/**
 *    Copyright (C) 2009-2015 MongoDB 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::kNetwork

#include "mongo/platform/basic.h"

#include "mongo/client/connection_string.h"

#include "mongo/base/status_with.h"
#include "mongo/util/mongoutils/str.h"

namespace mongo {

ConnectionString::ConnectionString(const HostAndPort& server) : _type(MASTER) {
    _servers.push_back(server);
    _finishInit();
}

ConnectionString::ConnectionString(StringData setName, std::vector<HostAndPort> servers)
    : _type(SET), _servers(std::move(servers)), _setName(setName.toString()) {
    _finishInit();
}

ConnectionString::ConnectionString(ConnectionType type,
                                   const std::string& s,
                                   const std::string& setName) {
    _type = type;
    _setName = setName;
    _fillServers(s);

    switch (_type) {
        case MASTER:
            verify(_servers.size() == 1);
            break;
        case SET:
            verify(_setName.size());
            verify(_servers.size() >= 1);  // 1 is ok since we can derive
            break;
        default:
            verify(_servers.size() > 0);
    }

    _finishInit();
}

ConnectionString::ConnectionString(const std::string& s, ConnectionType favoredMultipleType) {
    _fillServers(s);

    if (_type != INVALID) {
        // set already
    } else if (_servers.size() == 1) {
        _type = MASTER;
    } else {
        _type = favoredMultipleType;
        verify(_type == SET || _type == SYNC);
    }

    _finishInit();
}

ConnectionString ConnectionString::forReplicaSet(StringData setName,
                                                 std::vector<HostAndPort> servers) {
    return ConnectionString(setName, std::move(servers));
}

void ConnectionString::_fillServers(std::string s) {
    //
    // Custom-handled servers/replica sets start with '$'
    // According to RFC-1123/952, this will not overlap with valid hostnames
    // (also disallows $replicaSetName hosts)
    //

    if (s.find('$') == 0)
        _type = CUSTOM;

    {
        std::string::size_type idx = s.find('/');
        if (idx != std::string::npos) {
            _setName = s.substr(0, idx);
            s = s.substr(idx + 1);
            if (_type != CUSTOM)
                _type = SET;
        }
    }

    std::string::size_type idx;
    while ((idx = s.find(',')) != std::string::npos) {
        _servers.push_back(HostAndPort(s.substr(0, idx)));
        s = s.substr(idx + 1);
    }
    _servers.push_back(HostAndPort(s));
}

void ConnectionString::_finishInit() {
    // Needed here as well b/c the parsing logic isn't used in all constructors
    // TODO: Refactor so that the parsing logic *is* used in all constructors
    if (_type == MASTER && _servers.size() > 0) {
        if (_servers[0].host().find('$') == 0) {
            _type = CUSTOM;
        }
    }

    std::stringstream ss;

    if (_type == SET) {
        ss << _setName << "/";
    }

    for (unsigned i = 0; i < _servers.size(); i++) {
        if (i > 0) {
            ss << ",";
        }

        ss << _servers[i].toString();
    }

    _string = ss.str();
}

bool ConnectionString::sameLogicalEndpoint(const ConnectionString& other) const {
    if (_type != other._type) {
        return false;
    }

    switch (_type) {
        case INVALID:
            return true;
        case MASTER:
            return _servers[0] == other._servers[0];
        case SET:
            return _setName == other._setName;
        case SYNC:
            // The servers all have to be the same in each, but not in the same order.
            if (_servers.size() != other._servers.size()) {
                return false;
            }

            for (unsigned i = 0; i < _servers.size(); i++) {
                bool found = false;
                for (unsigned j = 0; j < other._servers.size(); j++) {
                    if (_servers[i] == other._servers[j]) {
                        found = true;
                        break;
                    }
                }

                if (!found)
                    return false;
            }

            return true;
        case CUSTOM:
            return _string == other._string;
    }

    MONGO_UNREACHABLE;
}

StatusWith<ConnectionString> ConnectionString::parse(const std::string& url) {
    const std::string::size_type i = url.find('/');

    // Replica set
    if (i != std::string::npos && i != 0) {
        return ConnectionString(SET, url.substr(i + 1), url.substr(0, i));
    }

    const int numCommas = str::count(url, ',');

    // Single host
    if (numCommas == 0) {
        HostAndPort singleHost;
        Status status = singleHost.initialize(url);
        if (!status.isOK()) {
            return status;
        }

        return ConnectionString(singleHost);
    }

    // Sharding config server
    if (numCommas == 2) {
        return ConnectionString(SYNC, url, "");
    }

    return Status(ErrorCodes::FailedToParse, str::stream() << "invalid url [" << url << "]");
}

std::string ConnectionString::typeToString(ConnectionType type) {
    switch (type) {
        case INVALID:
            return "invalid";
        case MASTER:
            return "master";
        case SET:
            return "set";
        case SYNC:
            return "sync";
        case CUSTOM:
            return "custom";
    }

    MONGO_UNREACHABLE;
}

}  // namespace mongo