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 | "log/slog" |
| 10 | "net/http" |
| 11 | "time" |
| 12 | |
| 13 | "olexsmir.xyz/rss-tools/app" |
| 14 | ) |
| 15 | |
| 16 | type telegram struct { |
| 17 | db *app.Bucket |
| 18 | messages *app.Bucket |
| 19 | client *http.Client |
| 20 | tg *TelegramSDK |
| 21 | allowedID int64 |
| 22 | } |
| 23 | |
| 24 | func Register(a *app.App) error { |
| 25 | db, err := a.Bucket("telegram") |
| 26 | if err != nil { |
| 27 | return err |
| 28 | } |
| 29 | |
| 30 | messages, err := a.Bucket("telegram:messages") |
| 31 | if err != nil { |
| 32 | return err |
| 33 | } |
| 34 | |
| 35 | t := &telegram{ |
| 36 | db: db, |
| 37 | messages: messages, |
| 38 | client: a.Client, |
| 39 | tg: NewSDK(a.Client, a.Config.TGToken), |
| 40 | allowedID: a.Config.TGUserID, |
| 41 | } |
| 42 | |
| 43 | a.AddWorker(t.worker) |
| 44 | a.Route("GET /telegram", t.handler) |
| 45 | return nil |
| 46 | } |
| 47 | |
| 48 | func (t *telegram) handler(w http.ResponseWriter, r *http.Request) { |
| 49 | // todo: cache feed contruction |
| 50 | // todo: dont include messages older than N days |
| 51 | |
| 52 | messages, err := t.loadMessages() |
| 53 | if err != nil { |
| 54 | http.Error(w, "failed to load messages", http.StatusInternalServerError) |
| 55 | return |
| 56 | } |
| 57 | |
| 58 | feed := app.NewFeed("Telegram feed", "telegram-feed") |
| 59 | for _, m := range messages { |
| 60 | title := m.Text |
| 61 | if len(title) > 64 { |
| 62 | title = title[:64] + "..." |
| 63 | } |
| 64 | feed.AddEntry(app.FeedEntry{ |
| 65 | Title: title, |
| 66 | ID: fmt.Sprintf("telegram-%d", m.MessageID), |
| 67 | Content: m.Text, |
| 68 | Updated: time.Unix(m.Date, 0), |
| 69 | }) |
| 70 | } |
| 71 | |
| 72 | w.WriteHeader(http.StatusOK) |
| 73 | feed.Render(w) |
| 74 | } |
| 75 | |
| 76 | func (t *telegram) worker(ctx context.Context) error { |
| 77 | offset, err := t.loadOffset() |
| 78 | if err != nil { |
| 79 | return err |
| 80 | } |
| 81 | |
| 82 | for { |
| 83 | updates, err := t.tg.GetUpdates(ctx, offset) |
| 84 | if err != nil { |
| 85 | slog.ErrorContext(ctx, "getUpdates failed", "err", err) |
| 86 | select { |
| 87 | case <-ctx.Done(): |
| 88 | return nil |
| 89 | case <-time.After(5 * time.Second): |
| 90 | continue |
| 91 | } |
| 92 | } |
| 93 | |
| 94 | for _, u := range updates { |
| 95 | if u.Message != nil && u.Message.From != nil { |
| 96 | slog.InfoContext(ctx, "message from", "user_id", u.Message.From.ID, "username", u.Message.From.Username, "msg", u.Message.Text) |
| 97 | } |
| 98 | |
| 99 | if u.Message == nil && u.Message.From == nil || u.Message.From.ID != t.allowedID { |
| 100 | offset = u.UpdateID + 1 |
| 101 | continue |
| 102 | } |
| 103 | |
| 104 | if err := t.saveMessage(u.Message); err != nil { |
| 105 | slog.ErrorContext(ctx, "failed to save message", "err", err) |
| 106 | } |
| 107 | |
| 108 | if err := t.tg.SetReaction(ctx, u.Message.From.ID, u.Message.MessageID, "👍"); err != nil { |
| 109 | slog.ErrorContext(ctx, "failed to set reaction", "err", err) |
| 110 | } |
| 111 | |
| 112 | offset = u.UpdateID + 1 |
| 113 | } |
| 114 | |
| 115 | if err := t.saveOffset(offset); err != nil { |
| 116 | slog.ErrorContext(ctx, "failed to save offset", "err", err) |
| 117 | } |
| 118 | |
| 119 | select { |
| 120 | case <-ctx.Done(): |
| 121 | return nil |
| 122 | case <-time.After(time.Second): |
| 123 | } |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | func (t *telegram) saveOffset(offset int64) error { |
| 128 | return t.db.Set([]byte("offset"), binary.BigEndian.AppendUint64(nil, uint64(offset))) |
| 129 | } |
| 130 | |
| 131 | func (t *telegram) loadOffset() (int64, error) { |
| 132 | val, err := t.db.Get([]byte("offset")) |
| 133 | if err != nil || val == nil { |
| 134 | return 0, err |
| 135 | } |
| 136 | return int64(binary.BigEndian.Uint64(val)), nil |
| 137 | } |
| 138 | |
| 139 | func (t *telegram) saveMessage(m *Message) error { |
| 140 | var buf bytes.Buffer |
| 141 | if err := gob.NewEncoder(&buf).Encode(m); err != nil { |
| 142 | return err |
| 143 | } |
| 144 | key := binary.BigEndian.AppendUint64(nil, uint64(m.MessageID)) |
| 145 | return t.messages.Set(key, buf.Bytes()) |
| 146 | } |
| 147 | |
| 148 | func (t *telegram) loadMessages() ([]*Message, error) { |
| 149 | var messages []*Message |
| 150 | err := t.messages.ForEach(func(k, v []byte) error { |
| 151 | var m Message |
| 152 | if err := gob.NewDecoder(bytes.NewReader(v)).Decode(&m); err != nil { |
| 153 | return err |
| 154 | } |
| 155 | messages = append(messages, &m) |
| 156 | return nil |
| 157 | }) |
| 158 | return messages, err |
| 159 | } |