package model

import (
	"fmt"
	"regexp"
	"strconv"
	"strings"

	"git.sundynix.cn/Blizzard/Veyra/internal/apperror"
)

var moneyPattern = regexp.MustCompile(`^(0|[1-9][0-9]{0,9})(\.[0-9]{1,2})?$`)

// ParseMoney converts decimal text into exact cents, rejecting rounding and exponents.
func ParseMoney(value string) (int64, error) {
	if !moneyPattern.MatchString(value) {
		return 0, apperror.ErrInvalidInput
	}
	whole, fraction, _ := strings.Cut(value, ".")
	units, err := strconv.ParseInt(whole, 10, 64)
	if err != nil {
		return 0, apperror.ErrInvalidInput
	}
	fraction += strings.Repeat("0", 2-len(fraction))
	cents, err := strconv.ParseInt(fraction, 10, 64)
	if err != nil {
		return 0, apperror.ErrInvalidInput
	}
	amount := units*100 + cents
	if amount > 100000000000 {
		return 0, apperror.ErrInvalidInput
	}
	return amount, nil
}

func FormatMoney(minor int64) string { return fmt.Sprintf("%d.%02d", minor/100, minor%100) }