From: Javier Sancho <jsf@jsancho.org>
Date: Tue, 12 Dec 2017 16:31:30 +0000 (+0100)
Subject: Add telnet file with support to send and receive text from Merc MUD
X-Git-Url: https://git.jsancho.org/?a=commitdiff_plain;h=HEAD;p=midgaard_bot.git

Add telnet file with support to send and receive text from Merc MUD
---

diff --git a/telnet.go b/telnet.go
new file mode 100644
index 0000000..f674e01
--- /dev/null
+++ b/telnet.go
@@ -0,0 +1,90 @@
+/*
+midgaard_bot, a Telegram bot which sets a bridge to Midgaard Merc MUD
+Copyright (C) 2017 by Javier Sancho Fernandez <jsf at jsancho dot org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package main
+
+import (
+	"bytes"
+	"time"
+
+	"github.com/reiver/go-oi"
+	"github.com/reiver/go-telnet"
+)
+
+type TelnetCaller struct {
+	Input chan string
+	Output chan string
+}
+
+func (caller TelnetCaller) CallTELNET(ctx telnet.Context, writer telnet.Writer, reader telnet.Reader) {
+
+	// Send text to MUD
+	go func() {
+		var buffer bytes.Buffer
+		var p []byte
+
+		crlfBuffer := [2]byte{'\r', '\n'}
+		crlf := crlfBuffer[:]
+
+		for {
+			message := <-caller.Input
+			buffer.Write([]byte(message))
+			buffer.Write(crlf)
+
+			p = buffer.Bytes()
+			oi.LongWrite(writer, p)
+			buffer.Reset()
+		}
+	}()
+
+	// Receive text from MUD
+	chunks := make(chan string)
+	chunk := ""
+	
+	go func() {
+		var buffer [1]byte
+		p := buffer[:]
+
+		for {
+			n, err := reader.Read(p)
+			if n <= 0 && err == nil {
+				continue
+			} else if n <= 0 && err != nil {
+				break
+			}
+
+			chunks <- string(p)
+		}
+	}()
+
+	for {
+		select {
+		case input := <-chunks:
+			chunk = input
+			for chunk != "" {
+				select {
+				case input := <-chunks:
+					chunk = chunk + input
+				case <-time.After(time.Millisecond * 500):
+					caller.Output <- chunk
+					chunk = ""
+				}
+			}
+		}
+	}
+}