From 662c7f54f3df0d6937751cdaaf98902a3e4f2d31 Mon Sep 17 00:00:00 2001
From: lukas <lukas.heiligenbrunner@gmail.com>
Date: Thu, 26 Aug 2021 16:32:51 +0200
Subject: [PATCH] init

---
 Main.go   | 166 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 README.md |   7 +++
 go.mod    |   3 +
 3 files changed, 176 insertions(+)
 create mode 100644 Main.go
 create mode 100644 README.md
 create mode 100644 go.mod

diff --git a/Main.go b/Main.go
new file mode 100644
index 0000000..9513b86
--- /dev/null
+++ b/Main.go
@@ -0,0 +1,166 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"log"
+	"os/exec"
+	"regexp"
+	"runtime"
+	"strconv"
+)
+
+func main() {
+	fmt.Printf("Pdflatex command exists: %t\n", commandExists("pdflatex"))
+	fmt.Printf("%s/%s\n", runtime.GOOS, runtime.GOARCH)
+
+	compileAndInstall()
+}
+
+func compileAndInstall() {
+	out, err := compileLatex("main.tex")
+	//fmt.Println(*out)
+	if err != nil {
+		fmt.Println("An error occured while compiling the document!")
+
+		filename := parseMissingFile(out)
+		if filename != "" {
+			fmt.Printf("We need to download: %s\n", filename)
+
+			// now we neet to perform a root check
+			if rootCheck() {
+				log.Println("Awesome! You are now running this program with root permissions!")
+
+				if installFile(filename) {
+					// if successfully installed we try to compile again
+					compileAndInstall()
+				}
+			} else {
+				log.Fatal("This program must be run as root! (sudo)")
+			}
+		} else {
+			fmt.Println(*out)
+
+			fmt.Println("another build error occured!")
+		}
+	} else {
+		fmt.Println("document built successfully!")
+	}
+}
+
+func parseMissingFile(output *string) string {
+	matchfile := regexp.MustCompile("! LaTeX Error: File `([^`']*)' not found|! I can't find file `([^`']*)'.")
+	matches := matchfile.FindStringSubmatch(*output)
+	fmt.Printf("%#v\n", matches)
+	if matches != nil {
+		if matches[1] != "" {
+			return matches[1]
+		} else {
+			return matches[2]
+		}
+	}
+
+	// ok now we try to find a font error
+	fontregex := regexp.MustCompile(`! Font \\[^=]*=([^\s]*)\s`)
+	fontmatch := fontregex.FindStringSubmatch(*output)
+	fmt.Printf("%#v\n", fontmatch)
+	if fontmatch != nil {
+		if fontmatch[1] != "" {
+			return fontmatch[1]
+		}
+	}
+
+	// now try babel errors
+	babelregex := regexp.MustCompile("Unknown option `([^`']*)'. Either you misspelled")
+	babelmatch := babelregex.FindStringSubmatch(*output)
+	if babelmatch != nil {
+		if babelmatch[1] != "" {
+			return babelmatch[1] + ".ldf"
+		}
+	}
+
+	return ""
+}
+
+// check if a specific system command is available
+func commandExists(cmd string) bool {
+	_, err := exec.LookPath(cmd)
+	return err == nil
+}
+
+// parse the thumbail picture from video file
+func compileLatex(filename string) (*string, error) {
+	app := "pdflatex"
+
+	cmd := exec.Command(app,
+		"-file-line-error",
+		"-interaction=nonstopmode",
+		"-synctex=1",
+		"-output-format=pdf",
+		filename)
+
+	stdout, err := cmd.Output()
+
+	output := string(stdout)
+
+	return &output, err
+}
+
+func rootCheck() bool {
+	cmd := exec.Command("id", "-u")
+	output, err := cmd.Output()
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// output has trailing \n
+	// need to remove the \n
+	// otherwise it will cause error for strconv.Atoi
+	// log.Println(output[:len(output)-1])
+
+	// 0 = root, 501 = non-root user
+	i, err := strconv.Atoi(string(output[:len(output)-1]))
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	if i == 0 {
+		return true
+	} else {
+		return false
+	}
+}
+
+func installFile(filename string) bool {
+	if !commandExists("dnf") {
+		fmt.Println("dnf not existing!")
+		return false
+	}
+
+	cmd := exec.Command("dnf", "-y", "install", fmt.Sprintf("tex(%s)", filename))
+	fmt.Println(cmd.String())
+
+	stdout, _ := cmd.StdoutPipe()
+	stderr, _ := cmd.StderrPipe()
+
+	fmt.Println("running dnf install now!")
+
+	go func() {
+		merged := io.MultiReader(stderr, stdout)
+		scanner := bufio.NewScanner(merged)
+		for scanner.Scan() {
+			m := scanner.Text()
+			fmt.Println(m)
+		}
+	}()
+
+	err := cmd.Run()
+	if err != nil {
+		fmt.Println(err.Error())
+		return false
+	}
+	return true
+}
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e58d75a
--- /dev/null
+++ b/README.md
@@ -0,0 +1,7 @@
+# LatexAutoInstaller
+
+This application installs all neccessary latex packages to perform a successfull build.
+
+## Currently Supported OS
+
+* Fedora
\ No newline at end of file
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..b6bc42c
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module latexautoinstaller
+
+go 1.16