use crate::{Toast, Workspace};
use anyhow::Context;
use anyhow::{anyhow, Result};
use gpui::{
    svg, AnyView, AppContext, AsyncWindowContext, ClipboardItem, DismissEvent, EventEmitter,
    Global, PromptLevel, Render, ScrollHandle, Task, View, ViewContext, VisualContext,
    WindowContext,
};
use std::rc::Rc;
use std::{any::TypeId, time::Duration};
use ui::{prelude::*, Tooltip};
use util::ResultExt;

pub fn init(cx: &mut AppContext) {
    cx.set_global(GlobalAppNotifications {
        app_notifications: Vec::new(),
    })
}

#[derive(Debug, PartialEq, Clone)]
pub enum NotificationId {
    Unique(TypeId),
    Composite(TypeId, ElementId),
    Named(SharedString),
}

impl NotificationId {
    /// Returns a unique [`NotificationId`] for the given type.
    pub fn unique<T: 'static>() -> Self {
        Self::Unique(TypeId::of::<T>())
    }

    /// Returns a [`NotificationId`] for the given type that is also identified
    /// by the provided ID.
    pub fn composite<T: 'static>(id: impl Into<ElementId>) -> Self {
        Self::Composite(TypeId::of::<T>(), id.into())
    }

    /// Builds a `NotificationId` out of the given string.
    pub fn named(id: SharedString) -> Self {
        Self::Named(id)
    }
}

pub trait Notification: EventEmitter<DismissEvent> + Render {}

impl<V: EventEmitter<DismissEvent> + Render> Notification for V {}

impl Workspace {
    #[cfg(any(test, feature = "test-support"))]
    pub fn notification_ids(&self) -> Vec<NotificationId> {
        self.notifications
            .iter()
            .map(|(id, _)| id)
            .cloned()
            .collect()
    }

    pub fn show_notification<V: Notification>(
        &mut self,
        id: NotificationId,
        cx: &mut ViewContext<Self>,
        build_notification: impl FnOnce(&mut ViewContext<Self>) -> View<V>,
    ) {
        self.show_notification_without_handling_dismiss_events(&id, cx, |cx| {
            let notification = build_notification(cx);
            cx.subscribe(&notification, {
                let id = id.clone();
                move |this, _, _: &DismissEvent, cx| {
                    this.dismiss_notification(&id, cx);
                }
            })
            .detach();
            notification.into()
        });
    }

    /// Shows a notification in this workspace's window. Caller must handle dismiss.
    ///
    /// This exists so that the `build_notification` closures stored for app notifications can
    /// return `AnyView`. Subscribing to events from an `AnyView` is not supported, so instead that
    /// responsibility is pushed to the caller where the `V` type is known.
    pub(crate) fn show_notification_without_handling_dismiss_events(
        &mut self,
        id: &NotificationId,
        cx: &mut ViewContext<Self>,
        build_notification: impl FnOnce(&mut ViewContext<Self>) -> AnyView,
    ) {
        self.dismiss_notification(id, cx);
        self.notifications
            .push((id.clone(), build_notification(cx)));
        cx.notify();
    }

    pub fn show_error<E>(&mut self, err: &E, cx: &mut ViewContext<Self>)
    where
        E: std::fmt::Debug + std::fmt::Display,
    {
        self.show_notification(workspace_error_notification_id(), cx, |cx| {
            cx.new_view(|_cx| ErrorMessagePrompt::new(format!("Error: {err}")))
        });
    }

    pub fn show_portal_error(&mut self, err: String, cx: &mut ViewContext<Self>) {
        struct PortalError;

        self.show_notification(NotificationId::unique::<PortalError>(), cx, |cx| {
            cx.new_view(|_cx| {
                ErrorMessagePrompt::new(err.to_string()).with_link_button(
                    "See docs",
                    "https://zed.dev/docs/linux#i-cant-open-any-files",
                )
            })
        });
    }

    pub fn dismiss_notification(&mut self, id: &NotificationId, cx: &mut ViewContext<Self>) {
        self.notifications.retain(|(existing_id, _)| {
            if existing_id == id {
                cx.notify();
                false
            } else {
                true
            }
        });
    }

    pub fn show_toast(&mut self, toast: Toast, cx: &mut ViewContext<Self>) {
        self.dismiss_notification(&toast.id, cx);
        self.show_notification(toast.id.clone(), cx, |cx| {
            cx.new_view(|_cx| match toast.on_click.as_ref() {
                Some((click_msg, on_click)) => {
                    let on_click = on_click.clone();
                    simple_message_notification::MessageNotification::new(toast.msg.clone())
                        .with_click_message(click_msg.clone())
                        .on_click(move |cx| on_click(cx))
                }
                None => simple_message_notification::MessageNotification::new(toast.msg.clone()),
            })
        });
        if toast.autohide {
            cx.spawn(|workspace, mut cx| async move {
                cx.background_executor()
                    .timer(Duration::from_millis(5000))
                    .await;
                workspace
                    .update(&mut cx, |workspace, cx| {
                        workspace.dismiss_toast(&toast.id, cx)
                    })
                    .ok();
            })
            .detach();
        }
    }

    pub fn dismiss_toast(&mut self, id: &NotificationId, cx: &mut ViewContext<Self>) {
        self.dismiss_notification(id, cx);
    }

    pub fn clear_all_notifications(&mut self, cx: &mut ViewContext<Self>) {
        self.notifications.clear();
        cx.notify();
    }

    pub fn show_initial_notifications(&mut self, cx: &mut ViewContext<Self>) {
        // Allow absence of the global so that tests don't need to initialize it.
        let app_notifications = cx
            .try_global::<GlobalAppNotifications>()
            .iter()
            .flat_map(|global| global.app_notifications.iter().cloned())
            .collect::<Vec<_>>();
        for (id, build_notification) in app_notifications {
            self.show_notification_without_handling_dismiss_events(&id, cx, |cx| {
                build_notification(cx)
            });
        }
    }
}

pub struct LanguageServerPrompt {
    request: Option<project::LanguageServerPromptRequest>,
    scroll_handle: ScrollHandle,
}

impl LanguageServerPrompt {
    pub fn new(request: project::LanguageServerPromptRequest) -> Self {
        Self {
            request: Some(request),
            scroll_handle: ScrollHandle::new(),
        }
    }

    async fn select_option(this: View<Self>, ix: usize, mut cx: AsyncWindowContext) {
        util::maybe!(async move {
            let potential_future = this.update(&mut cx, |this, _| {
                this.request.take().map(|request| request.respond(ix))
            });

            potential_future? // App Closed
                .ok_or_else(|| anyhow::anyhow!("Response already sent"))?
                .await
                .ok_or_else(|| anyhow::anyhow!("Stream already closed"))?;

            this.update(&mut cx, |_, cx| cx.emit(DismissEvent))?;

            anyhow::Ok(())
        })
        .await
        .log_err();
    }
}

impl Render for LanguageServerPrompt {
    fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
        let Some(request) = &self.request else {
            return div().id("language_server_prompt_notification");
        };

        let (icon, color) = match request.level {
            PromptLevel::Info => (IconName::Info, Color::Accent),
            PromptLevel::Warning => (IconName::Warning, Color::Warning),
            PromptLevel::Critical => (IconName::XCircle, Color::Error),
        };

        div()
            .id("language_server_prompt_notification")
            .group("language_server_prompt_notification")
            .occlude()
            .w_full()
            .max_h(vh(0.8, cx))
            .elevation_3(cx)
            .overflow_y_scroll()
            .track_scroll(&self.scroll_handle)
            .child(
                v_flex()
                    .p_3()
                    .overflow_hidden()
                    .child(
                        h_flex()
                            .justify_between()
                            .items_start()
                            .child(
                                h_flex()
                                    .gap_2()
                                    .child(Icon::new(icon).color(color))
                                    .child(Label::new(request.lsp_name.clone())),
                            )
                            .child(
                                h_flex()
                                    .child(
                                        IconButton::new("copy", IconName::Copy)
                                            .on_click({
                                                let message = request.message.clone();
                                                move |_, cx| {
                                                    cx.write_to_clipboard(
                                                        ClipboardItem::new_string(message.clone()),
                                                    )
                                                }
                                            })
                                            .tooltip(|cx| Tooltip::text("Copy Description", cx)),
                                    )
                                    .child(IconButton::new("close", IconName::Close).on_click(
                                        cx.listener(|_, _, cx| cx.emit(gpui::DismissEvent)),
                                    )),
                            ),
                    )
                    .child(Label::new(request.message.to_string()).size(LabelSize::Small))
                    .children(request.actions.iter().enumerate().map(|(ix, action)| {
                        let this_handle = cx.view().clone();
                        Button::new(ix, action.title.clone())
                            .size(ButtonSize::Large)
                            .on_click(move |_, cx| {
                                let this_handle = this_handle.clone();
                                cx.spawn(|cx| async move {
                                    LanguageServerPrompt::select_option(this_handle, ix, cx).await
                                })
                                .detach()
                            })
                    })),
            )
    }
}

impl EventEmitter<DismissEvent> for LanguageServerPrompt {}

fn workspace_error_notification_id() -> NotificationId {
    struct WorkspaceErrorNotification;
    NotificationId::unique::<WorkspaceErrorNotification>()
}

#[derive(Debug, Clone)]
pub struct ErrorMessagePrompt {
    message: SharedString,
    label_and_url_button: Option<(SharedString, SharedString)>,
}

impl ErrorMessagePrompt {
    pub fn new<S>(message: S) -> Self
    where
        S: Into<SharedString>,
    {
        Self {
            message: message.into(),
            label_and_url_button: None,
        }
    }

    pub fn with_link_button<S>(mut self, label: S, url: S) -> Self
    where
        S: Into<SharedString>,
    {
        self.label_and_url_button = Some((label.into(), url.into()));
        self
    }
}

impl Render for ErrorMessagePrompt {
    fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
        h_flex()
            .id("error_message_prompt_notification")
            .occlude()
            .elevation_3(cx)
            .items_start()
            .justify_between()
            .p_2()
            .gap_2()
            .w_full()
            .child(
                v_flex()
                    .w_full()
                    .child(
                        h_flex()
                            .w_full()
                            .justify_between()
                            .child(
                                svg()
                                    .size(cx.text_style().font_size)
                                    .flex_none()
                                    .mr_2()
                                    .mt(px(-2.0))
                                    .map(|icon| {
                                        icon.path(IconName::Warning.path())
                                            .text_color(Color::Error.color(cx))
                                    }),
                            )
                            .child(
                                ui::IconButton::new("close", ui::IconName::Close)
                                    .on_click(cx.listener(|_, _, cx| cx.emit(gpui::DismissEvent))),
                            ),
                    )
                    .child(
                        div()
                            .id("error_message")
                            .max_w_96()
                            .max_h_40()
                            .overflow_y_scroll()
                            .child(Label::new(self.message.clone()).size(LabelSize::Small)),
                    )
                    .when_some(self.label_and_url_button.clone(), |elm, (label, url)| {
                        elm.child(
                            div().mt_2().child(
                                ui::Button::new("error_message_prompt_notification_button", label)
                                    .on_click(move |_, cx| cx.open_url(&url)),
                            ),
                        )
                    }),
            )
    }
}

impl EventEmitter<DismissEvent> for ErrorMessagePrompt {}

pub mod simple_message_notification {
    use std::sync::Arc;

    use gpui::{
        div, AnyElement, DismissEvent, EventEmitter, ParentElement, Render, SharedString, Styled,
        ViewContext,
    };
    use ui::prelude::*;

    pub struct MessageNotification {
        content: Box<dyn Fn(&mut ViewContext<Self>) -> AnyElement>,
        on_click: Option<Arc<dyn Fn(&mut ViewContext<Self>)>>,
        click_message: Option<SharedString>,
        secondary_click_message: Option<SharedString>,
        secondary_on_click: Option<Arc<dyn Fn(&mut ViewContext<Self>)>>,
    }

    impl EventEmitter<DismissEvent> for MessageNotification {}

    impl MessageNotification {
        pub fn new<S>(message: S) -> MessageNotification
        where
            S: Into<SharedString>,
        {
            let message = message.into();
            Self::new_from_builder(move |_| Label::new(message.clone()).into_any_element())
        }

        pub fn new_from_builder<F>(content: F) -> MessageNotification
        where
            F: 'static + Fn(&mut ViewContext<Self>) -> AnyElement,
        {
            Self {
                content: Box::new(content),
                on_click: None,
                click_message: None,
                secondary_on_click: None,
                secondary_click_message: None,
            }
        }

        pub fn with_click_message<S>(mut self, message: S) -> Self
        where
            S: Into<SharedString>,
        {
            self.click_message = Some(message.into());
            self
        }

        pub fn on_click<F>(mut self, on_click: F) -> Self
        where
            F: 'static + Fn(&mut ViewContext<Self>),
        {
            self.on_click = Some(Arc::new(on_click));
            self
        }

        pub fn with_secondary_click_message<S>(mut self, message: S) -> Self
        where
            S: Into<SharedString>,
        {
            self.secondary_click_message = Some(message.into());
            self
        }

        pub fn on_secondary_click<F>(mut self, on_click: F) -> Self
        where
            F: 'static + Fn(&mut ViewContext<Self>),
        {
            self.secondary_on_click = Some(Arc::new(on_click));
            self
        }

        pub fn dismiss(&mut self, cx: &mut ViewContext<Self>) {
            cx.emit(DismissEvent);
        }
    }

    impl Render for MessageNotification {
        fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
            v_flex()
                .p_3()
                .gap_2()
                .elevation_3(cx)
                .child(
                    h_flex()
                        .gap_4()
                        .justify_between()
                        .items_start()
                        .child(div().max_w_96().child((self.content)(cx)))
                        .child(
                            IconButton::new("close", IconName::Close)
                                .on_click(cx.listener(|this, _, cx| this.dismiss(cx))),
                        ),
                )
                .child(
                    h_flex()
                        .gap_2()
                        .children(self.click_message.iter().map(|message| {
                            Button::new(message.clone(), message.clone())
                                .label_size(LabelSize::Small)
                                .icon(IconName::Check)
                                .icon_position(IconPosition::Start)
                                .icon_size(IconSize::Small)
                                .icon_color(Color::Success)
                                .on_click(cx.listener(|this, _, cx| {
                                    if let Some(on_click) = this.on_click.as_ref() {
                                        (on_click)(cx)
                                    };
                                    this.dismiss(cx)
                                }))
                        }))
                        .children(self.secondary_click_message.iter().map(|message| {
                            Button::new(message.clone(), message.clone())
                                .label_size(LabelSize::Small)
                                .icon(IconName::Close)
                                .icon_position(IconPosition::Start)
                                .icon_size(IconSize::Small)
                                .icon_color(Color::Error)
                                .on_click(cx.listener(|this, _, cx| {
                                    if let Some(on_click) = this.secondary_on_click.as_ref() {
                                        (on_click)(cx)
                                    };
                                    this.dismiss(cx)
                                }))
                        })),
                )
        }
    }
}

/// Stores app notifications so that they can be shown in new workspaces.
struct GlobalAppNotifications {
    app_notifications: Vec<(
        NotificationId,
        Rc<dyn Fn(&mut ViewContext<Workspace>) -> AnyView>,
    )>,
}

impl Global for GlobalAppNotifications {}

impl GlobalAppNotifications {
    pub fn insert(
        &mut self,
        id: NotificationId,
        build_notification: Rc<dyn Fn(&mut ViewContext<Workspace>) -> AnyView>,
    ) {
        self.remove(&id);
        self.app_notifications.push((id, build_notification))
    }

    pub fn remove(&mut self, id: &NotificationId) {
        self.app_notifications
            .retain(|(existing_id, _)| existing_id != id);
    }
}

/// Shows a notification in all workspaces. New workspaces will also receive the notification - this
/// is particularly to handle notifications that occur on initialization before any workspaces
/// exist. If the notification is dismissed within any workspace, it will be removed from all.
pub fn show_app_notification<V: Notification + 'static>(
    id: NotificationId,
    cx: &mut AppContext,
    build_notification: impl Fn(&mut ViewContext<Workspace>) -> View<V> + 'static,
) -> Result<()> {
    // Handle dismiss events by removing the notification from all workspaces.
    let build_notification: Rc<dyn Fn(&mut ViewContext<Workspace>) -> AnyView> = Rc::new({
        let id = id.clone();
        move |cx| {
            let notification = build_notification(cx);
            cx.subscribe(&notification, {
                let id = id.clone();
                move |_, _, _: &DismissEvent, cx| {
                    dismiss_app_notification(&id, cx);
                }
            })
            .detach();
            notification.into()
        }
    });

    // Store the notification so that new workspaces also receive it.
    cx.global_mut::<GlobalAppNotifications>()
        .insert(id.clone(), build_notification.clone());

    let mut notify_errors = Vec::new();

    for window in cx.windows() {
        if let Some(workspace_window) = window.downcast::<Workspace>() {
            let notify_result = workspace_window.update(cx, |workspace, cx| {
                workspace.show_notification_without_handling_dismiss_events(&id, cx, |cx| {
                    build_notification(cx)
                });
            });
            match notify_result {
                Ok(()) => {}
                Err(notify_err) => notify_errors.push(notify_err),
            }
        }
    }

    if notify_errors.is_empty() {
        Ok(())
    } else {
        Err(anyhow!(
            "No workspaces were able to show notification. Errors:\n\n{}",
            notify_errors
                .iter()
                .map(|e| e.to_string())
                .collect::<Vec<_>>()
                .join("\n\n")
        ))
    }
}

pub fn dismiss_app_notification(id: &NotificationId, cx: &mut AppContext) {
    cx.global_mut::<GlobalAppNotifications>().remove(id);
    for window in cx.windows() {
        if let Some(workspace_window) = window.downcast::<Workspace>() {
            let id = id.clone();
            // This spawn is necessary in order to dismiss the notification on which the click
            // occurred, because in that case we're already in the middle of an update.
            cx.spawn(move |mut cx| async move {
                workspace_window.update(&mut cx, |workspace, cx| {
                    workspace.dismiss_notification(&id, cx)
                })
            })
            .detach_and_log_err(cx);
        }
    }
}

pub trait NotifyResultExt {
    type Ok;

    fn notify_err(
        self,
        workspace: &mut Workspace,
        cx: &mut ViewContext<Workspace>,
    ) -> Option<Self::Ok>;

    fn notify_async_err(self, cx: &mut AsyncWindowContext) -> Option<Self::Ok>;

    /// Notifies the active workspace if there is one, otherwise notifies all workspaces.
    fn notify_app_err(self, cx: &mut AppContext) -> Option<Self::Ok>;
}

impl<T, E> NotifyResultExt for std::result::Result<T, E>
where
    E: std::fmt::Debug + std::fmt::Display,
{
    type Ok = T;

    fn notify_err(self, workspace: &mut Workspace, cx: &mut ViewContext<Workspace>) -> Option<T> {
        match self {
            Ok(value) => Some(value),
            Err(err) => {
                log::error!("Showing error notification in workspace: {err:?}");
                workspace.show_error(&err, cx);
                None
            }
        }
    }

    fn notify_async_err(self, cx: &mut AsyncWindowContext) -> Option<T> {
        match self {
            Ok(value) => Some(value),
            Err(err) => {
                log::error!("{err:?}");
                cx.update_root(|view, cx| {
                    if let Ok(workspace) = view.downcast::<Workspace>() {
                        workspace.update(cx, |workspace, cx| workspace.show_error(&err, cx))
                    }
                })
                .ok();
                None
            }
        }
    }

    fn notify_app_err(self, cx: &mut AppContext) -> Option<T> {
        match self {
            Ok(value) => Some(value),
            Err(err) => {
                let message: SharedString = format!("Error: {err}").into();
                log::error!("Showing error notification in app: {message}");
                show_app_notification(workspace_error_notification_id(), cx, {
                    let message = message.clone();
                    move |cx| {
                        cx.new_view({
                            let message = message.clone();
                            move |_cx| ErrorMessagePrompt::new(message)
                        })
                    }
                })
                .with_context(|| format!("Error while showing error notification: {message}"))
                .log_err();
                None
            }
        }
    }
}

pub trait NotifyTaskExt {
    fn detach_and_notify_err(self, cx: &mut WindowContext);
}

impl<R, E> NotifyTaskExt for Task<std::result::Result<R, E>>
where
    E: std::fmt::Debug + std::fmt::Display + Sized + 'static,
    R: 'static,
{
    fn detach_and_notify_err(self, cx: &mut WindowContext) {
        cx.spawn(|mut cx| async move { self.await.notify_async_err(&mut cx) })
            .detach();
    }
}

pub trait DetachAndPromptErr<R> {
    fn prompt_err(
        self,
        msg: &str,
        cx: &mut WindowContext,
        f: impl FnOnce(&anyhow::Error, &mut WindowContext) -> Option<String> + 'static,
    ) -> Task<Option<R>>;

    fn detach_and_prompt_err(
        self,
        msg: &str,
        cx: &mut WindowContext,
        f: impl FnOnce(&anyhow::Error, &mut WindowContext) -> Option<String> + 'static,
    );
}

impl<R> DetachAndPromptErr<R> for Task<anyhow::Result<R>>
where
    R: 'static,
{
    fn prompt_err(
        self,
        msg: &str,
        cx: &mut WindowContext,
        f: impl FnOnce(&anyhow::Error, &mut WindowContext) -> Option<String> + 'static,
    ) -> Task<Option<R>> {
        let msg = msg.to_owned();
        cx.spawn(|mut cx| async move {
            let result = self.await;
            if let Err(err) = result.as_ref() {
                log::error!("{err:?}");
                if let Ok(prompt) = cx.update(|cx| {
                    let detail = f(err, cx).unwrap_or_else(|| format!("{err}. Please try again."));
                    cx.prompt(PromptLevel::Critical, &msg, Some(&detail), &["Ok"])
                }) {
                    prompt.await.ok();
                }
                return None;
            }
            Some(result.unwrap())
        })
    }

    fn detach_and_prompt_err(
        self,
        msg: &str,
        cx: &mut WindowContext,
        f: impl FnOnce(&anyhow::Error, &mut WindowContext) -> Option<String> + 'static,
    ) {
        self.prompt_err(msg, cx, f).detach();
    }
}