(60);
    auto age = ledgerMaster_->getValidatedLedgerAge();
    OperatingMode mode = netOPs_->getOperatingMode();
    if (mode != OperatingMode::FULL || age > age_threshold)
    {
        JLOG(journal_.warn()) << "Not deleting. state: "
                              << app_.getOPs().strOperatingMode(mode, false)
                              << ". age " << age.count() << 's';
        healthy_ = false;
    }

    if (healthy_)
        return Health::ok;
    else
        return Health::unhealthy;
}

void
SHAMapStoreImp::onStop()
{
    if (deleteInterval_)
    {
        {
            std::lock_guard lock (mutex_);
            stop_ = true;
        }
        cond_.notify_one();
    }
    else
    {
        stopped();
    }
}

void
SHAMapStoreImp::onChildrenStopped()
{
    if (deleteInterval_)
    {
        {
            std::lock_guard lock (mutex_);
            stop_ = true;
        }
        cond_.notify_one();
    }
    else
    {
        stopped();
    }
}

//------------------------------------------------------------------------------

std::unique_ptr<SHAMapStore>
make_SHAMapStore(
    Application& app,
    Stoppable& parent,
    NodeStore::Scheduler& scheduler,
    beast::Journal journal)
{
    return std::make_unique<SHAMapStoreImp>(app, parent, scheduler, journal);
}

}