/**
 *    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.
 */

#pragma once

#include <deque>

#include "mongo/db/pipeline/document_source.h"

namespace mongo {

/**
 * Used in testing to store documents without using the storage layer. Methods are not marked as
 * final in order to allow tests to intercept calls if needed.
 */
class DocumentSourceMock : public DocumentSource {
public:
    DocumentSourceMock(std::deque<GetNextResult> results);
    DocumentSourceMock(std::deque<GetNextResult> results,
                       const boost::intrusive_ptr<ExpressionContext>& expCtx);

    GetNextResult getNext() override;
    const char* getSourceName() const override;
    Value serialize(
        boost::optional<ExplainOptions::Verbosity> explain = boost::none) const override;

    StageConstraints constraints(Pipeline::SplitState pipeState) const override {
        StageConstraints constraints(StreamType::kStreaming,
                                     PositionRequirement::kFirst,
                                     HostTypeRequirement::kNone,
                                     DiskUseRequirement::kNoDiskUse,
                                     FacetRequirement::kNotAllowed,
                                     TransactionRequirement::kAllowed);

        constraints.requiresInputDocSource = false;
        return constraints;
    }

    BSONObjSet getOutputSorts() override {
        return sorts;
    }

    static boost::intrusive_ptr<DocumentSourceMock> create();

    static boost::intrusive_ptr<DocumentSourceMock> create(Document doc);

    static boost::intrusive_ptr<DocumentSourceMock> create(const GetNextResult& result);
    static boost::intrusive_ptr<DocumentSourceMock> create(std::deque<GetNextResult> results);

    static boost::intrusive_ptr<DocumentSourceMock> create(const char* json);
    static boost::intrusive_ptr<DocumentSourceMock> create(
        const std::initializer_list<const char*>& jsons);

    void reattachToOperationContext(OperationContext* opCtx) {
        isDetachedFromOpCtx = false;
    }

    void detachFromOperationContext() {
        isDetachedFromOpCtx = true;
    }

    boost::intrusive_ptr<DocumentSource> optimize() override {
        isOptimized = true;
        return this;
    }

    /**
     * This stage does not modify anything.
     */
    GetModPathsReturn getModifiedPaths() const override {
        return {GetModPathsReturn::Type::kFiniteSet, std::set<std::string>{}, {}};
    }

    // Return documents from front of queue.
    std::deque<GetNextResult> queue;

    bool isDisposed = false;
    bool isDetachedFromOpCtx = false;
    bool isOptimized = false;
    bool isExpCtxInjected = false;

    BSONObjSet sorts;

protected:
    void doDispose() override;
};

}  // namespace mongo