From a2ea8a3e171a9f8d963522f36bf3bce0336348ba Mon Sep 17 00:00:00 2001
From: Alex <rupta3@gmail.com>
Date: Sat, 10 Nov 2018 20:39:11 +0300
Subject: [PATCH] Added QR code feature

---
 ansi.go  | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 app.go   |  9 ++++++---
 build.sh | 20 ++++++++++++++++++++
 sixel.go | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 utils.go | 21 +++++++++++++++++++++
 5 files changed, 152 insertions(+), 3 deletions(-)
 create mode 100644 ansi.go
 create mode 100755 build.sh
 create mode 100644 sixel.go

diff --git a/ansi.go b/ansi.go
new file mode 100644
index 0000000..3082180
--- /dev/null
+++ b/ansi.go
@@ -0,0 +1,50 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"github.com/mgutz/ansi"
+	"github.com/qpliu/qrencode-go/qrencode"
+	"io"
+)
+
+func printAnsiArtQr(w_in io.Writer, grid *qrencode.BitGrid, inverse bool) {
+	// Buffering required for Windows (go-colorable) support
+	w := bufio.NewWriterSize(w_in, 1024)
+
+	reset := ansi.ColorCode("reset")
+	black := ansi.ColorCode(":black")
+	white := ansi.ColorCode(":white")
+
+	if inverse {
+		black, white = white, black
+	}
+
+	height := grid.Height()
+	width := grid.Width()
+	line := white + fmt.Sprintf("%*s", width*2+2, "") + reset + "\n"
+
+	fmt.Fprint(w, line)
+	for y := 0; y < height; y++ {
+		fmt.Fprint(w, white, " ")
+		color_prev := white
+		for x := 0; x < width; x++ {
+			if grid.Get(x, y) {
+				if color_prev != black {
+					fmt.Fprint(w, black)
+					color_prev = black
+				}
+			} else {
+				if color_prev != white {
+					fmt.Fprint(w, white)
+					color_prev = white
+				}
+			}
+			fmt.Fprint(w, "  ")
+		}
+		fmt.Fprint(w, white, " ", reset, "\n")
+		w.Flush()
+	}
+	fmt.Fprint(w, line)
+	w.Flush()
+}
diff --git a/app.go b/app.go
index 64fc0a0..431744c 100644
--- a/app.go
+++ b/app.go
@@ -21,6 +21,7 @@ func main() {
 
 	address := findLocalIpAddress()
 	randomKey := generateRandomKey(4)
+	resultLink := "http://" + address + port + "/" + randomKey
 
 	router.GET("/"+randomKey, func(c *gin.Context) {
 		c.Writer.Header().Set("Content-Type", "text/html")
@@ -47,11 +48,13 @@ func main() {
 		}
 	})
 
-	println("Go to http://" + address + port + "/" + randomKey + " to control\n")
+	printQrCode(resultLink, true)
+	println("Go to " + resultLink + " to control")
+	println("Or scan this QR code to open the link on your device")
 
-	err := router.Run(port)
+	errServer := router.Run(port)
 
-	if err != nil {
+	if errServer != nil {
 		killWithMessage("Couldn't start the server, releasing the port, try again")
 	}
 }
diff --git a/build.sh b/build.sh
new file mode 100755
index 0000000..6b115a9
--- /dev/null
+++ b/build.sh
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+rm -rf ./dist/
+
+go generate
+goxc -bc="windows,darwin" -d=./dist
+
+find ./dist/ -type d -depth -empty -exec rmdir "{}" \;
+
+if [ ! -d "./dist/" ]; then
+  echo "Could build nothing"
+  exit 1
+fi
+
+echo "Done building, compressing"
+cd ./dist/snapshot/
+
+for i in */; do
+ zip -r "${i%/}.zip" "$i";
+done
\ No newline at end of file
diff --git a/sixel.go b/sixel.go
new file mode 100644
index 0000000..88c5da9
--- /dev/null
+++ b/sixel.go
@@ -0,0 +1,55 @@
+package main
+
+import (
+	"fmt"
+	"github.com/qpliu/qrencode-go/qrencode"
+	"io"
+)
+
+func printSixelQr(w io.Writer, grid *qrencode.BitGrid, inverse bool) {
+	black := "0"
+	white := "1"
+
+	fmt.Fprint(w,
+		"\x1BPq\"1;1",
+		"#", black, ";2;0;0;0",
+		"#", white, ";2;100;100;100",
+	)
+
+	if inverse {
+		black, white = white, black
+	}
+
+	height := grid.Height()
+	width := grid.Width()
+	line := "#" + white + "!" + fmt.Sprintf("%d", (width+2)*6) + "~"
+
+	fmt.Fprint(w, line, "-")
+	for y := 0; y < height; y++ {
+		fmt.Fprint(w, "#", white)
+		color := white
+		repeat := 6
+		var current string
+		for x := 0; x < width; x++ {
+			if grid.Get(x, y) {
+				current = black
+			} else {
+				current = white
+			}
+			if current != color {
+				fmt.Fprint(w, "#", color, "!", repeat, "~")
+				color = current
+				repeat = 0
+			}
+			repeat += 6
+		}
+		if color == white {
+			fmt.Fprintf(w, "#%s!%d~", white, repeat+6)
+		} else {
+			fmt.Fprintf(w, "#%s!%d~#%s!6~", color, repeat, white)
+		}
+		fmt.Fprint(w, "-")
+	}
+	fmt.Fprint(w, line)
+	fmt.Fprint(w, "\x1B\\")
+}
diff --git a/utils.go b/utils.go
index 051a0df..1dd339d 100644
--- a/utils.go
+++ b/utils.go
@@ -1,15 +1,36 @@
 package main
 
 import (
+	"github.com/fumiyas/go-tty"
 	"github.com/kardianos/osext"
+	"github.com/mattn/go-colorable"
+	"github.com/qpliu/qrencode-go/qrencode"
 	"github.com/russross/blackfriday"
 	"io/ioutil"
 	"math/rand"
 	"net"
+	"os"
 	"path"
 	"time"
 )
 
+func printQrCode(src string, inverse bool) {
+	grid, errQr := qrencode.Encode(src, qrencode.ECLevelL)
+
+	if errQr != nil {
+		panic(errQr)
+	}
+
+	da1, errQrText := tty.GetDeviceAttributes1(os.Stdout)
+
+	if errQrText == nil && da1[tty.DA1_SIXEL] {
+		printSixelQr(os.Stdout, grid, inverse)
+	} else {
+		stdout := colorable.NewColorableStdout()
+		printAnsiArtQr(stdout, grid, inverse)
+	}
+}
+
 func generateRandomKey(length int) string {
 	letters := []rune("abcdefghijklmnopqrstuvwxyz")
 	sequence := make([]rune, length)