// Copyright 2023 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#pragma once

#include <Core/Types.h>
#include <Storages/KVStore/Types.h>
#include <Storages/S3/S3Common.h>
#include <aws/core/utils/DateTime.h>
#include <aws/s3/S3Client.h>
#include <common/defines.h>
#include <common/types.h>

#include <map>
#include <vector>

namespace DB::S3
{
struct CheckpointManifestS3Object
{
    String key;
    Aws::Utils::DateTime last_modification;
};

class CheckpointManifestS3Set
{
public:
    static CheckpointManifestS3Set getFromS3(const S3::TiFlashS3Client & client, StoreID store_id);

    static CheckpointManifestS3Set create(const std::vector<CheckpointManifestS3Object> & manifest_keys);

    ALWAYS_INLINE bool empty() const { return manifests.empty(); }

    UInt64 latestUploadSequence() const
    {
        assert(!manifests.empty());
        return manifests.rbegin()->first;
    }

    const String & latestManifestKey() const
    {
        assert(!manifests.empty());
        return manifests.rbegin()->second.key;
    }

    // The number of preserved manifest file is 1 <= num <= max_preserved.
    // If the manifest modification time is older than timepoint - expired_hour,
    // we won't preserve it.
    Strings preservedManifests(size_t max_preserved, Int64 expired_hour, const Aws::Utils::DateTime & timepoint) const;

    // The manifest objects that should be removed from S3
    std::vector<CheckpointManifestS3Object> outdatedObjects(
        size_t max_preserved,
        Int64 expired_hour,
        const Aws::Utils::DateTime & timepoint) const;

    const std::map<UInt64, CheckpointManifestS3Object> & objects() const { return manifests; }

private:
    // a order map to let values sorted by upload_seq
    // upload_seq -> {manifest_key, mtime}
    std::map<UInt64, CheckpointManifestS3Object> manifests;
};

} // namespace DB::S3