// commands.cpp

/**
*    Copyright (C) 2012 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.
*/

#include "mongo/pch.h"

#include <time.h>

#include "mongo/bson/util/builder.h"
#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/commands.h"
#include "mongo/db/introspect.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/json.h"
#include "mongo/db/pdfile.h"
#include "mongo/scripting/engine.h"
#include "mongo/util/lruishmap.h"

namespace mongo {

    const int edebug=0;

    bool dbEval(const string& dbName, BSONObj& cmd, BSONObjBuilder& result, string& errmsg) {
        BSONElement e = cmd.firstElement();
        uassert( 10046 ,  "eval needs Code" , e.type() == Code || e.type() == CodeWScope || e.type() == String );

        const char *code = 0;
        switch ( e.type() ) {
        case String:
        case Code:
            code = e.valuestr();
            break;
        case CodeWScope:
            code = e.codeWScopeCode();
            break;
        default:
            verify(0);
        }
        verify( code );

        if ( ! globalScriptEngine ) {
            errmsg = "db side execution is disabled";
            return false;
        }

        const string userToken = ClientBasic::getCurrent()->getAuthorizationSession()
                                                          ->getAuthenticatedUserNamesToken();
        auto_ptr<Scope> s = globalScriptEngine->getPooledScope( dbName, "dbeval" + userToken );
        ScriptingFunction f = s->createFunction(code);
        if ( f == 0 ) {
            errmsg = (string)"compile failed: " + s->getError();
            return false;
        }

        if ( e.type() == CodeWScope )
            s->init( e.codeWScopeScopeDataUnsafe() );
        s->localConnect( dbName.c_str() );

        BSONObj args;
        {
            BSONElement argsElement = cmd.getField("args");
            if ( argsElement.type() == Array ) {
                args = argsElement.embeddedObject();
                if ( edebug ) {
                    out() << "args:" << args.toString() << endl;
                    out() << "code:\n" << code << endl;
                }
            }
        }

        int res;
        {
            Timer t;
            res = s->invoke(f, &args, 0, storageGlobalParams.quota ? 10 * 60 * 1000 : 0);
            int m = t.millis();
            if (m > serverGlobalParams.slowMS) {
                out() << "dbeval slow, time: " << dec << m << "ms " << dbName << endl;
                if ( m >= 1000 ) log() << code << endl;
                else OCCASIONALLY log() << code << endl;
            }
        }
        if (res || s->isLastRetNativeCode()) {
            result.append("errno", (double) res);
            errmsg = "invoke failed: ";
            if (s->isLastRetNativeCode())
                errmsg += "cannot return native function";
            else
                errmsg += s->getError();
            return false;
        }

        s->append( result , "retval" , "__returnValue" );

        return true;
    }

    // SERVER-4328 todo review for concurrency
    class CmdEval : public Command {
    public:
        virtual bool slaveOk() const {
            return false;
        }
        virtual void help( stringstream &help ) const {
            help << "Evaluate javascript at the server.\n" "http://dochub.mongodb.org/core/serversidecodeexecution";
        }
        virtual LockType locktype() const { return NONE; }
        virtual void addRequiredPrivileges(const std::string& dbname,
                                           const BSONObj& cmdObj,
                                           std::vector<Privilege>* out) {

            RoleGraph::generateUniversalPrivileges(out);
        }
        CmdEval() : Command("eval", false, "$eval") { }
        bool run(const string& dbname , BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
            if ( cmdObj["nolock"].trueValue() ) {
                return dbEval(dbname, cmdObj, result, errmsg);
            }

            Lock::GlobalWrite lk;
            Client::Context ctx( dbname );

            return dbEval(dbname, cmdObj, result, errmsg);
        }
    } cmdeval;

} // namespace mongo