Refactor utf-8 conversion (irc) (#1767)

bridge/irc/charset.go

@@ -0,0 +1,32 @@
+package birc
+
+import (
+	"golang.org/x/text/encoding"
+	"golang.org/x/text/encoding/japanese"
+	"golang.org/x/text/encoding/korean"
+	"golang.org/x/text/encoding/simplifiedchinese"
+	"golang.org/x/text/encoding/traditionalchinese"
+	"golang.org/x/text/encoding/unicode"
+)
+
+var encoders = map[string]encoding.Encoding{
+	"utf-8":       unicode.UTF8,
+	"iso-2022-jp": japanese.ISO2022JP,
+	"big5":        traditionalchinese.Big5,
+	"gbk":         simplifiedchinese.GBK,
+	"euc-kr":      korean.EUCKR,
+	"gb2312":      simplifiedchinese.HZGB2312,
+	"shift-jis":   japanese.ShiftJIS,
+	"euc-jp":      japanese.EUCJP,
+	"gb18030":     simplifiedchinese.GB18030,
+}
+
+func toUTF8(from string, input string) string {
+	enc, ok := encoders[from]
+	if !ok {
+		return input
+	}
+
+	res, _ := enc.NewDecoder().String(input)
+	return res
+}

bridge/irc/handlers.go

@@ -11,7 +11,6 @@ import (
 	"github.com/42wim/matterbridge/bridge/config"
 	"github.com/42wim/matterbridge/bridge/helper"
 	"github.com/lrstanley/girc"
-	"github.com/missdeer/golib/ic"
 	"github.com/paulrosania/go-charset/charset"
 	"github.com/saintfish/chardet"
 
@@ -24,12 +23,12 @@ func (b *Birc) handleCharset(msg *config.Message) error {
 	if b.GetString("Charset") != "" {
 		switch b.GetString("Charset") {
 		case "gbk", "gb18030", "gb2312", "big5", "euc-kr", "euc-jp", "shift-jis", "iso-2022-jp":
-			msg.Text = ic.ConvertString("utf-8", b.GetString("Charset"), msg.Text)
+			msg.Text = toUTF8(b.GetString("Charset"), msg.Text)
 		default:
 			buf := new(bytes.Buffer)
 			w, err := charset.NewWriter(b.GetString("Charset"), buf)
 			if err != nil {
-				b.Log.Errorf("charset from utf-8 conversion failed: %s", err)
+				b.Log.Errorf("charset to utf-8 conversion failed: %s", err)
 				return err
 			}
 			fmt.Fprint(w, msg.Text)
@@ -227,7 +226,7 @@ func (b *Birc) handlePrivMsg(client *girc.Client, event girc.Event) {
 	}
 	switch mycharset {
 	case "gbk", "gb18030", "gb2312", "big5", "euc-kr", "euc-jp", "shift-jis", "iso-2022-jp":
-		rmsg.Text = ic.ConvertString("utf-8", b.GetString("Charset"), rmsg.Text)
+		rmsg.Text = toUTF8(b.GetString("Charset"), rmsg.Text)
 	default:
 		r, err := charset.NewReader(mycharset, strings.NewReader(rmsg.Text))
 		if err != nil {