rss-tools/sources/telegram/sdk.go (view raw)
| 1 | package telegram |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "context" |
| 6 | "encoding/base64" |
| 7 | "encoding/json" |
| 8 | "fmt" |
| 9 | "io" |
| 10 | "net/http" |
| 11 | "net/url" |
| 12 | "strconv" |
| 13 | "strings" |
| 14 | ) |
| 15 | |
| 16 | const ( |
| 17 | apiBase = "https://api.telegram.org" |
| 18 | maxPhotoBytes = 20 << 20 |
| 19 | ) |
| 20 | |
| 21 | type TelegramSDK struct { |
| 22 | client *http.Client |
| 23 | token string |
| 24 | } |
| 25 | |
| 26 | func NewSDK(client *http.Client, token string) *TelegramSDK { |
| 27 | return &TelegramSDK{ |
| 28 | token: token, |
| 29 | client: client, |
| 30 | } |
| 31 | } |
| 32 | |
| 33 | type Response[T any] struct { |
| 34 | OK bool `json:"ok"` |
| 35 | Result T `json:"result"` |
| 36 | Description string `json:"description"` |
| 37 | } |
| 38 | |
| 39 | type Update struct { |
| 40 | UpdateID int64 `json:"update_id"` |
| 41 | Message *Message `json:"message"` |
| 42 | } |
| 43 | |
| 44 | type User struct { |
| 45 | ID int64 `json:"id"` |
| 46 | FirstName string `json:"first_name"` |
| 47 | Username string `json:"username"` |
| 48 | } |
| 49 | |
| 50 | type Chat struct { |
| 51 | ID int64 `json:"id"` |
| 52 | } |
| 53 | |
| 54 | type Message struct { |
| 55 | MessageID int64 `json:"message_id"` |
| 56 | From *User `json:"from"` |
| 57 | Chat *Chat `json:"chat"` |
| 58 | Text string `json:"text"` |
| 59 | Caption string `json:"caption,omitempty"` |
| 60 | Date int64 `json:"date"` |
| 61 | Photo []PhotoSize `json:"photo,omitempty"` |
| 62 | PhotoBase64 string `json:"photo_base64,omitempty"` |
| 63 | PhotoMIMEType string `json:"photo_mime_type,omitempty"` |
| 64 | } |
| 65 | |
| 66 | type PhotoSize struct { |
| 67 | FileID string `json:"file_id"` |
| 68 | Width int `json:"width"` |
| 69 | Height int `json:"height"` |
| 70 | FileSize int64 `json:"file_size"` |
| 71 | } |
| 72 | |
| 73 | func (t *TelegramSDK) GetUpdates(ctx context.Context, offset int64) ([]Update, error) { |
| 74 | params := url.Values{} |
| 75 | params.Set("offset", strconv.FormatInt(offset, 10)) |
| 76 | params.Set("timeout", "30") |
| 77 | |
| 78 | var resp Response[[]Update] |
| 79 | if err := t.req(ctx, "getUpdates", params, nil, &resp); err != nil { |
| 80 | return nil, err |
| 81 | } |
| 82 | |
| 83 | for i := range resp.Result { |
| 84 | msg := resp.Result[i].Message |
| 85 | if msg == nil || len(msg.Photo) == 0 { |
| 86 | continue |
| 87 | } |
| 88 | data, mimeType, err := t.downloadLargestPhoto(ctx, msg.Photo) |
| 89 | if err != nil { |
| 90 | return nil, err |
| 91 | } |
| 92 | msg.PhotoBase64 = base64.StdEncoding.EncodeToString(data) |
| 93 | msg.PhotoMIMEType = mimeType |
| 94 | } |
| 95 | return resp.Result, nil |
| 96 | } |
| 97 | |
| 98 | type messageReactionReq struct { |
| 99 | Type string `json:"type"` |
| 100 | Emoji string `json:"emoji"` |
| 101 | } |
| 102 | |
| 103 | type setReactionReq struct { |
| 104 | ChatID int64 `json:"chat_id"` |
| 105 | MessageID int64 `json:"message_id"` |
| 106 | Reaction []messageReactionReq `json:"reaction"` |
| 107 | } |
| 108 | |
| 109 | func (t *TelegramSDK) SetReaction(ctx context.Context, chatID, messageID int64, emoji string) error { |
| 110 | var resp Response[bool] |
| 111 | return t.req(ctx, "setMessageReaction", nil, setReactionReq{ |
| 112 | ChatID: chatID, |
| 113 | MessageID: messageID, |
| 114 | Reaction: []messageReactionReq{{Type: "emoji", Emoji: emoji}}, |
| 115 | }, &resp) |
| 116 | } |
| 117 | |
| 118 | type tgFile struct { |
| 119 | FilePath string `json:"file_path"` |
| 120 | } |
| 121 | |
| 122 | func (t *TelegramSDK) downloadLargestPhoto(ctx context.Context, photos []PhotoSize) ([]byte, string, error) { |
| 123 | if len(photos) == 0 { |
| 124 | return nil, "", nil |
| 125 | } |
| 126 | |
| 127 | filePath, err := t.getFilePath(ctx, photos[len(photos)-1].FileID) |
| 128 | if err != nil { |
| 129 | return nil, "", err |
| 130 | } |
| 131 | |
| 132 | fileURL := fmt.Sprintf("%s/file/bot%s/%s", apiBase, t.token, filePath) |
| 133 | req, err := http.NewRequestWithContext(ctx, http.MethodGet, fileURL, nil) |
| 134 | if err != nil { |
| 135 | return nil, "", err |
| 136 | } |
| 137 | |
| 138 | res, err := t.client.Do(req) |
| 139 | if err != nil { |
| 140 | return nil, "", err |
| 141 | } |
| 142 | defer res.Body.Close() |
| 143 | if res.StatusCode != http.StatusOK { |
| 144 | return nil, "", fmt.Errorf("photo download failed with status %d", res.StatusCode) |
| 145 | } |
| 146 | |
| 147 | data, err := io.ReadAll(io.LimitReader(res.Body, maxPhotoBytes+1)) |
| 148 | if err != nil { |
| 149 | return nil, "", err |
| 150 | } |
| 151 | if len(data) > maxPhotoBytes { |
| 152 | return nil, "", fmt.Errorf("photo too large: %d bytes", len(data)) |
| 153 | } |
| 154 | |
| 155 | mimeType := http.DetectContentType(data) |
| 156 | if !strings.HasPrefix(mimeType, "image/") { |
| 157 | mimeType = "image/jpeg" |
| 158 | } |
| 159 | return data, mimeType, nil |
| 160 | } |
| 161 | |
| 162 | func (t *TelegramSDK) getFilePath(ctx context.Context, fileID string) (string, error) { |
| 163 | params := url.Values{} |
| 164 | params.Set("file_id", fileID) |
| 165 | |
| 166 | var resp Response[tgFile] |
| 167 | if err := t.req(ctx, "getFile", params, nil, &resp); err != nil { |
| 168 | return "", err |
| 169 | } |
| 170 | return resp.Result.FilePath, nil |
| 171 | } |
| 172 | |
| 173 | func (t *TelegramSDK) req(ctx context.Context, method string, params url.Values, body any, out any) error { |
| 174 | u := fmt.Sprintf("%s/bot%s/%s", apiBase, t.token, method) |
| 175 | if params != nil { |
| 176 | u += "?" + params.Encode() |
| 177 | } |
| 178 | |
| 179 | var req *http.Request |
| 180 | var err error |
| 181 | if body != nil { |
| 182 | var data []byte |
| 183 | data, err = json.Marshal(body) |
| 184 | if err != nil { |
| 185 | return err |
| 186 | } |
| 187 | req, err = http.NewRequestWithContext(ctx, http.MethodPost, u, bytes.NewReader(data)) |
| 188 | if err != nil { |
| 189 | return err |
| 190 | } |
| 191 | req.Header.Set("Content-Type", "application/json") |
| 192 | } else { |
| 193 | req, err = http.NewRequestWithContext(ctx, http.MethodGet, u, nil) |
| 194 | if err != nil { |
| 195 | return err |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | res, err := t.client.Do(req) |
| 200 | if err != nil { |
| 201 | return err |
| 202 | } |
| 203 | defer res.Body.Close() |
| 204 | return json.NewDecoder(res.Body).Decode(out) |
| 205 | } |