fix(telegram): update docs and generator for private channels (#250)

docs/services/telegram.md

@@ -15,15 +15,18 @@ Talk to [the botfather](https://core.telegram.org/bots#6-botfather).
 
 The `chats` param consists of one or more `Chat ID`s or `channel name`s. 
 
-### Channels
-The channel names can be retrieved in the telegram client in the `Channel info` section. 
+### Public Channels
+The channel names can be retrieved in the telegram client in the `Channel info` section for public channels. 
 Replace the `t.me/` prefix from the link with a `@`.
 
 !!! note
     Channels names need to be prefixed by `@` to identify them as such.
 
+!!! note
+    If your channel only has an invite link (starting with `t.me/+`), you have to use it's Chat ID (see below)
+
 ### Chats
-Group chats and private chats are identifieds by `Chat ID`s. Unfortunatly, they are generally not visible in the
+Private channels, Group chats and private chats are identified by `Chat ID`s. Unfortunatly, they are generally not visible in the
 telegram clients.
 The easiest way to retrieve them is by using the `shoutrrr generate telegram` command which will guide you through
 creating a URL with your target chats.
@@ -34,6 +37,16 @@ creating a URL with your target chats.
     docker run --rm -it containrrr/shoutrrr generate telegram
     ```
 
+### Asking @shoutrrrbot
+Another way of retrieving the Chat IDs, is by forwarding a message from the target chat to the [@shoutrrrbot](https://t.me/shoutrrrbot).
+It will reply with the Chat ID for the chat where the forwarded message was originally posted.
+Note that it will not work correctly for Group chats, as those messages are just seen as being posted by a user, not in a specific chat.
+Instead you can use the second method, which is to invite the @shoutrrrbot into your group chat and address a message to it (start the message with @shoutrrrbot). You can then safely kick the bot from the group. 
+
+The bot should be constantly online, unless it's usage exceeds the free tier on GCP. It's source is available at [github.com/containrrr/shoutrrrbot](https://github.com/containrrr/shoutrrrbot).
+
+
+
 ## Optional parameters
 
 You can optionally specify the __`notification`__, __`parseMode`__ and __`preview`__ parameters in the URL:  

pkg/services/telegram/telegram_generator.go

@@ -15,17 +15,15 @@ import (
 
 // Generator is the telegram-specific URL generator
 type Generator struct {
-	ud            *generator.UserDialog
-	client        *Client
-	chats         []string
-	chatNames     []string
-	chatTypes     []string
-	done          bool
-	owner         *User
-	statusMessage int64
-	botName       string
-	Reader        io.Reader
-	Writer        io.Writer
+	ud        *generator.UserDialog
+	client    *Client
+	chats     []string
+	chatNames []string
+	chatTypes []string
+	done      bool
+	botName   string
+	Reader    io.Reader
+	Writer    io.Writer
 }
 
 // Generate a telegram Shoutrrr configuration from a user dialog
@@ -47,7 +45,6 @@ func (g *Generator) Generate(_ types.Service, props map[string]string, _ []strin
 	token := ud.QueryString("Enter your bot token:", generator.ValidateFormat(IsTokenValid), "token")
 
 	ud.Writeln("Fetching bot info...")
-	// ud.Writeln("Session token: %v", g.sessionToken)
 
 	g.client = &Client{token: token}
 	botInfo, err := g.client.GetBotInfo()
@@ -77,6 +74,9 @@ func (g *Generator) Generate(_ types.Service, props map[string]string, _ []strin
 			panic(err)
 		}
 
+		// If no updates were retrieved, prompt user to continue
+		promptDone := len(updates) == 0
+
 		for _, update := range updates {
 			lastUpdate = update.UpdateID + 1
 
@@ -88,25 +88,37 @@ func (g *Generator) Generate(_ types.Service, props map[string]string, _ []strin
 			if message != nil {
 				chat := message.Chat
 
-				source := message.Chat.Username
+				source := message.Chat.Name()
 				if message.From != nil {
-					source = message.From.Username
+					source = "@" + message.From.Username
 				}
-				ud.Writeln("Got Message '%v' from @%v in %v chat %v",
+
+				ud.Writeln("Got Message '%v' from %v in %v chat %v",
 					f.ColorizeString(message.Text),
 					f.ColorizeProp(source),
 					f.ColorizeEnum(chat.Type),
 					f.ColorizeNumber(chat.ID))
 				ud.Writeln(g.addChat(chat))
+				// Another chat was added, prompt user to continue
+				promptDone = true
+			} else if update.ChatMemberUpdate != nil {
+				cmu := update.ChatMemberUpdate
+				oldStatus := cmu.OldChatMember.Status
+				newStatus := cmu.NewChatMember.Status
+				ud.Writeln("Got a bot chat member update for %v, status was changed from %v to %v",
+					f.ColorizeProp(cmu.Chat.Name()),
+					f.ColorizeEnum(oldStatus),
+					f.ColorizeEnum(newStatus))
 			} else {
 				ud.Writeln("Got unknown Update. Ignored!")
 			}
 		}
+		if promptDone {
+			ud.Writeln("")
 
-		ud.Writeln("")
-
-		g.done = !ud.QueryBool(fmt.Sprintf("Got %v chat ID(s) so far. Want to add some more?",
-			f.ColorizeNumber(len(g.chats))), "")
+			g.done = !ud.QueryBool(fmt.Sprintf("Got %v chat ID(s) so far. Want to add some more?",
+				f.ColorizeNumber(len(g.chats))), "")
+		}
 	}
 
 	ud.Writeln("")

pkg/services/telegram/telegram_generator_test.go

@@ -2,13 +2,14 @@ package telegram_test
 
 import (
 	"fmt"
+	"io"
+	"strings"
+
 	"github.com/jarcoal/httpmock"
 	"github.com/mattn/go-colorable"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 	"github.com/onsi/gomega/gbytes"
-	"io"
-	"strings"
 
 	"github.com/containrrr/shoutrrr/pkg/services/telegram"
 )
@@ -78,6 +79,13 @@ var _ = Describe("TelegramGenerator", func() {
 		}{
 			true,
 			[]telegram.Update{
+				{
+					ChatMemberUpdate: &telegram.ChatMemberUpdate{
+						Chat:          &telegram.Chat{Type: `channel`, Title: `mockChannel`},
+						OldChatMember: &telegram.ChatMember{Status: `kicked`},
+						NewChatMember: &telegram.ChatMember{Status: `administrator`},
+					},
+				},
 				{
 					Message: &telegram.Message{
 						Text: "hi!",
@@ -102,6 +110,7 @@ var _ = Describe("TelegramGenerator", func() {
 		mockTyped(mockToken)
 		mockTyped(`no`)
 
+		Eventually(userIn).Should(gbytes.Say(`Got a bot chat member update for mockChannel, status was changed from kicked to administrator`))
 		Eventually(userIn).Should(gbytes.Say(`Got 1 chat ID\(s\) so far\. Want to add some more\?`))
 		Eventually(userIn).Should(gbytes.Say(`Selected chats:`))
 		Eventually(userIn).Should(gbytes.Say(`667 \(private\) @mockUser`))

pkg/services/telegram/telegram_json.go

@@ -138,16 +138,19 @@ type Update struct {
 	ChosenInlineResult *chosenInlineResult `json:"chosen_inline_result"`
 	//// 	Optional. New incoming callback query
 	CallbackQuery *callbackQuery `json:"callback_query"`
+
+	// API fields that are not used by the client has been commented out
+
 	//// 	Optional. New incoming shipping query. Only for invoices with flexible price
 	//ShippingQuery	ShippingQuery `json:"shipping_query"`
 	//// 	Optional. New incoming pre-checkout query. Contains full information about checkout
 	//PreCheckoutQuery	PreCheckoutQuery `json:"pre_checkout_query"`
-	/*
-		// 	Optional. New poll state. Bots receive only updates about stopped polls and polls, which are sent by the bot
-		Poll	Poll `json:"poll"`
-		// 	Optional. A User changed their answer in a non-anonymous poll. Bots receive new votes only in polls that were sent by the bot itself.
-		Poll_answer	PollAnswer `json:"poll_answer"`
-	*/
+	//// 	Optional. New poll state. Bots receive only updates about stopped polls and polls, which are sent by the bot
+	//Poll	Poll `json:"poll"`
+	//// 	Optional. A User changed their answer in a non-anonymous poll. Bots receive new votes only in polls that were sent by the bot itself.
+	//Poll_answer	PollAnswer `json:"poll_answer"`
+
+	ChatMemberUpdate *ChatMemberUpdate `json:"my_chat_member"`
 }
 
 // Chat represents a telegram conversation
@@ -160,7 +163,7 @@ type Chat struct {
 
 // Name returns the name of the channel based on its type
 func (c *Chat) Name() string {
-	if c.Type == "private" || c.Type == "channel" {
+	if c.Type == "private" || c.Type == "channel" && c.Username != "" {
 		return "@" + c.Username
 	}
 	return c.Title
@@ -191,3 +194,27 @@ type callbackQuery struct {
 	Message *Message `json:"Message"`
 	Data    string   `json:"data"`
 }
+
+// ChatMemberUpdate represents a member update in a telegram chat
+type ChatMemberUpdate struct {
+	// Chat the user belongs to
+	Chat *Chat `json:"chat"`
+	// Performer of the action, which resulted in the change
+	From *User `json:"from"`
+	// Date the change was done in Unix time
+	Date int `json:"date"`
+	// Previous information about the chat member
+	OldChatMember *ChatMember `json:"old_chat_member"`
+	// New information about the chat member
+	NewChatMember *ChatMember `json:"new_chat_member"`
+	// Optional. Chat invite link, which was used by the user to join the chat; for joining by invite link events only.
+	// invite_link ChatInviteLink
+}
+
+// ChatMember represents the membership state for a user in a telegram chat
+type ChatMember struct {
+	//	The member's status in the chat
+	Status string `json:"status"`
+	// Information about the user
+	User *User `json:"user"`
+}