// 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 <Storages/KVStore/MultiRaft/RegionMeta.h>

namespace DB
{
class MockTiKV : public ext::Singleton<MockTiKV>
{
    friend class ext::Singleton<MockTiKV>;

public:
    UInt64 getRaftIndex(RegionID region_id)
    {
        std::lock_guard lock(mutex);
        auto it = raft_index.find(region_id);
        if (it == raft_index.end())
        {
            // Usually index 6 is empty and we ignore it.
            // https://github.com/tikv/tikv/issues/7047
            auto init_index = RAFT_INIT_LOG_INDEX + 1;
            it = raft_index.emplace_hint(it, region_id, init_index);
        }
        ++(it->second);
        return it->second;
    }

    UInt64 getRaftTerm(RegionID region_id)
    {
        std::lock_guard lock(mutex);
        auto it = raft_term.find(region_id);
        if (it == raft_term.end())
            it = raft_term.emplace_hint(it, region_id, RAFT_INIT_LOG_TERM);
        return it->second;
    }

private:
    std::mutex mutex;

    std::unordered_map<RegionID, UInt64> raft_index;
    std::unordered_map<RegionID, UInt64> raft_term;
};

} // namespace DB