// Copyright (C) 2019-2020 Zilliz. All rights reserved.
//
// 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.

#include "server/delivery/request/DescribeIndexReq.h"
#include "db/SnapshotUtils.h"
#include "db/Utils.h"
#include "server/DBWrapper.h"
#include "server/ValidationUtil.h"
#include "utils/Log.h"
#include "utils/TimeRecorder.h"

#include <fiu/fiu-local.h>
#include <memory>
#include <string>
#include <unordered_map>
#include <vector>

namespace milvus {
namespace server {

DescribeIndexReq::DescribeIndexReq(const std::shared_ptr<milvus::server::Context>& context,
                                   const std::string& collection_name, const std::string& field_name,
                                   std::string& index_name, milvus::json& json_params)
    : BaseReq(context, ReqType::kDescribeIndex),
      collection_name_(collection_name),
      field_name_(field_name),
      index_name_(index_name),
      json_params_(json_params) {
}

BaseReqPtr
DescribeIndexReq::Create(const std::shared_ptr<milvus::server::Context>& context, const std::string& collection_name,
                         const std::string& field_name, std::string& index_name, milvus::json& json_params) {
    return std::shared_ptr<BaseReq>(
        new DescribeIndexReq(context, collection_name, field_name, index_name, json_params));
}

Status
DescribeIndexReq::OnExecute() {
    try {
        std::string hdr = "DescribeIndexReq(collection=" + collection_name_ + ")";
        TimeRecorderAuto rc(hdr);

        // step 1: check arguments
        STATUS_CHECK(ValidateCollectionName(collection_name_));
        STATUS_CHECK(ValidateFieldName(field_name_));

        // only process root collection, ignore partition collection
        engine::CollectionIndex index;
        auto status = DBWrapper::DB()->DescribeIndex(collection_name_, field_name_, index);
        if (!status.ok()) {
            if (status.code() == DB_NOT_FOUND) {
                return Status(SERVER_COLLECTION_NOT_EXIST, "Collection not exist: " + collection_name_);
            } else {
                return status;
            }
        }

        json_params_[engine::PARAM_INDEX_TYPE] = index.index_type_;
        json_params_[engine::PARAM_INDEX_METRIC_TYPE] = index.metric_name_;
        json_params_[engine::PARAM_INDEX_EXTRA_PARAMS] = index.extra_params_;
    } catch (std::exception& ex) {
        return Status(SERVER_UNEXPECTED_ERROR, ex.what());
    }

    return Status::OK();
}

}  // namespace server
}  // namespace milvus
