rss-tools/sources/telegram/telegram.go (view raw)
| 1 | package telegram |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "context" |
| 6 | "encoding/binary" |
| 7 | "encoding/gob" |
| 8 | "fmt" |
| 9 | "html" |
| 10 | "log/slog" |
| 11 | "net/http" |
| 12 | "strings" |
| 13 | "time" |
| 14 | |
| 15 | "olexsmir.xyz/rss-tools/app" |
| 16 | ) |
| 17 | |
| 18 | type telegram struct { |
| 19 | db *app.Bucket |
| 20 | messages *app.Bucket |
| 21 | client *http.Client |
| 22 | tg *TelegramSDK |
| 23 | allowedID int64 |
| 24 | } |
| 25 | |
| 26 | func Register(a *app.App) error { |
| 27 | db, err := a.Bucket("telegram") |
| 28 | if err != nil { |
| 29 | return err |
| 30 | } |
| 31 | |
| 32 | messages, err := a.Bucket("telegram:messages") |
| 33 | if err != nil { |
| 34 | return err |
| 35 | } |
| 36 | |
| 37 | t := &telegram{ |
| 38 | db: db, |
| 39 | messages: messages, |
| 40 | client: a.Client, |
| 41 | tg: NewSDK(a.Client, a.Config.TGToken), |
| 42 | allowedID: a.Config.TGUserID, |
| 43 | } |
| 44 | |
| 45 | a.AddWorker(t.worker) |
| 46 | a.Route("GET /telegram", t.handler) |
| 47 | return nil |
| 48 | } |
| 49 | |
| 50 | func (t *telegram) handler(w http.ResponseWriter, r *http.Request) { |
| 51 | // todo: cache feed contruction |
| 52 | // todo: dont include messages older than N days |
| 53 | |
| 54 | messages, err := t.loadMessages() |
| 55 | if err != nil { |
| 56 | http.Error(w, "failed to load messages", http.StatusInternalServerError) |
| 57 | return |
| 58 | } |
| 59 | |
| 60 | feed := app.NewFeed("Telegram feed", "telegram-feed") |
| 61 | for _, m := range messages { |
| 62 | feed.Add(feedEntryFromMessage(m)) |
| 63 | } |
| 64 | |
| 65 | if err := feed.Render(w); err != nil { |
| 66 | http.Error(w, "failed to render feed", http.StatusInternalServerError) |
| 67 | return |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | func (t *telegram) worker(ctx context.Context) error { |
| 72 | offset, err := t.loadOffset() |
| 73 | if err != nil { |
| 74 | return err |
| 75 | } |
| 76 | |
| 77 | for { |
| 78 | updates, err := t.tg.GetUpdates(ctx, offset) |
| 79 | if err != nil { |
| 80 | slog.ErrorContext(ctx, "getUpdates failed", "err", err) |
| 81 | select { |
| 82 | case <-ctx.Done(): |
| 83 | return nil |
| 84 | case <-time.After(5 * time.Second): |
| 85 | continue |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | for _, u := range updates { |
| 90 | if u.Message != nil && u.Message.From != nil { |
| 91 | slog.InfoContext(ctx, "message from", "user_id", u.Message.From.ID, "username", u.Message.From.Username, "msg", messageText(u.Message)) |
| 92 | } |
| 93 | |
| 94 | if u.Message == nil || u.Message.From == nil || u.Message.From.ID != t.allowedID { |
| 95 | offset = u.UpdateID + 1 |
| 96 | continue |
| 97 | } |
| 98 | |
| 99 | if err := t.saveMessage(u.Message); err != nil { |
| 100 | slog.ErrorContext(ctx, "failed to save message", "err", err) |
| 101 | } |
| 102 | |
| 103 | if err := t.tg.SetReaction(ctx, u.Message.From.ID, u.Message.MessageID, "👍"); err != nil { |
| 104 | slog.ErrorContext(ctx, "failed to set reaction", "err", err) |
| 105 | } |
| 106 | |
| 107 | offset = u.UpdateID + 1 |
| 108 | } |
| 109 | |
| 110 | if err := t.saveOffset(offset); err != nil { |
| 111 | slog.ErrorContext(ctx, "failed to save offset", "err", err) |
| 112 | } |
| 113 | |
| 114 | select { |
| 115 | case <-ctx.Done(): |
| 116 | return nil |
| 117 | case <-time.After(time.Second): |
| 118 | } |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | func (t *telegram) saveOffset(offset int64) error { |
| 123 | return t.db.Set([]byte("offset"), binary.BigEndian.AppendUint64(nil, uint64(offset))) |
| 124 | } |
| 125 | |
| 126 | func (t *telegram) loadOffset() (int64, error) { |
| 127 | val, err := t.db.Get([]byte("offset")) |
| 128 | if err != nil || val == nil { |
| 129 | return 0, err |
| 130 | } |
| 131 | return int64(binary.BigEndian.Uint64(val)), nil |
| 132 | } |
| 133 | |
| 134 | func (t *telegram) saveMessage(m *Message) error { |
| 135 | var buf bytes.Buffer |
| 136 | if err := gob.NewEncoder(&buf).Encode(m); err != nil { |
| 137 | return err |
| 138 | } |
| 139 | key := binary.BigEndian.AppendUint64(nil, uint64(m.MessageID)) |
| 140 | return t.messages.Set(key, buf.Bytes()) |
| 141 | } |
| 142 | |
| 143 | func (t *telegram) loadMessages() ([]*Message, error) { |
| 144 | var messages []*Message |
| 145 | err := t.messages.ForEach(func(k, v []byte) error { |
| 146 | var m Message |
| 147 | if err := gob.NewDecoder(bytes.NewReader(v)).Decode(&m); err != nil { |
| 148 | return err |
| 149 | } |
| 150 | messages = append(messages, &m) |
| 151 | return nil |
| 152 | }) |
| 153 | return messages, err |
| 154 | } |
| 155 | |
| 156 | func feedEntryFromMessage(m *Message) app.FeedEntry { |
| 157 | updated := time.Unix(m.Date, 0) |
| 158 | text := messageText(m) |
| 159 | if m.PhotoBase64 == "" { |
| 160 | title := text |
| 161 | if len(title) > 64 { |
| 162 | title = title[:64] + "..." |
| 163 | } |
| 164 | return app.FeedEntry{ |
| 165 | Title: title, |
| 166 | ID: fmt.Sprintf("telegram-%d", m.MessageID), |
| 167 | Content: text, |
| 168 | Updated: updated, |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | parts := make([]string, 0, 2) |
| 173 | if t := strings.TrimSpace(text); t != "" { |
| 174 | parts = append(parts, "<p>"+html.EscapeString(t)+"</p>") |
| 175 | } |
| 176 | mimeType := m.PhotoMIMEType |
| 177 | if mimeType == "" { |
| 178 | mimeType = "image/jpeg" |
| 179 | } |
| 180 | parts = append(parts, fmt.Sprintf(`<p><img src="data:%s;base64,%s" alt="telegram image"/></p>`, mimeType, m.PhotoBase64)) |
| 181 | |
| 182 | return app.FeedEntry{ |
| 183 | Title: fmt.Sprintf("🖼️ [%s]", updated.Format("2006-01-02")), |
| 184 | ID: fmt.Sprintf("telegram-%d", m.MessageID), |
| 185 | Content: strings.Join(parts, ""), |
| 186 | ContentType: "html", |
| 187 | Updated: updated, |
| 188 | } |
| 189 | } |
| 190 | |
| 191 | func messageText(m *Message) string { |
| 192 | if m == nil { |
| 193 | return "" |
| 194 | } |
| 195 | if caption := strings.TrimSpace(m.Caption); caption != "" { |
| 196 | return m.Caption |
| 197 | } |
| 198 | return m.Text |
| 199 | } |