From 8085ac84f4feec7e0a250bbbbdf07de7ddaecd27 Mon Sep 17 00:00:00 2001
From: Kae Bartlett <kae@voxelfox.co.uk>
Date: Wed, 24 Apr 2024 21:38:08 +0100
Subject: [PATCH] Add guildmember permission calculations

---
 novus/models/channel.py      | 32 +++++++++++++++++++
 novus/models/guild_member.py | 59 +++++++++++++++++++++++++++++++++---
 novus/payloads/channel.py    |  2 +-
 3 files changed, 88 insertions(+), 5 deletions(-)

diff --git a/novus/models/channel.py b/novus/models/channel.py
index b7688072..7e87c7b4 100644
--- a/novus/models/channel.py
+++ b/novus/models/channel.py
@@ -443,6 +443,38 @@ def _add_channel(self, channel: Channel) -> None:
     def _remove_channel(self, id: int | str) -> None:
         self._channels.pop(try_snowflake(id), None)
 
+    def permissions_for(self, user: GuildMember) -> Permissions:
+        """
+        Get the permissions for a given user in this channel.
+
+        .. note::
+
+            Permissions are only properly calculated when the guild and its
+            roles are cached (ie when the bot is connected to the gateway).
+
+        Parameters
+        ----------
+        user : novus.GuildMember
+            The user whose permissions you want to get.
+
+        Returns
+        -------
+        novus.Permissions
+            The calculated permissions for that user in this channel.
+        """
+
+        all = Permissions.all().value
+        permissions: int = user.permissions.value
+        for overwrite in self.overwrites or []:
+            if overwrite.type == PermissionOverwriteType.ROLE:
+                if overwrite.id in user.role_ids or overwrite.id == self.guild_id:
+                    permissions |= overwrite.allow.value
+                    permissions &= (all ^ overwrite.deny.value)
+            elif overwrite.type == PermissionOverwriteType.MEMBER:
+                if overwrite.id == user.id:
+                    permissions |= overwrite.allow.value
+                    permissions &= (all ^ overwrite.deny.value)
+        return Permissions(permissions)
 
     # API methods
 
diff --git a/novus/models/guild_member.py b/novus/models/guild_member.py
index c33ad4a1..1a348b0e 100644
--- a/novus/models/guild_member.py
+++ b/novus/models/guild_member.py
@@ -162,7 +162,7 @@ class GuildMember(Hashable, Messageable):
         'deaf',
         'mute',
         'pending',
-        'permissions',
+        '_permissions',  # calculated
         'timeout_until',
         'guild',
         '_cs_guild_avatar',
@@ -195,7 +195,6 @@ class GuildMember(Hashable, Messageable):
     deaf: bool
     mute: bool
     pending: bool
-    permissions: Permissions
     timeout_until: DiscordDatetime | None
     guild: BaseGuild
 
@@ -249,9 +248,9 @@ def __init__(
         self.deaf = data.get('deaf', False)
         self.mute = data.get('mute', False)
         self.pending = data.get('pending', False)
-        self.permissions = Permissions.none()
+        self._permissions = None
         if "permissions" in data:
-            self.permissions = Permissions(int(data["permissions"]))
+            self._permissions = Permissions(int(data["permissions"]))
         self.timeout_until = None
         if "communication_disabled_until" in data:
             self.timeout_until = parse_timestamp(data["communication_disabled_until"])
@@ -318,6 +317,58 @@ def _update(self, data: payloads.GuildMember) -> Self:
         self.timeout_until = parse_timestamp(data.get("communication_disabled_until"))
         return self
 
+    @property
+    def permissions(self) -> Permissions:
+        """
+        The calculated permissions for the user based on their roles and the
+        cached guild.
+        If permissions were provided (ie this member was created as part of an
+        interaction payload) then they will not be re-calculated.
+
+        .. note::
+
+            Permissions are only properly calculated when the guild and its
+            roles are cached (ie when the bot is connected to the gateway).
+        """
+
+        if self._permissions is not None:
+            return self._permissions
+
+        permissions = Permissions()
+
+        from .guild import Guild
+        if not isinstance(self.guild, Guild):
+            return permissions
+
+        for role_id in [self.guild.id] + self.role_ids:
+            role = self.guild.get_role(role_id)
+            if role is None:
+                continue
+            permissions = Permissions(permissions.value | role.permissions.value)
+        return permissions
+
+    def permissions_in(self, channel: Channel) -> Permissions:
+        """
+        Get the permissions for this guild member inside of a channel.
+
+        .. note::
+
+            Permissions are only properly calculated when the guild and its
+            roles are cached (ie when the bot is connected to the gateway).
+
+        Parameters
+        ----------
+        channel : novus.Channel
+            The channel that you want to get the user's permissions for.
+
+        Returns
+        -------
+        novus.Permissions
+            The calculated permissions for this user in that channel.
+        """
+
+        return channel.permissions_for(self)
+
     # API methods
 
     @classmethod
diff --git a/novus/payloads/channel.py b/novus/payloads/channel.py
index 612e9f76..6c66fb92 100644
--- a/novus/payloads/channel.py
+++ b/novus/payloads/channel.py
@@ -34,7 +34,7 @@
 
 class ChannelOverwrite(TypedDict):
     id: Snowflake
-    type: Literal[0, 1, "role", "channel"]
+    type: int
     allow: str
     deny: str