go: Build a quick binary for testing the git commands

This binary could probably be easily distributed to users of GitJournal
so that they can easily test out if GitJournal would work for their
particular SSH setup.

And this would also help contributors to diagnose why it doesn't work
for them.

Author: vHanda

src/cmd/gitjournal-ssh-test/main.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	git "github.com/gitjournal/go-git-dart/internal/git"
+	keygen "github.com/gitjournal/go-git-dart/internal/keygen"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Println("Please provide a command: clone, fetch, push, defaultBranch")
+		return
+	}
+
+	command := os.Args[1]
+	switch command {
+	case "clone":
+		if len(os.Args) != 6 {
+			fmt.Println("Usage: clone <url> <directory> <pemFile> <pemPassword>")
+			return
+		}
+		pemBytes, err := os.ReadFile(os.Args[4])
+		if err != nil {
+			fmt.Println("Error reading PEM file:", err)
+			return
+		}
+		err = git.Clone(os.Args[2], os.Args[3], pemBytes, os.Args[5])
+		if err != nil {
+			fmt.Println("Error cloning:", err)
+			return
+		}
+
+	case "fetch", "push", "defaultBranch":
+		if len(os.Args) != 5 {
+			fmt.Printf("Usage: %s <remote> <pemFile> <pemPassword>\n", command)
+			return
+		}
+		directory, err := os.Getwd()
+		if err != nil {
+			fmt.Println("Error getting current directory:", err)
+			return
+		}
+		fmt.Println(directory)
+		pemBytes, err := os.ReadFile(os.Args[3])
+		if err != nil {
+			fmt.Println("Error reading PEM file:", err)
+			return
+		}
+
+		switch command {
+		case "fetch":
+			err := git.Fetch(os.Args[2], directory, pemBytes, os.Args[4])
+			if err != nil {
+				fmt.Println("Error fetching:", err)
+				return
+			}
+
+		case "push":
+			err := git.Push(os.Args[2], directory, pemBytes, os.Args[4])
+			if err != nil {
+				fmt.Println("Error pushing:", err)
+				return
+			}
+
+		case "defaultBranch":
+			branch, err := git.DefaultBranch(os.Args[2], pemBytes, os.Args[4])
+			if err != nil {
+				fmt.Println("Error getting default branch:", err)
+				return
+			}
+			fmt.Printf("DefaultBranch: %s\n", branch)
+		}
+	case "keygen":
+		publicKey, privateKey, err := keygen.GenerateRSAKeys()
+		if err != nil {
+			fmt.Println("Error generating keys:", err)
+			return
+		}
+
+		fmt.Printf("Public Key: %s\n", publicKey)
+		fmt.Printf("Private Key: %s\n", privateKey)
+		return
+
+	default:
+		fmt.Printf("Unknown command: %s\n", command)
+	}
+}