package clause

// From from clause
type From struct {
	Tables []Table
	Joins  []Join
}

// Name from clause name
func (from From) Name() string {
	return "FROM"
}

// Build build from clause
func (from From) Build(builder Builder) {
	if len(from.Tables) > 0 {
		for idx, table := range from.Tables {
			if idx > 0 {
				builder.WriteByte(',')
			}

			builder.WriteQuoted(table)
		}
	} else {

	results := []struct {
		Clauses []clause.Interface
		Result  string
		Vars    []interface{}
	}{
		{
			[]clause.Interface{clause.Select{}, clause.From{}},
			"SELECT * FROM `users`", nil,
		},
		{
			[]clause.Interface{
				clause.Select{}, clause.From{
					Tables: []clause.Table{{Name: "users"}},
					Joins: []clause.Join{
						{
							Type:  clause.InnerJoin,
							Table: clause.Table{Name: "articles"},

				Exprs: []clause.Expression{clause.Or(clause.Neq{Column: "name", Value: "jinzhu"}), clause.Eq{Column: clause.PrimaryColumn, Value: "1"}, clause.Gt{Column: "age", Value: 18}},
			}},
			"SELECT * FROM `users` WHERE `users`.`id` = ? OR `name` <> ? AND `age` > ?",
			[]interface{}{"1", "jinzhu", 18},
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{

		Vars    []interface{}
	}{
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.GroupBy{
				Columns: []clause.Column{{Name: "role"}},
				Having:  []clause.Expression{clause.Eq{"role", "admin"}},
			}},
			"SELECT * FROM `users` GROUP BY `role` HAVING `role` = ?",
			[]interface{}{"admin"},
		},
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.GroupBy{
				Columns: []clause.Column{{Name: "role"}},

	t := tag.Get("gorm")
	if strings.Contains(t, value) {
		return tag
	}
	return reflect.StructTag(fmt.Sprintf(`gorm:"%s;%s"`, value, t))
}

// GetRelationsValues get relations's values from a reflect value
func GetRelationsValues(ctx context.Context, reflectValue reflect.Value, rels []*Relationship) (reflectResults reflect.Value) {
	for _, rel := range rels {

	}
}

// only postgres, sqlserver, sqlite support update from
func TestUpdateFrom(t *testing.T) {
	if DB.Dialector.Name() != "postgres" && DB.Dialector.Name() != "sqlite" && DB.Dialector.Name() != "sqlserver" {
		return
	}

	users := []*User{
		GetUser("update-from-1", Config{Account: true}),
		GetUser("update-from-2", Config{Account: true}),
		GetUser("update-from-3", Config{}),
	}

	})

	if len(results) != 2 || results[0].Name != user2.Name || results[1].Name != user3.Name {
		t.Errorf("Scan into struct map, got %#v", results)
	}

	type ID uint64
	var id ID
	DB.Raw("select id from users where id = ?", user2.ID).Scan(&id)
	if uint(id) != user2.ID {
		t.Errorf("Failed to scan to customized data type")
	}

	var resInt interface{}
	resInt = &User{}

func (i *Num) Scan(src interface{}) error {
	switch s := src.(type) {
	case []byte:
		n, _ := strconv.Atoi(string(s))
		*i = Num(n)
	case int64:
		*i = Num(s)
	default:
		return errors.New("Cannot scan NamedInt from " + reflect.ValueOf(src).String())
	}
	return nil
}

type StringsSlice []string

func (l StringsSlice) Value() (driver.Value, error) {
	bytes, err := json.Marshal(l)
	return string(bytes), err
}

		Result  string
		Vars    []interface{}
	}{
		{
			[]clause.Interface{clause.Select{}, clause.From{}, clause.OrderBy{
				Columns: []clause.OrderByColumn{{Column: clause.PrimaryColumn, Desc: true}},
			}},
			"SELECT * FROM `users` ORDER BY `users`.`id` DESC", nil,
		},
		{
			[]clause.Interface{
				clause.Select{}, clause.From{}, clause.OrderBy{
					Columns: []clause.OrderByColumn{{Column: clause.PrimaryColumn, Desc: true}},

			[]clause.Interface{clause.Select{}, clause.From{}, clause.Returning{
				[]clause.Column{clause.PrimaryColumn},
			}},
			"SELECT * FROM `users` RETURNING `users`.`id`", nil,
		}, {
			[]clause.Interface{clause.Select{}, clause.From{}, clause.Returning{
				[]clause.Column{clause.PrimaryColumn},
			}, clause.Returning{
				[]clause.Column{{Name: "name"}, {Name: "age"}},
			}},
			"SELECT * FROM `users` RETURNING `users`.`id`,`name`,`age`", nil,