/**
 *    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.
 */

#include "mongo/platform/basic.h"

#include "mongo/db/views/resolved_view.h"

#include "mongo/base/init.h"
#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/db/pipeline/aggregation_request.h"
#include "mongo/rpc/get_status_from_command_result.h"

namespace mongo {

MONGO_INIT_REGISTER_ERROR_EXTRA_INFO(ResolvedView);

ResolvedView ResolvedView::fromBSON(const BSONObj& commandResponseObj) {
    uassert(40248,
            "command response expected to have a 'resolvedView' field",
            commandResponseObj.hasField("resolvedView"));

    auto viewDef = commandResponseObj.getObjectField("resolvedView");
    uassert(40249, "resolvedView must be an object", !viewDef.isEmpty());

    uassert(40250,
            "View definition must have 'ns' field of type string",
            viewDef.hasField("ns") && viewDef.getField("ns").type() == BSONType::String);

    uassert(40251,
            "View definition must have 'pipeline' field of type array",
            viewDef.hasField("pipeline") && viewDef.getField("pipeline").type() == BSONType::Array);

    std::vector<BSONObj> pipeline;
    for (auto&& item : viewDef["pipeline"].Obj()) {
        pipeline.push_back(item.Obj().getOwned());
    }

    BSONObj collationSpec;
    if (auto collationElt = viewDef["collation"]) {
        uassert(40639,
                "View definition 'collation' field must be an object",
                collationElt.type() == BSONType::Object);
        collationSpec = collationElt.embeddedObject().getOwned();
    }

    return {NamespaceString(viewDef["ns"].valueStringData()),
            std::move(pipeline),
            std::move(collationSpec)};
}

void ResolvedView::serialize(BSONObjBuilder* builder) const {
    BSONObjBuilder subObj(builder->subobjStart("resolvedView"));
    subObj.append("ns", _namespace.ns());
    subObj.append("pipeline", _pipeline);
    if (!_defaultCollation.isEmpty()) {
        subObj.append("collation", _defaultCollation);
    }
}

std::shared_ptr<const ErrorExtraInfo> ResolvedView::parse(const BSONObj& cmdReply) {
    return std::make_shared<ResolvedView>(fromBSON(cmdReply));
}

AggregationRequest ResolvedView::asExpandedViewAggregation(
    const AggregationRequest& request) const {
    // Perform the aggregation on the resolved namespace.  The new pipeline consists of two parts:
    // first, 'pipeline' in this ResolvedView; then, the pipeline in 'request'.
    std::vector<BSONObj> resolvedPipeline;
    resolvedPipeline.reserve(_pipeline.size() + request.getPipeline().size());
    resolvedPipeline.insert(resolvedPipeline.end(), _pipeline.begin(), _pipeline.end());
    resolvedPipeline.insert(
        resolvedPipeline.end(), request.getPipeline().begin(), request.getPipeline().end());

    AggregationRequest expandedRequest{_namespace, resolvedPipeline};

    if (request.getExplain()) {
        expandedRequest.setExplain(request.getExplain());
    } else {
        expandedRequest.setBatchSize(request.getBatchSize());
    }

    expandedRequest.setHint(request.getHint());
    expandedRequest.setComment(request.getComment());
    expandedRequest.setMaxTimeMS(request.getMaxTimeMS());
    expandedRequest.setReadConcern(request.getReadConcern());
    expandedRequest.setUnwrappedReadPref(request.getUnwrappedReadPref());
    expandedRequest.setBypassDocumentValidation(request.shouldBypassDocumentValidation());
    expandedRequest.setAllowDiskUse(request.shouldAllowDiskUse());

    // Operations on a view must always use the default collation of the view. We must have already
    // checked that if the user's request specifies a collation, it matches the collation of the
    // view.
    expandedRequest.setCollation(_defaultCollation);

    return expandedRequest;
}

}  // namespace mongo