/**
 *    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects for
 *    all of the code used other than as permitted herein. If you modify file(s)
 *    with this exception, you may extend this exception to your version of the
 *    file(s), but you are not obligated to do so. If you do not wish to do so,
 *    delete this exception statement from your version. If you delete this
 *    exception statement from all source files in the program, then also delete
 *    it in the license file.
 */

#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kDefault

#include "mongo/platform/basic.h"

#include "mongo/db/dbhelpers.h"

#include <boost/filesystem/operations.hpp>
#include <fstream>

#include "mongo/db/catalog/collection.h"
#include "mongo/db/catalog/index_create.h"
#include "mongo/db/db.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/exec/working_set_common.h"
#include "mongo/db/index/btree_access_method.h"
#include "mongo/db/json.h"
#include "mongo/db/keypattern.h"
#include "mongo/db/matcher/extensions_callback_real.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/op_observer.h"
#include "mongo/db/ops/delete.h"
#include "mongo/db/ops/update.h"
#include "mongo/db/ops/update_lifecycle_impl.h"
#include "mongo/db/ops/update_request.h"
#include "mongo/db/ops/update_result.h"
#include "mongo/db/query/get_executor.h"
#include "mongo/db/query/internal_plans.h"
#include "mongo/db/query/query_planner.h"
#include "mongo/db/range_arithmetic.h"
#include "mongo/db/repl/repl_client_info.h"
#include "mongo/db/repl/replication_coordinator_global.h"
#include "mongo/db/s/collection_metadata.h"
#include "mongo/db/s/collection_sharding_state.h"
#include "mongo/db/s/sharding_state.h"
#include "mongo/db/service_context.h"
#include "mongo/db/storage/data_protector.h"
#include "mongo/db/storage/encryption_hooks.h"
#include "mongo/db/storage/storage_options.h"
#include "mongo/db/write_concern.h"
#include "mongo/db/write_concern_options.h"
#include "mongo/s/shard_key_pattern.h"
#include "mongo/util/log.h"
#include "mongo/util/mongoutils/str.h"
#include "mongo/util/scopeguard.h"

namespace mongo {

using std::unique_ptr;
using std::endl;
using std::ios_base;
using std::ofstream;
using std::set;
using std::string;
using std::stringstream;

using logger::LogComponent;

/* fetch a single object from collection ns that matches query
   set your db SavedContext first
*/
bool Helpers::findOne(OperationContext* opCtx,
                      Collection* collection,
                      const BSONObj& query,
                      BSONObj& result,
                      bool requireIndex) {
    RecordId loc = findOne(opCtx, collection, query, requireIndex);
    if (loc.isNull())
        return false;
    result = collection->docFor(opCtx, loc).value();
    return true;
}

/* fetch a single object from collection ns that matches query
   set your db SavedContext first
*/
RecordId Helpers::findOne(OperationContext* opCtx,
                          Collection* collection,
                          const BSONObj& query,
                          bool requireIndex) {
    if (!collection)
        return RecordId();

    auto qr = stdx::make_unique<QueryRequest>(collection->ns());
    qr->setFilter(query);
    return findOne(opCtx, collection, std::move(qr), requireIndex);
}

RecordId Helpers::findOne(OperationContext* opCtx,
                          Collection* collection,
                          std::unique_ptr<QueryRequest> qr,
                          bool requireIndex) {
    if (!collection)
        return RecordId();

    const ExtensionsCallbackReal extensionsCallback(opCtx, &collection->ns());

    const boost::intrusive_ptr<ExpressionContext> expCtx;
    auto statusWithCQ =
        CanonicalQuery::canonicalize(opCtx,
                                     std::move(qr),
                                     expCtx,
                                     extensionsCallback,
                                     MatchExpressionParser::kAllowAllSpecialFeatures &
                                         ~MatchExpressionParser::AllowedFeatures::kIsolated);

    massert(17244, "Could not canonicalize " + qr->asFindCommand().toString(), statusWithCQ.isOK());
    unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());

    size_t options = requireIndex ? QueryPlannerParams::NO_TABLE_SCAN : QueryPlannerParams::DEFAULT;
    auto exec = uassertStatusOK(
        getExecutor(opCtx, collection, std::move(cq), PlanExecutor::NO_YIELD, options));

    PlanExecutor::ExecState state;
    BSONObj obj;
    RecordId loc;
    if (PlanExecutor::ADVANCED == (state = exec->getNext(&obj, &loc))) {
        return loc;
    }
    massert(34427,
            "Plan executor error: " + WorkingSetCommon::toStatusString(obj),
            PlanExecutor::IS_EOF == state);
    return RecordId();
}

bool Helpers::findById(OperationContext* opCtx,
                       Database* database,
                       StringData ns,
                       BSONObj query,
                       BSONObj& result,
                       bool* nsFound,
                       bool* indexFound) {
    invariant(database);

    Collection* collection = database->getCollection(opCtx, ns);
    if (!collection) {
        return false;
    }

    if (nsFound)
        *nsFound = true;

    IndexCatalog* catalog = collection->getIndexCatalog();
    const IndexDescriptor* desc = catalog->findIdIndex(opCtx);

    if (!desc)
        return false;

    if (indexFound)
        *indexFound = 1;

    RecordId loc = catalog->getIndex(desc)->findSingle(opCtx, query["_id"].wrap());
    if (loc.isNull())
        return false;
    result = collection->docFor(opCtx, loc).value();
    return true;
}

RecordId Helpers::findById(OperationContext* opCtx,
                           Collection* collection,
                           const BSONObj& idquery) {
    verify(collection);
    IndexCatalog* catalog = collection->getIndexCatalog();
    const IndexDescriptor* desc = catalog->findIdIndex(opCtx);
    uassert(13430, "no _id index", desc);
    return catalog->getIndex(desc)->findSingle(opCtx, idquery["_id"].wrap());
}

bool Helpers::getSingleton(OperationContext* opCtx, const char* ns, BSONObj& result) {
    AutoGetCollectionForReadCommand ctx(opCtx, NamespaceString(ns));
    auto exec =
        InternalPlanner::collectionScan(opCtx, ns, ctx.getCollection(), PlanExecutor::NO_YIELD);
    PlanExecutor::ExecState state = exec->getNext(&result, NULL);

    CurOp::get(opCtx)->done();

    // Non-yielding collection scans from InternalPlanner will never error.
    invariant(PlanExecutor::ADVANCED == state || PlanExecutor::IS_EOF == state);

    if (PlanExecutor::ADVANCED == state) {
        result = result.getOwned();
        return true;
    }

    return false;
}

bool Helpers::getLast(OperationContext* opCtx, const char* ns, BSONObj& result) {
    AutoGetCollectionForReadCommand autoColl(opCtx, NamespaceString(ns));
    auto exec = InternalPlanner::collectionScan(
        opCtx, ns, autoColl.getCollection(), PlanExecutor::NO_YIELD, InternalPlanner::BACKWARD);
    PlanExecutor::ExecState state = exec->getNext(&result, NULL);

    // Non-yielding collection scans from InternalPlanner will never error.
    invariant(PlanExecutor::ADVANCED == state || PlanExecutor::IS_EOF == state);

    if (PlanExecutor::ADVANCED == state) {
        result = result.getOwned();
        return true;
    }

    return false;
}

void Helpers::upsert(OperationContext* opCtx,
                     const string& ns,
                     const BSONObj& o,
                     bool fromMigrate) {
    BSONElement e = o["_id"];
    verify(e.type());
    BSONObj id = e.wrap();

    OldClientContext context(opCtx, ns);

    const NamespaceString requestNs(ns);
    UpdateRequest request(requestNs);

    request.setQuery(id);
    request.setUpdates(o);
    request.setUpsert();
    request.setFromMigration(fromMigrate);
    UpdateLifecycleImpl updateLifecycle(requestNs);
    request.setLifecycle(&updateLifecycle);

    update(opCtx, context.db(), request);
}

void Helpers::putSingleton(OperationContext* opCtx, const char* ns, BSONObj obj) {
    OldClientContext context(opCtx, ns);

    const NamespaceString requestNs(ns);
    UpdateRequest request(requestNs);

    request.setUpdates(obj);
    request.setUpsert();
    UpdateLifecycleImpl updateLifecycle(requestNs);
    request.setLifecycle(&updateLifecycle);

    update(opCtx, context.db(), request);

    CurOp::get(opCtx)->done();
}

BSONObj Helpers::toKeyFormat(const BSONObj& o) {
    BSONObjBuilder keyObj(o.objsize());
    BSONForEach(e, o) {
        keyObj.appendAs(e, "");
    }
    return keyObj.obj();
}

BSONObj Helpers::inferKeyPattern(const BSONObj& o) {
    BSONObjBuilder kpBuilder;
    BSONForEach(e, o) {
        kpBuilder.append(e.fieldName(), 1);
    }
    return kpBuilder.obj();
}

void Helpers::emptyCollection(OperationContext* opCtx, const NamespaceString& nss) {
    OldClientContext context(opCtx, nss.ns());
    repl::UnreplicatedWritesBlock uwb(opCtx);
    Collection* collection = context.db() ? context.db()->getCollection(opCtx, nss) : nullptr;
    deleteObjects(opCtx, collection, nss, BSONObj(), false);
}

Helpers::RemoveSaver::RemoveSaver(const string& a, const string& b, const string& why) {
    static int NUM = 0;

    _root = storageGlobalParams.dbpath;
    if (a.size())
        _root /= a;
    if (b.size())
        _root /= b;
    verify(a.size() || b.size());

    _file = _root;

    stringstream ss;
    ss << why << "." << terseCurrentTime(false) << "." << NUM++ << ".bson";
    _file /= ss.str();

    auto encryptionHooks = EncryptionHooks::get(getGlobalServiceContext());
    if (encryptionHooks->enabled()) {
        _protector = encryptionHooks->getDataProtector();
        _file += encryptionHooks->getProtectedPathSuffix();
    }
}

Helpers::RemoveSaver::~RemoveSaver() {
    if (_protector && _out) {
        auto encryptionHooks = EncryptionHooks::get(getGlobalServiceContext());
        invariant(encryptionHooks->enabled());

        size_t protectedSizeMax = encryptionHooks->additionalBytesForProtectedBuffer();
        std::unique_ptr<uint8_t[]> protectedBuffer(new uint8_t[protectedSizeMax]);

        size_t resultLen;
        Status status = _protector->finalize(protectedBuffer.get(), protectedSizeMax, &resultLen);
        if (!status.isOK()) {
            severe() << "Unable to finalize DataProtector while closing RemoveSaver: "
                     << redact(status);
            fassertFailed(34350);
        }

        _out->write(reinterpret_cast<const char*>(protectedBuffer.get()), resultLen);
        if (_out->fail()) {
            severe() << "Couldn't write finalized DataProtector data to: " << _file.string()
                     << " for remove saving: " << redact(errnoWithDescription());
            fassertFailed(34351);
        }

        protectedBuffer.reset(new uint8_t[protectedSizeMax]);
        status = _protector->finalizeTag(protectedBuffer.get(), protectedSizeMax, &resultLen);
        if (!status.isOK()) {
            severe() << "Unable to get finalizeTag from DataProtector while closing RemoveSaver: "
                     << redact(status);
            fassertFailed(34352);
        }
        if (resultLen != _protector->getNumberOfBytesReservedForTag()) {
            severe() << "Attempted to write tag of size " << resultLen
                     << " when DataProtector only reserved "
                     << _protector->getNumberOfBytesReservedForTag() << " bytes";
            fassertFailed(34353);
        }
        _out->seekp(0);
        _out->write(reinterpret_cast<const char*>(protectedBuffer.get()), resultLen);
        if (_out->fail()) {
            severe() << "Couldn't write finalizeTag from DataProtector to: " << _file.string()
                     << " for remove saving: " << redact(errnoWithDescription());
            fassertFailed(34354);
        }
    }
}

Status Helpers::RemoveSaver::goingToDelete(const BSONObj& o) {
    if (!_out) {
        // We don't expect to ever pass "" to create_directories below, but catch
        // this anyway as per SERVER-26412.
        invariant(!_root.empty());
        boost::filesystem::create_directories(_root);
        _out.reset(new ofstream(_file.string().c_str(), ios_base::out | ios_base::binary));
        if (_out->fail()) {
            string msg = str::stream() << "couldn't create file: " << _file.string()
                                       << " for remove saving: " << redact(errnoWithDescription());
            error() << msg;
            _out.reset();
            _out = 0;
            return Status(ErrorCodes::FileNotOpen, msg);
        }
    }

    const uint8_t* data = reinterpret_cast<const uint8_t*>(o.objdata());
    size_t dataSize = o.objsize();

    std::unique_ptr<uint8_t[]> protectedBuffer;
    if (_protector) {
        auto encryptionHooks = EncryptionHooks::get(getGlobalServiceContext());
        invariant(encryptionHooks->enabled());

        size_t protectedSizeMax = dataSize + encryptionHooks->additionalBytesForProtectedBuffer();
        protectedBuffer.reset(new uint8_t[protectedSizeMax]);

        size_t resultLen;
        Status status = _protector->protect(
            data, dataSize, protectedBuffer.get(), protectedSizeMax, &resultLen);
        if (!status.isOK()) {
            return status;
        }

        data = protectedBuffer.get();
        dataSize = resultLen;
    }

    _out->write(reinterpret_cast<const char*>(data), dataSize);
    if (_out->fail()) {
        string msg = str::stream() << "couldn't write document to file: " << _file.string()
                                   << " for remove saving: " << redact(errnoWithDescription());
        error() << msg;
        return Status(ErrorCodes::OperationFailed, msg);
    }
    return Status::OK();
}


}  // namespace mongo
