feat: add presence handling

Author: sevensolutions

README.md

@@ -12,6 +12,9 @@ away, stop it (Ctrl-C) when you're back. That's the whole model.
 - Never replies to your own messages (including its own prior replies).
 - Sends at most one reply per sender per calendar day.
 - Supports end-to-end encrypted DMs (which is most of them, by default).
+- Also sets your Matrix presence (default: "unavailable"/"Away") for as long
+  as it runs, so you don't show as available just because the bot is
+  connected and polling `/sync`.
 
 ## 1. Create a dedicated login session for the bot
 
@@ -76,7 +79,8 @@ cp config.example.yaml config.yaml
 
 Fill in `homeserver`, `user_id`, `access_token`, `device_id`, `pickle_key`,
 and (recommended) `recovery_key`. Adjust `reply_message` to whatever you
-want people to see. `config.yaml` is gitignored - it holds secrets.
+want people to see, and `presence` if you don't want the default "Away"
+status (see below). `config.yaml` is gitignored - it holds secrets.
 
 ## 5. Build & run
 
@@ -176,6 +180,18 @@ Example: `"Hello {firstName}, I'm currently away and will get back to you as soo
 Falls back to the username wherever a display name isn't known yet (e.g. the
 bot hasn't seen their profile before their first message).
 
+## Presence
+
+Every `/sync` request a client makes tells the homeserver `set_presence`,
+and the Matrix spec's default for that is `online` - so a bot that's just
+connected and long-polling `/sync`, with no presence handling of its own,
+makes you show up as available to everyone the whole time it runs, no
+matter what the auto-reply says. This bot sets `presence` (default
+`"unavailable"`, shown as "Away" in most clients) on every sync request
+instead, so your status matches reality. Set it to `"offline"` to look
+fully offline, or `"online"` if you'd rather leave your real presence
+alone and rely on the auto-reply only.
+
 ## How "one reply per sender per day" works
 
 `state.json` maps each sender's user ID to the last calendar day (local

config.example.yaml

@@ -28,3 +28,11 @@ state_path: "state.json"
 # The message sent back to each DM sender, at most once per day. Supports
 # placeholders: {firstName}, {displayName}, {username} - see README.md.
 reply_message: "Hello {firstName}, I'm currently away and will get back to you as soon as I can."
+
+# Presence shown to others while the bot is running. One of "unavailable"
+# (shown as "Away" in most clients), "offline", or "online" (leaves your
+# real presence alone - use this if you only want the auto-reply and don't
+# want the bot to touch presence at all). Without this, simply polling
+# /sync marks you "online" on every request, so you'd always show as
+# available regardless of what the auto-reply says.
+presence: "unavailable"

config.go

@@ -30,6 +30,15 @@ type Config struct {
 	StatePath    string `yaml:"state_path"`
 
 	ReplyMessage string `yaml:"reply_message"`
+
+	// Presence is sent as set_presence on every /sync request, so it's what
+	// makes you show up as "away" to others while the bot runs - without it,
+	// the mere act of the bot polling /sync marks you "online" on every
+	// request, regardless of what the auto-reply says. One of "unavailable"
+	// (shown as "Away" in most clients - the default), "offline", or
+	// "online" (to leave your real presence alone and only use the
+	// auto-reply).
+	Presence string `yaml:"presence"`
 }
 
 func LoadConfig(path string) (*Config, error) {
@@ -42,6 +51,7 @@ func LoadConfig(path string) (*Config, error) {
 		CryptoDBPath: "crypto.db",
 		StatePath:    "state.json",
 		ReplyMessage: "I'm currently away and will get back to you as soon as I can.",
+		Presence:     "unavailable",
 	}
 	if err := yaml.Unmarshal(data, cfg); err != nil {
 		return nil, fmt.Errorf("failed to parse config file %q: %w", path, err)
@@ -69,5 +79,10 @@ func (c *Config) validate() error {
 	if problems != "" {
 		return fmt.Errorf("config is missing required field(s): %s", problems)
 	}
+	switch c.Presence {
+	case "online", "offline", "unavailable":
+	default:
+		return fmt.Errorf("presence must be one of \"online\", \"offline\", \"unavailable\", got %q", c.Presence)
+	}
 	return nil
 }

main.go

@@ -42,6 +42,11 @@ func main() {
 	}
 	client.DeviceID = id.DeviceID(cfg.DeviceID)
 	client.Log = log
+	// Sent as set_presence on every /sync request. Without this, the mere
+	// act of the bot polling /sync marks the account "online" on every
+	// request - regardless of the auto-reply - which is why presence would
+	// otherwise always show as available while the bot runs.
+	client.SyncPresence = event.Presence(cfg.Presence)
 
 	syncer := mautrix.NewDefaultSyncer()
 	client.Syncer = syncer