delete.go

// Copyright (c) 2022 MindStand Technologies, Inc
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

package gogm

import (
	"errors"
	dsl "github.com/mindstand/go-cypherdsl"
	"github.com/neo4j/neo4j-go-driver/v4/neo4j"
	"reflect"
)

// deleteNode is used to remove nodes from the database
func deleteNode(deleteObj interface{}) (neo4j.TransactionWork, error) {
	rawType := reflect.TypeOf(deleteObj)

	if rawType.Kind() != reflect.Ptr && rawType.Kind() != reflect.Slice {
		return nil, errors.New("delete obj can only be ptr or slice")
	}

	var ids []int64

	if rawType.Kind() == reflect.Ptr {
		delValue := reflect.ValueOf(deleteObj).Elem()
		idPtr, ok := delValue.FieldByName("Id").Interface().(*int64)
		if !ok {
			return nil, errors.New("unable to cast id to int64")
		}

		ids = append(ids, *idPtr)
	} else {
		slType := rawType.Elem()

		extraElem := false

		if slType.Kind() == reflect.Ptr {
			extraElem = true
		}

		slVal := reflect.ValueOf(deleteObj)

		slLen := slVal.Len()

		for i := 0; i < slLen; i++ {
			val := slVal.Index(i)
			if extraElem {
				val = val.Elem()
			}

			id, ok := val.FieldByName("Id").Interface().(int64)
			if !ok {
				return nil, errors.New("unable to cast id to int64")
			}

			ids = append(ids, id)
		}
	}

	return deleteByIds(ids...), nil
}

// deleteByIds deletes node by graph ids
func deleteByIds(ids ...int64) neo4j.TransactionWork {
	return func(tx neo4j.Transaction) (interface{}, error) {
		cyp, err := dsl.QB().
			Cypher("UNWIND $rows as row").
			Match(dsl.Path().V(dsl.V{Name: "n"}).Build()).
			Where(dsl.C(&dsl.ConditionConfig{
				FieldManipulationFunction: "ID",
				Name:                      "n",
				ConditionOperator:         dsl.EqualToOperator,
				Check:                     dsl.ParamString("row"),
			})).
			Delete(true, "n").
			ToCypher()
		if err != nil {
			return nil, err
		}

		_, err = tx.Run(cyp, map[string]interface{}{
			"rows": ids,
		})
		if err != nil {
			return nil, err
		}

		return nil, nil
	}
}

// deleteByUuids deletes nodes by uuids
func deleteByUuids(ids ...string) neo4j.TransactionWork {
	return func(tx neo4j.Transaction) (interface{}, error) {
		cyp, err := dsl.QB().
			Cypher("UNWIND {rows} as row").
			Match(dsl.Path().V(dsl.V{Name: "n"}).Build()).
			Where(dsl.C(&dsl.ConditionConfig{
				Name:              "n",
				Field:             "uuid",
				ConditionOperator: dsl.EqualToOperator,
				Check:             dsl.ParamString("row"),
			})).
			Delete(true, "n").
			ToCypher()
		if err != nil {
			return nil, err
		}
		_, err = tx.Run(cyp, map[string]interface{}{
			"rows": ids,
		})
		if err != nil {
			return nil, err
		}

		return nil, nil
	}
}