split spaces service

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

src/service/rooms/spaces/pagination_token.rs

@@ -0,0 +1,76 @@
+use std::{
+	fmt::{Display, Formatter},
+	str::FromStr,
+};
+
+use conduwuit::{Error, Result};
+use ruma::{api::client::error::ErrorKind, UInt};
+
+use crate::rooms::short::ShortRoomId;
+
+// TODO: perhaps use some better form of token rather than just room count
+#[derive(Debug, Eq, PartialEq)]
+pub struct PaginationToken {
+	/// Path down the hierarchy of the room to start the response at,
+	/// excluding the root space.
+	pub short_room_ids: Vec<ShortRoomId>,
+	pub limit: UInt,
+	pub max_depth: UInt,
+	pub suggested_only: bool,
+}
+
+impl FromStr for PaginationToken {
+	type Err = Error;
+
+	fn from_str(value: &str) -> Result<Self> {
+		let mut values = value.split('_');
+		let mut pag_tok = || {
+			let short_room_ids = values
+				.next()?
+				.split(',')
+				.filter_map(|room_s| u64::from_str(room_s).ok())
+				.collect();
+
+			let limit = UInt::from_str(values.next()?).ok()?;
+			let max_depth = UInt::from_str(values.next()?).ok()?;
+			let slice = values.next()?;
+			let suggested_only = if values.next().is_none() {
+				if slice == "true" {
+					true
+				} else if slice == "false" {
+					false
+				} else {
+					None?
+				}
+			} else {
+				None?
+			};
+
+			Some(Self {
+				short_room_ids,
+				limit,
+				max_depth,
+				suggested_only,
+			})
+		};
+
+		if let Some(token) = pag_tok() {
+			Ok(token)
+		} else {
+			Err(Error::BadRequest(ErrorKind::InvalidParam, "invalid token"))
+		}
+	}
+}
+
+impl Display for PaginationToken {
+	fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+		let short_room_ids = self
+			.short_room_ids
+			.iter()
+			.map(ToString::to_string)
+			.collect::<Vec<_>>()
+			.join(",");
+
+		write!(f, "{short_room_ids}_{}_{}_{}", self.limit, self.max_depth, self.suggested_only)
+	}
+}