/**
*    Copyright (C) 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.
*/

#include "mongo/platform/basic.h"

#include <boost/thread/locks.hpp>

#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/db/auth/action_type.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/client.h"
#include "mongo/db/commands.h"
#include "mongo/db/curop.h"
#include "mongo/db/dbwebserver.h"
#include "mongo/db/matcher/expression_parser.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/service_context.h"
#include "mongo/db/stats/fill_locker_info.h"
#include "mongo/util/mongoutils/html.h"
#include "mongo/util/stringutils.h"

namespace mongo {

using std::unique_ptr;
using std::string;

namespace {

class ClientListPlugin : public WebStatusPlugin {
public:
    ClientListPlugin() : WebStatusPlugin("clients", 20) {}
    virtual void init() {}

    virtual void run(OperationContext* txn, std::stringstream& ss) {
        using namespace html;

        ss << "\n<table border=1 cellpadding=2 cellspacing=0>";
        ss << "<tr align='left'>"
           << th(a("", "Connections to the database, both internal and external.", "Client"))
           << th(a("http://dochub.mongodb.org/core/viewingandterminatingcurrentoperation",
                   "",
                   "OpId")) << "<th>Locking</th>"
           << "<th>Waiting</th>"
           << "<th>SecsRunning</th>"
           << "<th>Op</th>"
           << th(a("http://dochub.mongodb.org/core/whatisanamespace", "", "Namespace"))
           << "<th>Query</th>"
           << "<th>client</th>"
           << "<th>msg</th>"
           << "<th>progress</th>"

           << "</tr>\n";

        _processAllClients(txn->getClient()->getServiceContext(), ss);

        ss << "</table>\n";
    }

private:
    static void _processAllClients(ServiceContext* service, std::stringstream& ss) {
        using namespace html;

        for (ServiceContext::LockedClientsCursor cursor(service); Client* client = cursor.next();) {
            invariant(client);

            // Make the client stable
            stdx::lock_guard<Client> lk(*client);
            const OperationContext* txn = client->getOperationContext();
            if (!txn)
                continue;

            CurOp* curOp = CurOp::get(txn);
            if (!curOp)
                continue;

            ss << "<tr><td>" << client->desc() << "</td>";

            tablecell(ss, txn->getOpID());
            tablecell(ss, true);

            // LockState
            {
                Locker::LockerInfo lockerInfo;
                txn->lockState()->getLockerInfo(&lockerInfo);

                BSONObjBuilder lockerInfoBuilder;
                fillLockerInfo(lockerInfo, lockerInfoBuilder);

                tablecell(ss, lockerInfoBuilder.obj());
            }

            tablecell(ss, curOp->elapsedSeconds());

            tablecell(ss, curOp->getOp());
            tablecell(ss, html::escape(curOp->getNS()));

            if (curOp->haveQuery()) {
                tablecell(ss, html::escape(curOp->query().toString()));
            } else {
                tablecell(ss, "");
            }

            tablecell(ss, client->clientAddress(true /*includePort*/));

            tablecell(ss, curOp->getMessage());
            tablecell(ss, curOp->getProgressMeter().toString());

            ss << "</tr>\n";
        }
    }

} clientListPlugin;


class CurrentOpContexts : public Command {
public:
    CurrentOpContexts() : Command("currentOpCtx") {}

    virtual bool isWriteCommandForConfigServer() const {
        return false;
    }

    virtual bool slaveOk() const {
        return true;
    }

    virtual Status checkAuthForCommand(ClientBasic* client,
                                       const std::string& dbname,
                                       const BSONObj& cmdObj) {
        if (AuthorizationSession::get(client)->isAuthorizedForActionsOnResource(
                ResourcePattern::forClusterResource(), ActionType::inprog)) {
            return Status::OK();
        }

        return Status(ErrorCodes::Unauthorized, "unauthorized");
    }

    bool run(OperationContext* txn,
             const string& dbname,
             BSONObj& cmdObj,
             int,
             string& errmsg,
             BSONObjBuilder& result) {
        unique_ptr<MatchExpression> filter;
        if (cmdObj["filter"].isABSONObj()) {
            StatusWithMatchExpression res = MatchExpressionParser::parse(cmdObj["filter"].Obj());
            if (!res.isOK()) {
                return appendCommandStatus(result, res.getStatus());
            }
            filter.reset(res.getValue());
        }

        result.appendArray("operations",
                           _processAllClients(txn->getClient()->getServiceContext(), filter.get()));

        return true;
    }


private:
    static BSONArray _processAllClients(ServiceContext* service, MatchExpression* matcher) {
        BSONArrayBuilder array;

        for (ServiceContext::LockedClientsCursor cursor(service); Client* client = cursor.next();) {
            invariant(client);

            BSONObjBuilder b;

            // Make the client stable
            stdx::lock_guard<Client> lk(*client);

            client->reportState(b);

            const OperationContext* txn = client->getOperationContext();
            b.appendBool("active", static_cast<bool>(txn));
            if (txn) {
                b.append("opid", txn->getOpID());
                if (txn->isKillPending()) {
                    b.append("killPending", true);
                }

                CurOp::get(txn)->reportState(&b);

                // LockState
                if (txn->lockState()) {
                    StringBuilder ss;
                    ss << txn->lockState();
                    b.append("lockStatePointer", ss.str());

                    Locker::LockerInfo lockerInfo;
                    txn->lockState()->getLockerInfo(&lockerInfo);

                    BSONObjBuilder lockerInfoBuilder;
                    fillLockerInfo(lockerInfo, lockerInfoBuilder);

                    b.append("lockState", lockerInfoBuilder.obj());
                }

                // RecoveryUnit
                if (txn->recoveryUnit()) {
                    txn->recoveryUnit()->reportState(&b);
                }
            }

            const BSONObj obj = b.obj();

            if (!matcher || matcher->matchesBSON(obj)) {
                array.append(obj);
            }
        }

        return array.arr();
    }

} currentOpContexts;

}  // namespace
}  // namespace mongo