package dts

import (
	"context"
	"database/sql/driver"
	"encoding/json"
	"errors"
	"fmt"

	"gorm.io/gorm"
	"gorm.io/gorm/clause"
	"gorm.io/gorm/schema"
	"zestack.dev/is"
)

// Color 颜色，仅支持16进制
type Color string

// Set 设置颜色值
func (c *Color) Set(s string) bool {
	if s == "" || is.HEXColor(s) {
		*c = Color(s)
		return true
	}
	return false
}

func (c Color) Value() (driver.Value, error) {
	if len(c) == 0 {
		return nil, nil
	}
	return string(c), nil
}

func (c *Color) Scan(value any) error {
	if value == nil {
		*c = ""
		return nil
	}
	var ok bool
	switch v := value.(type) {
	case []byte:
		ok = c.Set(string(v))
	case string:
		ok = c.Set(v)
	}
	if !ok {
		return errors.New(fmt.Sprint("failed to unmarshal value:", value))
	}
	return nil
}

func (c Color) MarshalJSON() ([]byte, error) {
	return json.Marshal(string(c))
}

func (c *Color) UnmarshalJSON(b []byte) error {
	var str string
	err := json.Unmarshal(b, &str)
	if err != nil {
		return err
	}
	if !c.Set(str) {
		return errors.New("failed to unmarshal value")
	}
	return nil
}

func (c Color) String() string {
	return string(c)
}

// GormDBDataType gorm db data type
func (Color) GormDBDataType(db *gorm.DB, field *schema.Field) string {
	return "varchar(7)"
}

func (c Color) GormValue(ctx context.Context, db *gorm.DB) clause.Expr {
	if len(c) == 0 {
		return gorm.Expr("NULL")
	}
	data, _ := c.MarshalJSON()
	return gorm.Expr("?", string(data))
}