// Copyright 2024 The Matrix.org Foundation C.I.C.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use matrix_sdk_base::RoomState;

use super::{super::RoomListItem, Filter};

fn matches<F>(state: F, room: &RoomListItem) -> bool
where
    F: Fn(&RoomListItem) -> RoomState,
{
    match state(room) {
        RoomState::Joined | RoomState::Invited | RoomState::Knocked => true,
        RoomState::Left | RoomState::Banned => false,
    }
}

/// Create a new filter that will filter out left rooms.
pub fn new_filter() -> impl Filter {
    let state = |room: &RoomListItem| room.cached_state;

    move |room| -> bool { matches(state, room) }
}

#[cfg(test)]
mod tests {
    use matrix_sdk::test_utils::mocks::MatrixMockServer;
    use matrix_sdk_base::RoomState;
    use matrix_sdk_test::async_test;
    use ruma::room_id;

    use super::{super::new_rooms, *};

    #[async_test]
    async fn test_all_non_left_kind_of_room_list_entry() {
        let server = MatrixMockServer::new().await;
        let client = server.client_builder().build().await;
        let [room] = new_rooms([room_id!("!a:b.c")], &client, &server).await;

        // When a room has been left, it doesn't match.
        assert!(!matches(|_| RoomState::Left, &room));

        // When a room is in the banned state, it doesn't match either.
        assert!(!matches(|_| RoomState::Banned, &room));

        // When a room has been joined, it does match (unless it's empty).
        assert!(matches(|_| RoomState::Joined, &room));
    }
}
