af83/edwig

package ls

import (
    "regexp"
    "strconv"
    "strings"
    "time"
)

type optionParser struct{}

var durationRegex = regexp.MustCompile(`P(?:(\d+)Y)?(?:(\d+)M)?(?:(\d+)D)?(?:T(?:(\d+)H)?(?:(\d+)M)?(?:(\d+)(?:[\.,](\d{1,3}))?S)?)?`)

func (parser *optionParser) getOptionDuration(option string) time.Duration {
    matches := durationRegex.FindStringSubmatch(strings.TrimSpace(option))

    if len(matches) == 0 {
        return 0
    }
    years := parser.parseDuration(matches[1]) * 24 * 365 * time.Hour
    months := parser.parseDuration(matches[2]) * 30 * 24 * time.Hour
    days := parser.parseDuration(matches[3]) * 24 * time.Hour
    hours := parser.parseDuration(matches[4]) * time.Hour
    minutes := parser.parseDuration(matches[5]) * time.Minute
    seconds := parser.parseDuration(matches[6]) * time.Second
    rest := parser.parseDuration(matches[7]) * parser.durationPow(10, 3-len(matches[7])) * time.Millisecond

    return time.Duration(years + months + days + hours + minutes + seconds + rest)
}

func (parser *optionParser) parseDuration(value string) time.Duration {
    if len(value) == 0 {
        return 0
    }
    parsed, err := strconv.Atoi(value)
    if err != nil {
        return 0
    }
    return time.Duration(parsed)
}

func (parser *optionParser) durationPow(a, b int) time.Duration {
    p := 1
    for b > 0 {
        if b&1 != 0 {
            p *= a
        }
        b >>= 1
        a *= a
    }
    return time.Duration(p)
}