meifamily/ptt-alertor

package myutil

import (
    "unicode/utf8"
)

func SplitTextByLineBreak(text string, limit int) (texts []string) {
    var runeCount, index, lineBreak, start int
    copyText := text
    for len(copyText) > 0 {
        if utf8.RuneCountInString(text[start:]) <= limit {
            texts = append(texts, text[start:])
            break
        }
        r, size := utf8.DecodeRuneInString(copyText)
        runeCount++
        index += size

        if runeCount > limit {
            runeCount = utf8.RuneCountInString(text[start:index])
            if lineBreak > start {
                texts = append(texts, text[start:lineBreak])
                start = lineBreak
            } else {
                texts = append(texts, text[start:index])
                start = index
            }
        }

        if string(r) == "\n" {
            lineBreak = index
        }
        copyText = copyText[size:]
    }
    return texts
}