// drop_indexes.cpp

/**
*    Copyright (C) 2013 10gen 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::kCommand

#include "mongo/platform/basic.h"

#include <string>
#include <vector>

#include "mongo/db/background.h"
#include "mongo/db/catalog/collection.h"
#include "mongo/db/catalog/collection_catalog_entry.h"
#include "mongo/db/catalog/database.h"
#include "mongo/db/catalog/drop_indexes.h"
#include "mongo/db/catalog/index_catalog.h"
#include "mongo/db/catalog/index_create.h"
#include "mongo/db/catalog/index_key_validate.h"
#include "mongo/db/client.h"
#include "mongo/db/commands.h"
#include "mongo/db/concurrency/write_conflict_exception.h"
#include "mongo/db/curop.h"
#include "mongo/db/db_raii.h"
#include "mongo/db/dbdirectclient.h"
#include "mongo/db/service_context.h"
#include "mongo/db/index/index_descriptor.h"
#include "mongo/db/index_builder.h"
#include "mongo/db/op_observer.h"
#include "mongo/db/operation_context_impl.h"
#include "mongo/db/repl/replication_coordinator_global.h"
#include "mongo/util/log.h"

namespace mongo {

    using std::endl;
    using std::string;
    using std::stringstream;
    using std::vector;

    /* "dropIndexes" is now the preferred form - "deleteIndexes" deprecated */
    class CmdDropIndexes : public Command {
    public:
        virtual bool slaveOk() const {
            return false;
        }
        virtual bool isWriteCommandForConfigServer() const { return true; }
        virtual void help( stringstream& help ) const {
            help << "drop indexes for a collection";
        }
        virtual void addRequiredPrivileges(const std::string& dbname,
                                           const BSONObj& cmdObj,
                                           std::vector<Privilege>* out) {
            ActionSet actions;
            actions.addAction(ActionType::dropIndex);
            out->push_back(Privilege(parseResourcePattern(dbname, cmdObj), actions));
        }

        CmdDropIndexes() : Command("dropIndexes", false, "deleteIndexes") { }
        bool run(OperationContext* txn,
                 const string& dbname,
                 BSONObj& jsobj,
                 int,
                 string& errmsg,
                 BSONObjBuilder& result) {
            const std::string ns = parseNsCollectionRequired(dbname, jsobj);
            return appendCommandStatus(result,
                                       dropIndexes(txn,
                                                   NamespaceString(ns),
                                                   jsobj,
                                                   &result));
        }

    } cmdDropIndexes;

    class CmdReIndex : public Command {
    public:
        virtual bool slaveOk() const { return true; }    // can reindex on a secondary
        virtual bool isWriteCommandForConfigServer() const { return true; }
        virtual void help( stringstream& help ) const {
            help << "re-index a collection";
        }
        virtual void addRequiredPrivileges(const std::string& dbname,
                                           const BSONObj& cmdObj,
                                           std::vector<Privilege>* out) {
            ActionSet actions;
            actions.addAction(ActionType::reIndex);
            out->push_back(Privilege(parseResourcePattern(dbname, cmdObj), actions));
        }
        CmdReIndex() : Command("reIndex") { }

        bool run(OperationContext* txn,
                 const string& dbname,
                 BSONObj& jsobj,
                 int,
                 string& errmsg,
                 BSONObjBuilder& result) {
            DBDirectClient db(txn);

            const std::string toDeleteNs = parseNsCollectionRequired(dbname, jsobj);

            LOG(0) << "CMD: reIndex " << toDeleteNs << endl;

            ScopedTransaction transaction(txn, MODE_IX);
            Lock::DBLock dbXLock(txn->lockState(), dbname, MODE_X);
            OldClientContext ctx(txn, toDeleteNs);

            Collection* collection = ctx.db()->getCollection( toDeleteNs );

            if ( !collection ) {
                errmsg = "ns not found";
                return false;
            }

            BackgroundOperation::assertNoBgOpInProgForNs( toDeleteNs );

            vector<BSONObj> all;
            {
                vector<string> indexNames;
                collection->getCatalogEntry()->getAllIndexes( txn, &indexNames );
                for ( size_t i = 0; i < indexNames.size(); i++ ) {
                    const string& name = indexNames[i];
                    BSONObj spec = collection->getCatalogEntry()->getIndexSpec( txn, name );
                    all.push_back(spec.removeField("v").getOwned());

                    const BSONObj key = spec.getObjectField("key");
                    const Status keyStatus = validateKeyPattern(key);
                    if (!keyStatus.isOK()) {
                        errmsg = str::stream()
                            << "Cannot rebuild index " << spec << ": " << keyStatus.reason()
                            << " For more info see http://dochub.mongodb.org/core/index-validation";
                        return false;
                    }
                }
            }

            result.appendNumber( "nIndexesWas", all.size() );

            {
                WriteUnitOfWork wunit(txn);
                Status s = collection->getIndexCatalog()->dropAllIndexes(txn, true);
                if ( !s.isOK() ) {
                    errmsg = "dropIndexes failed";
                    return appendCommandStatus( result, s );
                }
                wunit.commit();
            }

            MultiIndexBlock indexer(txn, collection);
            // do not want interruption as that will leave us without indexes.

            Status status = indexer.init(all);
            if (!status.isOK())
                return appendCommandStatus( result, status );

            status = indexer.insertAllDocumentsInCollection();
            if (!status.isOK())
                return appendCommandStatus( result, status );

            {
                WriteUnitOfWork wunit(txn);
                indexer.commit();
                wunit.commit();
            }

            result.append( "nIndexes", (int)all.size() );
            result.append( "indexes", all );

            return true;
        }
    } cmdReIndex;


}