package main

import (
	"errors"
	"fmt"
	"os"
	"reflect"
	"strconv"
	"strings"
)

type Point struct {
	X uint64
	Y string
	Z int32
}

func ToStuct(row string, value interface{}) error {
	return toStruct(row, reflect.ValueOf(value).Elem())
}

func ToCSV(value interface{}) (string, error) {
	return toCSV(reflect.ValueOf(value).Elem())
}

func toStruct(row string, v reflect.Value) error {
	lexems := strings.Split(row, ",")

	if len(lexems) != v.NumField() {
		return errors.New("invalid amount of fields")
	}

	for i := 0; i < v.NumField(); i++ {
		fx := v.Field(i)
		switch fx.Kind() {
		case reflect.String:
			s, _ := strconv.Unquote(lexems[i])
			fx.SetString(s)
		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
			s, _ := strconv.ParseUint(lexems[i], 10, 64)
			fx.SetUint(s)
		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
			s, _ := strconv.ParseInt(lexems[i], 10, 64)
			fx.SetInt(s)
		}
	}

	return nil
}

func toCSV(v reflect.Value) (string, error) {
	str := strings.Builder{}

	for i := 0; i < v.NumField(); i++ {
		fx := v.Field(i)
		switch fx.Kind() {
		case reflect.String:
			s, _ := strconv.Unquote(strconv.Quote(fx.String()))
			str.WriteString(s)
		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
			str.WriteString(strconv.FormatUint(fx.Uint(), 10))
		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
			str.WriteString(strconv.FormatInt(fx.Int(), 10))
		}
		if i != v.NumField()-1 {
			str.WriteString(", ")
		}
	}

	return str.String(), nil
}

func main() {
	p := new(Point)
	err := ToStuct("1,\"hello\",112", p)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	fmt.Println(*p)

	res, err := ToCSV(p)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	fmt.Println(res)
}