feat: add update command which looks at os and tries to update

this command will try to download and replace your current binary with
the latest release binary

src/cmd/update.go

@@ -0,0 +1,211 @@
+package cmd
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"regexp"
+	"runtime"
+
+	"github.com/spf13/cobra"
+)
+
+// updateCmd represents the update command
+var updateCmd = &cobra.Command{
+	Use:   "update",
+	Short: "Tries to update the cocommit cli tool by either running the update script or by running the go get command if the -g flag is set",
+	Long:  `This command will try to update the cocommit cli tool by either running the update script or by running the go get Command if the -g flag is set.`,
+	Run: func(cmd *cobra.Command, args []string) {
+		gflag, _ := cmd.Flags().GetBool("go-get")
+
+		if gflag {
+			fmt.Println("Running go get command to update cocommit cli tool")
+			cmd := exec.Command("go", "get", "-u", "github.com/Slug-Boi/cocommit")
+			err := cmd.Run()
+			if err != nil {
+				fmt.Println("Error running go get command")
+			}
+			fmt.Println("Cocommit cli tool updated successfully")
+		} else {
+			fmt.Println("Running update script to update cocommit cli tool")
+			updateScript()
+		}
+
+	},
+}
+
+func cleanup() {
+	os.Remove("cocommit.tar.gz")
+}
+
+func updateScript() {
+
+	exec_path, err := os.Executable()
+	if err != nil {
+		fmt.Println("Error getting executable path")
+	}
+	if filepath.Base(exec_path) == "main" {
+		fmt.Println("Cancelling update running as source code")
+		return
+	}
+
+	exec_path, err = filepath.EvalSymlinks(exec_path)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	file, err := os.Create("cocommit.tar.gz")
+	if err != nil {
+		fmt.Println("Error creating file")
+	}
+
+	defer cleanup()
+
+	defer file.Close()
+
+	var resp *http.Response
+	switch runtime.GOOS {
+	case "darwin":
+		fmt.Println("Downloading mac version")
+		if runtime.GOARCH == "amd64" {
+			resp, err = http.Get("https://github.com/Slug-Boi/cocommit/releases/latest/download/cocommit-darwin-x86_64.tar.gz")
+		} else {
+			resp, err = http.Get("https://github.com/Slug-Boi/cocommit/releases/latest/download/cocommit-darwin-aarch64.tar.gz")
+		}
+	case "windows":
+		fmt.Println("Downloading windows version")
+		resp, err = http.Get("https://github.com/Slug-Boi/cocommit/releases/latest/download/cocommit-win.tar.gz")
+	default:
+		fmt.Println("Downloading linux version")
+		resp, err = http.Get("https://github.com/Slug-Boi/cocommit/releases/latest/download/cocommit-linux.tar.gz")
+	}
+
+	if err != nil {
+		fmt.Println("Error downloading file")
+	}
+
+	defer resp.Body.Close()
+	_, err = io.Copy(file, resp.Body)
+	if err != nil {
+		fmt.Println("Error copying file")
+	}
+
+	r, err := os.Open("cocommit.tar.gz")
+	if err != nil {
+		fmt.Println("Error opening file")
+	}
+	err = unzipper("./", r)
+	if err != nil {
+		fmt.Println("Error unzipping file")
+	}
+
+	swapper(exec_path)
+
+	fmt.Println("Cocommit cli tool updated successfully")
+}
+
+func swapper(exec_path string) {
+
+	regExp, err := regexp.Compile("cocommit_go-darwin")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	var new_binary string
+
+	err = filepath.Walk("./", func(path string, info os.FileInfo, err error) error {
+		if err == nil && regExp.MatchString(info.Name()) {
+			new_binary = info.Name()
+			return nil
+		}
+		return nil
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	defer os.Remove(new_binary)
+
+	if new_binary != "" {
+		err = os.Rename(new_binary, exec_path)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+}
+
+func unzipper(dst string, r io.Reader) error {
+	gzr, err := gzip.NewReader(r)
+	if err != nil {
+		return err
+	}
+	defer gzr.Close()
+
+	tr := tar.NewReader(gzr)
+
+	for {
+		header, err := tr.Next()
+
+		switch {
+
+		// if no more files are found return
+		case err == io.EOF:
+			return nil
+
+		// return any other error
+		case err != nil:
+			return err
+
+		// if the header is nil, just skip it (not sure how this happens)
+		case header == nil:
+			continue
+		}
+
+		// the target location where the dir/file should be created
+		target := filepath.Join(dst, header.Name)
+
+		// the following switch could also be done using fi.Mode(), not sure if there
+		// a benefit of using one vs. the other.
+		// fi := header.FileInfo()
+
+		// check the file type
+		switch header.Typeflag {
+
+		// if its a dir and it doesn't exist create it
+		case tar.TypeDir:
+			if _, err := os.Stat(target); err != nil {
+				if err := os.MkdirAll(target, 0755); err != nil {
+					return err
+				}
+			}
+
+		// if it's a file create it
+		case tar.TypeReg:
+			f, err := os.OpenFile(target, os.O_CREATE|os.O_RDWR, os.FileMode(header.Mode))
+			if err != nil {
+				return err
+			}
+
+			// copy over contents
+			if _, err := io.Copy(f, tr); err != nil {
+				return err
+			}
+
+			// manually close here after each file operation; defering would cause each file close
+			// to wait until all operations have completed.
+			f.Close()
+		}
+	}
+}
+
+func init() {
+	rootCmd.AddCommand(updateCmd)
+	updateCmd.Flags().BoolP("go-get", "g", false, "Use the go get command to update the cocommit cli tool")
+}