use crate::{
    rpc::{CLEANUP_TIMEOUT, RECONNECT_TIMEOUT},
    tests::TestServer,
};
use client::{Collaborator, UserId};
use collections::HashMap;
use futures::future;
use gpui::{BackgroundExecutor, Model, TestAppContext};
use rpc::{proto::PeerId, RECEIVE_TIMEOUT};

#[gpui::test]
async fn test_core_channel_buffers(
    executor: BackgroundExecutor,
    cx_a: &mut TestAppContext,
    cx_b: &mut TestAppContext,
) {
    let mut server = TestServer::start(executor.clone()).await;
    let client_a = server.create_client(cx_a, "user_a").await;
    let client_b = server.create_client(cx_b, "user_b").await;

    let channel_id = server
        .make_channel("zed", None, (&client_a, cx_a), &mut [(&client_b, cx_b)])
        .await;

    // Client A joins the channel buffer
    let channel_buffer_a = client_a
        .channel_store()
        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();

    // Client A edits the buffer
    let buffer_a = channel_buffer_a.read_with(cx_a, |buffer, _| buffer.buffer());
    buffer_a.update(cx_a, |buffer, cx| {
        buffer.edit([(0..0, "hello world")], None, cx)
    });
    buffer_a.update(cx_a, |buffer, cx| {
        buffer.edit([(5..5, ", cruel")], None, cx)
    });
    buffer_a.update(cx_a, |buffer, cx| {
        buffer.edit([(0..5, "goodbye")], None, cx)
    });
    buffer_a.update(cx_a, |buffer, cx| buffer.undo(cx));
    assert_eq!(buffer_text(&buffer_a, cx_a), "hello, cruel world");
    executor.run_until_parked();

    // Client B joins the channel buffer
    let channel_buffer_b = client_b
        .channel_store()
        .update(cx_b, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();
    channel_buffer_b.read_with(cx_b, |buffer, _| {
        assert_collaborators(
            buffer.collaborators(),
            &[client_a.user_id(), client_b.user_id()],
        );
    });

    // Client B sees the correct text, and then edits it
    let buffer_b = channel_buffer_b.read_with(cx_b, |buffer, _| buffer.buffer());
    assert_eq!(
        buffer_b.read_with(cx_b, |buffer, _| buffer.remote_id()),
        buffer_a.read_with(cx_a, |buffer, _| buffer.remote_id())
    );
    assert_eq!(buffer_text(&buffer_b, cx_b), "hello, cruel world");
    buffer_b.update(cx_b, |buffer, cx| {
        buffer.edit([(7..12, "beautiful")], None, cx)
    });

    // Both A and B see the new edit
    executor.run_until_parked();
    assert_eq!(buffer_text(&buffer_a, cx_a), "hello, beautiful world");
    assert_eq!(buffer_text(&buffer_b, cx_b), "hello, beautiful world");

    // Client A closes the channel buffer.
    cx_a.update(|_| drop(channel_buffer_a));
    executor.run_until_parked();

    // Client B sees that client A is gone from the channel buffer.
    channel_buffer_b.read_with(cx_b, |buffer, _| {
        assert_collaborators(&buffer.collaborators(), &[client_b.user_id()]);
    });

    // Client A rejoins the channel buffer
    let _channel_buffer_a = client_a
        .channel_store()
        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();
    executor.run_until_parked();

    // Sanity test, make sure we saw A rejoining
    channel_buffer_b.read_with(cx_b, |buffer, _| {
        assert_collaborators(
            &buffer.collaborators(),
            &[client_a.user_id(), client_b.user_id()],
        );
    });

    // Client A loses connection.
    server.forbid_connections();
    server.disconnect_client(client_a.peer_id().unwrap());
    executor.advance_clock(RECEIVE_TIMEOUT + RECONNECT_TIMEOUT);

    // Client B observes A disconnect
    channel_buffer_b.read_with(cx_b, |buffer, _| {
        assert_collaborators(&buffer.collaborators(), &[client_b.user_id()]);
    });

    // TODO:
    // - Test synchronizing offline updates, what happens to A's channel buffer when A disconnects
    // - Test interaction with channel deletion while buffer is open
}

// todo!("collab_ui")
// #[gpui::test]
// async fn test_channel_notes_participant_indices(
//     executor: BackgroundExecutor,
//     mut cx_a: &mut TestAppContext,
//     mut cx_b: &mut TestAppContext,
//     cx_c: &mut TestAppContext,
// ) {
//     let mut server = TestServer::start(&executor).await;
//     let client_a = server.create_client(cx_a, "user_a").await;
//     let client_b = server.create_client(cx_b, "user_b").await;
//     let client_c = server.create_client(cx_c, "user_c").await;

//     let active_call_a = cx_a.read(ActiveCall::global);
//     let active_call_b = cx_b.read(ActiveCall::global);

//     cx_a.update(editor::init);
//     cx_b.update(editor::init);
//     cx_c.update(editor::init);

//     let channel_id = server
//         .make_channel(
//             "the-channel",
//             None,
//             (&client_a, cx_a),
//             &mut [(&client_b, cx_b), (&client_c, cx_c)],
//         )
//         .await;

//     client_a
//         .fs()
//         .insert_tree("/root", json!({"file.txt": "123"}))
//         .await;
//     let (project_a, worktree_id_a) = client_a.build_local_project("/root", cx_a).await;
//     let project_b = client_b.build_empty_local_project(cx_b);
//     let project_c = client_c.build_empty_local_project(cx_c);
//     let workspace_a = client_a.build_workspace(&project_a, cx_a).root(cx_a);
//     let workspace_b = client_b.build_workspace(&project_b, cx_b).root(cx_b);
//     let workspace_c = client_c.build_workspace(&project_c, cx_c).root(cx_c);

//     // Clients A, B, and C open the channel notes
//     let channel_view_a = cx_a
//         .update(|cx| ChannelView::open(channel_id, workspace_a.clone(), cx))
//         .await
//         .unwrap();
//     let channel_view_b = cx_b
//         .update(|cx| ChannelView::open(channel_id, workspace_b.clone(), cx))
//         .await
//         .unwrap();
//     let channel_view_c = cx_c
//         .update(|cx| ChannelView::open(channel_id, workspace_c.clone(), cx))
//         .await
//         .unwrap();

//     // Clients A, B, and C all insert and select some text
//     channel_view_a.update(cx_a, |notes, cx| {
//         notes.editor.update(cx, |editor, cx| {
//             editor.insert("a", cx);
//             editor.change_selections(None, cx, |selections| {
//                 selections.select_ranges(vec![0..1]);
//             });
//         });
//     });
//     executor.run_until_parked();
//     channel_view_b.update(cx_b, |notes, cx| {
//         notes.editor.update(cx, |editor, cx| {
//             editor.move_down(&Default::default(), cx);
//             editor.insert("b", cx);
//             editor.change_selections(None, cx, |selections| {
//                 selections.select_ranges(vec![1..2]);
//             });
//         });
//     });
//     executor.run_until_parked();
//     channel_view_c.update(cx_c, |notes, cx| {
//         notes.editor.update(cx, |editor, cx| {
//             editor.move_down(&Default::default(), cx);
//             editor.insert("c", cx);
//             editor.change_selections(None, cx, |selections| {
//                 selections.select_ranges(vec![2..3]);
//             });
//         });
//     });

//     // Client A sees clients B and C without assigned colors, because they aren't
//     // in a call together.
//     executor.run_until_parked();
//     channel_view_a.update(cx_a, |notes, cx| {
//         notes.editor.update(cx, |editor, cx| {
//             assert_remote_selections(editor, &[(None, 1..2), (None, 2..3)], cx);
//         });
//     });

//     // Clients A and B join the same call.
//     for (call, cx) in [(&active_call_a, &mut cx_a), (&active_call_b, &mut cx_b)] {
//         call.update(*cx, |call, cx| call.join_channel(channel_id, cx))
//             .await
//             .unwrap();
//     }

//     // Clients A and B see each other with two different assigned colors. Client C
//     // still doesn't have a color.
//     executor.run_until_parked();
//     channel_view_a.update(cx_a, |notes, cx| {
//         notes.editor.update(cx, |editor, cx| {
//             assert_remote_selections(
//                 editor,
//                 &[(Some(ParticipantIndex(1)), 1..2), (None, 2..3)],
//                 cx,
//             );
//         });
//     });
//     channel_view_b.update(cx_b, |notes, cx| {
//         notes.editor.update(cx, |editor, cx| {
//             assert_remote_selections(
//                 editor,
//                 &[(Some(ParticipantIndex(0)), 0..1), (None, 2..3)],
//                 cx,
//             );
//         });
//     });

//     // Client A shares a project, and client B joins.
//     let project_id = active_call_a
//         .update(cx_a, |call, cx| call.share_project(project_a.clone(), cx))
//         .await
//         .unwrap();
//     let project_b = client_b.build_remote_project(project_id, cx_b).await;
//     let workspace_b = client_b.build_workspace(&project_b, cx_b).root(cx_b);

//     // Clients A and B open the same file.
//     let editor_a = workspace_a
//         .update(cx_a, |workspace, cx| {
//             workspace.open_path((worktree_id_a, "file.txt"), None, true, cx)
//         })
//         .await
//         .unwrap()
//         .downcast::<Editor>()
//         .unwrap();
//     let editor_b = workspace_b
//         .update(cx_b, |workspace, cx| {
//             workspace.open_path((worktree_id_a, "file.txt"), None, true, cx)
//         })
//         .await
//         .unwrap()
//         .downcast::<Editor>()
//         .unwrap();

//     editor_a.update(cx_a, |editor, cx| {
//         editor.change_selections(None, cx, |selections| {
//             selections.select_ranges(vec![0..1]);
//         });
//     });
//     editor_b.update(cx_b, |editor, cx| {
//         editor.change_selections(None, cx, |selections| {
//             selections.select_ranges(vec![2..3]);
//         });
//     });
//     executor.run_until_parked();

//     // Clients A and B see each other with the same colors as in the channel notes.
//     editor_a.update(cx_a, |editor, cx| {
//         assert_remote_selections(editor, &[(Some(ParticipantIndex(1)), 2..3)], cx);
//     });
//     editor_b.update(cx_b, |editor, cx| {
//         assert_remote_selections(editor, &[(Some(ParticipantIndex(0)), 0..1)], cx);
//     });
// }

//todo!(editor)
// #[track_caller]
// fn assert_remote_selections(
//     editor: &mut Editor,
//     expected_selections: &[(Option<ParticipantIndex>, Range<usize>)],
//     cx: &mut ViewContext<Editor>,
// ) {
//     let snapshot = editor.snapshot(cx);
//     let range = Anchor::min()..Anchor::max();
//     let remote_selections = snapshot
//         .remote_selections_in_range(&range, editor.collaboration_hub().unwrap(), cx)
//         .map(|s| {
//             let start = s.selection.start.to_offset(&snapshot.buffer_snapshot);
//             let end = s.selection.end.to_offset(&snapshot.buffer_snapshot);
//             (s.participant_index, start..end)
//         })
//         .collect::<Vec<_>>();
//     assert_eq!(
//         remote_selections, expected_selections,
//         "incorrect remote selections"
//     );
// }

#[gpui::test]
async fn test_multiple_handles_to_channel_buffer(
    deterministic: BackgroundExecutor,
    cx_a: &mut TestAppContext,
) {
    let mut server = TestServer::start(deterministic.clone()).await;
    let client_a = server.create_client(cx_a, "user_a").await;

    let channel_id = server
        .make_channel("the-channel", None, (&client_a, cx_a), &mut [])
        .await;

    let channel_buffer_1 = client_a
        .channel_store()
        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx));
    let channel_buffer_2 = client_a
        .channel_store()
        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx));
    let channel_buffer_3 = client_a
        .channel_store()
        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx));

    // All concurrent tasks for opening a channel buffer return the same model handle.
    let (channel_buffer, channel_buffer_2, channel_buffer_3) =
        future::try_join3(channel_buffer_1, channel_buffer_2, channel_buffer_3)
            .await
            .unwrap();
    let channel_buffer_model_id = channel_buffer.entity_id();
    assert_eq!(channel_buffer, channel_buffer_2);
    assert_eq!(channel_buffer, channel_buffer_3);

    channel_buffer.update(cx_a, |buffer, cx| {
        buffer.buffer().update(cx, |buffer, cx| {
            buffer.edit([(0..0, "hello")], None, cx);
        })
    });
    deterministic.run_until_parked();

    cx_a.update(|_| {
        drop(channel_buffer);
        drop(channel_buffer_2);
        drop(channel_buffer_3);
    });
    deterministic.run_until_parked();

    // The channel buffer can be reopened after dropping it.
    let channel_buffer = client_a
        .channel_store()
        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();
    assert_ne!(channel_buffer.entity_id(), channel_buffer_model_id);
    channel_buffer.update(cx_a, |buffer, cx| {
        buffer.buffer().update(cx, |buffer, _| {
            assert_eq!(buffer.text(), "hello");
        })
    });
}

#[gpui::test]
async fn test_channel_buffer_disconnect(
    deterministic: BackgroundExecutor,
    cx_a: &mut TestAppContext,
    cx_b: &mut TestAppContext,
) {
    let mut server = TestServer::start(deterministic.clone()).await;
    let client_a = server.create_client(cx_a, "user_a").await;
    let client_b = server.create_client(cx_b, "user_b").await;

    let channel_id = server
        .make_channel(
            "the-channel",
            None,
            (&client_a, cx_a),
            &mut [(&client_b, cx_b)],
        )
        .await;

    let channel_buffer_a = client_a
        .channel_store()
        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();
    let channel_buffer_b = client_b
        .channel_store()
        .update(cx_b, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();

    server.forbid_connections();
    server.disconnect_client(client_a.peer_id().unwrap());
    deterministic.advance_clock(RECEIVE_TIMEOUT + RECONNECT_TIMEOUT);

    channel_buffer_a.update(cx_a, |buffer, cx| {
        assert_eq!(buffer.channel(cx).unwrap().name, "the-channel");
        assert!(!buffer.is_connected());
    });

    deterministic.run_until_parked();

    server.allow_connections();
    deterministic.advance_clock(RECEIVE_TIMEOUT + RECONNECT_TIMEOUT);

    deterministic.run_until_parked();

    client_a
        .channel_store()
        .update(cx_a, |channel_store, _| {
            channel_store.remove_channel(channel_id)
        })
        .await
        .unwrap();
    deterministic.run_until_parked();

    // Channel buffer observed the deletion
    channel_buffer_b.update(cx_b, |buffer, cx| {
        assert!(buffer.channel(cx).is_none());
        assert!(!buffer.is_connected());
    });
}

#[gpui::test]
async fn test_rejoin_channel_buffer(
    deterministic: BackgroundExecutor,
    cx_a: &mut TestAppContext,
    cx_b: &mut TestAppContext,
) {
    let mut server = TestServer::start(deterministic.clone()).await;
    let client_a = server.create_client(cx_a, "user_a").await;
    let client_b = server.create_client(cx_b, "user_b").await;

    let channel_id = server
        .make_channel(
            "the-channel",
            None,
            (&client_a, cx_a),
            &mut [(&client_b, cx_b)],
        )
        .await;

    let channel_buffer_a = client_a
        .channel_store()
        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();
    let channel_buffer_b = client_b
        .channel_store()
        .update(cx_b, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();

    channel_buffer_a.update(cx_a, |buffer, cx| {
        buffer.buffer().update(cx, |buffer, cx| {
            buffer.edit([(0..0, "1")], None, cx);
        })
    });
    deterministic.run_until_parked();

    // Client A disconnects.
    server.forbid_connections();
    server.disconnect_client(client_a.peer_id().unwrap());

    // Both clients make an edit.
    channel_buffer_a.update(cx_a, |buffer, cx| {
        buffer.buffer().update(cx, |buffer, cx| {
            buffer.edit([(1..1, "2")], None, cx);
        })
    });
    channel_buffer_b.update(cx_b, |buffer, cx| {
        buffer.buffer().update(cx, |buffer, cx| {
            buffer.edit([(0..0, "0")], None, cx);
        })
    });

    // Both clients see their own edit.
    deterministic.run_until_parked();
    channel_buffer_a.read_with(cx_a, |buffer, cx| {
        assert_eq!(buffer.buffer().read(cx).text(), "12");
    });
    channel_buffer_b.read_with(cx_b, |buffer, cx| {
        assert_eq!(buffer.buffer().read(cx).text(), "01");
    });

    // Client A reconnects. Both clients see each other's edits, and see
    // the same collaborators.
    server.allow_connections();
    deterministic.advance_clock(RECEIVE_TIMEOUT);
    channel_buffer_a.read_with(cx_a, |buffer, cx| {
        assert_eq!(buffer.buffer().read(cx).text(), "012");
    });
    channel_buffer_b.read_with(cx_b, |buffer, cx| {
        assert_eq!(buffer.buffer().read(cx).text(), "012");
    });

    channel_buffer_a.read_with(cx_a, |buffer_a, _| {
        channel_buffer_b.read_with(cx_b, |buffer_b, _| {
            assert_eq!(buffer_a.collaborators(), buffer_b.collaborators());
        });
    });
}

#[gpui::test]
async fn test_channel_buffers_and_server_restarts(
    deterministic: BackgroundExecutor,
    cx_a: &mut TestAppContext,
    cx_b: &mut TestAppContext,
    cx_c: &mut TestAppContext,
) {
    let mut server = TestServer::start(deterministic.clone()).await;
    let client_a = server.create_client(cx_a, "user_a").await;
    let client_b = server.create_client(cx_b, "user_b").await;
    let client_c = server.create_client(cx_c, "user_c").await;

    let channel_id = server
        .make_channel(
            "the-channel",
            None,
            (&client_a, cx_a),
            &mut [(&client_b, cx_b), (&client_c, cx_c)],
        )
        .await;

    let channel_buffer_a = client_a
        .channel_store()
        .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();
    let channel_buffer_b = client_b
        .channel_store()
        .update(cx_b, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();
    let _channel_buffer_c = client_c
        .channel_store()
        .update(cx_c, |store, cx| store.open_channel_buffer(channel_id, cx))
        .await
        .unwrap();

    channel_buffer_a.update(cx_a, |buffer, cx| {
        buffer.buffer().update(cx, |buffer, cx| {
            buffer.edit([(0..0, "1")], None, cx);
        })
    });
    deterministic.run_until_parked();

    // Client C can't reconnect.
    client_c.override_establish_connection(|_, cx| cx.spawn(|_| future::pending()));

    // Server stops.
    server.reset().await;
    deterministic.advance_clock(RECEIVE_TIMEOUT);

    // While the server is down, both clients make an edit.
    channel_buffer_a.update(cx_a, |buffer, cx| {
        buffer.buffer().update(cx, |buffer, cx| {
            buffer.edit([(1..1, "2")], None, cx);
        })
    });
    channel_buffer_b.update(cx_b, |buffer, cx| {
        buffer.buffer().update(cx, |buffer, cx| {
            buffer.edit([(0..0, "0")], None, cx);
        })
    });

    // Server restarts.
    server.start().await.unwrap();
    deterministic.advance_clock(CLEANUP_TIMEOUT);

    // Clients reconnects. Clients A and B see each other's edits, and see
    // that client C has disconnected.
    channel_buffer_a.read_with(cx_a, |buffer, cx| {
        assert_eq!(buffer.buffer().read(cx).text(), "012");
    });
    channel_buffer_b.read_with(cx_b, |buffer, cx| {
        assert_eq!(buffer.buffer().read(cx).text(), "012");
    });

    channel_buffer_a.read_with(cx_a, |buffer_a, _| {
        channel_buffer_b.read_with(cx_b, |buffer_b, _| {
            assert_collaborators(
                buffer_a.collaborators(),
                &[client_a.user_id(), client_b.user_id()],
            );
            assert_eq!(buffer_a.collaborators(), buffer_b.collaborators());
        });
    });
}

//todo!(collab_ui)
// #[gpui::test(iterations = 10)]
// async fn test_following_to_channel_notes_without_a_shared_project(
//     deterministic: BackgroundExecutor,
//     mut cx_a: &mut TestAppContext,
//     mut cx_b: &mut TestAppContext,
//     mut cx_c: &mut TestAppContext,
// ) {
//     let mut server = TestServer::start(&deterministic).await;
//     let client_a = server.create_client(cx_a, "user_a").await;
//     let client_b = server.create_client(cx_b, "user_b").await;

//     let client_c = server.create_client(cx_c, "user_c").await;

//     cx_a.update(editor::init);
//     cx_b.update(editor::init);
//     cx_c.update(editor::init);
//     cx_a.update(collab_ui::channel_view::init);
//     cx_b.update(collab_ui::channel_view::init);
//     cx_c.update(collab_ui::channel_view::init);

//     let channel_1_id = server
//         .make_channel(
//             "channel-1",
//             None,
//             (&client_a, cx_a),
//             &mut [(&client_b, cx_b), (&client_c, cx_c)],
//         )
//         .await;
//     let channel_2_id = server
//         .make_channel(
//             "channel-2",
//             None,
//             (&client_a, cx_a),
//             &mut [(&client_b, cx_b), (&client_c, cx_c)],
//         )
//         .await;

//     // Clients A, B, and C join a channel.
//     let active_call_a = cx_a.read(ActiveCall::global);
//     let active_call_b = cx_b.read(ActiveCall::global);
//     let active_call_c = cx_c.read(ActiveCall::global);
//     for (call, cx) in [
//         (&active_call_a, &mut cx_a),
//         (&active_call_b, &mut cx_b),
//         (&active_call_c, &mut cx_c),
//     ] {
//         call.update(*cx, |call, cx| call.join_channel(channel_1_id, cx))
//             .await
//             .unwrap();
//     }
//     deterministic.run_until_parked();

//     // Clients A, B, and C all open their own unshared projects.
//     client_a.fs().insert_tree("/a", json!({})).await;
//     client_b.fs().insert_tree("/b", json!({})).await;
//     client_c.fs().insert_tree("/c", json!({})).await;
//     let (project_a, _) = client_a.build_local_project("/a", cx_a).await;
//     let (project_b, _) = client_b.build_local_project("/b", cx_b).await;
//     let (project_c, _) = client_b.build_local_project("/c", cx_c).await;
//     let workspace_a = client_a.build_workspace(&project_a, cx_a).root(cx_a);
//     let workspace_b = client_b.build_workspace(&project_b, cx_b).root(cx_b);
//     let _workspace_c = client_c.build_workspace(&project_c, cx_c).root(cx_c);

//     active_call_a
//         .update(cx_a, |call, cx| call.set_location(Some(&project_a), cx))
//         .await
//         .unwrap();

//     // Client A opens the notes for channel 1.
//     let channel_view_1_a = cx_a
//         .update(|cx| ChannelView::open(channel_1_id, workspace_a.clone(), cx))
//         .await
//         .unwrap();
//     channel_view_1_a.update(cx_a, |notes, cx| {
//         assert_eq!(notes.channel(cx).unwrap().name, "channel-1");
//         notes.editor.update(cx, |editor, cx| {
//             editor.insert("Hello from A.", cx);
//             editor.change_selections(None, cx, |selections| {
//                 selections.select_ranges(vec![3..4]);
//             });
//         });
//     });

//     // Client B follows client A.
//     workspace_b
//         .update(cx_b, |workspace, cx| {
//             workspace.follow(client_a.peer_id().unwrap(), cx).unwrap()
//         })
//         .await
//         .unwrap();

//     // Client B is taken to the notes for channel 1, with the same
//     // text selected as client A.
//     deterministic.run_until_parked();
//     let channel_view_1_b = workspace_b.read_with(cx_b, |workspace, cx| {
//         assert_eq!(
//             workspace.leader_for_pane(workspace.active_pane()),
//             Some(client_a.peer_id().unwrap())
//         );
//         workspace
//             .active_item(cx)
//             .expect("no active item")
//             .downcast::<ChannelView>()
//             .expect("active item is not a channel view")
//     });
//     channel_view_1_b.read_with(cx_b, |notes, cx| {
//         assert_eq!(notes.channel(cx).unwrap().name, "channel-1");
//         let editor = notes.editor.read(cx);
//         assert_eq!(editor.text(cx), "Hello from A.");
//         assert_eq!(editor.selections.ranges::<usize>(cx), &[3..4]);
//     });

//     // Client A opens the notes for channel 2.
//     let channel_view_2_a = cx_a
//         .update(|cx| ChannelView::open(channel_2_id, workspace_a.clone(), cx))
//         .await
//         .unwrap();
//     channel_view_2_a.read_with(cx_a, |notes, cx| {
//         assert_eq!(notes.channel(cx).unwrap().name, "channel-2");
//     });

//     // Client B is taken to the notes for channel 2.
//     deterministic.run_until_parked();
//     let channel_view_2_b = workspace_b.read_with(cx_b, |workspace, cx| {
//         assert_eq!(
//             workspace.leader_for_pane(workspace.active_pane()),
//             Some(client_a.peer_id().unwrap())
//         );
//         workspace
//             .active_item(cx)
//             .expect("no active item")
//             .downcast::<ChannelView>()
//             .expect("active item is not a channel view")
//     });
//     channel_view_2_b.read_with(cx_b, |notes, cx| {
//         assert_eq!(notes.channel(cx).unwrap().name, "channel-2");
//     });
// }

//todo!(collab_ui)
// #[gpui::test]
// async fn test_channel_buffer_changes(
//     deterministic: BackgroundExecutor,
//     cx_a: &mut TestAppContext,
//     cx_b: &mut TestAppContext,
// ) {
//     let mut server = TestServer::start(&deterministic).await;
//     let client_a = server.create_client(cx_a, "user_a").await;
//     let client_b = server.create_client(cx_b, "user_b").await;

//     let channel_id = server
//         .make_channel(
//             "the-channel",
//             None,
//             (&client_a, cx_a),
//             &mut [(&client_b, cx_b)],
//         )
//         .await;

//     let channel_buffer_a = client_a
//         .channel_store()
//         .update(cx_a, |store, cx| store.open_channel_buffer(channel_id, cx))
//         .await
//         .unwrap();

//     // Client A makes an edit, and client B should see that the note has changed.
//     channel_buffer_a.update(cx_a, |buffer, cx| {
//         buffer.buffer().update(cx, |buffer, cx| {
//             buffer.edit([(0..0, "1")], None, cx);
//         })
//     });
//     deterministic.run_until_parked();

//     let has_buffer_changed = cx_b.update(|cx| {
//         client_b
//             .channel_store()
//             .read(cx)
//             .has_channel_buffer_changed(channel_id)
//             .unwrap()
//     });
//     assert!(has_buffer_changed);

//     // Opening the buffer should clear the changed flag.
//     let project_b = client_b.build_empty_local_project(cx_b);
//     let workspace_b = client_b.build_workspace(&project_b, cx_b).root(cx_b);
//     let channel_view_b = cx_b
//         .update(|cx| ChannelView::open(channel_id, workspace_b.clone(), cx))
//         .await
//         .unwrap();
//     deterministic.run_until_parked();

//     let has_buffer_changed = cx_b.update(|cx| {
//         client_b
//             .channel_store()
//             .read(cx)
//             .has_channel_buffer_changed(channel_id)
//             .unwrap()
//     });
//     assert!(!has_buffer_changed);

//     // Editing the channel while the buffer is open should not show that the buffer has changed.
//     channel_buffer_a.update(cx_a, |buffer, cx| {
//         buffer.buffer().update(cx, |buffer, cx| {
//             buffer.edit([(0..0, "2")], None, cx);
//         })
//     });
//     deterministic.run_until_parked();

//     let has_buffer_changed = cx_b.read(|cx| {
//         client_b
//             .channel_store()
//             .read(cx)
//             .has_channel_buffer_changed(channel_id)
//             .unwrap()
//     });
//     assert!(!has_buffer_changed);

//     deterministic.advance_clock(ACKNOWLEDGE_DEBOUNCE_INTERVAL);

//     // Test that the server is tracking things correctly, and we retain our 'not changed'
//     // state across a disconnect
//     server.simulate_long_connection_interruption(client_b.peer_id().unwrap(), &deterministic);
//     let has_buffer_changed = cx_b.read(|cx| {
//         client_b
//             .channel_store()
//             .read(cx)
//             .has_channel_buffer_changed(channel_id)
//             .unwrap()
//     });
//     assert!(!has_buffer_changed);

//     // Closing the buffer should re-enable change tracking
//     cx_b.update(|cx| {
//         workspace_b.update(cx, |workspace, cx| {
//             workspace.close_all_items_and_panes(&Default::default(), cx)
//         });

//         drop(channel_view_b)
//     });

//     deterministic.run_until_parked();

//     channel_buffer_a.update(cx_a, |buffer, cx| {
//         buffer.buffer().update(cx, |buffer, cx| {
//             buffer.edit([(0..0, "3")], None, cx);
//         })
//     });
//     deterministic.run_until_parked();

//     let has_buffer_changed = cx_b.read(|cx| {
//         client_b
//             .channel_store()
//             .read(cx)
//             .has_channel_buffer_changed(channel_id)
//             .unwrap()
//     });
//     assert!(has_buffer_changed);
// }

#[track_caller]
fn assert_collaborators(collaborators: &HashMap<PeerId, Collaborator>, ids: &[Option<UserId>]) {
    let mut user_ids = collaborators
        .values()
        .map(|collaborator| collaborator.user_id)
        .collect::<Vec<_>>();
    user_ids.sort();
    assert_eq!(
        user_ids,
        ids.into_iter().map(|id| id.unwrap()).collect::<Vec<_>>()
    );
}

fn buffer_text(channel_buffer: &Model<language::Buffer>, cx: &mut TestAppContext) -> String {
    channel_buffer.read_with(cx, |buffer, _| buffer.text())
}