refactor simple screen output into screenHandler function to parse ANSI files (with optional go template fields)

go.mod

@@ -6,5 +6,5 @@ require (
 	github.com/creack/pty v1.1.11
 	github.com/xtaci/gaio v1.2.9
 	golang.org/x/sys v0.0.0-20210415045647-66c3f260301c // indirect
-	golang.org/x/term v0.0.0-20210406210042-72f3dc4e9b72 // indirect
+	golang.org/x/term v0.0.0-20210406210042-72f3dc4e9b72
 )

go.sum

@@ -3,8 +3,6 @@ github.com/creack/pty v1.1.11/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ
 github.com/xtaci/gaio v1.2.9 h1:EuVc7Q2JDzIY2mk5mjtq4K5BgTuO+kj5LXzCwjOK+mo=
 github.com/xtaci/gaio v1.2.9/go.mod h1:rJMerwiLCLnKa14YTM/sRggTPrnBZrlCg9U3DnV5VBE=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210414055047-fe65e336abe0 h1:g9s1Ppvvun/fI+BptTMj909BBIcGrzQ32k9FNlcevOE=
-golang.org/x/sys v0.0.0-20210414055047-fe65e336abe0/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210415045647-66c3f260301c h1:6L+uOeS3OQt/f4eFHXZcTxeZrGCuz+CLElgEBjbcTA4=
 golang.org/x/sys v0.0.0-20210415045647-66c3f260301c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20210406210042-72f3dc4e9b72 h1:VqE9gduFZ4dbR7XoL77lHFp0/DyDUBKSXK7CMFkVcV0=

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"flag"
@@ -12,6 +13,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"text/template"
 	"time"
 
 	"github.com/creack/pty"
@@ -102,7 +104,11 @@ func main() {
 		log.Printf("new context for client %v: %v\n", conn.RemoteAddr(), ctx)
 
 		// submit the first async write IO request
-		err = w.Write(ctx, conn, welcomeHandler())
+		welcomeScreen, err := screenHandler("welcome")
+		if err != nil {
+			log.Printf("err loading initial welcome screen: %v\n", err)
+		}
+		err = w.Write(ctx, conn, welcomeScreen)
 		if err != nil {
 			log.Printf("err sending welcomeHandler: %v\n", err)
 			return
@@ -179,7 +185,11 @@ func menuHandler(ctx context.Context, conn net.Conn, w *gaio.Watcher) {
 							switch string(strings.TrimSpace(string(res.Buffer[:res.Size-2]))) {
 
 							case "welcome":
-								if err := w.Write(ctx, conn, welcomeHandler()); err != nil {
+								welcomeStr, err := screenHandler("welcome")
+								if err != nil {
+									log.Printf("err loading welcome screen: %v\n", err)
+								}
+								if err := w.Write(ctx, conn, welcomeStr); err != nil {
 									log.Printf("error sending welcomeHandler from cmd `welcome`: %v", err)
 								}
 
@@ -199,22 +209,18 @@ func menuHandler(ctx context.Context, conn net.Conn, w *gaio.Watcher) {
 								}
 
 							case "exit":
-								if err := w.Write(ctx, conn, exitHandler()); err != nil {
+								exitStr, err := screenHandler("exit")
-									log.Printf("error sending exitHandler from cmd `exit`: %v\n", err)
-								} else {
-									// let's wait before we actually close the connection to try and ensure the write gets through
-									time.Sleep(time.Second)
-									log.Println("exiting...")
-									log.Printf("Goodbye %s!\n", conn.RemoteAddr())
-									err := w.Free(conn)
 								if err != nil {
-										log.Printf("err closing connection: %v\n", err)
+									log.Printf("err loading exit screen: %v\n", err)
 								}
-									MenuControl <- "stop"
+								if err := w.Write(ctx, conn, exitStr); err != nil {
-									break ControlLoop
+									log.Printf("error sending exitHandler from cmd `exit`: %v", err)
 								}
-							default:
+								// wait a second before really closing the connection
+								time.Sleep(time.Second)
+								w.Free(conn)
 
+							default:
 								err := w.Write(ctx, conn, []byte("huh?\n\n> "))
 								if err != nil {
 									log.Printf("error writing to connection: %v", err)
@@ -244,47 +250,16 @@ func menuHandler(ctx context.Context, conn net.Conn, w *gaio.Watcher) {
 	log.Println("terminating menucontrol for client")
 }
 
-func welcomeHandler() []byte {
+func screenHandler(screenName string) (screen []byte, err error) {
-	const bannerText = "\x1b[2J\x1b[H\x1b[31m\x1b[J\r\n" + `
+	var screenBuf *bytes.Buffer
+	if tmpl, err := template.ParseFiles("screens/" + screenName + ".ans"); err != nil {
+		log.Printf("err loading welcome template: %v\n", err)
+	} else {
+		screenBuf = new(bytes.Buffer)
+		tmpl.Execute(screenBuf, nil)
+	}
 
-    _       __     _ ` + "" + `
+	return screenBuf.Bytes(), err
-   | |     / /__  / /________  ____ ___  ___` + "" + `
-   | | /| / / _ \/ / ___/ __ \/ __ '__ \/ _ \` + "" + `
-   | |/ |/ /  __/ / /__/ /_/ / / / / / /  __/` + "" + `
-   |__/|__/\___/_/\___/\____/_/ /_/ /_/\___/` + "\r\n\x1b[33m" + `
-                __` + "" + `
-               / /_____ ` + "" + `
-              / __/ __ \` + "" + `
-             / /_/ /_/ /` + "" + `
-             \__/\____/` + "\x1b[35m\r\n" + `
-                    _    __` + "" + `
-                   | |  / /__  _____________` + "" + `
-                   | | / / _ \/ ___/ ___/ _ \` + "" + `
-                   | |/ /  __/ /  (__  )  __/` + "" + `
-                   |___/\___/_/  /____/\___/` + "\x1b[37m\r\n" + `
-                          _____ __            ___` + "" + `
-                         / ___// /___  ______/ (_)___  _____` + "" + `
-                         \__ \/ __/ / / / __  / / __ \/ ___/` + "" + `
-                        ___/ / /_/ /_/ / /_/ / / /_/ (__  ) ` + "" + `
-                       /____/\__/\__,_/\__,_/_/\____/____/  ` + "\x1b[32m\r\n\r\n\r\n" + `
-   Help is available: type help` + "\r\n\r\n> "
-
-	return []byte(bannerText)
-}
-
-func exitHandler() []byte {
-	const exitMessage = "\x1b[2J\x1b[H\x1b[31m\x1b[J\r\n" + `
-
-      ___|                                                                                  |                 |
-    \___ \   _ \  _ \  |   |  _ \  |   |     __| __ \   _' |  __|  _ \   __|  _ \\ \  \   / __ \   _ \  |   | |
-          |  __/  __/  |   | (   | |   |   \__ \ |   | (   | (     __/  (    (   |\ \  \ /  |   | (   | |   |_|
-    _____/ \___|\___| \__, |\___/ \__,_| ) ____/ .__/ \__,_|\___|\___| \___|\___/  \_/\_/  _.__/ \___/ \__, |_)
-                      ____/             /       _|                                                     ____/
-
-
-`
-
-	return []byte(exitMessage)
 }
 
 func doorHandler(ctx context.Context, c net.Conn, w *gaio.Watcher, menuwg *sync.WaitGroup) error {

screens/exit.ans

@@ -0,0 +1,8 @@
+
+
+      ___|                                                                                  |                 |
+    \___ \   _ \  _ \  |   |  _ \  |   |     __| __ \   _' |  __|  _ \   __|  _ \\ \  \   / __ \   _ \  |   | |
+          |  __/  __/  |   | (   | |   |   \__ \ |   | (   | (     __/  (    (   |\ \  \ /  |   | (   | |   |_|
+    _____/ \___|\___| \__, |\___/ \__,_| ) ____/ .__/ \__,_|\___|\___| \___|\___/  \_/\_/  _.__/ \___/ \__, |_)
+                      ____/             /       _|                                                     ____/
+

screens/welcome.ans

@@ -0,0 +1,29 @@
+
+
+    _       __     _ 
+   | |     / /__  / /________  ____ ___  ___
+   | | /| / / _ \/ / ___/ __ \/ __ `__ \/ _ \
+   | |/ |/ /  __/ / /__/ /_/ / / / / / /  __/
+   |__/|__/\___/_/\___/\____/_/ /_/ /_/\___/
+                __
+               / /_____ 
+              / __/ __ \
+             / /_/ /_/ /
+             \__/\____/
+                    _    __
+                   | |  / /__  _____________
+                   | | / / _ \/ ___/ ___/ _ \
+                   | |/ /  __/ /  (__  )  __/
+                   |___/\___/_/  /____/\___/
+                          _____ __            ___
+                         / ___// /___  ______/ (_)___  _____
+                         \__ \/ __/ / / / __  / / __ \/ ___/
+                        ___/ / /_/ /_/ / /_/ / / /_/ (__  ) 
+                       /____/\__/\__,_/\__,_/_/\____/____/  
+                       
+
+    
+   Help is available: type help
+   
+
+>