X-Git-Url: http://git.giacomolli.uk/onechat/blobdiff_plain/d206de3a2e839ffbda9cbdb10a3ed93c4915fce3..f80b058ae0550a56b4e62f8e65c2a74349b970e4:/botapi.go?ds=inline

diff --git a/botapi.go b/botapi.go
index 9086fdc..f48465c 100644
--- a/botapi.go
+++ b/botapi.go
@@ -21,6 +21,13 @@ const (
 	// take before the bot gives it up.
 	pollSlack = 20 * time.Second
 
+	// sendTimeout is how long a sendMessage or sendChatAction call can
+	// take. A connection that stops without a close, such as after a
+	// network change, then fails the call, and the sender tries again,
+	// instead of a wait until TCP gives up. The client has no timeout of
+	// its own, because the long poll of getUpdates needs a longer limit.
+	sendTimeout = 30 * time.Second
+
 	// botAnswerBytes is the most bytes of one answer of the Bot API.
 	botAnswerBytes = 16 << 20
 )
@@ -30,11 +37,13 @@ const (
 var errBotNetwork = errors.New("no valid answer from the Bot API")
 
 // botAPI calls the Telegram Bot API. The bot token is a part of each URL, so no
-// error of botAPI holds a URL, a net/http error, or the token.
+// error of botAPI holds a URL, a net/http error, or the token. SendTimeout
+// limits each sendMessage and sendChatAction call.
 type botAPI struct {
-	base  string
-	token string
-	http  *http.Client
+	base        string
+	token       string
+	http        *http.Client
+	sendTimeout time.Duration
 }
 
 // botError is an answer of the Bot API that tells of a failure. RetryAfter is
@@ -78,6 +87,17 @@ type botChat struct {
 	Type string `json:"type"`
 }
 
+// botEntity is a message entity of sendMessage: a part of the text with a
+// format, such as bold or a link. Offset and Length count UTF-16 code units.
+// URL is the target of a text_link, and Language the language of a pre.
+type botEntity struct {
+	Type     string `json:"type"`
+	Offset   int    `json:"offset"`
+	Length   int    `json:"length"`
+	URL      string `json:"url,omitempty"`
+	Language string `json:"language,omitempty"`
+}
+
 // botUser is the sender of a message.
 type botUser struct {
 	ID int64 `json:"id"`
@@ -86,9 +106,10 @@ type botUser struct {
 // newBotAPI returns the client of the Bot API at base with token.
 func newBotAPI(base, token string) *botAPI {
 	return &botAPI{
-		base:  base,
-		token: token,
-		http:  &http.Client{},
+		base:        base,
+		token:       token,
+		http:        &http.Client{},
+		sendTimeout: sendTimeout,
 	}
 }
 
@@ -109,16 +130,31 @@ func (b *botAPI) GetUpdates(ctx context.Context, offset int64) ([]botUpdate, err
 	return updates, err
 }
 
-// SendMessage sends text to chat as plain text, with no parse mode.
-func (b *botAPI) SendMessage(ctx context.Context, chat int64, text string) error {
-	return b.call(ctx, "sendMessage", map[string]any{
+// SendMessage sends text to chat with the format of entities, with no parse
+// mode, so the text needs no escaping. With no entities, the text is plain. A
+// call that takes longer than sendTimeout fails with errBotNetwork.
+func (b *botAPI) SendMessage(ctx context.Context, chat int64, text string, entities []botEntity) error {
+	ctx, cancel := context.WithTimeout(ctx, b.sendTimeout)
+	defer cancel()
+
+	params := map[string]any{
 		"chat_id": chat,
 		"text":    text,
-	}, nil)
+	}
+
+	if len(entities) > 0 {
+		params["entities"] = entities
+	}
+
+	return b.call(ctx, "sendMessage", params, nil)
 }
 
-// SendTyping shows the typing action in chat for about five seconds.
+// SendTyping shows the typing action in chat for about five seconds. A call
+// that takes longer than sendTimeout fails with errBotNetwork.
 func (b *botAPI) SendTyping(ctx context.Context, chat int64) error {
+	ctx, cancel := context.WithTimeout(ctx, b.sendTimeout)
+	defer cancel()
+
 	return b.call(ctx, "sendChatAction", map[string]any{
 		"chat_id": chat,
 		"action":  "typing",