// s_only.cpp

/*    Copyright 2009 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::kSharding

#include "mongo/platform/basic.h"

#include <tuple>

#include "mongo/db/auth/authorization_manager.h"
#include "mongo/db/auth/authorization_manager_global.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/client.h"
#include "mongo/db/commands.h"
#include "mongo/db/service_context.h"
#include "mongo/rpc/metadata.h"
#include "mongo/rpc/reply_builder_interface.h"
#include "mongo/rpc/request_interface.h"
#include "mongo/s/cluster_last_error_info.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/concurrency/thread_name.h"
#include "mongo/util/log.h"

namespace mongo {

    using std::string;
    using std::stringstream;


    bool isMongos() {
        return true;
    }

    /** When this callback is run, we record a shard that we've used for useful work
     *  in an operation to be read later by getLastError()
    */
    void usingAShardConnection(const std::string& addr) {
        ClusterLastErrorInfo::get(cc()).addShardHost(addr);
    }

    // called into by the web server. For now we just translate the parameters
    // to their old style equivalents.
    void Command::execCommand(OperationContext* txn,
                              Command* command,
                              const rpc::RequestInterface& request,
                              rpc::ReplyBuilderInterface* replyBuilder) {

        int queryFlags = 0;
        BSONObj cmdObj;

        std::tie(cmdObj, queryFlags) = uassertStatusOK(
            rpc::downconvertRequestMetadata(request.getCommandArgs(),
                                            request.getMetadata())
        );

        std::string db = request.getDatabase().rawData();
        BSONObjBuilder result;

        execCommandClientBasic(txn,
                               command,
                               *txn->getClient(),
                               queryFlags,
                               request.getDatabase().rawData(),
                               cmdObj,
                               result);

        replyBuilder
            ->setMetadata(rpc::makeEmptyMetadata())
            .setCommandReply(result.done());
    }

    void Command::execCommandClientBasic(OperationContext* txn,
                                         Command * c ,
                                         ClientBasic& client,
                                         int queryOptions,
                                         const char *ns,
                                         BSONObj& cmdObj,
                                         BSONObjBuilder& result) {
        std::string dbname = nsToDatabase(ns);

        if (cmdObj.getBoolField("help")) {
            stringstream help;
            help << "help for: " << c->name << " ";
            c->help( help );
            result.append( "help" , help.str() );
            result.append("lockType", c->isWriteCommandForConfigServer() ? 1 : 0);
            appendCommandStatus(result, true, "");
            return;
        }

        Status status = _checkAuthorization(c, &client, dbname, cmdObj);
        if (!status.isOK()) {
            appendCommandStatus(result, status);
            return;
        }

        c->_commandsExecuted.increment();

        std::string errmsg;
        bool ok;
        try {
            ok = c->run(txn, dbname , cmdObj, queryOptions, errmsg, result);
        }
        catch (const DBException& e) {
            ok = false;
            int code = e.getCode();
            if (code == RecvStaleConfigCode) { // code for StaleConfigException
                throw;
            }

            errmsg = e.what();
            result.append("code", code);
        }

        if ( !ok ) {
            c->_commandsFailed.increment();
        }

        appendCommandStatus(result, ok, errmsg);
    }

    void Command::runAgainstRegistered(const char *ns,
                                       BSONObj& jsobj,
                                       BSONObjBuilder& anObjBuilder,
                                       int queryOptions) {

        // It should be impossible for this uassert to fail since there should be no way to get
        // into this function with any other collection name.
        uassert(16618,
            "Illegal attempt to run a command against a namespace other than $cmd.",
            nsToCollectionSubstring(ns) == "$cmd");

        BSONElement e = jsobj.firstElement();
        std::string commandName = e.fieldName();
        Command* c = e.type() ? Command::findCommand(commandName) : NULL;
        if (!c) {
            Command::appendCommandStatus(anObjBuilder,
                                         false,
                                         str::stream() << "no such cmd: " << commandName);
            anObjBuilder.append("code", ErrorCodes::CommandNotFound);
            Command::unknownCommands.increment();
            return;
        }

        auto txn = cc().makeOperationContext();
        execCommandClientBasic(txn.get(), c, cc(), queryOptions, ns, jsobj, anObjBuilder);
    }

    void Command::registerError(OperationContext* txn, const DBException& exception) {
    }

} //namespace mongo