package base

import "strings"

// BaseExtensionField 结构体，类似于 Java 中的 BaseExtensionField
type BaseExtensionField struct {
	ID         int64  `gorm:"primaryKey;autoIncrement" json:"id"` // 主键ID
	TableName  string `gorm:"type:varchar(255);not null" json:"table_name"`
	FieldName  string `gorm:"type:varchar(255);not null" json:"field_name"`
	Extension  string `gorm:"type:varchar(255)" json:"extension"`
	FieldValue string `gorm:"type:varchar(255)" json:"field_value"`
	OwnerID    int64  `gorm:"index" json:"owner_id"` // 外键关联到主结构体
}

// ExtensionFieldManageable 接口定义获取扩展字段的方法
type ExtensionFieldManageable interface {
	GetExtensionFields() []BaseExtensionField
	GetExtensionFieldsByFieldName(fieldName string) []BaseExtensionField
	GetExtensionFieldsByFieldNameAndExtension(fieldName, extension string) []BaseExtensionField
	GetExtensionFieldValueByFieldName(fieldName string) *string
	GetExtensionFieldValueByFieldNameAndExtension(fieldName, extension string) *string
}

// DefaultExtensionFieldManager 用于实现 ExtensionFieldManageable 的默认行为
type DefaultExtensionFieldManager struct {
	ExtensionFields          []BaseExtensionField `gorm:"foreignKey:OwnerID;references:ID" json:"extensions"` // 扩展字段列表
	ExtensionFieldManageable `gorm:"-"`
}

// GetExtensionFields 实现了 ExtensionFieldManageable 接口的 GetExtensionFields 方法
func (m *DefaultExtensionFieldManager) GetExtensionFields() []BaseExtensionField {
	return m.ExtensionFields
}

// GetExtensionFieldsByFieldName 过滤指定字段名的扩展字段
func (m *DefaultExtensionFieldManager) GetExtensionFieldsByFieldName(fieldName string) []BaseExtensionField {
	var result []BaseExtensionField
	for _, field := range m.ExtensionFields {
		if strings.EqualFold(field.FieldName, fieldName) {
			result = append(result, field)
		}
	}
	return result
}

// GetExtensionFieldsByFieldNameAndExtension 过滤指定字段名和扩展名的扩展字段
func (m *DefaultExtensionFieldManager) GetExtensionFieldsByFieldNameAndExtension(fieldName, extension string) []BaseExtensionField {
	var result []BaseExtensionField
	for _, field := range m.GetExtensionFieldsByFieldName(fieldName) {
		if strings.EqualFold(field.Extension, extension) {
			result = append(result, field)
		}
	}
	return result
}

// GetExtensionFieldValueByFieldName 返回指定字段名的第一个扩展字段值
func (m *DefaultExtensionFieldManager) GetExtensionFieldValueByFieldName(fieldName string) string {
	fields := m.GetExtensionFieldsByFieldName(fieldName)
	if len(fields) > 0 {
		return fields[0].FieldValue
	}
	return ""
}

// GetExtensionFieldValueByFieldNameAndExtension 返回指定字段名和扩展名的第一个扩展字段值
func (m *DefaultExtensionFieldManager) GetExtensionFieldValueByFieldNameAndExtension(fieldName, extension string) string {
	fields := m.GetExtensionFieldsByFieldNameAndExtension(fieldName, extension)
	if len(fields) > 0 {
		return fields[0].FieldValue
	}
	return ""
}