use std::sync::Arc;

use crate::{ProjectDiagnosticsEditor, ToggleDiagnosticsRefresh};
use gpui::{Context, Entity, EventEmitter, ParentElement, Render, WeakEntity, Window};
use ui::prelude::*;
use ui::{IconButton, IconButtonShape, IconName, Tooltip};
use workspace::{ToolbarItemEvent, ToolbarItemLocation, ToolbarItemView, item::ItemHandle};

pub struct ToolbarControls {
    editor: Option<WeakEntity<ProjectDiagnosticsEditor>>,
}

impl Render for ToolbarControls {
    fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
        let mut include_warnings = false;
        let mut has_stale_excerpts = false;
        let mut is_updating = false;
        let cargo_diagnostics_sources = Arc::new(self.diagnostics().map_or(Vec::new(), |editor| {
            editor.read(cx).cargo_diagnostics_sources(cx)
        }));
        let fetch_cargo_diagnostics = !cargo_diagnostics_sources.is_empty();

        if let Some(editor) = self.diagnostics() {
            let diagnostics = editor.read(cx);
            include_warnings = diagnostics.include_warnings;
            has_stale_excerpts = !diagnostics.paths_to_update.is_empty();
            is_updating = if fetch_cargo_diagnostics {
                diagnostics.cargo_diagnostics_fetch.fetch_task.is_some()
            } else {
                diagnostics.update_excerpts_task.is_some()
                    || diagnostics
                        .project
                        .read(cx)
                        .language_servers_running_disk_based_diagnostics(cx)
                        .next()
                        .is_some()
            };
        }

        let tooltip = if include_warnings {
            "Exclude Warnings"
        } else {
            "Include Warnings"
        };

        let warning_color = if include_warnings {
            Color::Warning
        } else {
            Color::Muted
        };

        h_flex()
            .gap_1()
            .map(|div| {
                if is_updating {
                    div.child(
                        IconButton::new("stop-updating", IconName::Stop)
                            .icon_color(Color::Info)
                            .shape(IconButtonShape::Square)
                            .tooltip(Tooltip::for_action_title(
                                "Stop diagnostics update",
                                &ToggleDiagnosticsRefresh,
                            ))
                            .on_click(cx.listener(move |toolbar_controls, _, _, cx| {
                                if let Some(diagnostics) = toolbar_controls.diagnostics() {
                                    diagnostics.update(cx, |diagnostics, cx| {
                                        diagnostics.stop_cargo_diagnostics_fetch(cx);
                                        diagnostics.update_excerpts_task = None;
                                        cx.notify();
                                    });
                                }
                            })),
                    )
                } else {
                    div.child(
                        IconButton::new("refresh-diagnostics", IconName::ArrowCircle)
                            .icon_color(Color::Info)
                            .shape(IconButtonShape::Square)
                            .disabled(!has_stale_excerpts && !fetch_cargo_diagnostics)
                            .tooltip(Tooltip::for_action_title(
                                "Refresh diagnostics",
                                &ToggleDiagnosticsRefresh,
                            ))
                            .on_click(cx.listener({
                                move |toolbar_controls, _, window, cx| {
                                    if let Some(diagnostics) = toolbar_controls.diagnostics() {
                                        let cargo_diagnostics_sources =
                                            Arc::clone(&cargo_diagnostics_sources);
                                        diagnostics.update(cx, move |diagnostics, cx| {
                                            if fetch_cargo_diagnostics {
                                                diagnostics.fetch_cargo_diagnostics(
                                                    cargo_diagnostics_sources,
                                                    cx,
                                                );
                                            } else {
                                                diagnostics.update_all_excerpts(window, cx);
                                            }
                                        });
                                    }
                                }
                            })),
                    )
                }
            })
            .child(
                IconButton::new("toggle-warnings", IconName::Warning)
                    .icon_color(warning_color)
                    .shape(IconButtonShape::Square)
                    .tooltip(Tooltip::text(tooltip))
                    .on_click(cx.listener(|this, _, window, cx| {
                        if let Some(editor) = this.diagnostics() {
                            editor.update(cx, |editor, cx| {
                                editor.toggle_warnings(&Default::default(), window, cx);
                            });
                        }
                    })),
            )
    }
}

impl EventEmitter<ToolbarItemEvent> for ToolbarControls {}

impl ToolbarItemView for ToolbarControls {
    fn set_active_pane_item(
        &mut self,
        active_pane_item: Option<&dyn ItemHandle>,
        _window: &mut Window,
        _: &mut Context<Self>,
    ) -> ToolbarItemLocation {
        if let Some(pane_item) = active_pane_item.as_ref() {
            if let Some(editor) = pane_item.downcast::<ProjectDiagnosticsEditor>() {
                self.editor = Some(editor.downgrade());
                ToolbarItemLocation::PrimaryRight
            } else {
                ToolbarItemLocation::Hidden
            }
        } else {
            ToolbarItemLocation::Hidden
        }
    }
}

impl Default for ToolbarControls {
    fn default() -> Self {
        Self::new()
    }
}

impl ToolbarControls {
    pub fn new() -> Self {
        ToolbarControls { editor: None }
    }

    fn diagnostics(&self) -> Option<Entity<ProjectDiagnosticsEditor>> {
        self.editor.as_ref()?.upgrade()
    }
}