X-Git-Url: https://git.giacomolli.uk/onechat/blobdiff_plain/3cdbd017da9ae7a7045f4272f16d4b262fd01c79..2a528fe2981639cf099c713a6be16b8ea0e2cc67:/telegram_api.go?ds=inline

diff --git a/telegram_api.go b/telegram_api.go
index 508010e..ce4e0e0 100644
--- a/telegram_api.go
+++ b/telegram_api.go
@@ -35,11 +35,12 @@ const (
 	// its own, because the long poll of getUpdates needs a longer limit.
 	telegramSendTimeout = 30 * time.Second
 
-	// telegramFileLookupTimeout is the longest wait for image file details.
+	// telegramFileLookupTimeout is the longest wait for media file details.
 	telegramFileLookupTimeout = 30 * time.Second
 
-	// telegramImageDownloadTimeout is the longest wait for image bytes.
-	telegramImageDownloadTimeout = 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
@@ -48,50 +49,113 @@ const (
 	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{},
-	}
+// 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.
-type TelegramAPI struct {
-	base  string
-	token string
-	http  *http.Client
+// 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"`
+}
+
+// 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
@@ -109,9 +173,110 @@ func (b *TelegramAPI) GetUpdates(ctx context.Context, offset int64) ([]TelegramU
 	return updates, err
 }
 
-// GetImage downloads a file through the authenticated file endpoint. Errors
-// never include its token or URL, and the body is limited before storage.
-func (b *TelegramAPI) GetImage(ctx context.Context, id string) (data []byte, err error) {
+// call sends one call of method with the JSON params and decodes its result
+// into result, when result is not nil. The call can take up to timeout. Its
+// request setup errors name the method. Network and answer errors give a safe
+// cause, so the caller can add the operation without exposing the request URL.
+func (b *TelegramAPI) call(ctx context.Context, timeout time.Duration, method string, params, result any) error {
+	ctx, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+
+	body, err := json.Marshal(params)
+	if err != nil {
+		return fmt.Errorf("%s: encode request: %w", method, err)
+	}
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodPost, b.base+"/bot"+b.token+"/"+method, bytes.NewReader(body))
+	if err != nil {
+		return fmt.Errorf("%s: make request: %s", method, b.redact(err))
+	}
+
+	request.Header.Set("Content-Type", "application/json")
+
+	return b.answer(request, timeout, result)
+}
+
+// redact returns the text of err without a URL and without the token. A
+// *url.Error holds the URL of the call, which holds the token, so only its
+// cause is kept.
+func (b *TelegramAPI) redact(err error) string {
+	var urlError *url.Error
+
+	if errors.As(err, &urlError) {
+		err = urlError.Err
+	}
+
+	return strings.ReplaceAll(err.Error(), b.token, "TOKEN")
+}
+
+// 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)
+	}
+
+	data, err := io.ReadAll(io.LimitReader(response.Body, telegramAnswerBytes))
+	err = errors.Join(err, response.Body.Close())
+	if err != nil {
+		return b.networkError("answer cut off", err, timeout)
+	}
+
+	var answer TelegramAnswer
+
+	err = json.Unmarshal(data, &answer)
+	if err != nil && response.StatusCode != http.StatusOK {
+		return &TelegramError{
+			Status:      response.StatusCode,
+			Description: http.StatusText(response.StatusCode),
+		}
+	}
+
+	if err != nil {
+		return b.networkError("invalid JSON", err, timeout)
+	}
+
+	if !answer.OK {
+		return &TelegramError{
+			Status:      response.StatusCode,
+			Description: b.redact(errors.New(answer.Description)),
+			RetryAfter:  time.Duration(answer.Parameters.RetryAfter) * time.Second,
+			Refused:     true,
+		}
+	}
+
+	if result == nil {
+		return nil
+	}
+
+	err = json.Unmarshal(answer.Result, result)
+	if err != nil {
+		return b.networkError("invalid result", err, timeout)
+	}
+
+	return nil
+}
+
+// networkError returns the TelegramNetworkError of err, which happened at the
+// step that what names. When the call used all of its time timeout, the cause
+// is "no answer in TIMEOUT", because the Go text of a deadline does not tell
+// how long the wait was.
+func (b *TelegramAPI) networkError(what string, err error, timeout time.Duration) error {
+	if errors.Is(err, context.DeadlineExceeded) {
+		return &TelegramNetworkError{
+			Cause: "no answer in " + timeout.String(),
+		}
+	}
+
+	return &TelegramNetworkError{
+		Cause: what + ": " + b.redact(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"`
@@ -119,34 +284,34 @@ func (b *TelegramAPI) GetImage(ctx context.Context, id string) (data []byte, err
 
 	err = b.call(ctx, telegramFileLookupTimeout, "getFile", map[string]any{"file_id": id}, &file)
 	if err != nil {
-		return nil, fmt.Errorf("get image file: %w", err)
+		return nil, fmt.Errorf("get media file: %w", err)
 	}
 
-	if file.Size > imageMaxBytes {
-		return nil, errImageSize
+	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 image file path")
+		return nil, errors.New("invalid media file path")
 	}
 
-	ctx, cancel := context.WithTimeout(ctx, telegramImageDownloadTimeout)
+	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 image request: %s", b.redact(err))
+		return nil, fmt.Errorf("make media request: %s", b.redact(err))
 	}
 
 	response, err := b.http.Do(request)
 	if err != nil {
-		return nil, b.networkError("image download failed", err, telegramImageDownloadTimeout)
+		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 image download", closeErr, telegramImageDownloadTimeout))
+			err = errors.Join(err, b.networkError("close media download", closeErr, telegramFileDownloadTimeout))
 		}
 	}()
 
@@ -157,13 +322,13 @@ func (b *TelegramAPI) GetImage(ctx context.Context, id string) (data []byte, err
 		}
 	}
 
-	data, err = io.ReadAll(io.LimitReader(response.Body, imageMaxBytes+1))
+	data, err = io.ReadAll(io.LimitReader(response.Body, limit+1))
 	if err != nil {
-		return nil, b.networkError("image cut off", err, telegramImageDownloadTimeout)
+		return nil, b.networkError("media cut off", err, telegramFileDownloadTimeout)
 	}
 
-	if len(data) > imageMaxBytes {
-		return nil, errImageSize
+	if int64(len(data)) > limit {
+		return nil, tooLarge
 	}
 
 	return data, nil
@@ -266,195 +431,39 @@ func (b *TelegramAPI) SendTyping(ctx context.Context, chat int64) error {
 	}, nil)
 }
 
-// call sends one call of method with the JSON params and decodes its result
-// into result, when result is not nil. The call can take up to timeout. Its
-// errors tell the cause in plain words, with no method name, so that a log line
-// can say first what the call was for.
-func (b *TelegramAPI) call(ctx context.Context, timeout time.Duration, method string, params, result any) error {
-	ctx, cancel := context.WithTimeout(ctx, timeout)
-	defer cancel()
-
-	body, err := json.Marshal(params)
-	if err != nil {
-		return fmt.Errorf("%s: encode request: %w", method, err)
-	}
-
-	request, err := http.NewRequestWithContext(ctx, http.MethodPost, b.base+"/bot"+b.token+"/"+method, bytes.NewReader(body))
-	if err != nil {
-		return fmt.Errorf("%s: make request: %s", method, b.redact(err))
-	}
-
-	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)
-	}
-
-	data, err := io.ReadAll(io.LimitReader(response.Body, telegramAnswerBytes))
-	err = errors.Join(err, response.Body.Close())
-	if err != nil {
-		return b.networkError("answer cut off", err, timeout)
-	}
-
-	var answer TelegramAnswer
-
-	err = json.Unmarshal(data, &answer)
-	if err != nil && response.StatusCode != http.StatusOK {
-		return &TelegramError{
-			Status:      response.StatusCode,
-			Description: http.StatusText(response.StatusCode),
-		}
-	}
-
-	if err != nil {
-		return b.networkError("invalid JSON", err, timeout)
-	}
-
-	if !answer.OK {
-		return &TelegramError{
-			Status:      response.StatusCode,
-			Description: b.redact(errors.New(answer.Description)),
-			RetryAfter:  time.Duration(answer.Parameters.RetryAfter) * time.Second,
-			Refused:     true,
-		}
-	}
-
-	if result == nil {
-		return nil
-	}
-
-	err = json.Unmarshal(answer.Result, result)
-	if err != nil {
-		return b.networkError("invalid result", err, timeout)
-	}
-
-	return nil
-}
-
-// networkError returns the TelegramNetworkError of err, which happened at the
-// step that what names. When the call used all of its time timeout, the cause
-// is "no answer in TIMEOUT", because the Go text of a deadline does not tell
-// how long the wait was.
-func (b *TelegramAPI) networkError(what string, err error, timeout time.Duration) error {
-	if errors.Is(err, context.DeadlineExceeded) {
-		return &TelegramNetworkError{
-			Cause: "no answer in " + timeout.String(),
-		}
-	}
-
-	return &TelegramNetworkError{
-		Cause: what + ": " + b.redact(err),
-	}
-}
-
-// redact returns the text of err without a URL and without the token. A
-// *url.Error holds the URL of the call, which holds the token, so only its
-// cause is kept.
-func (b *TelegramAPI) redact(err error) string {
-	var urlError *url.Error
-
-	if errors.As(err, &urlError) {
-		err = urlError.Err
-	}
-
-	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"`
-}
-
-// 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"`
-}
+// 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
 
-// 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"`
+	return errors.As(err, &answer) && answer.Refused && (answer.Status == http.StatusBadRequest || answer.Status == http.StatusNotFound)
 }
 
-// TelegramMessage holds the text, caption, and image sizes 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"`
-}
+// 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
 
-// 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"`
-}
+	if errors.As(err, &network) {
+		return true, 0
+	}
 
-// 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"`
-}
+	var answer *TelegramError
 
-// 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"`
-}
+	if errors.As(err, &answer) {
+		return answer.Status == http.StatusTooManyRequests || answer.Status >= 500, answer.RetryAfter
+	}
 
-// TelegramUser is the sender of a message.
-type TelegramUser struct {
-	ID int64 `json:"id"`
+	return false, 0
 }