"errors"
"fmt"
"io"
+ "mime/multipart"
"net/http"
"net/url"
+ "path"
+ "strconv"
"strings"
"time"
)
const (
- // telegramPollSeconds is how long one getUpdates call waits for an
- // update.
- telegramPollSeconds = 50
+ // telegramUpdateWaitTimeout is how long one getUpdates call waits for
+ // an update.
+ telegramUpdateWaitTimeout = 50 * time.Second
- // telegramPollSlack is how much longer than telegramPollSeconds a
+ // telegramPollSlack is how much longer than telegramUpdateWaitTimeout a
// getUpdates call can take before the bot gives it up.
telegramPollSlack = 20 * time.Second
// telegramPollTimeout is how long one getUpdates call can take.
- telegramPollTimeout = telegramPollSeconds*time.Second + telegramPollSlack
-
- // telegramSendTimeout is how long a sendMessage, sendRichMessage, 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.
+ telegramPollTimeout = telegramUpdateWaitTimeout + telegramPollSlack
+
+ // telegramSendTimeout is how long a sendMessage or sendRichMessage 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.
telegramSendTimeout = 30 * time.Second
+ // telegramFileLookupTimeout is the longest wait for media file details.
+ telegramFileLookupTimeout = 30 * time.Second
+
+ // telegramFileDownloadTimeout is the longest wait for downloaded media
+ // bytes.
+ telegramFileDownloadTimeout = 30 * time.Second
+
+ // telegramTypingTimeout is the longest wait to show the typing action.
+ telegramTypingTimeout = 30 * time.Second
+
// telegramAnswerBytes is the most bytes of one answer of the Bot API.
telegramAnswerBytes = 16 << 20
)
-// newTelegramAPI returns the client of the Bot API at base with token.
-func newTelegramAPI(base, token string) *TelegramAPI {
- return &TelegramAPI{
- base: base,
- token: token,
- http: &http.Client{},
- sendTimeout: telegramSendTimeout,
- }
+// TelegramAPI calls the Telegram Bot API. The bot token is a part of each URL,
+// so no error of TelegramAPI holds a URL, a net/http error, or the token.
+type TelegramAPI struct {
+ base string
+ token string
+ http *http.Client
}
-// telegramRetryable tells if a later try of a failed Bot API call can work:
-// after a network error, HTTP 429, or a server error. It returns the wait that
-// the Bot API asks for, or 0.
-func telegramRetryable(err error) (bool, time.Duration) {
- var network *TelegramNetworkError
+// TelegramNetworkError tells that a Bot API call got no valid answer, such as
+// after a network error. A later call can work. Cause tells why in plain words,
+// with no URL and no token.
+type TelegramNetworkError struct {
+ Cause string
+}
- if errors.As(err, &network) {
- return true, 0
- }
+// TelegramError is an answer of the Bot API that tells of a failure. Its text
+// gives the HTTP status and the description, such as "502 Bad Gateway".
+// RetryAfter is the wait that the Bot API asks for after HTTP 429. Refused
+// tells that the answer is a Bot API answer with ok false, not a page of a
+// proxy or of a server error.
+type TelegramError struct {
+ Status int
+ Description string
+ RetryAfter time.Duration
+ Refused bool
+}
- var answer *TelegramError
+// TelegramUpdate is one update of getUpdates. Message is nil for the kinds of
+// updates that are not a new message.
+type TelegramUpdate struct {
+ UpdateID int64 `json:"update_id"`
+ Message *TelegramMessage `json:"message"`
+}
- if errors.As(err, &answer) {
- return answer.Status == http.StatusTooManyRequests || answer.Status >= 500, answer.RetryAfter
- }
+// TelegramEntity 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 TelegramEntity struct {
+ Type string `json:"type"`
+ Offset int `json:"offset"`
+ Length int `json:"length"`
+ URL string `json:"url,omitempty"`
+ Language string `json:"language,omitempty"`
+}
- return false, 0
+// TelegramAnswer is the envelope of each answer of the Bot API.
+type TelegramAnswer struct {
+ OK bool `json:"ok"`
+ Result json.RawMessage `json:"result"`
+ ErrorCode int `json:"error_code"`
+ Description string `json:"description"`
+ Parameters struct {
+ RetryAfter int `json:"retry_after"`
+ } `json:"parameters"`
}
-// telegramRejected tells if the Bot API refused a call with ok false and HTTP
-// 400 or 404. Then the call did nothing: 400 refuses the request, and 404 tells
-// that the method is not there. An error page with no Bot API answer does not
-// tell this, so it is not a refusal.
-func telegramRejected(err error) bool {
- var answer *TelegramError
+// TelegramMessage holds text and supported media metadata of a bot message.
+type TelegramMessage struct {
+ Chat TelegramChat `json:"chat"`
+ From *TelegramUser `json:"from"`
+ Text string `json:"text"`
+ Caption string `json:"caption"`
+ Photo []TelegramPhoto `json:"photo"`
+ Document *TelegramDocument `json:"document"`
+ Voice *TelegramVoice `json:"voice"`
+}
- return errors.As(err, &answer) && answer.Refused && (answer.Status == http.StatusBadRequest || answer.Status == http.StatusNotFound)
+// TelegramVoice identifies a voice note in the authenticated file API.
+type TelegramVoice struct {
+ FileID string `json:"file_id"`
+ FileSize int64 `json:"file_size"`
}
-// TelegramAPI calls the Telegram Bot API. The bot token is a part of each URL,
-// so no error of TelegramAPI holds a URL, a net/http error, or the token. Its
-// sendTimeout field limits each sendMessage, sendRichMessage, and
-// sendChatAction call.
-type TelegramAPI struct {
- base string
- token string
- http *http.Client
- sendTimeout time.Duration
+// TelegramPhoto is one supplied size of a photo.
+type TelegramPhoto struct {
+ FileID string `json:"file_id"`
+ Width int `json:"width"`
+ Height int `json:"height"`
+ FileSize int64 `json:"file_size"`
+}
+
+// TelegramDocument is a file sent without photo compression.
+type TelegramDocument struct {
+ FileID string `json:"file_id"`
+ MimeType string `json:"mime_type"`
+ FileSize int64 `json:"file_size"`
+}
+
+// TelegramChat is the chat of a message. Type is private for a chat with one
+// user.
+type TelegramChat struct {
+ ID int64 `json:"id"`
+ Type string `json:"type"`
+}
+
+// TelegramUser is the sender of a message.
+type TelegramUser struct {
+ ID int64 `json:"id"`
}
-// GetUpdates waits for the updates from offset on, up to telegramPollSeconds,
-// and returns them. Telegram forgets each update before offset. Only new
-// messages are asked for.
+// newTelegramAPI returns the client of the Bot API at base with token.
+func newTelegramAPI(base, token string) *TelegramAPI {
+ return &TelegramAPI{
+ base: base,
+ token: token,
+ http: &http.Client{},
+ }
+}
+
+// GetUpdates waits for the updates from offset on, up to
+// telegramUpdateWaitTimeout, and returns them. Telegram forgets each update
+// before offset. Only new messages are asked for.
func (b *TelegramAPI) GetUpdates(ctx context.Context, offset int64) ([]TelegramUpdate, error) {
var updates []TelegramUpdate
err := b.call(ctx, telegramPollTimeout, "getUpdates", map[string]any{
"offset": offset,
- "timeout": telegramPollSeconds,
+ "timeout": int(telegramUpdateWaitTimeout / time.Second),
"allowed_updates": []string{"message"},
}, &updates)
return updates, err
}
+// GetFile downloads bounded media through the authenticated file endpoint.
+// Errors never include its token or URL, and the body is limited before
+// storage.
+func (b *TelegramAPI) GetFile(ctx context.Context, id string, limit int64, tooLarge error) (data []byte, err error) {
+ var file struct {
+ Path string `json:"file_path"`
+ Size int64 `json:"file_size"`
+ }
+
+ err = b.call(ctx, telegramFileLookupTimeout, "getFile", map[string]any{"file_id": id}, &file)
+ if err != nil {
+ return nil, fmt.Errorf("get media file: %w", err)
+ }
+
+ if file.Size > limit {
+ return nil, tooLarge
+ }
+
+ if file.Path == "" || path.Clean(file.Path) != file.Path || strings.HasPrefix(file.Path, "/") || strings.HasPrefix(file.Path, "../") || strings.ContainsAny(file.Path, "?%#\\") {
+ return nil, errors.New("invalid media file path")
+ }
+
+ ctx, cancel := context.WithTimeout(ctx, telegramFileDownloadTimeout)
+ defer cancel()
+
+ request, err := http.NewRequestWithContext(ctx, http.MethodGet, b.base+"/file/bot"+b.token+"/"+file.Path, nil)
+ if err != nil {
+ return nil, fmt.Errorf("make media request: %s", b.redact(err))
+ }
+
+ response, err := b.http.Do(request)
+ if err != nil {
+ return nil, b.networkError("media download failed", err, telegramFileDownloadTimeout)
+ }
+
+ defer func() {
+ closeErr := response.Body.Close()
+ if closeErr != nil {
+ err = errors.Join(err, b.networkError("close media download", closeErr, telegramFileDownloadTimeout))
+ }
+ }()
+
+ if response.StatusCode != http.StatusOK {
+ return nil, &TelegramError{
+ Status: response.StatusCode,
+ Description: http.StatusText(response.StatusCode),
+ }
+ }
+
+ data, err = io.ReadAll(io.LimitReader(response.Body, limit+1))
+ if err != nil {
+ return nil, b.networkError("media cut off", err, telegramFileDownloadTimeout)
+ }
+
+ if int64(len(data)) > limit {
+ return nil, tooLarge
+ }
+
+ return data, nil
+}
+
// 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 telegramSendTimeout fails with a
params["entities"] = entities
}
- return b.call(ctx, b.sendTimeout, "sendMessage", params, nil)
+ return b.call(ctx, telegramSendTimeout, "sendMessage", params, nil)
}
// SendRichMessage sends markdown to chat as a rich message, which Telegram
// renders itself, tables included. A call that takes longer than
// telegramSendTimeout fails with a TelegramNetworkError.
func (b *TelegramAPI) SendRichMessage(ctx context.Context, chat int64, markdown string) error {
- return b.call(ctx, b.sendTimeout, "sendRichMessage", map[string]any{
+ return b.call(ctx, telegramSendTimeout, "sendRichMessage", map[string]any{
"chat_id": chat,
"rich_message": map[string]any{
"markdown": markdown,
}, nil)
}
+// SendImage uploads an image to the owner as a photo, or as a document when the
+// Bot API refuses the photo. Network failures do not trigger a second send.
+func (b *TelegramAPI) SendImage(ctx context.Context, chat int64, name string, data []byte, caption string) error {
+ err := b.sendImage(ctx, "sendPhoto", "photo", chat, name, data, caption)
+ if telegramRejected(err) {
+ err = b.sendImage(ctx, "sendDocument", "document", chat, name, data, caption)
+ }
+
+ return err
+}
+
+func (b *TelegramAPI) sendImage(ctx context.Context, method, field string, chat int64, name string, data []byte, caption string) error {
+ ctx, cancel := context.WithTimeout(ctx, telegramSendTimeout)
+ defer cancel()
+
+ var body bytes.Buffer
+
+ writer := multipart.NewWriter(&body)
+ err := writer.WriteField("chat_id", strconv.FormatInt(chat, 10))
+ if err != nil {
+ return fmt.Errorf("write image chat: %w", err)
+ }
+
+ err = writer.WriteField("caption", caption)
+ if err != nil {
+ return fmt.Errorf("write image caption: %w", err)
+ }
+
+ part, err := writer.CreateFormFile(field, name)
+ if err != nil {
+ return fmt.Errorf("make image part: %w", err)
+ }
+
+ _, err = part.Write(data)
+ if err != nil {
+ return fmt.Errorf("write image part: %w", err)
+ }
+
+ err = writer.Close()
+ if err != nil {
+ return fmt.Errorf("close image form: %w", err)
+ }
+
+ request, err := http.NewRequestWithContext(ctx, http.MethodPost, b.base+"/bot"+b.token+"/"+method, &body)
+ if err != nil {
+ return fmt.Errorf("make image upload: %s", b.redact(err))
+ }
+
+ request.Header.Set("Content-Type", writer.FormDataContentType())
+
+ err = b.answer(request, telegramSendTimeout, nil)
+ if err != nil {
+ return fmt.Errorf("upload image: %w", err)
+ }
+
+ return nil
+}
+
// SendTyping shows the typing action in chat for about five seconds. A call
-// that takes longer than telegramSendTimeout fails with a TelegramNetworkError.
+// that takes longer than telegramTypingTimeout fails with a
+// TelegramNetworkError.
func (b *TelegramAPI) SendTyping(ctx context.Context, chat int64) error {
- return b.call(ctx, b.sendTimeout, "sendChatAction", map[string]any{
+ return b.call(ctx, telegramTypingTimeout, "sendChatAction", map[string]any{
"chat_id": chat,
"action": "typing",
}, nil)
request.Header.Set("Content-Type", "application/json")
+ return b.answer(request, timeout, result)
+}
+
+// answer reads the bounded Bot API response without keeping its request URL.
+func (b *TelegramAPI) answer(request *http.Request, timeout time.Duration, result any) error {
response, err := b.http.Do(request)
if err != nil {
return b.networkError("no answer", err, timeout)
return strings.ReplaceAll(err.Error(), b.token, "TOKEN")
}
-// TelegramNetworkError tells that a Bot API call got no valid answer, such as
-// after a network error. A later call can work. Cause tells why in plain words,
-// with no URL and no token.
-type TelegramNetworkError struct {
- Cause string
-}
-
func (e *TelegramNetworkError) Error() string {
return e.Cause
}
-// TelegramError is an answer of the Bot API that tells of a failure. Its text
-// gives the HTTP status and the description, such as "502 Bad Gateway".
-// RetryAfter is the wait that the Bot API asks for after HTTP 429. Refused
-// tells that the answer is a Bot API answer with ok false, not a page of a
-// proxy or of a server error.
-type TelegramError struct {
- Status int
- Description string
- RetryAfter time.Duration
- Refused bool
-}
-
func (e *TelegramError) Error() string {
return fmt.Sprintf("%d %s", e.Status, e.Description)
}
-// TelegramUpdate is one update of getUpdates. Message is nil for the kinds of
-// updates that are not a new message.
-type TelegramUpdate struct {
- UpdateID int64 `json:"update_id"`
- Message *TelegramMessage `json:"message"`
-}
+// telegramRetryable tells if a later try of a failed Bot API call can work:
+// after a network error, HTTP 429, or a server error. It returns the wait that
+// the Bot API asks for, or 0.
+func telegramRetryable(err error) (bool, time.Duration) {
+ var network *TelegramNetworkError
-// TelegramEntity 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 TelegramEntity struct {
- Type string `json:"type"`
- Offset int `json:"offset"`
- Length int `json:"length"`
- URL string `json:"url,omitempty"`
- Language string `json:"language,omitempty"`
-}
+ if errors.As(err, &network) {
+ return true, 0
+ }
-// TelegramAnswer is the envelope of each answer of the Bot API.
-type TelegramAnswer struct {
- OK bool `json:"ok"`
- Result json.RawMessage `json:"result"`
- ErrorCode int `json:"error_code"`
- Description string `json:"description"`
- Parameters struct {
- RetryAfter int `json:"retry_after"`
- } `json:"parameters"`
-}
+ var answer *TelegramError
-// TelegramMessage is a message to the bot. Text is empty for a message that is
-// not text, such as a photo.
-type TelegramMessage struct {
- Chat TelegramChat `json:"chat"`
- From *TelegramUser `json:"from"`
- Text string `json:"text"`
-}
+ if errors.As(err, &answer) {
+ return answer.Status == http.StatusTooManyRequests || answer.Status >= 500, answer.RetryAfter
+ }
-// TelegramChat is the chat of a message. Type is private for a chat with one
-// user.
-type TelegramChat struct {
- ID int64 `json:"id"`
- Type string `json:"type"`
+ return false, 0
}
-// TelegramUser is the sender of a message.
-type TelegramUser struct {
- ID int64 `json:"id"`
+// telegramRejected tells if the Bot API refused a call with ok false and HTTP
+// 400 or 404. Then the call did nothing: 400 refuses the request, and 404 tells
+// that the method is not there. An error page with no Bot API answer does not
+// tell this, so it is not a refusal.
+func telegramRejected(err error) bool {
+ var answer *TelegramError
+
+ return errors.As(err, &answer) && answer.Refused && (answer.Status == http.StatusBadRequest || answer.Status == http.StatusNotFound)
}
projects / onechat / blobdiff