use std::path::PathBuf;

use dev_server_projects::DevServer;
use gpui::{ClickEvent, DismissEvent, EventEmitter, FocusHandle, FocusableView, Render, WeakView};
use remote::SshConnectionOptions;
use ui::{
    div, h_flex, rems, Button, ButtonCommon, ButtonStyle, Clickable, ElevationIndex, FluentBuilder,
    Headline, HeadlineSize, IconName, IconPosition, InteractiveElement, IntoElement, Label, Modal,
    ModalFooter, ModalHeader, ParentElement, Section, Styled, StyledExt, ViewContext,
};
use workspace::{notifications::DetachAndPromptErr, ModalView, OpenOptions, Workspace};

use crate::{
    dev_servers::reconnect_to_dev_server_project, open_dev_server_project, open_ssh_project,
    DevServerProjects,
};

enum Host {
    RemoteProject,
    DevServerProject(DevServer),
    SshRemoteProject(SshConnectionOptions),
}

pub struct DisconnectedOverlay {
    workspace: WeakView<Workspace>,
    host: Host,
    focus_handle: FocusHandle,
}

impl EventEmitter<DismissEvent> for DisconnectedOverlay {}
impl FocusableView for DisconnectedOverlay {
    fn focus_handle(&self, _cx: &gpui::AppContext) -> gpui::FocusHandle {
        self.focus_handle.clone()
    }
}
impl ModalView for DisconnectedOverlay {
    fn fade_out_background(&self) -> bool {
        true
    }
}

impl DisconnectedOverlay {
    pub fn register(workspace: &mut Workspace, cx: &mut ViewContext<Workspace>) {
        cx.subscribe(workspace.project(), |workspace, project, event, cx| {
            if !matches!(
                event,
                project::Event::DisconnectedFromHost | project::Event::DisconnectedFromSshRemote
            ) {
                return;
            }
            let handle = cx.view().downgrade();
            let dev_server = project
                .read(cx)
                .dev_server_project_id()
                .and_then(|id| {
                    dev_server_projects::Store::global(cx)
                        .read(cx)
                        .dev_server_for_project(id)
                })
                .cloned();

            let ssh_connection_options = project.read(cx).ssh_connection_options(cx);
            let host = if let Some(dev_server) = dev_server {
                Host::DevServerProject(dev_server)
            } else if let Some(ssh_connection_options) = ssh_connection_options {
                Host::SshRemoteProject(ssh_connection_options)
            } else {
                Host::RemoteProject
            };

            workspace.toggle_modal(cx, |cx| DisconnectedOverlay {
                workspace: handle,
                host,
                focus_handle: cx.focus_handle(),
            });
        })
        .detach();
    }

    fn handle_reconnect(&mut self, _: &ClickEvent, cx: &mut ViewContext<Self>) {
        cx.emit(DismissEvent);

        match &self.host {
            Host::DevServerProject(dev_server) => {
                self.reconnect_to_dev_server(dev_server.clone(), cx);
            }
            Host::SshRemoteProject(ssh_connection_options) => {
                self.reconnect_to_ssh_remote(ssh_connection_options.clone(), cx);
            }
            _ => {}
        }
    }

    fn reconnect_to_dev_server(&self, dev_server: DevServer, cx: &mut ViewContext<Self>) {
        let Some(workspace) = self.workspace.upgrade() else {
            return;
        };
        let Some(dev_server_project_id) = workspace
            .read(cx)
            .project()
            .read(cx)
            .dev_server_project_id()
        else {
            return;
        };

        if let Some(project_id) = dev_server_projects::Store::global(cx)
            .read(cx)
            .dev_server_project(dev_server_project_id)
            .and_then(|project| project.project_id)
        {
            return workspace.update(cx, move |_, cx| {
                open_dev_server_project(true, dev_server_project_id, project_id, cx)
                    .detach_and_prompt_err("Failed to reconnect", cx, |_, _| None)
            });
        }

        if dev_server.ssh_connection_string.is_some() {
            let task = workspace.update(cx, |_, cx| {
                reconnect_to_dev_server_project(
                    cx.view().clone(),
                    dev_server,
                    dev_server_project_id,
                    true,
                    cx,
                )
            });

            task.detach_and_prompt_err("Failed to reconnect", cx, |_, _| None);
        } else {
            return workspace.update(cx, |workspace, cx| {
                let handle = cx.view().downgrade();
                workspace.toggle_modal(cx, |cx| DevServerProjects::new(cx, handle))
            });
        }
    }

    fn reconnect_to_ssh_remote(
        &self,
        connection_options: SshConnectionOptions,
        cx: &mut ViewContext<Self>,
    ) {
        let Some(workspace) = self.workspace.upgrade() else {
            return;
        };

        let Some(ssh_project) = workspace.read(cx).serialized_ssh_project() else {
            return;
        };

        let Some(window) = cx.window_handle().downcast::<Workspace>() else {
            return;
        };

        let app_state = workspace.read(cx).app_state().clone();

        let paths = ssh_project.paths.iter().map(PathBuf::from).collect();

        cx.spawn(move |_, mut cx| async move {
            open_ssh_project(
                connection_options,
                paths,
                app_state,
                OpenOptions {
                    replace_window: Some(window),
                    ..Default::default()
                },
                &mut cx,
            )
            .await?;
            Ok(())
        })
        .detach_and_prompt_err("Failed to reconnect", cx, |_, _| None);
    }

    fn cancel(&mut self, _: &menu::Cancel, cx: &mut ViewContext<Self>) {
        cx.emit(DismissEvent)
    }
}

impl Render for DisconnectedOverlay {
    fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
        let can_reconnect = matches!(
            self.host,
            Host::DevServerProject(_) | Host::SshRemoteProject(_)
        );

        let message = match &self.host {
            Host::RemoteProject | Host::DevServerProject(_) => {
                "Your connection to the remote project has been lost.".to_string()
            }
            Host::SshRemoteProject(options) => {
                format!(
                    "Your connection to {} has been lost",
                    options.connection_string()
                )
            }
        };

        div()
            .track_focus(&self.focus_handle)
            .elevation_3(cx)
            .on_action(cx.listener(Self::cancel))
            .occlude()
            .w(rems(24.))
            .max_h(rems(40.))
            .child(
                Modal::new("disconnected", None)
                    .header(
                        ModalHeader::new()
                            .show_dismiss_button(true)
                            .child(Headline::new("Disconnected").size(HeadlineSize::Small)),
                    )
                    .section(Section::new().child(Label::new(message)))
                    .footer(
                        ModalFooter::new().end_slot(
                            h_flex()
                                .gap_2()
                                .child(
                                    Button::new("close-window", "Close Window")
                                        .style(ButtonStyle::Filled)
                                        .layer(ElevationIndex::ModalSurface)
                                        .on_click(cx.listener(move |_, _, cx| {
                                            cx.remove_window();
                                        })),
                                )
                                .when(can_reconnect, |el| {
                                    el.child(
                                        Button::new("reconnect", "Reconnect")
                                            .style(ButtonStyle::Filled)
                                            .layer(ElevationIndex::ModalSurface)
                                            .icon(IconName::ArrowCircle)
                                            .icon_position(IconPosition::Start)
                                            .on_click(cx.listener(Self::handle_reconnect)),
                                    )
                                }),
                        ),
                    ),
            )
    }
}