Add Danmaku decode CLI tool

cli/main.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"bufio"
+	"encoding/base64"
+	"encoding/hex"
+	"fmt"
+	"github.com/keuin/slbr/danmaku/dmpkg"
+	"log"
+	"os"
+)
+
+func main() {
+	r := bufio.NewReader(os.Stdin)
+	for {
+		line, _, err := r.ReadLine()
+		if err != nil {
+			panic(err)
+		}
+		var data []byte
+		err = func() error {
+			data, err = hex.DecodeString(string(line))
+			if err == nil {
+				return nil
+			}
+			data, err = base64.StdEncoding.DecodeString(string(line))
+			if err != nil {
+				log.Println("Failed to decode as Hex or Base64 string")
+			}
+			return err
+		}()
+		if err != nil {
+			continue
+		}
+		ex, err := dmpkg.DecodeExchange(data)
+		if err != nil {
+			log.Println("Failed to decode Danmaku exchange: ", err)
+			continue
+		}
+		ex, err = ex.Inflate()
+		if err != nil {
+			log.Println("Failed to decompress Danmaku exchange: ", err)
+			continue
+		}
+		fmt.Println(ex.PrettyString())
+	}
+}

danmaku/dmpkg/package.go

@@ -31,6 +31,11 @@ func (e *DanmakuExchange) String() string {
 		e.Length, e.ProtocolVer, e.Operation, e.Body)
 }
 
+func (e *DanmakuExchange) PrettyString() string {
+	return fmt.Sprintf("DanmakuExchange{length=%v, protocol=%v, operation=%v, body=%v}",
+		e.Length, e.ProtocolVer, e.Operation.String(), string(e.Body))
+}
+
 const (
 	HeaderLength = 16
 	SequenceId   = 1