Send the Telegram replies as rich messages

[onechat] / telegram.go

diff --git a/telegram.go b/telegram.go
index 9dbe86e1cf24e6b629245bd71414aa9d2334bf58..dd62ef0221db72fc88a1893b1421ce301cab0cff 100644 (file)
--- a/telegram.go
+++ b/telegram.go
@@ -60,8 +60,9 @@ type botConfig struct {
 // agent. It ignores every other update. Its sender sends the replies, the
 // errors, the notices of the bot, and the user messages of the other clients to
 // the chat, and shows the typing action while a turn runs. Only the replies
 // agent. It ignores every other update. Its sender sends the replies, the
 // errors, the notices of the bot, and the user messages of the other clients to
 // the chat, and shows the typing action while a turn runs. Only the replies

-// have a format: their Markdown goes as message entities. The rest is plain
-// text. Tool calls do not go to the chat.
+// have a format: their Markdown goes as rich messages, which Telegram renders
+// itself, and as message entities only when Telegram refuses a rich message.
+// The rest is plain text. Tool calls do not go to the chat.

 //
 // The offset file holds the ID of the next update. It moves past an update
 // only after the message of the update is durable in the log, so a restart
 //
 // The offset file holds the ID of the next update. It moves past an update
 // only after the message of the update is durable in the log, so a restart


@@ -244,9 +245,7 @@ func (b *telegramBot) send(ctx context.Context) {
                case "idle":
                        busy = false
                default:
                case "idle":
                        busy = false
                default:

-                       for _, part := range botParts(event) {
-                               b.deliver(ctx, part)
-                       }
+                       b.post(ctx, event)

 
                        if busy {
                                b.typing(ctx)
 
                        if busy {
                                b.typing(ctx)


@@ -276,6 +275,57 @@ func (b *telegramBot) typing(ctx context.Context) {
        _ = b.api.SendTyping(ctx, b.owner)
 }
 
        _ = b.api.SendTyping(ctx, b.owner)
 }
 

+// post sends event to the chat. A reply goes as rich messages of its Markdown,
+// split with splitRich. Every other event goes as plain text, split with
+// splitMessage.
+func (b *telegramBot) post(ctx context.Context, event Event) {
+       if event.Kind != "reply" {
+               for _, text := range splitMessage(botText(event), messageUnits) {
+                       b.deliver(ctx, botPart{
+                               text: text,
+                       })
+               }
+
+               return
+       }
+
+       for _, markdown := range splitRich(event.Text, richMessageBytes) {
+               b.deliverRich(ctx, markdown)
+       }
+}
+
+// deliverRich sends markdown to the chat as a rich message. When the Bot API
+// refuses it with HTTP 400 or 404, the message was not sent, so deliverRich
+// sends the same Markdown once with message entities, and the reply is not
+// lost and does not repeat. It tries again after each failure that a later try
+// can fix, until ctx ends. It drops the message after any other failure.
+func (b *telegramBot) deliverRich(ctx context.Context, markdown string) {
+       wait := b.minWait
+       for {
+               err := b.api.SendRichMessage(ctx, b.owner, markdown)
+               if err == nil || ctx.Err() != nil {
+                       return
+               }
+
+               if rejected(err) {
+                       b.logger.Printf("rich message refused, the reply goes with entities: %v", err)
+                       for _, part := range replyParts(markdown) {
+                               b.deliver(ctx, part)
+                       }
+
+                       return
+               }
+
+               retry, asked := retryable(err)
+               if !retry {
+                       b.logger.Printf("message dropped: %v", err)
+                       return
+               }
+
+               wait = b.pause(ctx, err, wait, asked)
+       }
+}
+

 // deliver sends part to the chat. When Telegram refuses a part with entities
 // (HTTP 400), it sends the text of the part again once with no entities, so a
 // reply is not lost to a bad entity. It tries again after each failure that a
 // deliver sends part to the chat. When Telegram refuses a part with entities
 // (HTTP 400), it sends the text of the part again once with no entities, so a
 // reply is not lost to a bad entity. It tries again after each failure that a


@@ -448,23 +498,6 @@ func saveOffset(path string, offset int64) error {
        return nil
 }
 
        return nil
 }
 

-// botParts returns the messages of event for the chat. The Markdown of a reply
-// becomes text with entities. Every other event is plain text. A reply that has
-// no text left after the conversion, such as an empty code block, goes as its
-// Markdown.
-func botParts(event Event) []botPart {
-       text, entities := botText(event), []botEntity(nil)
-       if event.Kind == "reply" {
-               text, entities = markdownEntities(event.Text)
-       }
-
-       if strings.TrimSpace(text) == "" {
-               text, entities = event.Text, nil
-       }
-
-       return splitEntities(text, entities, messageUnits)
-}
-

 // botText returns the text of event for the chat. A user message of another
 // client has its source as a mark.
 func botText(event Event) string {
 // botText returns the text of event for the chat. A user message of another
 // client has its source as a mark.
 func botText(event Event) string {


@@ -478,38 +511,6 @@ func botText(event Event) string {
        }
 }
 
        }
 }
 

-// splitEntities cuts text into parts with splitMessage, and gives each part the
-// entities in it, with offsets from the start of the part. An entity that
-// crosses a cut becomes one entity in each part.
-func splitEntities(text string, entities []botEntity, limit int) []botPart {
-       var parts []botPart
-       start := 0
-       for _, part := range splitMessage(text, limit) {
-               end := start + utf16Units(part)
-               var kept []botEntity
-               for _, entity := range entities {
-                       from := max(entity.Offset, start)
-                       to := min(entity.Offset+entity.Length, end)
-                       if to <= from {
-                               continue
-                       }
-
-                       entity.Offset = from - start
-                       entity.Length = to - from
-                       kept = append(kept, entity)
-               }
-
-               parts = append(parts, botPart{
-                       text:     part,
-                       entities: kept,
-               })
-
-               start = end
-       }
-
-       return parts
-}
-

 // splitMessage cuts text into parts of at most limit UTF-16 code units, the
 // unit of the Telegram message limit. It cuts after the last line break or
 // space of a part when one is in its second half, and else at the limit. It
 // splitMessage cuts text into parts of at most limit UTF-16 code units, the
 // unit of the Telegram message limit. It cuts after the last line break or
 // space of a part when one is in its second half, and else at the limit. It


@@ -635,3 +636,47 @@ func richCut(markdown string, limit int) (int, string, string) {
 
        return cut, "", ""
 }
 
        return cut, "", ""
 }

+
+// replyParts returns the messages of the Markdown of a reply with message
+// entities. A reply that has no text left after the conversion, such as an
+// empty code block, goes as its Markdown.
+func replyParts(markdown string) []botPart {
+       text, entities := markdownEntities(markdown)
+       if strings.TrimSpace(text) == "" {
+               text, entities = markdown, nil
+       }
+
+       return splitEntities(text, entities, messageUnits)
+}
+
+// splitEntities cuts text into parts with splitMessage, and gives each part the
+// entities in it, with offsets from the start of the part. An entity that
+// crosses a cut becomes one entity in each part.
+func splitEntities(text string, entities []botEntity, limit int) []botPart {
+       var parts []botPart
+       start := 0
+       for _, part := range splitMessage(text, limit) {
+               end := start + utf16Units(part)
+               var kept []botEntity
+               for _, entity := range entities {
+                       from := max(entity.Offset, start)
+                       to := min(entity.Offset+entity.Length, end)
+                       if to <= from {
+                               continue
+                       }
+
+                       entity.Offset = from - start
+                       entity.Length = to - from
+                       kept = append(kept, entity)
+               }
+
+               parts = append(parts, botPart{
+                       text:     part,
+                       entities: kept,
+               })
+
+               start = end
+       }
+
+       return parts
+}