// use crate::{
//     pane, persistence::model::ItemId, searchable::SearchableItemHandle, FollowableItemBuilders,
//     ItemNavHistory, Pane, ToolbarItemLocation, ViewId, Workspace, WorkspaceId,
// };
// use crate::{AutosaveSetting, DelayedDebouncedEditAction, WorkspaceSettings};
use anyhow::Result;
use client2::{
    proto::{self, PeerId, ViewId},
    Client,
};
use settings2::Settings;
use theme2::Theme;
// use client2::{
//     proto::{self, PeerId},
//     Client,
// };
// use gpui2::geometry::vector::Vector2F;
// use gpui2::AnyWindowHandle;
// use gpui2::{
//     fonts::HighlightStyle, AnyElement, AnyViewHandle, AppContext, Handle, Task, View,
//     ViewContext, View, WeakViewHandle, WindowContext,
// };
// use project2::{Project, ProjectEntryId, ProjectPath};
// use schemars::JsonSchema;
// use serde_derive::{Deserialize, Serialize};
// use settings2::Setting;
// use smallvec::SmallVec;
// use std::{
//     any::{Any, TypeId},
//     borrow::Cow,
//     cell::RefCell,
//     fmt,
//     ops::Range,
//     path::PathBuf,
//     rc::Rc,
//     sync::{
//         atomic::{AtomicBool, Ordering},
//         Arc,
//     },
//     time::Duration,
// };
// use theme2::Theme;

// #[derive(Deserialize)]
// pub struct ItemSettings {
//     pub git_status: bool,
//     pub close_position: ClosePosition,
// }

// #[derive(Clone, Default, Serialize, Deserialize, JsonSchema)]
// #[serde(rename_all = "lowercase")]
// pub enum ClosePosition {
//     Left,
//     #[default]
//     Right,
// }

// impl ClosePosition {
//     pub fn right(&self) -> bool {
//         match self {
//             ClosePosition::Left => false,
//             ClosePosition::Right => true,
//         }
//     }
// }

// #[derive(Clone, Default, Serialize, Deserialize, JsonSchema)]
// pub struct ItemSettingsContent {
//     git_status: Option<bool>,
//     close_position: Option<ClosePosition>,
// }

// impl Setting for ItemSettings {
//     const KEY: Option<&'static str> = Some("tabs");

//     type FileContent = ItemSettingsContent;

//     fn load(
//         default_value: &Self::FileContent,
//         user_values: &[&Self::FileContent],
//         _: &gpui2::AppContext,
//     ) -> anyhow::Result<Self> {
//         Self::load_via_json_merge(default_value, user_values)
//     }
// }

#[derive(Eq, PartialEq, Hash, Debug)]
pub enum ItemEvent {
    CloseItem,
    UpdateTab,
    UpdateBreadcrumbs,
    Edit,
}

// TODO: Combine this with existing HighlightedText struct?
pub struct BreadcrumbText {
    pub text: String,
    pub highlights: Option<Vec<(Range<usize>, HighlightStyle)>>,
}

pub trait Item: EventEmitter + Sized {
    //     fn deactivated(&mut self, _: &mut ViewContext<Self>) {}
    //     fn workspace_deactivated(&mut self, _: &mut ViewContext<Self>) {}
    //     fn navigate(&mut self, _: Box<dyn Any>, _: &mut ViewContext<Self>) -> bool {
    //         false
    //     }
    fn tab_tooltip_text(&self, _: &AppContext) -> Option<SharedString> {
        None
    }
    fn tab_description(&self, _: usize, _: &AppContext) -> Option<SharedString> {
        None
    }
    fn tab_content<V: 'static>(&self, detail: Option<usize>, cx: &AppContext) -> AnyElement<V>;

    fn for_each_project_item(&self, _: &AppContext, _: &mut dyn FnMut(usize, &dyn project2::Item)) {
    } // (model id, Item)
    fn is_singleton(&self, _cx: &AppContext) -> bool {
        false
    }
    //     fn set_nav_history(&mut self, _: ItemNavHistory, _: &mut ViewContext<Self>) {}
    fn clone_on_split(&self, _workspace_id: WorkspaceId, _: &mut ViewContext<Self>) -> Option<Self>
    where
        Self: Sized,
    {
        None
    }
    //     fn is_dirty(&self, _: &AppContext) -> bool {
    //         false
    //     }
    //     fn has_conflict(&self, _: &AppContext) -> bool {
    //         false
    //     }
    //     fn can_save(&self, _cx: &AppContext) -> bool {
    //         false
    //     }
    //     fn save(
    //         &mut self,
    //         _project: Handle<Project>,
    //         _cx: &mut ViewContext<Self>,
    //     ) -> Task<Result<()>> {
    //         unimplemented!("save() must be implemented if can_save() returns true")
    //     }
    //     fn save_as(
    //         &mut self,
    //         _project: Handle<Project>,
    //         _abs_path: PathBuf,
    //         _cx: &mut ViewContext<Self>,
    //     ) -> Task<Result<()>> {
    //         unimplemented!("save_as() must be implemented if can_save() returns true")
    //     }
    //     fn reload(
    //         &mut self,
    //         _project: Handle<Project>,
    //         _cx: &mut ViewContext<Self>,
    //     ) -> Task<Result<()>> {
    //         unimplemented!("reload() must be implemented if can_save() returns true")
    //     }
    fn to_item_events(_event: &Self::Event) -> SmallVec<[ItemEvent; 2]> {
        SmallVec::new()
    }
    //     fn should_close_item_on_event(_: &Self::Event) -> bool {
    //         false
    //     }
    //     fn should_update_tab_on_event(_: &Self::Event) -> bool {
    //         false
    //     }

    //     fn act_as_type<'a>(
    //         &'a self,
    //         type_id: TypeId,
    //         self_handle: &'a View<Self>,
    //         _: &'a AppContext,
    //     ) -> Option<&AnyViewHandle> {
    //         if TypeId::of::<Self>() == type_id {
    //             Some(self_handle)
    //         } else {
    //             None
    //         }
    //     }

    //     fn as_searchable(&self, _: &View<Self>) -> Option<Box<dyn SearchableItemHandle>> {
    //         None
    //     }

    //     fn breadcrumb_location(&self) -> ToolbarItemLocation {
    //         ToolbarItemLocation::Hidden
    //     }

    //     fn breadcrumbs(&self, _theme: &Theme, _cx: &AppContext) -> Option<Vec<BreadcrumbText>> {
    //         None
    //     }

    //     fn added_to_workspace(&mut self, _workspace: &mut Workspace, _cx: &mut ViewContext<Self>) {}

    //     fn serialized_item_kind() -> Option<&'static str> {
    //         None
    //     }

    //     fn deserialize(
    //         _project: Handle<Project>,
    //         _workspace: WeakViewHandle<Workspace>,
    //         _workspace_id: WorkspaceId,
    //         _item_id: ItemId,
    //         _cx: &mut ViewContext<Pane>,
    //     ) -> Task<Result<View<Self>>> {
    //         unimplemented!(
    //             "deserialize() must be implemented if serialized_item_kind() returns Some(_)"
    //         )
    //     }
    //     fn show_toolbar(&self) -> bool {
    //         true
    //     }
    //     fn pixel_position_of_cursor(&self, _: &AppContext) -> Option<Vector2F> {
    //         None
    //     }
}

use std::{
    any::Any,
    cell::RefCell,
    ops::Range,
    path::PathBuf,
    rc::Rc,
    sync::{
        atomic::{AtomicBool, Ordering},
        Arc,
    },
    time::Duration,
};

use gpui2::{
    AnyElement, AnyWindowHandle, AppContext, EventEmitter, Handle, HighlightStyle, Pixels, Point,
    SharedString, Task, View, ViewContext, VisualContext, WindowContext,
};
use project2::{Project, ProjectEntryId, ProjectPath};
use smallvec::SmallVec;

use crate::{
    pane::{self, Pane},
    searchable::SearchableItemHandle,
    workspace_settings::{AutosaveSetting, WorkspaceSettings},
    DelayedDebouncedEditAction, FollowableItemBuilders, ToolbarItemLocation, Workspace,
    WorkspaceId,
};

pub trait ItemHandle: 'static + Send {
    fn subscribe_to_item_events(
        &self,
        cx: &mut WindowContext,
        handler: Box<dyn Fn(ItemEvent, &mut WindowContext) + Send>,
    ) -> gpui2::Subscription;
    fn tab_tooltip_text(&self, cx: &AppContext) -> Option<SharedString>;
    fn tab_description(&self, detail: usize, cx: &AppContext) -> Option<SharedString>;
    fn tab_content(&self, detail: Option<usize>, cx: &AppContext) -> AnyElement<Pane>;
    fn dragged_tab_content(&self, detail: Option<usize>, cx: &AppContext) -> AnyElement<Workspace>;
    fn project_path(&self, cx: &AppContext) -> Option<ProjectPath>;
    fn project_entry_ids(&self, cx: &AppContext) -> SmallVec<[ProjectEntryId; 3]>;
    fn project_item_model_ids(&self, cx: &AppContext) -> SmallVec<[usize; 3]>;
    fn for_each_project_item(&self, _: &AppContext, _: &mut dyn FnMut(usize, &dyn project2::Item));
    fn is_singleton(&self, cx: &AppContext) -> bool;
    fn boxed_clone(&self) -> Box<dyn ItemHandle>;
    fn clone_on_split(
        &self,
        workspace_id: WorkspaceId,
        cx: &mut WindowContext,
    ) -> Option<Box<dyn ItemHandle>>;
    fn added_to_pane(
        &self,
        workspace: &mut Workspace,
        pane: View<Pane>,
        cx: &mut ViewContext<Workspace>,
    );
    fn deactivated(&self, cx: &mut WindowContext);
    fn workspace_deactivated(&self, cx: &mut WindowContext);
    fn navigate(&self, data: Box<dyn Any>, cx: &mut WindowContext) -> bool;
    fn id(&self) -> usize;
    fn window(&self) -> AnyWindowHandle;
    // fn as_any(&self) -> &AnyView; todo!()
    fn is_dirty(&self, cx: &AppContext) -> bool;
    fn has_conflict(&self, cx: &AppContext) -> bool;
    fn can_save(&self, cx: &AppContext) -> bool;
    fn save(&self, project: Handle<Project>, cx: &mut WindowContext) -> Task<Result<()>>;
    fn save_as(
        &self,
        project: Handle<Project>,
        abs_path: PathBuf,
        cx: &mut WindowContext,
    ) -> Task<Result<()>>;
    fn reload(&self, project: Handle<Project>, cx: &mut WindowContext) -> Task<Result<()>>;
    // fn act_as_type<'a>(&'a self, type_id: TypeId, cx: &'a AppContext) -> Option<&'a AnyViewHandle>; todo!()
    fn to_followable_item_handle(&self, cx: &AppContext) -> Option<Box<dyn FollowableItemHandle>>;
    fn on_release(
        &self,
        cx: &mut AppContext,
        callback: Box<dyn FnOnce(&mut AppContext)>,
    ) -> gpui2::Subscription;
    fn to_searchable_item_handle(&self, cx: &AppContext) -> Option<Box<dyn SearchableItemHandle>>;
    fn breadcrumb_location(&self, cx: &AppContext) -> ToolbarItemLocation;
    fn breadcrumbs(&self, theme: &Theme, cx: &AppContext) -> Option<Vec<BreadcrumbText>>;
    fn serialized_item_kind(&self) -> Option<&'static str>;
    fn show_toolbar(&self, cx: &AppContext) -> bool;
    fn pixel_position_of_cursor(&self, cx: &AppContext) -> Option<Point<Pixels>>;
}

pub trait WeakItemHandle {
    fn id(&self) -> usize;
    fn window(&self) -> AnyWindowHandle;
    fn upgrade(&self, cx: &AppContext) -> Option<Box<dyn ItemHandle>>;
}

// todo!()
// impl dyn ItemHandle {
//     pub fn downcast<T: View>(&self) -> Option<View<T>> {
//         self.as_any().clone().downcast()
//     }

//     pub fn act_as<T: View>(&self, cx: &AppContext) -> Option<View<T>> {
//         self.act_as_type(TypeId::of::<T>(), cx)
//             .and_then(|t| t.clone().downcast())
//     }
// }

impl<T: Item> ItemHandle for View<T> {
    fn subscribe_to_item_events(
        &self,
        cx: &mut WindowContext,
        handler: Box<dyn Fn(ItemEvent, &mut WindowContext) + Send>,
    ) -> gpui2::Subscription {
        cx.subscribe(self, move |_, event, cx| {
            for item_event in T::to_item_events(event) {
                handler(item_event, cx)
            }
        })
    }

    fn tab_tooltip_text(&self, cx: &AppContext) -> Option<SharedString> {
        self.read(cx).tab_tooltip_text(cx)
    }

    fn tab_description(&self, detail: usize, cx: &AppContext) -> Option<SharedString> {
        self.read(cx).tab_description(detail, cx)
    }

    fn tab_content(&self, detail: Option<usize>, cx: &AppContext) -> AnyElement<Pane> {
        self.read(cx).tab_content(detail, cx)
    }

    fn dragged_tab_content(&self, detail: Option<usize>, cx: &AppContext) -> AnyElement<Workspace> {
        self.read(cx).tab_content(detail, cx)
    }

    fn project_path(&self, cx: &AppContext) -> Option<ProjectPath> {
        let this = self.read(cx);
        let mut result = None;
        if this.is_singleton(cx) {
            this.for_each_project_item(cx, &mut |_, item| {
                result = item.project_path(cx);
            });
        }
        result
    }

    fn project_entry_ids(&self, cx: &AppContext) -> SmallVec<[ProjectEntryId; 3]> {
        let mut result = SmallVec::new();
        self.read(cx).for_each_project_item(cx, &mut |_, item| {
            if let Some(id) = item.entry_id(cx) {
                result.push(id);
            }
        });
        result
    }

    fn project_item_model_ids(&self, cx: &AppContext) -> SmallVec<[usize; 3]> {
        let mut result = SmallVec::new();
        self.read(cx).for_each_project_item(cx, &mut |id, _| {
            result.push(id);
        });
        result
    }

    fn for_each_project_item(
        &self,
        cx: &AppContext,
        f: &mut dyn FnMut(usize, &dyn project2::Item),
    ) {
        self.read(cx).for_each_project_item(cx, f)
    }

    fn is_singleton(&self, cx: &AppContext) -> bool {
        self.read(cx).is_singleton(cx)
    }

    fn boxed_clone(&self) -> Box<dyn ItemHandle> {
        Box::new(self.clone())
    }

    fn clone_on_split(
        &self,
        workspace_id: WorkspaceId,
        cx: &mut WindowContext,
    ) -> Option<Box<dyn ItemHandle>> {
        self.update(cx, |item, cx| {
            cx.add_option_view(|cx| item.clone_on_split(workspace_id, cx))
        })
        .map(|handle| Box::new(handle) as Box<dyn ItemHandle>)
    }

    fn added_to_pane(
        &self,
        workspace: &mut Workspace,
        pane: View<Pane>,
        cx: &mut ViewContext<Workspace>,
    ) {
        let history = pane.read(cx).nav_history_for_item(self);
        self.update(cx, |this, cx| {
            this.set_nav_history(history, cx);
            this.added_to_workspace(workspace, cx);
        });

        if let Some(followed_item) = self.to_followable_item_handle(cx) {
            if let Some(message) = followed_item.to_state_proto(cx) {
                workspace.update_followers(
                    followed_item.is_project_item(cx),
                    proto::update_followers::Variant::CreateView(proto::View {
                        id: followed_item
                            .remote_id(&workspace.app_state.client, cx)
                            .map(|id| id.to_proto()),
                        variant: Some(message),
                        leader_id: workspace.leader_for_pane(&pane),
                    }),
                    cx,
                );
            }
        }

        if workspace
            .panes_by_item
            .insert(self.id(), pane.downgrade())
            .is_none()
        {
            let mut pending_autosave = DelayedDebouncedEditAction::new();
            let pending_update = Rc::new(RefCell::new(None));
            let pending_update_scheduled = Rc::new(AtomicBool::new(false));

            let mut event_subscription =
                Some(cx.subscribe(self, move |workspace, item, event, cx| {
                    let pane = if let Some(pane) = workspace
                        .panes_by_item
                        .get(&item.id())
                        .and_then(|pane| pane.upgrade(cx))
                    {
                        pane
                    } else {
                        log::error!("unexpected item event after pane was dropped");
                        return;
                    };

                    if let Some(item) = item.to_followable_item_handle(cx) {
                        let is_project_item = item.is_project_item(cx);
                        let leader_id = workspace.leader_for_pane(&pane);

                        if leader_id.is_some() && item.should_unfollow_on_event(event, cx) {
                            workspace.unfollow(&pane, cx);
                        }

                        if item.add_event_to_update_proto(
                            event,
                            &mut *pending_update.borrow_mut(),
                            cx,
                        ) && !pending_update_scheduled.load(Ordering::SeqCst)
                        {
                            pending_update_scheduled.store(true, Ordering::SeqCst);
                            cx.after_window_update({
                                let pending_update = pending_update.clone();
                                let pending_update_scheduled = pending_update_scheduled.clone();
                                move |this, cx| {
                                    pending_update_scheduled.store(false, Ordering::SeqCst);
                                    this.update_followers(
                                        is_project_item,
                                        proto::update_followers::Variant::UpdateView(
                                            proto::UpdateView {
                                                id: item
                                                    .remote_id(&this.app_state.client, cx)
                                                    .map(|id| id.to_proto()),
                                                variant: pending_update.borrow_mut().take(),
                                                leader_id,
                                            },
                                        ),
                                        cx,
                                    );
                                }
                            });
                        }
                    }

                    for item_event in T::to_item_events(event).into_iter() {
                        match item_event {
                            ItemEvent::CloseItem => {
                                pane.update(cx, |pane, cx| {
                                    pane.close_item_by_id(item.id(), crate::SaveIntent::Close, cx)
                                })
                                .detach_and_log_err(cx);
                                return;
                            }

                            ItemEvent::UpdateTab => {
                                pane.update(cx, |_, cx| {
                                    cx.emit(pane::Event::ChangeItemTitle);
                                    cx.notify();
                                });
                            }

                            ItemEvent::Edit => {
                                let autosave = WorkspaceSettings::get_global(cx).autosave;
                                if let AutosaveSetting::AfterDelay { milliseconds } = autosave {
                                    let delay = Duration::from_millis(milliseconds);
                                    let item = item.clone();
                                    pending_autosave.fire_new(delay, cx, move |workspace, cx| {
                                        Pane::autosave_item(&item, workspace.project().clone(), cx)
                                    });
                                }
                            }

                            _ => {}
                        }
                    }
                }));

            cx.observe_focus(self, move |workspace, item, focused, cx| {
                if !focused
                    && WorkspaceSettings::get_global(cx).autosave == AutosaveSetting::OnFocusChange
                {
                    Pane::autosave_item(&item, workspace.project.clone(), cx)
                        .detach_and_log_err(cx);
                }
            })
            .detach();

            let item_id = self.id();
            cx.observe_release(self, move |workspace, _, _| {
                workspace.panes_by_item.remove(&item_id);
                event_subscription.take();
            })
            .detach();
        }

        cx.defer(|workspace, cx| {
            workspace.serialize_workspace(cx);
        });
    }

    fn deactivated(&self, cx: &mut WindowContext) {
        self.update(cx, |this, cx| this.deactivated(cx));
    }

    fn workspace_deactivated(&self, cx: &mut WindowContext) {
        self.update(cx, |this, cx| this.workspace_deactivated(cx));
    }

    fn navigate(&self, data: Box<dyn Any>, cx: &mut WindowContext) -> bool {
        self.update(cx, |this, cx| this.navigate(data, cx))
    }

    fn id(&self) -> usize {
        self.id()
    }

    fn window(&self) -> AnyWindowHandle {
        todo!()
        // AnyViewHandle::window(self)
    }

    // todo!()
    // fn as_any(&self) -> &AnyViewHandle {
    //     self
    // }

    fn is_dirty(&self, cx: &AppContext) -> bool {
        self.read(cx).is_dirty(cx)
    }

    fn has_conflict(&self, cx: &AppContext) -> bool {
        self.read(cx).has_conflict(cx)
    }

    fn can_save(&self, cx: &AppContext) -> bool {
        self.read(cx).can_save(cx)
    }

    fn save(&self, project: Handle<Project>, cx: &mut WindowContext) -> Task<Result<()>> {
        self.update(cx, |item, cx| item.save(project, cx))
    }

    fn save_as(
        &self,
        project: Handle<Project>,
        abs_path: PathBuf,
        cx: &mut WindowContext,
    ) -> Task<anyhow::Result<()>> {
        self.update(cx, |item, cx| item.save_as(project, abs_path, cx))
    }

    fn reload(&self, project: Handle<Project>, cx: &mut WindowContext) -> Task<Result<()>> {
        self.update(cx, |item, cx| item.reload(project, cx))
    }

    // todo!()
    // fn act_as_type<'a>(&'a self, type_id: TypeId, cx: &'a AppContext) -> Option<&'a AnyViewHandle> {
    //     self.read(cx).act_as_type(type_id, self, cx)
    // }

    fn to_followable_item_handle(&self, cx: &AppContext) -> Option<Box<dyn FollowableItemHandle>> {
        if cx.has_global::<FollowableItemBuilders>() {
            let builders = cx.global::<FollowableItemBuilders>();
            let item = self.as_any();
            Some(builders.get(&item.view_type())?.1(item))
        } else {
            None
        }
    }

    fn on_release(
        &self,
        cx: &mut AppContext,
        callback: Box<dyn FnOnce(&mut AppContext)>,
    ) -> gpui2::Subscription {
        cx.observe_release(self, move |_, cx| callback(cx))
    }

    fn to_searchable_item_handle(&self, cx: &AppContext) -> Option<Box<dyn SearchableItemHandle>> {
        self.read(cx).as_searchable(self)
    }

    fn breadcrumb_location(&self, cx: &AppContext) -> ToolbarItemLocation {
        self.read(cx).breadcrumb_location()
    }

    fn breadcrumbs(&self, theme: &Theme, cx: &AppContext) -> Option<Vec<BreadcrumbText>> {
        self.read(cx).breadcrumbs(theme, cx)
    }

    fn serialized_item_kind(&self) -> Option<&'static str> {
        T::serialized_item_kind()
    }

    fn show_toolbar(&self, cx: &AppContext) -> bool {
        self.read(cx).show_toolbar()
    }

    fn pixel_position_of_cursor(&self, cx: &AppContext) -> Option<Point<Pixels>> {
        self.read(cx).pixel_position_of_cursor(cx)
    }
}

// impl From<Box<dyn ItemHandle>> for AnyViewHandle {
//     fn from(val: Box<dyn ItemHandle>) -> Self {
//         val.as_any().clone()
//     }
// }

// impl From<&Box<dyn ItemHandle>> for AnyViewHandle {
//     fn from(val: &Box<dyn ItemHandle>) -> Self {
//         val.as_any().clone()
//     }
// }

impl Clone for Box<dyn ItemHandle> {
    fn clone(&self) -> Box<dyn ItemHandle> {
        self.boxed_clone()
    }
}

// impl<T: Item> WeakItemHandle for WeakViewHandle<T> {
//     fn id(&self) -> usize {
//         self.id()
//     }

//     fn window(&self) -> AnyWindowHandle {
//         self.window()
//     }

//     fn upgrade(&self, cx: &AppContext) -> Option<Box<dyn ItemHandle>> {
//         self.upgrade(cx).map(|v| Box::new(v) as Box<dyn ItemHandle>)
//     }
// }

pub trait ProjectItem: Item {
    type Item: project2::Item;

    fn for_project_item(
        project: Handle<Project>,
        item: Handle<Self::Item>,
        cx: &mut ViewContext<Self>,
    ) -> Self
    where
        Self: Sized;
}

pub trait FollowableItem: Item {
    fn remote_id(&self) -> Option<ViewId>;
    fn to_state_proto(&self, cx: &AppContext) -> Option<proto::view::Variant>;
    fn from_state_proto(
        pane: View<Pane>,
        project: View<Workspace>,
        id: ViewId,
        state: &mut Option<proto::view::Variant>,
        cx: &mut AppContext,
    ) -> Option<Task<Result<View<Self>>>>;
    fn add_event_to_update_proto(
        &self,
        event: &Self::Event,
        update: &mut Option<proto::update_view::Variant>,
        cx: &AppContext,
    ) -> bool;
    fn apply_update_proto(
        &mut self,
        project: &Handle<Project>,
        message: proto::update_view::Variant,
        cx: &mut ViewContext<Self>,
    ) -> Task<Result<()>>;
    fn is_project_item(&self, cx: &AppContext) -> bool;

    fn set_leader_peer_id(&mut self, leader_peer_id: Option<PeerId>, cx: &mut ViewContext<Self>);
    fn should_unfollow_on_event(event: &Self::Event, cx: &AppContext) -> bool;
}

pub trait FollowableItemHandle: ItemHandle {
    fn remote_id(&self, client: &Arc<Client>, cx: &AppContext) -> Option<ViewId>;
    fn set_leader_peer_id(&self, leader_peer_id: Option<PeerId>, cx: &mut WindowContext);
    fn to_state_proto(&self, cx: &AppContext) -> Option<proto::view::Variant>;
    fn add_event_to_update_proto(
        &self,
        event: &dyn Any,
        update: &mut Option<proto::update_view::Variant>,
        cx: &AppContext,
    ) -> bool;
    fn apply_update_proto(
        &self,
        project: &Handle<Project>,
        message: proto::update_view::Variant,
        cx: &mut WindowContext,
    ) -> Task<Result<()>>;
    fn should_unfollow_on_event(&self, event: &dyn Any, cx: &AppContext) -> bool;
    fn is_project_item(&self, cx: &AppContext) -> bool;
}

// impl<T: FollowableItem> FollowableItemHandle for View<T> {
//     fn remote_id(&self, client: &Arc<Client>, cx: &AppContext) -> Option<ViewId> {
//         self.read(cx).remote_id().or_else(|| {
//             client.peer_id().map(|creator| ViewId {
//                 creator,
//                 id: self.id() as u64,
//             })
//         })
//     }

//     fn set_leader_peer_id(&self, leader_peer_id: Option<PeerId>, cx: &mut WindowContext) {
//         self.update(cx, |this, cx| this.set_leader_peer_id(leader_peer_id, cx))
//     }

//     fn to_state_proto(&self, cx: &AppContext) -> Option<proto::view::Variant> {
//         self.read(cx).to_state_proto(cx)
//     }

//     fn add_event_to_update_proto(
//         &self,
//         event: &dyn Any,
//         update: &mut Option<proto::update_view::Variant>,
//         cx: &AppContext,
//     ) -> bool {
//         if let Some(event) = event.downcast_ref() {
//             self.read(cx).add_event_to_update_proto(event, update, cx)
//         } else {
//             false
//         }
//     }

//     fn apply_update_proto(
//         &self,
//         project: &Handle<Project>,
//         message: proto::update_view::Variant,
//         cx: &mut WindowContext,
//     ) -> Task<Result<()>> {
//         self.update(cx, |this, cx| this.apply_update_proto(project, message, cx))
//     }

//     fn should_unfollow_on_event(&self, event: &dyn Any, cx: &AppContext) -> bool {
//         if let Some(event) = event.downcast_ref() {
//             T::should_unfollow_on_event(event, cx)
//         } else {
//             false
//         }
//     }

//     fn is_project_item(&self, cx: &AppContext) -> bool {
//         self.read(cx).is_project_item(cx)
//     }
// }

// #[cfg(any(test, feature = "test-support"))]
// pub mod test {
//     use super::{Item, ItemEvent};
//     use crate::{ItemId, ItemNavHistory, Pane, Workspace, WorkspaceId};
//     use gpui2::{
//         elements::Empty, AnyElement, AppContext, Element, Entity, Handle, Task, View,
//         ViewContext, View, WeakViewHandle,
//     };
//     use project2::{Project, ProjectEntryId, ProjectPath, WorktreeId};
//     use smallvec::SmallVec;
//     use std::{any::Any, borrow::Cow, cell::Cell, path::Path};

//     pub struct TestProjectItem {
//         pub entry_id: Option<ProjectEntryId>,
//         pub project_path: Option<ProjectPath>,
//     }

//     pub struct TestItem {
//         pub workspace_id: WorkspaceId,
//         pub state: String,
//         pub label: String,
//         pub save_count: usize,
//         pub save_as_count: usize,
//         pub reload_count: usize,
//         pub is_dirty: bool,
//         pub is_singleton: bool,
//         pub has_conflict: bool,
//         pub project_items: Vec<Handle<TestProjectItem>>,
//         pub nav_history: Option<ItemNavHistory>,
//         pub tab_descriptions: Option<Vec<&'static str>>,
//         pub tab_detail: Cell<Option<usize>>,
//     }

//     impl Entity for TestProjectItem {
//         type Event = ();
//     }

//     impl project2::Item for TestProjectItem {
//         fn entry_id(&self, _: &AppContext) -> Option<ProjectEntryId> {
//             self.entry_id
//         }

//         fn project_path(&self, _: &AppContext) -> Option<ProjectPath> {
//             self.project_path.clone()
//         }
//     }

//     pub enum TestItemEvent {
//         Edit,
//     }

//     impl Clone for TestItem {
//         fn clone(&self) -> Self {
//             Self {
//                 state: self.state.clone(),
//                 label: self.label.clone(),
//                 save_count: self.save_count,
//                 save_as_count: self.save_as_count,
//                 reload_count: self.reload_count,
//                 is_dirty: self.is_dirty,
//                 is_singleton: self.is_singleton,
//                 has_conflict: self.has_conflict,
//                 project_items: self.project_items.clone(),
//                 nav_history: None,
//                 tab_descriptions: None,
//                 tab_detail: Default::default(),
//                 workspace_id: self.workspace_id,
//             }
//         }
//     }

//     impl TestProjectItem {
//         pub fn new(id: u64, path: &str, cx: &mut AppContext) -> Handle<Self> {
//             let entry_id = Some(ProjectEntryId::from_proto(id));
//             let project_path = Some(ProjectPath {
//                 worktree_id: WorktreeId::from_usize(0),
//                 path: Path::new(path).into(),
//             });
//             cx.add_model(|_| Self {
//                 entry_id,
//                 project_path,
//             })
//         }

//         pub fn new_untitled(cx: &mut AppContext) -> Handle<Self> {
//             cx.add_model(|_| Self {
//                 project_path: None,
//                 entry_id: None,
//             })
//         }
//     }

//     impl TestItem {
//         pub fn new() -> Self {
//             Self {
//                 state: String::new(),
//                 label: String::new(),
//                 save_count: 0,
//                 save_as_count: 0,
//                 reload_count: 0,
//                 is_dirty: false,
//                 has_conflict: false,
//                 project_items: Vec::new(),
//                 is_singleton: true,
//                 nav_history: None,
//                 tab_descriptions: None,
//                 tab_detail: Default::default(),
//                 workspace_id: 0,
//             }
//         }

//         pub fn new_deserialized(id: WorkspaceId) -> Self {
//             let mut this = Self::new();
//             this.workspace_id = id;
//             this
//         }

//         pub fn with_label(mut self, state: &str) -> Self {
//             self.label = state.to_string();
//             self
//         }

//         pub fn with_singleton(mut self, singleton: bool) -> Self {
//             self.is_singleton = singleton;
//             self
//         }

//         pub fn with_dirty(mut self, dirty: bool) -> Self {
//             self.is_dirty = dirty;
//             self
//         }

//         pub fn with_conflict(mut self, has_conflict: bool) -> Self {
//             self.has_conflict = has_conflict;
//             self
//         }

//         pub fn with_project_items(mut self, items: &[Handle<TestProjectItem>]) -> Self {
//             self.project_items.clear();
//             self.project_items.extend(items.iter().cloned());
//             self
//         }

//         pub fn set_state(&mut self, state: String, cx: &mut ViewContext<Self>) {
//             self.push_to_nav_history(cx);
//             self.state = state;
//         }

//         fn push_to_nav_history(&mut self, cx: &mut ViewContext<Self>) {
//             if let Some(history) = &mut self.nav_history {
//                 history.push(Some(Box::new(self.state.clone())), cx);
//             }
//         }
//     }

//     impl Entity for TestItem {
//         type Event = TestItemEvent;
//     }

//     impl View for TestItem {
//         fn ui_name() -> &'static str {
//             "TestItem"
//         }

//         fn render(&mut self, _: &mut ViewContext<Self>) -> AnyElement<Self> {
//             Empty::new().into_any()
//         }
//     }

//     impl Item for TestItem {
//         fn tab_description(&self, detail: usize, _: &AppContext) -> Option<Cow<str>> {
//             self.tab_descriptions.as_ref().and_then(|descriptions| {
//                 let description = *descriptions.get(detail).or_else(|| descriptions.last())?;
//                 Some(description.into())
//             })
//         }

//         fn tab_content<V: 'static>(
//             &self,
//             detail: Option<usize>,
//             _: &theme2::Tab,
//             _: &AppContext,
//         ) -> AnyElement<V> {
//             self.tab_detail.set(detail);
//             Empty::new().into_any()
//         }

//         fn for_each_project_item(
//             &self,
//             cx: &AppContext,
//             f: &mut dyn FnMut(usize, &dyn project2::Item),
//         ) {
//             self.project_items
//                 .iter()
//                 .for_each(|item| f(item.id(), item.read(cx)))
//         }

// fn is_singleton(&self, _: &AppContext) -> bool {
//     self.is_singleton
// }

//         fn set_nav_history(&mut self, history: ItemNavHistory, _: &mut ViewContext<Self>) {
//             self.nav_history = Some(history);
//         }

//         fn navigate(&mut self, state: Box<dyn Any>, _: &mut ViewContext<Self>) -> bool {
//             let state = *state.downcast::<String>().unwrap_or_default();
//             if state != self.state {
//                 self.state = state;
//                 true
//             } else {
//                 false
//             }
//         }

//         fn deactivated(&mut self, cx: &mut ViewContext<Self>) {
//             self.push_to_nav_history(cx);
//         }

//         fn clone_on_split(
//             &self,
//             _workspace_id: WorkspaceId,
//             _: &mut ViewContext<Self>,
//         ) -> Option<Self>
//         where
//             Self: Sized,
//         {
//             Some(self.clone())
//         }

//         fn is_dirty(&self, _: &AppContext) -> bool {
//             self.is_dirty
//         }

//         fn has_conflict(&self, _: &AppContext) -> bool {
//             self.has_conflict
//         }

//         fn can_save(&self, cx: &AppContext) -> bool {
//             !self.project_items.is_empty()
//                 && self
//                     .project_items
//                     .iter()
//                     .all(|item| item.read(cx).entry_id.is_some())
//         }

//         fn save(
//             &mut self,
//             _: Handle<Project>,
//             _: &mut ViewContext<Self>,
//         ) -> Task<anyhow::Result<()>> {
//             self.save_count += 1;
//             self.is_dirty = false;
//             Task::ready(Ok(()))
//         }

//         fn save_as(
//             &mut self,
//             _: Handle<Project>,
//             _: std::path::PathBuf,
//             _: &mut ViewContext<Self>,
//         ) -> Task<anyhow::Result<()>> {
//             self.save_as_count += 1;
//             self.is_dirty = false;
//             Task::ready(Ok(()))
//         }

//         fn reload(
//             &mut self,
//             _: Handle<Project>,
//             _: &mut ViewContext<Self>,
//         ) -> Task<anyhow::Result<()>> {
//             self.reload_count += 1;
//             self.is_dirty = false;
//             Task::ready(Ok(()))
//         }

//         fn to_item_events(_: &Self::Event) -> SmallVec<[ItemEvent; 2]> {
//             [ItemEvent::UpdateTab, ItemEvent::Edit].into()
//         }

//         fn serialized_item_kind() -> Option<&'static str> {
//             Some("TestItem")
//         }

//         fn deserialize(
//             _project: Handle<Project>,
//             _workspace: WeakViewHandle<Workspace>,
//             workspace_id: WorkspaceId,
//             _item_id: ItemId,
//             cx: &mut ViewContext<Pane>,
//         ) -> Task<anyhow::Result<View<Self>>> {
//             let view = cx.add_view(|_cx| Self::new_deserialized(workspace_id));
//             Task::Ready(Some(anyhow::Ok(view)))
//         }
//     }
// }