Implement set room command; common code for list and set rooms.

Adds fuzzy room search that can also set by exact ID, and refactors
the code to get room list for user into a common function and struct
for use by both commands.

Cargo.lock

@@ -576,6 +576,15 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fed34cd105917e91daa4da6b3728c47b068749d6a62c59811f06ed2ac71d9da7"
 
+[[package]]
+name = "fuse-rust"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "00df1351ccd6b34c2f67658bd4524b677e30f7269a6de44b038ec20211853e5e"
+dependencies = [
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "futf"
 version = "0.1.4"
@@ -2544,6 +2553,7 @@ dependencies = [
  "barrel",
  "combine",
  "dirs",
+ "fuse-rust",
  "futures",
  "html2text",
  "indoc",

Cargo.toml

@@ -32,6 +32,7 @@ refinery = { version = "0.5", features = ["rusqlite"]}
 barrel = { version = "0.6", features = ["sqlite3"] }
 tempfile = "3"
 substring = "1.4"
+fuse-rust = "0.2"
 
 [dependencies.sqlx]
 version = "0.5"

src/commands/parser.rs

@@ -9,7 +9,7 @@ use crate::commands::{
     cthulhu::{CthAdvanceRoll, CthRoll},
     management::{CheckCommand, LinkCommand, RegisterCommand, UnlinkCommand, UnregisterCommand},
     misc::HelpCommand,
-    rooms::ListRoomsCommand,
+    rooms::{ListRoomsCommand, SetRoomCommand},
     variables::{
         DeleteVariableCommand, GetAllVariablesCommand, GetVariableCommand, SetVariableCommand,
     },
@@ -91,6 +91,7 @@ pub fn parse_command(input: &str) -> Result<Box<dyn Command>, BotError> {
             "check" => convert_to!(CheckCommand, cmd_input),
             "unregister" => convert_to!(UnregisterCommand, cmd_input),
             "rooms" => convert_to!(ListRoomsCommand, cmd_input),
+            "room" => convert_to!(SetRoomCommand, cmd_input),
             _ => Err(CommandParsingError::UnrecognizedCommand(cmd).into()),
         },
         //All other errors passed up.

src/commands/rooms.rs

@@ -1,11 +1,78 @@
 use super::{Command, Execution, ExecutionResult};
 use crate::context::Context;
 use crate::error::BotError;
+use crate::matrix;
 use async_trait::async_trait;
+use fuse_rust::{Fuse, FuseProperty, Fuseable};
 use futures::stream::{self, StreamExt, TryStreamExt};
-use matrix_sdk::identifiers::UserId;
+use matrix_sdk::{identifiers::UserId, Client};
 use std::convert::TryFrom;
 
+/// Holds matrix room ID and display name as strings, for use with
+/// searching. See search_for_room.
+#[derive(Clone, Debug)]
+struct RoomNameAndId {
+    id: String,
+    name: String,
+}
+
+/// Allows searching for a room name and ID struct, instead of just
+/// searching room display names directly.
+impl Fuseable for RoomNameAndId {
+    fn properties(&self) -> Vec<FuseProperty> {
+        return vec![FuseProperty {
+            value: String::from("name"),
+            weight: 1.0,
+        }];
+    }
+
+    fn lookup(&self, key: &str) -> Option<&str> {
+        return match key {
+            "name" => Some(&self.name),
+            _ => None,
+        };
+    }
+}
+
+/// Attempt to find a room by either name or Matrix Room ID query
+/// string. It prefers the exact room ID first, and then falls back to
+/// fuzzy searching based on room display name. The best match is
+/// returned, or None if no matches were found.
+fn search_for_room<'a>(
+    rooms_for_user: &'a [RoomNameAndId],
+    query: &str,
+) -> Option<&'a RoomNameAndId> {
+    rooms_for_user
+        .iter()
+        .find(|room| room.id == query)
+        .or_else(|| {
+            Fuse::default()
+                .search_text_in_fuse_list(query, &rooms_for_user)
+                .into_iter()
+                .min_by(|r1, r2| r1.score.partial_cmp(&r2.score).unwrap())
+                .and_then(|result| rooms_for_user.get(result.index))
+        })
+}
+
+async fn get_rooms_for_user(
+    client: &Client,
+    user_id: &str,
+) -> Result<Vec<RoomNameAndId>, BotError> {
+    let user_id = UserId::try_from(user_id)?;
+    let rooms_for_user = matrix::get_rooms_for_user(client, &user_id).await?;
+    let rooms_for_user: Vec<RoomNameAndId> = stream::iter(rooms_for_user)
+        .filter_map(|room| async move {
+            Some(room.display_name().await.map(|room_name| RoomNameAndId {
+                id: room.room_id().to_string(),
+                name: room_name,
+            }))
+        })
+        .try_collect()
+        .await?;
+
+    Ok(rooms_for_user)
+}
+
 pub struct ListRoomsCommand;
 
 impl From<ListRoomsCommand> for Box<dyn Command> {
@@ -25,7 +92,7 @@ impl TryFrom<String> for ListRoomsCommand {
 #[async_trait]
 impl Command for ListRoomsCommand {
     fn name(&self) -> &'static str {
-        "list rooms command"
+        "list rooms"
     }
 
     fn is_secure(&self) -> bool {
@@ -33,22 +100,54 @@ impl Command for ListRoomsCommand {
     }
 
     async fn execute(&self, ctx: &Context<'_>) -> ExecutionResult {
-        let user_id = UserId::try_from(ctx.username)?;
-        let rooms_for_user = crate::matrix::get_rooms_for_user(ctx.matrix_client, &user_id).await?;
-
-        let rooms_for_user: Vec<String> = stream::iter(rooms_for_user)
-            .filter_map(|room| async move {
-                Some(
-                    room.display_name()
-                        .await
-                        .map(|room_name| (room.room_id().to_string(), room_name)),
-                )
-            })
-            .map_ok(|(room_id, room_name)| format!("  {}  |  {}", room_id, room_name))
-            .try_collect()
-            .await?;
+        let rooms_for_user: Vec<String> = get_rooms_for_user(ctx.matrix_client, ctx.username)
+            .await
+            .map(|rooms| {
+                rooms
+                    .into_iter()
+                    .map(|room| format!("  {}  |  {}", room.id, room.name))
+                    .collect()
+            })?;
 
         let html = format!("<pre>{}</pre>", rooms_for_user.join("\n"));
         Execution::success(html)
     }
 }
+
+pub struct SetRoomCommand(String);
+
+impl From<SetRoomCommand> for Box<dyn Command> {
+    fn from(cmd: SetRoomCommand) -> Self {
+        Box::new(cmd)
+    }
+}
+
+impl TryFrom<String> for SetRoomCommand {
+    type Error = BotError;
+
+    fn try_from(input: String) -> Result<Self, Self::Error> {
+        Ok(SetRoomCommand(input))
+    }
+}
+
+#[async_trait]
+impl Command for SetRoomCommand {
+    fn name(&self) -> &'static str {
+        "set active room"
+    }
+
+    fn is_secure(&self) -> bool {
+        true
+    }
+
+    async fn execute(&self, ctx: &Context<'_>) -> ExecutionResult {
+        let rooms_for_user = get_rooms_for_user(ctx.matrix_client, ctx.username).await?;
+        let room = search_for_room(&rooms_for_user, &self.0);
+
+        if let Some(room) = room {
+            Execution::success(format!(r#"Active room set to "{}""#, room.name))
+        } else {
+            Err(BotError::RoomDoesNotExist)
+        }
+    }
+}

src/error.rs

@@ -90,6 +90,9 @@ pub enum BotError {
 
     #[error("user account already exists")]
     AccountAlreadyExists,
+
+    #[error("room name or id does not exist")]
+    RoomDoesNotExist,
 }
 
 #[derive(Error, Debug)]