/**
 *    Copyright (C) 2018-present MongoDB, Inc.
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the Server Side Public License, version 1,
 *    as published by MongoDB, Inc.
 *
 *    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
 *    Server Side Public License for more details.
 *
 *    You should have received a copy of the Server Side Public License
 *    along with this program. If not, see
 *    <http://www.mongodb.com/licensing/server-side-public-license>.
 *
 *    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 Server Side 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::kCommand

#include "mongo/platform/basic.h"

#include "mongo/base/init.h"
#include "mongo/base/status.h"
#include "mongo/bson/util/builder.h"
#include "mongo/client/dbclient_connection.h"
#include "mongo/db/auth/action_set.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/auth/resource_pattern.h"
#include "mongo/db/catalog/collection.h"
#include "mongo/db/catalog/document_validation.h"
#include "mongo/db/cloner.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/rename_collection.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/ops/insert.h"
#include "mongo/db/repl/isself.h"
#include "mongo/db/storage/storage_options.h"
#include "mongo/util/log.h"

namespace mongo {

using std::unique_ptr;
using std::string;
using std::stringstream;
using std::endl;

/**
 * The cloneCollection command is deprecated.
 * See http://dochub.mongodb.org/core/clonecollection-deprecation.
 */
class CmdCloneCollection : public ErrmsgCommandDeprecated {
public:
    CmdCloneCollection() : ErrmsgCommandDeprecated("cloneCollection") {}

    AllowedOnSecondary secondaryAllowed(ServiceContext*) const override {
        return AllowedOnSecondary::kNever;
    }

    virtual bool supportsWriteConcern(const BSONObj& cmd) const override {
        return true;
    }

    virtual std::string parseNs(const std::string& dbname, const BSONObj& cmdObj) const {
        return CommandHelpers::parseNsFullyQualified(cmdObj);
    }

    virtual Status checkAuthForCommand(Client* client,
                                       const std::string& dbname,
                                       const BSONObj& cmdObj) const {
        std::string ns = parseNs(dbname, cmdObj);

        ActionSet actions;
        actions.addAction(ActionType::insert);
        actions.addAction(ActionType::createIndex);  // SERVER-11418
        if (shouldBypassDocumentValidationForCommand(cmdObj)) {
            actions.addAction(ActionType::bypassDocumentValidation);
        }

        if (!AuthorizationSession::get(client)->isAuthorizedForActionsOnResource(
                ResourcePattern::forExactNamespace(NamespaceString(ns)), actions)) {
            return Status(ErrorCodes::Unauthorized, "Unauthorized");
        }
        return Status::OK();
    }

    std::string help() const override {
        return "{ cloneCollection: <collection>, from: <host> [,query: <query_filter>] "
               "[,copyIndexes:<bool>] }"
               "\nCopies a collection from one server to another. Do not use on a single server "
               "as the destination "
               "is placed at the same db.collection (namespace) as the source.\n";
    }

    virtual bool errmsgRun(OperationContext* opCtx,
                           const string& dbname,
                           const BSONObj& cmdObj,
                           string& errmsg,
                           BSONObjBuilder& result) {
        const char* deprecationWarning =
            "Support for the cloneCollection command has been deprecated. See "
            "http://dochub.mongodb.org/core/clonecollection-deprecation";
        warning() << deprecationWarning;
        result.append("note", deprecationWarning);

        boost::optional<DisableDocumentValidation> maybeDisableValidation;
        if (shouldBypassDocumentValidationForCommand(cmdObj))
            maybeDisableValidation.emplace(opCtx);

        string fromhost = cmdObj.getStringField("from");
        if (fromhost.empty()) {
            errmsg = "missing 'from' parameter";
            return false;
        }

        {
            HostAndPort h(fromhost);
            if (repl::isSelf(h, opCtx->getServiceContext())) {
                errmsg = "can't cloneCollection from self";
                return false;
            }
        }

        auto ns = parseNs(dbname, cmdObj);

        // In order to clone a namespace, a user must be allowed to both create and write to that
        // namespace. There exist namespaces that are legal to create but not write to (e.g.
        // system.profile), and there exist namespaces that are legal to write to but not create,
        // so we must check that it is legal to both create and write to the namespace.
        auto allowedCreateStatus = userAllowedCreateNS(dbname, nsToCollectionSubstring(ns));
        uassertStatusOK(allowedCreateStatus);
        auto allowedWriteStatus = userAllowedWriteNS(dbname, nsToCollectionSubstring(ns));
        uassertStatusOK(allowedWriteStatus);

        BSONObj query = cmdObj.getObjectField("query");
        if (query.isEmpty())
            query = BSONObj();

        BSONElement copyIndexesSpec = cmdObj.getField("copyindexes");
        bool copyIndexes = copyIndexesSpec.isBoolean() ? copyIndexesSpec.boolean() : true;

        log() << "cloneCollection.  collection: " << ns << " from: " << fromhost
              << " query: " << redact(query) << " " << (copyIndexes ? "" : ", not copying indexes");

        Cloner cloner;
        auto myconn = std::make_unique<DBClientConnection>();
        if (!myconn->connect(HostAndPort(fromhost), StringData(), errmsg))
            return false;

        cloner.setConnection(std::move(myconn));

        return cloner.copyCollection(
            opCtx, ns, query, errmsg, copyIndexes, CollectionOptions::parseForCommand);
    }

} cmdCloneCollection;

}  // namespace mongo