Add update command

cmd/crunchyroll-go/cmd/update.go

@@ -0,0 +1,134 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/spf13/cobra"
+	"io"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+)
+
+var (
+	updateInstallFlag bool
+)
+
+var updateCmd = &cobra.Command{
+	Use:   "update",
+	Short: "Check if updates are available",
+	Args:  cobra.MaximumNArgs(0),
+
+	RunE: func(cmd *cobra.Command, args []string) error {
+		return update()
+	},
+}
+
+func init() {
+	updateCmd.Flags().BoolVarP(&updateInstallFlag,
+		"install",
+		"i",
+		false,
+		"If set and a new version is available, the new version gets installed")
+
+	rootCmd.AddCommand(updateCmd)
+}
+
+func update() error {
+	var release map[string]interface{}
+
+	resp, err := client.Get("https://api.github.com/repos/ByteDream/crunchyroll-go/releases/latest")
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if err = json.NewDecoder(resp.Body).Decode(&release); err != nil {
+		return err
+	}
+	releaseVersion := strings.TrimPrefix(release["tag_name"].(string), "v")
+
+	if Version == "development" {
+		out.Info("Development version, update service not available")
+		return nil
+	}
+
+	latestRelease := strings.SplitN(releaseVersion, ".", 4)
+	if len(latestRelease) != 3 {
+		return fmt.Errorf("latest tag name (%s) is not parsable", releaseVersion)
+	}
+
+	internalVersion := strings.SplitN(Version, ".", 4)
+	if len(internalVersion) != 3 {
+		return fmt.Errorf("internal version (%s) is not parsable", Version)
+	}
+
+	var hasUpdate bool
+	for i := 0; i < 3; i++ {
+		if latestRelease[i] < internalVersion[i] {
+			out.Info("Local version (%s) is newer than version in latest release (%s)", Version, releaseVersion)
+			return nil
+		} else if latestRelease[i] > internalVersion[i] {
+			hasUpdate = true
+		}
+	}
+
+	if !hasUpdate {
+		out.Info("Version is up-to-date")
+		return nil
+	}
+
+	out.Info("A new version is available (%s). Installed version is %s: https://github.com/ByteDream/crunchyroll-go/releases/tag/v%s", releaseVersion, Version, releaseVersion)
+
+	if updateInstallFlag {
+		if runtime.GOARCH != "amd64" {
+			return fmt.Errorf("invalid architecture found (%s), only amd64 is currently supported for automatic updating. "+
+				"You have to update manually (https://github.com/ByteDream/crunchyroll-go)", runtime.GOARCH)
+		}
+
+		var downloadFile string
+		switch runtime.GOOS {
+		case "linux":
+			yayCommand := exec.Command("pacman -Q crunchyroll-go")
+			if yayCommand.Run() == nil && yayCommand.ProcessState.Success() {
+				out.Info("crunchyroll-go was probably installed via an Arch Linux AUR helper (like yay). Updating via this AUR helper is recommended")
+				return nil
+			}
+			downloadFile = fmt.Sprintf("crunchy-v%s_linux", releaseVersion)
+		case "darwin":
+			downloadFile = fmt.Sprintf("crunchy-v%s_darwin", releaseVersion)
+		case "windows":
+			downloadFile = fmt.Sprintf("crunchy-v%s_windows.exe", releaseVersion)
+		default:
+			return fmt.Errorf("invalid operation system found (%s), only linux, windows and darwin / macos are currently supported. "+
+				"You have to update manually (https://github.com/ByteDream/crunchyroll-go)", runtime.GOOS)
+		}
+
+		out.SetProgress("Updating executable %s", os.Args[0])
+
+		perms, err := os.Stat(os.Args[0])
+		if err != nil {
+			return err
+		}
+		os.Remove(os.Args[0])
+		executeFile, err := os.OpenFile(os.Args[0], os.O_CREATE|os.O_WRONLY, perms.Mode())
+		if err != nil {
+			return err
+		}
+		defer executeFile.Close()
+
+		resp, err := client.Get(fmt.Sprintf("https://github.com/ByteDream/crunchyroll-go/releases/download/v%s/%s", releaseVersion, downloadFile))
+		if err != nil {
+			return err
+		}
+		defer resp.Body.Close()
+
+		if _, err = io.Copy(executeFile, resp.Body); err != nil {
+			return err
+		}
+
+		out.StopProgress("Updated executable %s", os.Args[0])
+	}
+
+	return nil
+}

crunchyroll-go.1

@@ -13,6 +13,8 @@ crunchyroll-go login [\fB--persistent\fR] [\fB--session-id\fR \fISESSION_ID\fR]
 crunchyroll-go download [\fB-a\fR \fIAUDIO\fR] [\fB-s\fR \fISUBTITLE\fR] [\fB-d\fR \fIDIRECTORY\fR] [\fB-o\fR \fIOUTPUT\fR] [\fB-r\fR \fIRESOLUTION\fR] [\fB-g\fR \fIGOROUTINES\fR] \fIURLs...\fR
 .br
 crunchyroll-go archive [\fB-l\fR \fILANGUAGE\fR] [\fB-d\fR \fIDIRECTORY\fR] [\fB-o\fR \fIOUTPUT\fR] [\fB-m\fR \fIMERGE BEHAVIOR\fR] [\fB-c\fR \fICOMPRESS\fR] [\fB-r\fR \fIRESOLUTION\fR] [\fB-g\fR \fIGOROUTINES\fR] \fIURLs...\fR
+.br
+crunchyroll-go update [\fB-i\fR \fIINSTALL\fR]
 
 .SH DESCRIPTION
 .TP
@@ -141,6 +143,13 @@ The video resolution. Can either be specified via the pixels (e.g. 1920x1080), t
 \fB-g, --goroutines GOROUTINES\fR
 Sets the number of parallel downloads for the segments the final video is made of. Default is the number of cores the computer has.
 
+.SH UPDATE COMMAND
+Checks if a newer version is available.
+.TP
+
+\fB-i, --install INSTALL\fR
+If given, the command tries to update the executable with the newer version (if a newer is available).
+
 .SH URL OPTIONS
 If you want to download only specific episode of a series, you could either pass every single episode url to the downloader (which is fine for 1 - 3 episodes) or use filtering.
 It works pretty simple, just put a specific pattern surrounded by square brackets at the end of the url from the anime you want to download. A season and / or episode as well as a range from where to where episodes should be downloaded can be specified.