Add user commands for presence and presence subscription handling

References: https://todo.sr.ht/~nicoco/slidge-whatsapp/7
References: https://todo.sr.ht/~nicoco/slidge-whatsapp/1

slidge_whatsapp/__init__.py

@@ -4,8 +4,8 @@ WhatsApp gateway using the multi-device API.
 
 from slidge.util.util import get_version  # noqa: F401
 
-from . import config, contact, group, session
+from . import command, config, contact, group, session
 from .gateway import Gateway
 
 __version__ = get_version()
-__all__ = "Gateway", "session", "contact", "config", "group"
+__all__ = "Gateway", "session", "command", "contact", "config", "group"

slidge_whatsapp/command.py

@@ -0,0 +1,76 @@
+from typing import TYPE_CHECKING, Optional
+
+from slidge.core.command import Command, CommandAccess, Form, FormField
+from slixmpp import JID
+
+from .generated import whatsapp
+
+if TYPE_CHECKING:
+    from .session import Session
+
+
+class ChangePresence(Command):
+    NAME = "Set WhatsApp web presence"
+    HELP = (
+        "If you want to receive notifications in the WhatsApp official client,"
+        "you need to set your presence to unavailable. As a side effect, you "
+        "won't receive receipts and presences from your contacts."
+    )
+    NODE = "wa_presence"
+    CHAT_COMMAND = "presence"
+    ACCESS = CommandAccess.USER_LOGGED
+
+    async def run(
+        self,
+        session: Optional["Session"],  # type:ignore
+        ifrom: JID,
+        *args,
+    ) -> Form:
+        return Form(
+            title="Set WhatsApp web presence",
+            instructions="Choose what type of presence you want to set",
+            fields=[
+                FormField(
+                    var="presence",
+                    value="available",
+                    type="list-single",
+                    options=[
+                        {"label": "Available", "value": "available"},
+                        {"label": "Unavailable", "value": "unavailable"},
+                    ],
+                )
+            ],
+            handler=self.finish,
+        )
+
+    @staticmethod
+    async def finish(form_values: dict[str, str], session: "Session", _ifrom: JID):
+        p = form_values.get("presence")
+        if p == "available":
+            session.whatsapp.SendPresence(whatsapp.PresenceAvailable)
+        elif p == "unavailable":
+            session.whatsapp.SendPresence(whatsapp.PresenceUnavailable)
+        else:
+            raise ValueError("Not a valid presence kind.", p)
+        return f"Presence succesfully set to {p}"
+
+
+class SubscribeToPresences(Command):
+    NAME = "Subscribe to contacts' presences"
+    HELP = (
+        "This command is here for tests about "
+        "https://todo.sr.ht/~nicoco/slidge-whatsapp/7 ."
+    )
+    NODE = "wa_subscribe"
+    CHAT_COMMAND = "subscribe"
+    ACCESS = CommandAccess.USER_LOGGED
+
+    async def run(
+        self,
+        session: Optional["Session"],  # type:ignore
+        ifrom: JID,
+        *args,
+    ) -> str:
+        assert session is not None
+        session.whatsapp.GetContacts(False)
+        return "Looks like no exception was raised. Success, I guess?"