package callbacks

import (
	"gorm.io/gorm"
)

func BeginTransaction(db *gorm.DB) {
	if !db.Config.SkipDefaultTransaction && db.Error == nil {
		if tx := db.Begin(); tx.Error == nil {
			db.Statement.ConnPool = tx.Statement.ConnPool
			db.InstanceSet("gorm:started_transaction", true)
		} else if tx.Error == gorm.ErrInvalidTransaction {
			tx.Error = nil
		} else {
			db.Error = tx.Error
		}
	}
}

	"gorm.io/gorm/schema"
	"gorm.io/gorm/utils/tests"
)

func BenchmarkSelect(b *testing.B) {
	user, _ := schema.Parse(&tests.User{}, &sync.Map{}, db.NamingStrategy)

	for i := 0; i < b.N; i++ {
		stmt := gorm.Statement{DB: db, Table: user.Table, Schema: user, Clauses: map[string]clause.Clause{}}

	if !regexp.MustCompile(`SELECT DISTINCT u\.id, u\.\* FROM user_speaks as s inner join users as u`).MatchString(r.Statement.SQL.String()) {
		t.Fatalf("Build Distinct with u.*, but got %v", r.Statement.SQL.String())
	}

	tx := db.Session(&gorm.Session{NewDB: true})
	if called := fc(db.Statement.ReflectValue.Interface(), tx); !called {
		switch db.Statement.ReflectValue.Kind() {
		case reflect.Slice, reflect.Array:
			db.Statement.CurDestIndex = 0
			for i := 0; i < db.Statement.ReflectValue.Len(); i++ {
				if value := reflect.Indirect(db.Statement.ReflectValue.Index(i)); value.CanAddr() {
					fc(value.Addr().Interface(), tx)
				} else {

import (
	"reflect"

	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
)

// Migrator returns migrator
func (db *DB) Migrator() Migrator {
	tx := db.getInstance()

	// apply scopes to migrator
	for len(tx.Statement.scopes) > 0 {
		tx = tx.executeScopes()
	}

	return tx.Dialector.Migrator(tx.Session(&Session{}))
}

// AutoMigrate run auto migration for given models
func (db *DB) AutoMigrate(dst ...interface{}) error {

	}

	db := DB.Scopes(func(tx *gorm.DB) *gorm.DB {
		return tx.Table("custom_table")
	}).Session(&gorm.Session{})

	db.AutoMigrate(&User{})
	if db.Find(&User{}).Statement.Table != "custom_table" {
		t.Errorf("failed to call Scopes")
	}

	result := DB.Scopes(NameIn1And2, func(tx *gorm.DB) *gorm.DB {
		return tx.Session(&gorm.Session{})
	}).Find(&users1)

			sql: "INNER JOIN `user` USING (`id`)",
		},
	}
	for _, result := range results {
		t.Run(result.name, func(t *testing.T) {
			user, _ := schema.Parse(&tests.User{}, &sync.Map{}, db.NamingStrategy)
			stmt := &gorm.Statement{DB: db, Table: user.Table, Schema: user, Clauses: map[string]clause.Clause{}}
			result.join.Build(stmt)
			if result.sql != stmt.SQL.String() {
				t.Errorf("want: %s, got: %s", result.sql, stmt.SQL.String())
			}
		})

	if db.Error == nil && db.Statement.Schema != nil {
		if !db.Statement.ReflectValue.CanAddr() || db.Statement.Model != db.Statement.Dest {
			db.Statement.ReflectValue = reflect.ValueOf(db.Statement.Model)
			for db.Statement.ReflectValue.Kind() == reflect.Ptr {
				db.Statement.ReflectValue = db.Statement.ReflectValue.Elem()
			}

			if dest, ok := db.Statement.Dest.(map[string]interface{}); ok {

		}
	}
	return false, 0
}

func checkMissingWhereConditions(db *gorm.DB) {
	if !db.AllowGlobalUpdate && db.Error == nil {
		where, withCondition := db.Statement.Clauses["WHERE"]
		if withCondition {
			if _, withSoftDelete := db.Statement.Clauses["soft_delete_enabled"]; withSoftDelete {
				whereClause, _ := where.Expression.(clause.Where)
				withCondition = len(whereClause.Exprs) > 1
			}
		}

	return clause.Expr{SQL: "DEFAULT"}
}

func (DummyDialector) Migrator(*gorm.DB) gorm.Migrator {
	return nil
}

func (DummyDialector) BindVarTo(writer clause.Writer, stmt *gorm.Statement, v interface{}) {
	writer.WriteByte('?')
}

func (DummyDialector) QuoteTo(writer clause.Writer, str string) {
	var (
		underQuoted, selfQuoted bool
		continuousBacktick      int8
		shiftDelimiter          int8