grokify/mogo

package month

import (
    "errors"

    "github.com/grokify/mogo/sort/sortutil"
    "github.com/grokify/mogo/time/timeutil"
)

// DT6FormatOrDefault coverts an `int32` to a `layout`, using `def`ault. Panics on
// `time.Parse()` error.
func MustDT6FormatOrDefault(layout string, dt6 int32, def string) string {
    str, err := DT6FormatOrDefault(layout, dt6, def)
    if err != nil {
        panic(err)
    }
    return str
}

// DT6FormatOrDefault coverts an `int32` to a `layout`, using `def`ault
func DT6FormatOrDefault(layout string, dt6 int32, def string) (string, error) {
    if dt6 <= 0 {
        return def, nil
    }
    dt, err := timeutil.TimeForDT6(dt6)
    if err != nil {
        return "", err
    }
    return dt.Format(layout), nil
}

// StartEndDT6s returns a start and end from a range. `-1` is returned if a 0 lenth slice
// is provided. If only a start date is provided, a `0` is returned to represent "not provided",
// which can indicate something like "the present".
func StartEndDT6s(dt6s []int32) (int32, int32) {
    if len(dt6s) == 0 {
        return -1, -1
    }

    // dt6s = slicesutil.Dedupe(dt6s) // Support if start and end months are the identical.
    sortutil.Slice(dt6s)

    if dt6s[0] <= 0 {
        if len(dt6s) > 1 {
            return dt6s[1], 0
        } else {
            return -1, -1
        }
    }

    if len(dt6s) > 1 {
        return dt6s[0], dt6s[len(dt6s)-1]
    } else {
        return dt6s[0], 0
    }
}

// DT6sToString returns a formatted date range. This function is can be used to generate a string such as:
// ` (Jan 2007-Dec2008)` with the call `DT6sToString(200701, 200812, "Jan 2006", "Present", " (", "-", ")")` or
// ` (Jan 2007-Present)` with the call `DT6sToString(200701, 0, "Jan 2006", "Present", " (", "-", ")")`.
func DT6sToString(startDT6, endDT6 int32, layout, presentText, prefixText, joinText, suffixText string) (string, error) {
    if startDT6 <= 0 && endDT6 <= 0 {
        return "", nil
    }
    startText, endText, err := DT6sToStrings(startDT6, endDT6, layout, presentText)
    if err != nil {
        return "", err
    }
    if startText != "" && endText != "" {
        return prefixText + startText + joinText + endText + suffixText, nil
    } else if startText != "" {
        return prefixText + startText + suffixText, nil
    } else if endText != "" {
        return prefixText + endText + suffixText, nil
    }
    return "", nil
}

func DT6sToStrings(startDT6, endDT6 int32, layout, presentText string) (string, string, error) {
    if startDT6 <= 0 && endDT6 <= 0 {
        return "", "", nil
    }
    if startDT6 <= 0 && endDT6 > 0 {
        return "", "", errors.New("start date cannot be undefined (lte zero)")
    }
    startDT6Fmt, err := DT6FormatOrDefault(layout, startDT6, presentText)
    if err != nil {
        return startDT6Fmt, "", err
    }
    endDT6Fmt, err := DT6FormatOrDefault(layout, endDT6, presentText)
    return startDT6Fmt, endDT6Fmt, err
}