// 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.

package datasource

import (
	pb "github.com/go-chassis/cari/discovery"
)

// @titile SchemasAnalysis
// @description schemasanlysis decide the schema to be deleted,updated or added
// @param schemas []*pb.Schema "the schemas from request"
// @param schemasFromDb []*pb.Schema "the schemas from database by the serviceID"
// @param schemaIDsInService []string "the schema field in service struct"
func SchemasAnalysis(schemas []*pb.Schema, schemasFromDb []*pb.Schema, schemaIDsInService []string) (
	[]*pb.Schema, []*pb.Schema, []*pb.Schema, []string) {
	needUpdateSchemas := make([]*pb.Schema, 0, len(schemas))
	needAddSchemas := make([]*pb.Schema, 0, len(schemas))
	needDeleteSchemas := make([]*pb.Schema, 0, len(schemasFromDb))
	nonExistSchemaIds := make([]string, 0, len(schemas))

	duplicate := make(map[string]struct{})
	for _, schema := range schemas {
		if _, ok := duplicate[schema.SchemaId]; ok {
			continue
		}
		duplicate[schema.SchemaId] = struct{}{}

		exist := false
		for _, schemaFromDb := range schemasFromDb {
			if schema.SchemaId == schemaFromDb.SchemaId {
				needUpdateSchemas = append(needUpdateSchemas, schema)
				exist = true
				break
			}
		}
		if !exist {
			needAddSchemas = append(needAddSchemas, schema)
		}

		exist = false
		for _, schemaID := range schemaIDsInService {
			if schema.SchemaId == schemaID {
				exist = true
			}
		}
		if !exist {
			nonExistSchemaIds = append(nonExistSchemaIds, schema.SchemaId)
		}
	}

	for _, schemaFromDb := range schemasFromDb {
		exist := false
		for _, schema := range schemas {
			if schema.SchemaId == schemaFromDb.SchemaId {
				exist = true
				break
			}
		}
		if !exist {
			needDeleteSchemas = append(needDeleteSchemas, schemaFromDb)
		}
	}

	return needUpdateSchemas, needAddSchemas, needDeleteSchemas, nonExistSchemaIds
}