use crate::{prelude::*, Avatar};
use gpui::{AnyElement, StyleRefinement};
use smallvec::SmallVec;

/// A facepile is a collection of faces stacked horizontally–
/// always with the leftmost face on top and descending in z-index
///
/// Facepiles are used to display a group of people or things,
/// such as a list of participants in a collaboration session.
#[derive(IntoElement, IntoComponent)]
pub struct Facepile {
    base: Div,
    faces: SmallVec<[AnyElement; 2]>,
}

impl Facepile {
    /// Creates a new empty facepile.
    pub fn empty() -> Self {
        Self::new(SmallVec::new())
    }

    /// Creates a new facepile with the given faces.
    pub fn new(faces: SmallVec<[AnyElement; 2]>) -> Self {
        Self { base: div(), faces }
    }
}

impl ParentElement for Facepile {
    fn extend(&mut self, elements: impl IntoIterator<Item = AnyElement>) {
        self.faces.extend(elements);
    }
}

// Style methods.
impl Facepile {
    fn style(&mut self) -> &mut StyleRefinement {
        self.base.style()
    }

    gpui::padding_style_methods!({
        visibility: pub
    });
}

impl RenderOnce for Facepile {
    fn render(self, _window: &mut Window, _cx: &mut App) -> impl IntoElement {
        // Lay the faces out in reverse so they overlap in the desired order (left to right, front to back)
        self.base
            .flex()
            .flex_row_reverse()
            .items_center()
            .justify_start()
            .children(
                self.faces
                    .into_iter()
                    .enumerate()
                    .rev()
                    .map(|(ix, player)| div().when(ix > 0, |div| div.ml_neg_1()).child(player)),
            )
    }
}

impl ComponentPreview for Facepile {
    fn preview(_window: &mut Window, _cx: &mut App) -> AnyElement {
        let faces: [&'static str; 6] = [
            "https://avatars.githubusercontent.com/u/326587?s=60&v=4",
            "https://avatars.githubusercontent.com/u/2280405?s=60&v=4",
            "https://avatars.githubusercontent.com/u/1789?s=60&v=4",
            "https://avatars.githubusercontent.com/u/67129314?s=60&v=4",
            "https://avatars.githubusercontent.com/u/482957?s=60&v=4",
            "https://avatars.githubusercontent.com/u/1714999?s=60&v=4",
        ];

        v_flex()
            .gap_6()
            .children(vec![
                example_group_with_title(
                    "Facepile Examples",
                    vec![
                        single_example(
                            "Default",
                            Facepile::new(
                                faces
                                    .iter()
                                    .map(|&url| Avatar::new(url).into_any_element())
                                    .collect(),
                            )
                            .into_any_element(),
                        ),
                        single_example(
                            "Custom Size",
                            Facepile::new(
                                faces
                                    .iter()
                                    .map(|&url| Avatar::new(url).size(px(24.)).into_any_element())
                                    .collect(),
                            )
                            .into_any_element(),
                        ),
                    ],
                ),
                example_group_with_title(
                    "Special Cases",
                    vec![
                        single_example("Empty Facepile", Facepile::empty().into_any_element()),
                        single_example(
                            "Single Face",
                            Facepile::new(vec![Avatar::new(faces[0]).into_any_element()].into())
                                .into_any_element(),
                        ),
                    ],
                ),
            ])
            .into_any_element()
    }
}