Initial codex telegram bot source

internal/telegram/api.go

@@ -0,0 +1,211 @@
+package telegram
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"net/url"
+	"path/filepath"
+	"time"
+)
+
+type Client struct {
+	token       string
+	baseURL     string
+	fileBaseURL string
+	httpClient  *http.Client
+}
+
+func NewClient(token string) *Client {
+	return &Client{
+		token:       token,
+		baseURL:     "https://api.telegram.org/bot" + token,
+		fileBaseURL: "https://api.telegram.org/file/bot" + token,
+		httpClient:  &http.Client{Timeout: 90 * time.Second},
+	}
+}
+
+func (c *Client) GetUpdates(ctx context.Context, offset int, timeoutSeconds int) ([]Update, error) {
+	params := map[string]any{
+		"offset":          offset,
+		"timeout":         timeoutSeconds,
+		"allowed_updates": []string{"message", "callback_query"},
+	}
+	var updates []Update
+	if err := c.postJSON(ctx, "getUpdates", params, &updates); err != nil {
+		return nil, err
+	}
+	return updates, nil
+}
+
+func (c *Client) SendMessage(ctx context.Context, chatID int64, text string, opts SendMessageOptions) (Message, error) {
+	params := map[string]any{
+		"chat_id": chatID,
+		"text":    text,
+	}
+	if opts.ParseMode != "" {
+		params["parse_mode"] = opts.ParseMode
+	}
+	if opts.ReplyMarkup != nil {
+		params["reply_markup"] = opts.ReplyMarkup
+	}
+	var message Message
+	if err := c.postJSON(ctx, "sendMessage", params, &message); err != nil {
+		return Message{}, err
+	}
+	return message, nil
+}
+
+func (c *Client) EditMessageText(ctx context.Context, chatID int64, messageID int, text string, opts EditMessageTextOptions) (Message, error) {
+	params := map[string]any{
+		"chat_id":    chatID,
+		"message_id": messageID,
+		"text":       text,
+	}
+	if opts.ParseMode != "" {
+		params["parse_mode"] = opts.ParseMode
+	}
+	if opts.ReplyMarkup != nil {
+		params["reply_markup"] = opts.ReplyMarkup
+	}
+	var message Message
+	if err := c.postJSON(ctx, "editMessageText", params, &message); err != nil {
+		return Message{}, err
+	}
+	return message, nil
+}
+
+func (c *Client) PinChatMessage(ctx context.Context, chatID int64, messageID int, disableNotification bool) error {
+	params := map[string]any{
+		"chat_id":              chatID,
+		"message_id":           messageID,
+		"disable_notification": disableNotification,
+	}
+	var ignored bool
+	return c.postJSON(ctx, "pinChatMessage", params, &ignored)
+}
+
+func (c *Client) AnswerCallbackQuery(ctx context.Context, callbackQueryID, text string) error {
+	params := map[string]any{
+		"callback_query_id": callbackQueryID,
+	}
+	if text != "" {
+		params["text"] = text
+	}
+	var ignored bool
+	return c.postJSON(ctx, "answerCallbackQuery", params, &ignored)
+}
+
+func (c *Client) GetFile(ctx context.Context, fileID string) (File, error) {
+	var file File
+	if err := c.postJSON(ctx, "getFile", map[string]any{"file_id": fileID}, &file); err != nil {
+		return File{}, err
+	}
+	return file, nil
+}
+
+func (c *Client) DownloadFile(ctx context.Context, filePath string) ([]byte, error) {
+	u := c.fileBaseURL + "/" + url.PathEscape(filePath)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u, nil)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return nil, fmt.Errorf("download file: telegram returned %s", resp.Status)
+	}
+	return io.ReadAll(resp.Body)
+}
+
+func (c *Client) SendDocumentBytes(ctx context.Context, chatID int64, filename string, data []byte, caption string) (Message, error) {
+	var body bytes.Buffer
+	writer := multipart.NewWriter(&body)
+	if err := writer.WriteField("chat_id", fmt.Sprint(chatID)); err != nil {
+		return Message{}, err
+	}
+	if caption != "" {
+		if err := writer.WriteField("caption", caption); err != nil {
+			return Message{}, err
+		}
+	}
+	part, err := writer.CreateFormFile("document", filepath.Base(filename))
+	if err != nil {
+		return Message{}, err
+	}
+	if _, err := part.Write(data); err != nil {
+		return Message{}, err
+	}
+	if err := writer.Close(); err != nil {
+		return Message{}, err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.baseURL+"/sendDocument", &body)
+	if err != nil {
+		return Message{}, err
+	}
+	req.Header.Set("Content-Type", writer.FormDataContentType())
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return Message{}, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		payload, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
+		return Message{}, fmt.Errorf("sendDocument: telegram returned %s: %s", resp.Status, string(payload))
+	}
+	var decoded apiResponse[Message]
+	if err := json.NewDecoder(resp.Body).Decode(&decoded); err != nil {
+		return Message{}, err
+	}
+	if !decoded.OK {
+		return Message{}, fmt.Errorf("sendDocument: telegram error %d: %s", decoded.ErrorCode, decoded.Description)
+	}
+	return decoded.Result, nil
+}
+
+func (c *Client) postJSON(ctx context.Context, method string, params any, result any) error {
+	body, err := json.Marshal(params)
+	if err != nil {
+		return err
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.baseURL+"/"+method, bytes.NewReader(body))
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		payload, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
+		return fmt.Errorf("%s: telegram returned %s: %s", method, resp.Status, string(payload))
+	}
+	var decoded apiResponse[json.RawMessage]
+	if err := json.NewDecoder(resp.Body).Decode(&decoded); err != nil {
+		return err
+	}
+	if !decoded.OK {
+		return fmt.Errorf("%s: telegram error %d: %s", method, decoded.ErrorCode, decoded.Description)
+	}
+	if result == nil {
+		return nil
+	}
+	return json.Unmarshal(decoded.Result, result)
+}
+
+type apiResponse[T any] struct {
+	OK          bool   `json:"ok"`
+	Result      T      `json:"result"`
+	ErrorCode   int    `json:"error_code,omitempty"`
+	Description string `json:"description,omitempty"`
+}