Add ability to revert to non-hyphenated user IDs

The first 10.7.0 build i tried used hyphens, but a later one didn't.
emails.json can now be converted between the two forms depending on what
the server uses.

jfapi/jfapi.go

@@ -44,6 +44,7 @@ type Jellyfin struct {
 	CacheExpiry    time.Time
 	cacheLength    int
 	noFail         bool
+	Hyphens        bool
 	timeoutHandler common.TimeoutHandler
 }
 
@@ -208,8 +209,8 @@ func (jf *Jellyfin) post(url string, data map[string]interface{}, response bool)
 }
 
 // DeleteUser deletes the user corresponding to the provided ID.
-func (jf *Jellyfin) DeleteUser(id string) (int, error) {
-	url := fmt.Sprintf("%s/Users/%s", jf.Server, id)
+func (jf *Jellyfin) DeleteUser(userID string) (int, error) {
+	url := fmt.Sprintf("%s/Users/%s", jf.Server, userID)
 	req, _ := http.NewRequest("DELETE", url, nil)
 	for name, value := range jf.header {
 		req.Header.Add(name, value)
@@ -239,6 +240,11 @@ func (jf *Jellyfin) GetUsers(public bool) ([]map[string]interface{}, int, error)
 		json.Unmarshal([]byte(data), &result)
 		jf.userCache = result
 		jf.CacheExpiry = time.Now().Add(time.Minute * time.Duration(jf.cacheLength))
+		if id, ok := result[0]["Id"]; ok {
+			if id.(string)[8] == '-' {
+				jf.Hyphens = true
+			}
+		}
 		return result, status, nil
 	}
 	return jf.userCache, 200, nil

main.go

@@ -42,6 +42,7 @@ type User struct {
 	Password string `json:"password"`
 }
 
+// contains everything the application needs, essentially. Wouldn't do this in the future.
 type appContext struct {
 	// defaults         *Config
 	config           *ini.File
@@ -461,7 +462,7 @@ func start(asDaemon, firstCall bool) {
 			app.err.Fatalf("Failed to authenticate with Jellyfin @ %s: Code %d", server, status)
 		}
 		app.info.Printf("Authenticated with %s", server)
-		// from 10.7.0, jellyfin hyphenates user IDs. This checks if the version is equal or higher.
+		// from 10.7.0, jellyfin may hyphenate user IDs. This checks if the version is equal or higher.
 		checkVersion := func(version string) int {
 			numberStrings := strings.Split(version, ".")
 			n := 0
@@ -474,6 +475,9 @@ func start(asDaemon, firstCall bool) {
 			return n
 		}
 		if checkVersion(app.jf.ServerInfo.Version) >= checkVersion("10.7.0") {
+			// Get users to check if server uses hyphenated userIDs
+			app.jf.GetUsers(false)
+
 			noHyphens := true
 			for id := range app.storage.emails {
 				if strings.Contains(id, "-") {
@@ -481,10 +485,19 @@ func start(asDaemon, firstCall bool) {
 					break
 				}
 			}
-			if noHyphens {
-				app.info.Println(aurora.Yellow("From Jellyfin 10.7.0 onwards, user IDs are hyphenated.\nYour emails.json file will be modified to match this new format.\nA backup will be placed next to the file.\n"))
+			if noHyphens == app.jf.Hyphens {
+				var newEmails map[string]interface{}
+				var status int
+				var err error
+				if app.jf.Hyphens {
+					app.info.Println(aurora.Yellow("Your build of Jellyfin appears to hypenate user IDs. Your emails.json file will be modified to match."))
 					time.Sleep(time.Second * time.Duration(3))
-				newEmails, status, err := app.upgradeEmailStorage(app.storage.emails)
+					newEmails, status, err = app.hyphenateEmailStorage(app.storage.emails)
+				} else {
+					app.info.Println(aurora.Yellow("Your emails.json file uses hyphens, but the Jellyfin server no longer does. It will be modified."))
+					time.Sleep(time.Second * time.Duration(3))
+					newEmails, status, err = app.deHyphenateEmailStorage(app.storage.emails)
+				}
 				if status != 200 || err != nil {
 					app.err.Printf("Failed to get users from Jellyfin: Code %d", status)
 					app.debug.Printf("Error: %s", err)

storage.go

@@ -192,10 +192,34 @@ func storeJSON(path string, obj interface{}) error {
 	return err
 }
 
-// JF 10.7.0 added hyphens to user IDs like this and we need to upgrade email storage to match it:
-// [8 chars]-[4]-[4]-[4]-[12]
-// This seems consistent, but we'll grab IDs from jellyfin just in case theres some variation.
-func (app *appContext) upgradeEmailStorage(old map[string]interface{}) (map[string]interface{}, int, error) {
+// One build of JF 10.7.0 hyphenated to user IDs like this and we need to upgrade email storage to match it:
+// One build of JF 10.7.0 hyphenated user IDs while another one later didn't. These functions will hyphenate/de-hyphenate email storage.
+
+func hyphenate(userID string) string {
+	if userID[8] == '-' {
+		return userID
+	}
+	return userID[:8] + "-" + userID[8:12] + "-" + userID[12:16] + "-" + userID[16:20] + "-" + userID[20:]
+}
+
+func (app *appContext) deHyphenateEmailStorage(old map[string]interface{}) (map[string]interface{}, int, error) {
+	jfUsers, status, err := app.jf.GetUsers(false)
+	if status != 200 || err != nil {
+		return nil, status, err
+	}
+	newEmails := map[string]interface{}{}
+	for _, user := range jfUsers {
+		unHyphenated := user["Id"].(string)
+		hyphenated := hyphenate(unHyphenated)
+		email, ok := old[hyphenated]
+		if ok {
+			newEmails[unHyphenated] = email
+		}
+	}
+	return newEmails, status, err
+}
+
+func (app *appContext) hyphenateEmailStorage(old map[string]interface{}) (map[string]interface{}, int, error) {
 	jfUsers, status, err := app.jf.GetUsers(false)
 	if status != 200 || err != nil {
 		return nil, status, err