package model

import (
	"database/sql/driver"
	"encoding/json"
	"fmt"
	"time"
)

// JSON 类型，用于 custom_fields
type JSON map[string]interface{}

func (j JSON) Value() (driver.Value, error) {
	if j == nil {
		return nil, nil
	}
	b, err := json.Marshal(j)
	return string(b), err
}

func (j *JSON) Scan(value interface{}) error {
	if value == nil {
		*j = nil
		return nil
	}
	var bytes []byte
	switch v := value.(type) {
	case string:
		bytes = []byte(v)
	case []byte:
		bytes = v
	default:
		return fmt.Errorf("cannot scan type %T into JSON", value)
	}
	return json.Unmarshal(bytes, j)
}

// Date 仅含日期（YYYY-MM-DD）的类型，兼容前端只传日期字符串的场景
type Date struct{ time.Time }

const dateFmt = "2006-01-02"

func (d *Date) UnmarshalJSON(b []byte) error {
	s := string(b)
	// 去掉引号
	if len(s) >= 2 && s[0] == '"' {
		s = s[1 : len(s)-1]
	}
	if s == "" || s == "null" {
		d.Time = time.Time{}
		return nil
	}
	// 尝试纯日期格式 YYYY-MM-DD
	if t, err := time.ParseInLocation(dateFmt, s, time.Local); err == nil {
		d.Time = t
		return nil
	}
	// 回退：标准 RFC3339
	t, err := time.Parse(time.RFC3339, s)
	if err != nil {
		return fmt.Errorf("cannot parse date %q", s)
	}
	d.Time = t
	return nil
}

func (d Date) MarshalJSON() ([]byte, error) {
	if d.Time.IsZero() {
		return []byte(`""`), nil
	}
	return []byte(`"` + d.Time.Format(dateFmt) + `"`), nil
}

// Value / Scan 让 GORM 正确读写 MySQL DATE 列
func (d Date) Value() (driver.Value, error) {
	if d.Time.IsZero() {
		return nil, nil
	}
	return d.Time.Format(dateFmt), nil
}

func (d *Date) Scan(value interface{}) error {
	if value == nil {
		d.Time = time.Time{}
		return nil
	}
	switch v := value.(type) {
	case time.Time:
		d.Time = v
	case []byte:
		t, err := time.ParseInLocation(dateFmt, string(v), time.Local)
		if err != nil {
			return err
		}
		d.Time = t
	case string:
		t, err := time.ParseInLocation(dateFmt, v, time.Local)
		if err != nil {
			return err
		}
		d.Time = t
	default:
		return fmt.Errorf("cannot scan type %T into Date", value)
	}
	return nil
}

// Base 公共字段
type Base struct {
	ID        uint64     `gorm:"primaryKey;autoIncrement" json:"id"`
	CreatedAt time.Time  `json:"created_at"`
	UpdatedAt time.Time  `json:"updated_at"`
	DeletedAt *time.Time `gorm:"index" json:"-"`
}

// TenantBase 含租户隔离的公共字段
type TenantBase struct {
	Base
	ShopID uint64 `gorm:"not null;index" json:"shop_id"`
}