// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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 <memory>
#include <utility>

#include "VecIndex.h"
#include "knowhere/index/vector_index/VectorIndex.h"

namespace milvus {
namespace engine {

class VecIndexImpl : public VecIndex {
 public:
    explicit VecIndexImpl(std::shared_ptr<knowhere::VectorIndex> index, const IndexType& type)
        : index_(std::move(index)), type(type) {
    }

    Status
    BuildAll(const int64_t& nb, const float* xb, const int64_t* ids, const Config& cfg, const int64_t& nt,
             const float* xt) override;

    VecIndexPtr
    CopyToGpu(const int64_t& device_id, const Config& cfg) override;

    VecIndexPtr
    CopyToCpu(const Config& cfg) override;

    IndexType
    GetType() override;

    int64_t
    Dimension() override;

    int64_t
    Count() override;

    Status
    Add(const int64_t& nb, const float* xb, const int64_t* ids, const Config& cfg) override;

    knowhere::BinarySet
    Serialize() override;

    Status
    Load(const knowhere::BinarySet& index_binary) override;

    VecIndexPtr
    Clone() override;

    int64_t
    GetDeviceId() override;

    Status
    Search(const int64_t& nq, const float* xq, float* dist, int64_t* ids, const Config& cfg) override;

 protected:
    int64_t dim = 0;

    IndexType type = IndexType::INVALID;

    std::shared_ptr<knowhere::VectorIndex> index_ = nullptr;
};

class IVFMixIndex : public VecIndexImpl {
 public:
    explicit IVFMixIndex(std::shared_ptr<knowhere::VectorIndex> index, const IndexType& type)
        : VecIndexImpl(std::move(index), type) {
    }

    Status
    BuildAll(const int64_t& nb, const float* xb, const int64_t* ids, const Config& cfg, const int64_t& nt,
             const float* xt) override;

    Status
    Load(const knowhere::BinarySet& index_binary) override;
};

class IVFHybridIndex : public IVFMixIndex {
 public:
    explicit IVFHybridIndex(std::shared_ptr<knowhere::VectorIndex> index, const IndexType& type)
        : IVFMixIndex(std::move(index), type) {
    }

    knowhere::QuantizerPtr
    LoadQuantizer(const Config& conf) override;

    Status
    SetQuantizer(const knowhere::QuantizerPtr& q) override;

    Status
    UnsetQuantizer() override;
    std::pair<VecIndexPtr, knowhere::QuantizerPtr>
    CopyToGpuWithQuantizer(const int64_t& device_id, const Config& cfg) override;

    VecIndexPtr
    LoadData(const knowhere::QuantizerPtr& q, const Config& conf) override;
};

class BFIndex : public VecIndexImpl {
 public:
    explicit BFIndex(std::shared_ptr<knowhere::VectorIndex> index)
        : VecIndexImpl(std::move(index), IndexType::FAISS_IDMAP) {
    }

    ErrorCode
    Build(const Config& cfg);

    float*
    GetRawVectors();

    Status
    BuildAll(const int64_t& nb, const float* xb, const int64_t* ids, const Config& cfg, const int64_t& nt,
             const float* xt) override;

    int64_t*
    GetRawIds();
};

class ToIndexData : public cache::DataObj {
 public:
    explicit ToIndexData(int64_t size) : size_(size) {
    }

    int64_t
    Size() override {
        return size_;
    }

 private:
    int64_t size_;
};

}  // namespace engine
}  // namespace milvus