use std::sync::Arc;

use crate::{Disclosure, prelude::*};
use component::{Component, ComponentScope, example_group_with_title, single_example};
use gpui::{AnyElement, ClickEvent, FontWeight};
use theme::UiDensity;

#[derive(IntoElement, RegisterComponent)]
pub struct ListHeader {
    /// The label of the header.
    label: SharedString,
    /// A slot for content that appears before the label, like an icon or avatar.
    start_slot: Option<AnyElement>,
    /// A slot for content that appears after the label, usually on the other side of the header.
    /// This might be a button, a disclosure arrow, a face pile, etc.
    end_slot: Option<AnyElement>,
    /// A slot for content that appears on hover after the label
    /// It will obscure the `end_slot` when visible.
    end_hover_slot: Option<AnyElement>,
    toggle: Option<bool>,
    on_toggle: Option<Arc<dyn Fn(&ClickEvent, &mut Window, &mut App) + 'static>>,
    inset: bool,
    selected: bool,
}

impl ListHeader {
    pub fn new(label: impl Into<SharedString>) -> Self {
        Self {
            label: label.into(),
            start_slot: None,
            end_slot: None,
            end_hover_slot: None,
            inset: false,
            toggle: None,
            on_toggle: None,
            selected: false,
        }
    }

    pub fn toggle(mut self, toggle: impl Into<Option<bool>>) -> Self {
        self.toggle = toggle.into();
        self
    }

    pub fn on_toggle(
        mut self,
        on_toggle: impl Fn(&ClickEvent, &mut Window, &mut App) + 'static,
    ) -> Self {
        self.on_toggle = Some(Arc::new(on_toggle));
        self
    }

    pub fn start_slot<E: IntoElement>(mut self, start_slot: impl Into<Option<E>>) -> Self {
        self.start_slot = start_slot.into().map(IntoElement::into_any_element);
        self
    }

    pub fn end_slot<E: IntoElement>(mut self, end_slot: impl Into<Option<E>>) -> Self {
        self.end_slot = end_slot.into().map(IntoElement::into_any_element);
        self
    }

    pub fn end_hover_slot<E: IntoElement>(mut self, end_hover_slot: impl Into<Option<E>>) -> Self {
        self.end_hover_slot = end_hover_slot.into().map(IntoElement::into_any_element);
        self
    }

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

impl Toggleable for ListHeader {
    fn toggle_state(mut self, selected: bool) -> Self {
        self.selected = selected;
        self
    }
}

impl RenderOnce for ListHeader {
    fn render(self, _window: &mut Window, cx: &mut App) -> impl IntoElement {
        let ui_density = theme::theme_settings(cx).ui_density(cx);

        h_flex()
            .id(self.label.clone())
            .w_full()
            .relative()
            .group("list_header")
            .child(
                div()
                    .map(|this| match ui_density {
                        UiDensity::Comfortable => this.h_5(),
                        _ => this.h_7(),
                    })
                    .when(self.inset, |this| this.px_2())
                    .when(self.selected, |this| this.bg(semantic::active_bg(cx)))
                    .flex()
                    .flex_1()
                    .items_center()
                    .justify_between()
                    .w_full()
                    .gap(DynamicSpacing::Base04.rems(cx))
                    .child(
                        h_flex()
                            .gap(DynamicSpacing::Base04.rems(cx))
                            .children(self.toggle.map(|is_open| {
                                Disclosure::new("toggle", is_open)
                                    .on_toggle_expanded(self.on_toggle.clone())
                            }))
                            .child(
                                div()
                                    .id("label_container")
                                    .flex()
                                    .gap(DynamicSpacing::Base04.rems(cx))
                                    .items_center()
                                    .children(self.start_slot)
                                    .child(
                                        Label::new(self.label.clone())
                                            .size(LabelSize::Small)
                                            .weight(FontWeight::MEDIUM)
                                            .color(Color::Muted),
                                    )
                                    .when_some(self.on_toggle, |this, on_toggle| {
                                        this.on_click(move |event, window, cx| {
                                            on_toggle(event, window, cx)
                                        })
                                    }),
                            ),
                    )
                    .child(h_flex().children(self.end_slot))
                    .when_some(self.end_hover_slot, |this, end_hover_slot| {
                        this.child(
                            div()
                                .absolute()
                                .right_0()
                                .visible_on_hover("list_header")
                                .child(end_hover_slot),
                        )
                    }),
            )
    }
}

impl Component for ListHeader {
    fn scope() -> ComponentScope {
        ComponentScope::DataDisplay
    }

    fn description() -> Option<&'static str> {
        Some(
            "A header component for lists with support for icons, actions, and collapsible sections.",
        )
    }

    fn preview(_window: &mut Window, _cx: &mut App) -> Option<AnyElement> {
        Some(
            v_flex()
                .gap_6()
                .children(vec![
                    example_group_with_title(
                        "Basic Headers",
                        vec![
                            single_example(
                                "Simple",
                                ListHeader::new("Section Header").into_any_element(),
                            ),
                            single_example(
                                "With Icon",
                                ListHeader::new("Files")
                                    .start_slot(Icon::new(IconName::File))
                                    .into_any_element(),
                            ),
                            single_example(
                                "With End Slot",
                                ListHeader::new("Recent")
                                    .end_slot(Label::new("5").color(Color::Muted))
                                    .into_any_element(),
                            ),
                        ],
                    ),
                    example_group_with_title(
                        "Collapsible Headers",
                        vec![
                            single_example(
                                "Expanded",
                                ListHeader::new("Expanded Section")
                                    .toggle(Some(true))
                                    .into_any_element(),
                            ),
                            single_example(
                                "Collapsed",
                                ListHeader::new("Collapsed Section")
                                    .toggle(Some(false))
                                    .into_any_element(),
                            ),
                        ],
                    ),
                    example_group_with_title(
                        "States",
                        vec![
                            single_example(
                                "Selected",
                                ListHeader::new("Selected Header")
                                    .toggle_state(true)
                                    .into_any_element(),
                            ),
                            single_example(
                                "Inset",
                                ListHeader::new("Inset Header")
                                    .inset(true)
                                    .into_any_element(),
                            ),
                        ],
                    ),
                ])
                .into_any_element(),
        )
    }
}
