/**
 *    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.
 */

#pragma once

#include <string>

#include "mongo/base/disallow_copying.h"
#include "mongo/base/string_data.h"
#include "mongo/db/jsobj.h"

namespace mongo {

/**
 * This class represents the layout and contents of documents contained in the
 * config.mongos collection. All manipulation of documents coming from that
 * collection should be done with this class.
 *
 * Usage Example:
 *
 *     // Contact the config. 'conn' has been obtained before.
 *     DBClientBase* conn;
 *     BSONObj query = QUERY(MongosType::exampleField("exampleFieldName"));
 *     exampleDoc = conn->findOne(MongosType::ConfigNS, query);
 *
 *     // Process the response.
 *     MongosType exampleType;
 *     std::string errMsg;
 *     if (!exampleType.parseBSON(exampleDoc, &errMsg) || !exampleType.isValid(&errMsg)) {
 *         // Can't use 'exampleType'. Take action.
 *     }
 *     // use 'exampleType'
 *
 */
class MongosType {
    MONGO_DISALLOW_COPYING(MongosType);

public:
    //
    // schema declarations
    //

    // Name of the mongos collection in the config server.
    static const std::string ConfigNS;

    // Field names and types in the mongos collection type.
    static const BSONField<std::string> name;
    static const BSONField<Date_t> ping;
    static const BSONField<int> up;
    static const BSONField<bool> waiting;
    static const BSONField<std::string> mongoVersion;
    static const BSONField<int> configVersion;

    //
    // mongos type methods
    //

    MongosType();
    ~MongosType();

    /**
     * Returns true if all the mandatory fields are present and have valid
     * representations. Otherwise returns false and fills in the optional 'errMsg' string.
     */
    bool isValid(std::string* errMsg) const;

    /**
     * Returns the BSON representation of the entry.
     */
    BSONObj toBSON() const;

    /**
     * Clears and populates the internal state using the 'source' BSON object if the
     * latter contains valid values. Otherwise sets errMsg and returns false.
     */
    bool parseBSON(const BSONObj& source, std::string* errMsg);

    /**
     * Clears the internal state.
     */
    void clear();

    /**
     * Copies all the fields present in 'this' to 'other'.
     */
    void cloneTo(MongosType* other) const;

    /**
     * Returns a std::string representation of the current internal state.
     */
    std::string toString() const;

    //
    // individual field accessors
    //

    // Mandatory Fields
    void setName(StringData name) {
        _name = name.toString();
        _isNameSet = true;
    }

    void unsetName() {
        _isNameSet = false;
    }

    bool isNameSet() const {
        return _isNameSet;
    }

    // Calling get*() methods when the member is not set results in undefined behavior
    const std::string& getName() const {
        dassert(_isNameSet);
        return _name;
    }

    void setPing(const Date_t ping) {
        _ping = ping;
        _isPingSet = true;
    }

    void unsetPing() {
        _isPingSet = false;
    }

    bool isPingSet() const {
        return _isPingSet;
    }

    // Calling get*() methods when the member is not set results in undefined behavior
    const Date_t getPing() const {
        dassert(_isPingSet);
        return _ping;
    }

    void setUp(const int up) {
        _up = up;
        _isUpSet = true;
    }

    void unsetUp() {
        _isUpSet = false;
    }

    bool isUpSet() const {
        return _isUpSet;
    }

    // Calling get*() methods when the member is not set results in undefined behavior
    int getUp() const {
        dassert(_isUpSet);
        return _up;
    }

    void setWaiting(const bool waiting) {
        _waiting = waiting;
        _isWaitingSet = true;
    }

    void unsetWaiting() {
        _isWaitingSet = false;
    }

    bool isWaitingSet() const {
        return _isWaitingSet;
    }

    // Calling get*() methods when the member is not set results in undefined behavior
    bool getWaiting() const {
        dassert(_isWaitingSet);
        return _waiting;
    }

    // Optional Fields
    void setMongoVersion(StringData mongoVersion) {
        _mongoVersion = mongoVersion.toString();
        _isMongoVersionSet = true;
    }

    void unsetMongoVersion() {
        _isMongoVersionSet = false;
    }

    bool isMongoVersionSet() const {
        return _isMongoVersionSet || mongoVersion.hasDefault();
    }

    // Calling get*() methods when the member is not set and has no default results in undefined
    // behavior
    std::string getMongoVersion() const {
        if (_isMongoVersionSet) {
            return _mongoVersion;
        } else {
            dassert(mongoVersion.hasDefault());
            return mongoVersion.getDefault();
        }
    }
    void setConfigVersion(const int configVersion) {
        _configVersion = configVersion;
        _isConfigVersionSet = true;
    }

    void unsetConfigVersion() {
        _isConfigVersionSet = false;
    }

    bool isConfigVersionSet() const {
        return _isConfigVersionSet || configVersion.hasDefault();
    }

    // Calling get*() methods when the member is not set and has no default results in undefined
    // behavior
    int getConfigVersion() const {
        if (_isConfigVersionSet) {
            return _configVersion;
        } else {
            dassert(configVersion.hasDefault());
            return configVersion.getDefault();
        }
    }

private:
    // Convention: (M)andatory, (O)ptional, (S)pecial rule.
    std::string _name;  // (M)  "host:port" for this mongos
    bool _isNameSet;
    Date_t _ping;  // (M)  last time it was seen alive
    bool _isPingSet;
    int _up;  // (M)  uptime at the last ping
    bool _isUpSet;
    bool _waiting;  // (M)  for testing purposes
    bool _isWaitingSet;
    std::string _mongoVersion;  // (O)  the mongodb version of the pinging mongos
    bool _isMongoVersionSet;
    int _configVersion;  // (O)  the config version of the pinging mongos
    bool _isConfigVersionSet;
};

}  // namespace mongo