/**
 *    Copyright (C) 2019-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/pipeline/aggregation_context_fixture.h"
#include "mongo/db/pipeline/process_interface_standalone.h"
#include "mongo/unittest/unittest.h"

namespace mongo {
namespace {

class MongoProcessInterfaceForTest : public MongoInterfaceStandalone {
public:
    using MongoInterfaceStandalone::MongoInterfaceStandalone;

    bool fieldsHaveSupportingUniqueIndex(const boost::intrusive_ptr<ExpressionContext>& expCtx,
                                         const NamespaceString& nss,
                                         const std::set<FieldPath>& fields) const override {
        return hasSupportingIndexForFields;
    }

    void checkRoutingInfoEpochOrThrow(const boost::intrusive_ptr<ExpressionContext>& expCtx,
                                      const NamespaceString&,
                                      ChunkVersion) const override {
        // Assume it always matches for our tests here.
        return;
    }

    bool hasSupportingIndexForFields{true};
};

class ProcessInterfaceStandaloneTest : public AggregationContextFixture {
public:
    auto makeProcessInterface() {
        return std::make_unique<MongoProcessInterfaceForTest>(getExpCtx()->opCtx);
    }
};

TEST_F(ProcessInterfaceStandaloneTest, FailsToEnsureFieldsUniqueIfFieldsHaveDuplicates) {
    auto expCtx = getExpCtx();
    auto targetCollectionVersion = boost::none;
    auto processInterface = makeProcessInterface();

    ASSERT_THROWS_CODE(processInterface->ensureFieldsUniqueOrResolveDocumentKey(
                           expCtx, {{"_id", "_id"}}, targetCollectionVersion, expCtx->ns),
                       AssertionException,
                       ErrorCodes::BadValue);
    ASSERT_THROWS_CODE(processInterface->ensureFieldsUniqueOrResolveDocumentKey(
                           expCtx, {{"x", "y", "x"}}, targetCollectionVersion, expCtx->ns),
                       AssertionException,
                       ErrorCodes::BadValue);
}

TEST_F(ProcessInterfaceStandaloneTest,
       FailsToEnsureFieldsUniqueIfTargetCollectionVersionIsSpecifiedOnMongos) {
    auto expCtx = getExpCtx();
    auto targetCollectionVersion = boost::make_optional(ChunkVersion(0, 0, OID::gen()));
    auto processInterface = makeProcessInterface();

    // Test that 'targetCollectionVersion' is not accepted if not from mongos.
    expCtx->fromMongos = false;
    ASSERT_THROWS_CODE(processInterface->ensureFieldsUniqueOrResolveDocumentKey(
                           expCtx, {{"_id"}}, targetCollectionVersion, expCtx->ns),
                       AssertionException,
                       51123);

    // Test that 'targetCollectionVersion' is accepted if from mongos.
    expCtx->fromMongos = true;
    auto[joinKey, chunkVersion] = processInterface->ensureFieldsUniqueOrResolveDocumentKey(
        expCtx, {{"_id"}}, targetCollectionVersion, expCtx->ns);
    ASSERT_EQ(joinKey.size(), 1UL);
    ASSERT_EQ(joinKey.count(FieldPath("_id")), 1UL);
    ASSERT(chunkVersion);
    ASSERT_EQ(*chunkVersion, *targetCollectionVersion);
}

TEST_F(ProcessInterfaceStandaloneTest, FailsToEnsureFieldsUniqueIfJoinFieldsAreNotSentFromMongos) {
    auto expCtx = getExpCtx();
    auto targetCollectionVersion = boost::make_optional(ChunkVersion(0, 0, OID::gen()));
    auto processInterface = makeProcessInterface();

    expCtx->fromMongos = true;
    ASSERT_THROWS_CODE(processInterface->ensureFieldsUniqueOrResolveDocumentKey(
                           expCtx, boost::none, targetCollectionVersion, expCtx->ns),
                       AssertionException,
                       51124);
}

TEST_F(ProcessInterfaceStandaloneTest,
       FailsToEnsureFieldsUniqueIfFieldsDoesNotHaveSupportingUniqueIndex) {
    auto expCtx = getExpCtx();
    auto targetCollectionVersion = boost::none;
    auto processInterface = makeProcessInterface();

    expCtx->fromMongos = false;
    processInterface->hasSupportingIndexForFields = false;
    ASSERT_THROWS_CODE(processInterface->ensureFieldsUniqueOrResolveDocumentKey(
                           expCtx, {{"x"}}, targetCollectionVersion, expCtx->ns),
                       AssertionException,
                       51183);
}
}  // namespace
}  // namespace mongo