abstract supported room versions apis

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/info/room_version.rs

@@ -0,0 +1,58 @@
+//! Room version support
+
+use std::iter::once;
+
+use ruma::{api::client::discovery::get_capabilities::RoomVersionStability, RoomVersionId};
+
+use crate::{at, is_equal_to};
+
+/// Supported and stable room versions
+pub const STABLE_ROOM_VERSIONS: &[RoomVersionId] = &[
+	RoomVersionId::V6,
+	RoomVersionId::V7,
+	RoomVersionId::V8,
+	RoomVersionId::V9,
+	RoomVersionId::V10,
+	RoomVersionId::V11,
+];
+
+/// Experimental, partially supported room versions
+pub const UNSTABLE_ROOM_VERSIONS: &[RoomVersionId] =
+	&[RoomVersionId::V2, RoomVersionId::V3, RoomVersionId::V4, RoomVersionId::V5];
+
+impl crate::Server {
+	#[inline]
+	pub fn supported_room_version(&self, version: &RoomVersionId) -> bool {
+		self.supported_room_versions().any(is_equal_to!(*version))
+	}
+
+	#[inline]
+	pub fn supported_room_versions(&self) -> impl Iterator<Item = RoomVersionId> + '_ {
+		self.available_room_versions()
+			.filter(|(_, stability)| self.supported_stability(stability))
+			.map(at!(0))
+	}
+
+	#[inline]
+	pub fn available_room_versions(&self) -> impl Iterator<Item = (RoomVersionId, RoomVersionStability)> {
+		available_room_versions()
+	}
+
+	#[inline]
+	fn supported_stability(&self, stability: &RoomVersionStability) -> bool {
+		self.config.allow_unstable_room_versions || *stability == RoomVersionStability::Stable
+	}
+}
+
+pub fn available_room_versions() -> impl Iterator<Item = (RoomVersionId, RoomVersionStability)> {
+	let unstable_room_versions = UNSTABLE_ROOM_VERSIONS
+		.iter()
+		.cloned()
+		.zip(once(RoomVersionStability::Unstable).cycle());
+
+	STABLE_ROOM_VERSIONS
+		.iter()
+		.cloned()
+		.zip(once(RoomVersionStability::Stable).cycle())
+		.chain(unstable_room_versions)
+}