package nstore

import (
	"database/sql"
	"fmt"
	"reflect"
	"strings"
)

func (d *Database) deleteFieldRelations(tx *sql.Tx, srcID int64, rType reflect.Type, rField reflect.StructField) error {
	if fieldRelationTypeToDatabaseType(rField.Type) == "" {
		return errInvalidRelationType
	}
	relTableName := structFieldTableName(rType, rField)
	query := fmt.Sprintf(`DELETE FROM "%s" WHERE src_id = ?`, relTableName)
	d.debugQuery(query, srcID)
	if _, err := tx.Exec(query, srcID); err != nil {
		return err
	}
	return nil
}

func (d *Database) deleteFieldRelationsByValues(tx *sql.Tx, srcID int64, rType reflect.Type, rField reflect.StructField, fieldValues []any) error {
	if fieldRelationTypeToDatabaseType(rField.Type) == "" {
		return errInvalidRelationType
	}
	relTableName := structFieldTableName(rType, rField)
	query := fmt.Sprintf(`DELETE FROM "%s" WHERE value NOT IN (%s) AND src_id = ? `, relTableName, strings.TrimSuffix(strings.Repeat("?,", len(fieldValues)), ","))
	args := append(fieldValues, srcID)
	d.debugQuery(query, args...)
	if _, err := tx.Exec(query, args...); err != nil {
		return err
	}
	return nil
}

func (d *Database) deleteStruct(tx *sql.Tx, ID int64, rType reflect.Type) error {
	if rType.Kind() != reflect.Struct {
		return errInvalidStruct
	}

	tableName := structTypeTableName(rType)

	for rField := range rType.Fields() {
		if rField.IsExported() && fieldRelationTypeToDatabaseType(rField.Type) != "" {
			if err := d.deleteFieldRelations(tx, ID, rType, rField); err != nil {
				return err
			}
		}
	}

	query := fmt.Sprintf(`DELETE FROM "%s" WHERE _id = ?`, tableName)
	d.debugQuery(query, ID)
	if _, err := tx.Exec(query, ID); err != nil {
		return err
	}

	return nil
}