package persist

import (
	"fmt"
	"reflect"
	"strings"
)

// ReflectGormData todo cache data type info
func ReflectGormData(data any) (table string, columns []string, values map[string]any, err error) {
	defer func() {
		if r := recover(); r != nil {
			err = fmt.Errorf("%T parse gorm data error %v", data, r)
		}
	}()

	values = make(map[string]any)
	refValue := reflect.ValueOf(data)
	refType := reflect.TypeOf(data)

	tableNameM := refValue.MethodByName("TableName")
	if !tableNameM.IsValid() {
		err = fmt.Errorf("type %T not has method TableName", data)
		return
	}
	rsp := tableNameM.Call(nil)
	table = rsp[0].Interface().(string)

	if refValue.Kind() == reflect.Ptr {
		refValue = refValue.Elem()
	}
	if refType.Kind() == reflect.Ptr {
		refType = refType.Elem()
	}

	for i := 0; i < refType.NumField(); i++ {
		field := refType.Field(i)
		value := refValue.Field(i).Interface()
		// value
		tag := field.Tag.Get("gorm")
		column := getGormTagColumnName(tag)
		if column == "" || strings.HasPrefix(column, "-") { // 忽略字段
			continue
		}
		columns = append(columns, column)
		values[column] = value
	}
	return
}

func getGormTagColumnName(tag string) (column string) {
	i1 := strings.Index(tag, "column:")
	if i1 < 0 {
		return
	}
	i2 := strings.Index(tag[i1+7:], ";")
	if i2 < 0 {
		return tag[i1+7:]
	}
	return tag[i1+7 : i2+7]
}