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

type UserIndex struct {
	Name         string `gorm:"index"`
	Name2        string `gorm:"index:idx_name,unique"`
	Name3        string `gorm:"index:,sort:desc,collate:utf8,type:btree,length:10,where:name3 != 'jinzhu'"`
	Name4        string `gorm:"uniqueIndex"`
	Name5        int64  `gorm:"index:,class:FULLTEXT,comment:hello \\, world,where:age > 10"`

	Comment string
	Option  string        // WITH PARSER parser_name
	Fields  []IndexOption // Note: IndexOption's Field maybe the same
}

type IndexOption struct {
	*Field
	Expression string
	Sort       string // DESC, ASC
	Collate    string
	Length     int
	priority   int
}

// ParseIndexes parse schema indexes
func (schema *Schema) ParseIndexes() map[string]Index {
	indexes := map[string]Index{}

				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.OrderBy{
					Columns: []clause.OrderByColumn{{Column: clause.Column{Name: "name"}}},

			clause.Limit{Limit: &limit10, Offset: 20},
			clause.OrderBy{Columns: []clause.OrderByColumn{{Column: clause.PrimaryColumn, Desc: true}}},
		}

		for _, clause := range clauses {
			stmt.AddClause(clause)
		}

		stmt.Build("SELECT", "FROM", "WHERE", "GROUP BY", "LIMIT", "ORDER BY")
		_ = stmt.SQL.String()
	}

	PercentOff       float32          `gorm:"column:percent_off"`
}

type CouponProduct struct {
	CouponId  int    `gorm:"primarykey;size:255"`
	ProductId string `gorm:"primarykey;size:255"`
	Desc      string
}

type Order struct {
	gorm.Model
	Num      string
	Coupon   *Coupon
	CouponID string
}

type Parent struct {
	gorm.Model
	FavChildID uint
	FavChild   *Child

	AssertEqual(t, names2, []string{"distinct", "distinct", "distinct", "distinct-2", "distinct-3"})

	var results []User
	if err := DB.Distinct("name", "age").Where("name like ?", "distinct%").Order("name, age desc").Find(&results).Error; err != nil {
		t.Errorf("failed to query users, got error: %v", err)
	}

	expects := []User{
		{Name: "distinct", Age: 20},
		{Name: "distinct", Age: 18},
		{Name: "distinct-2", Age: 18},

		Having: tx.Statement.BuildCondition(query, args...),
	})
	return
}

// Order specify order when retrieving records from database
//
//	db.Order("name DESC")
//	db.Order(clause.OrderByColumn{Column: clause.Column{Name: "name"}, Desc: true})
func (db *DB) Order(value interface{}) (tx *DB) {
	tx = db.getInstance()

	switch v := value.(type) {
	case clause.OrderByColumn:

	// find
	sql := DB.ToSQL(func(tx *gorm.DB) *gorm.DB {
		return tx.Model(&User{}).Where("id = ?", 100).Limit(10).Order("age desc").Find(&[]User{})
	})
	assertEqualSQL(t, `SELECT * FROM "users" WHERE id = 100 AND "users"."deleted_at" IS NULL ORDER BY age desc LIMIT 10`, sql)

	// after model changed
	if DB.Statement.DryRun || DB.DryRun {
		t.Fatal("Failed expect DB.DryRun and DB.Statement.ToSQL to be false")

	}

	result = dryDB.Order("age desc, name").Find(&User{})
	if !regexp.MustCompile("SELECT \\* FROM .*users.* ORDER BY age desc, name").MatchString(result.Statement.SQL.String()) {
		t.Fatalf("Build Order condition, but got %v", result.Statement.SQL.String())
	}

	result = dryDB.Order("age desc").Order("name").Find(&User{})
	if !regexp.MustCompile("SELECT \\* FROM .*users.* ORDER BY age desc,name").MatchString(result.Statement.SQL.String()) {

		})
	}
	tx.Statement.Dest = dest
	return tx.callbacks.Query().Execute(tx)
}

func (db *DB) ScanRows(rows *sql.Rows, dest interface{}) error {
	tx := db.getInstance()
	if err := tx.Statement.Parse(dest); !errors.Is(err, schema.ErrUnsupportedDataType) {
		tx.AddError(err)
	}
	tx.Statement.Dest = dest
	tx.Statement.ReflectValue = reflect.ValueOf(dest)