// Licensed to the LF AI & Data foundation 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.

package indexparamcheck

import (
	"sync"

	"github.com/cockroachdb/errors"

	"github.com/milvus-io/milvus/internal/util/vecindexmgr"
)

type IndexCheckerMgr interface {
	GetChecker(indexType string) (IndexChecker, error)
}

// indexCheckerMgrImpl implements IndexChecker.
type indexCheckerMgrImpl struct {
	checkers map[IndexType]IndexChecker
	once     sync.Once
}

func (mgr *indexCheckerMgrImpl) GetChecker(indexType string) (IndexChecker, error) {
	mgr.once.Do(mgr.registerIndexChecker)
	// Unify the vector index checker
	if vecindexmgr.GetVecIndexMgrInstance().IsVecIndex(indexType) {
		return mgr.checkers[IndexVector], nil
	}
	adapter, ok := mgr.checkers[indexType]
	if ok {
		return adapter, nil
	}
	return nil, errors.New("Can not find index: " + indexType + " , please check")
}

func (mgr *indexCheckerMgrImpl) registerIndexChecker() {
	mgr.checkers[IndexVector] = newVecIndexChecker()
	mgr.checkers[IndexINVERTED] = newINVERTEDChecker()
	mgr.checkers[IndexSTLSORT] = newSTLSORTChecker()
	mgr.checkers["Asceneding"] = newSTLSORTChecker()
	mgr.checkers[IndexTRIE] = newTRIEChecker()
	mgr.checkers[IndexTrie] = newTRIEChecker()
	mgr.checkers[IndexBitmap] = newBITMAPChecker()
	mgr.checkers[IndexHybrid] = newHYBRIDChecker()
	mgr.checkers["marisa-trie"] = newTRIEChecker()
	mgr.checkers[AutoIndex] = newAUTOINDEXChecker()
}

func newIndexCheckerMgr() *indexCheckerMgrImpl {
	return &indexCheckerMgrImpl{
		checkers: make(map[IndexType]IndexChecker),
	}
}

var indexCheckerMgr IndexCheckerMgr

var getIndexCheckerMgrOnce sync.Once

// GetIndexCheckerMgrInstance gets the instance of IndexCheckerMgr.
func GetIndexCheckerMgrInstance() IndexCheckerMgr {
	getIndexCheckerMgrOnce.Do(func() {
		indexCheckerMgr = newIndexCheckerMgr()
	})
	return indexCheckerMgr
}