use gpui::{
    canvas, div, linear_color_stop, linear_gradient, point, prelude::*, px, size, App, AppContext,
    Bounds, ColorSpace, Half, Render, ViewContext, WindowOptions,
};

struct GradientViewer {
    color_space: ColorSpace,
}

impl GradientViewer {
    fn new() -> Self {
        Self {
            color_space: ColorSpace::default(),
        }
    }
}

impl Render for GradientViewer {
    fn render(&mut self, cx: &mut ViewContext<Self>) -> impl IntoElement {
        let color_space = self.color_space;

        div()
            .font_family(".SystemUIFont")
            .bg(gpui::white())
            .size_full()
            .p_4()
            .flex()
            .flex_col()
            .gap_3()
            .child(
                div()
                    .flex()
                    .gap_2()
                    .justify_between()
                    .items_center()
                    .child("Gradient Examples")
                    .child(
                        div().flex().gap_2().items_center().child(
                            div()
                                .id("method")
                                .flex()
                                .px_3()
                                .py_1()
                                .text_sm()
                                .bg(gpui::black())
                                .text_color(gpui::white())
                                .child(format!("{}", color_space))
                                .active(|this| this.opacity(0.8))
                                .on_click(cx.listener(move |this, _, cx| {
                                    this.color_space = match this.color_space {
                                        ColorSpace::Oklab => ColorSpace::Srgb,
                                        ColorSpace::Srgb => ColorSpace::Oklab,
                                    };
                                    cx.notify();
                                })),
                        ),
                    ),
            )
            .child(
                div()
                    .flex()
                    .flex_1()
                    .gap_3()
                    .child(
                        div()
                            .size_full()
                            .rounded_xl()
                            .flex()
                            .items_center()
                            .justify_center()
                            .bg(gpui::red())
                            .text_color(gpui::white())
                            .child("Solid Color"),
                    )
                    .child(
                        div()
                            .size_full()
                            .rounded_xl()
                            .flex()
                            .items_center()
                            .justify_center()
                            .bg(gpui::blue())
                            .text_color(gpui::white())
                            .child("Solid Color"),
                    ),
            )
            .child(
                div()
                    .flex()
                    .flex_1()
                    .gap_3()
                    .h_24()
                    .text_color(gpui::white())
                    .child(
                        div().flex_1().rounded_xl().bg(linear_gradient(
                            45.,
                            linear_color_stop(gpui::red(), 0.),
                            linear_color_stop(gpui::blue(), 1.),
                        )
                        .color_space(color_space)),
                    )
                    .child(
                        div().flex_1().rounded_xl().bg(linear_gradient(
                            135.,
                            linear_color_stop(gpui::red(), 0.),
                            linear_color_stop(gpui::green(), 1.),
                        )
                        .color_space(color_space)),
                    )
                    .child(
                        div().flex_1().rounded_xl().bg(linear_gradient(
                            225.,
                            linear_color_stop(gpui::green(), 0.),
                            linear_color_stop(gpui::blue(), 1.),
                        )
                        .color_space(color_space)),
                    )
                    .child(
                        div().flex_1().rounded_xl().bg(linear_gradient(
                            315.,
                            linear_color_stop(gpui::green(), 0.),
                            linear_color_stop(gpui::yellow(), 1.),
                        )
                        .color_space(color_space)),
                    ),
            )
            .child(
                div()
                    .flex()
                    .flex_1()
                    .gap_3()
                    .h_24()
                    .text_color(gpui::white())
                    .child(
                        div().flex_1().rounded_xl().bg(linear_gradient(
                            0.,
                            linear_color_stop(gpui::red(), 0.),
                            linear_color_stop(gpui::white(), 1.),
                        )
                        .color_space(color_space)),
                    )
                    .child(
                        div().flex_1().rounded_xl().bg(linear_gradient(
                            90.,
                            linear_color_stop(gpui::blue(), 0.),
                            linear_color_stop(gpui::white(), 1.),
                        )
                        .color_space(color_space)),
                    )
                    .child(
                        div().flex_1().rounded_xl().bg(linear_gradient(
                            180.,
                            linear_color_stop(gpui::green(), 0.),
                            linear_color_stop(gpui::white(), 1.),
                        )
                        .color_space(color_space)),
                    )
                    .child(
                        div().flex_1().rounded_xl().bg(linear_gradient(
                            360.,
                            linear_color_stop(gpui::yellow(), 0.),
                            linear_color_stop(gpui::white(), 1.),
                        )
                        .color_space(color_space)),
                    ),
            )
            .child(
                div().flex_1().rounded_xl().bg(linear_gradient(
                    0.,
                    linear_color_stop(gpui::green(), 0.05),
                    linear_color_stop(gpui::yellow(), 0.95),
                )
                .color_space(color_space)),
            )
            .child(
                div().flex_1().rounded_xl().bg(linear_gradient(
                    90.,
                    linear_color_stop(gpui::blue(), 0.05),
                    linear_color_stop(gpui::red(), 0.95),
                )
                .color_space(color_space)),
            )
            .child(
                div()
                    .flex()
                    .flex_1()
                    .gap_3()
                    .child(
                        div().flex().flex_1().gap_3().child(
                            div().flex_1().rounded_xl().bg(linear_gradient(
                                90.,
                                linear_color_stop(gpui::blue(), 0.5),
                                linear_color_stop(gpui::red(), 0.5),
                            )
                            .color_space(color_space)),
                        ),
                    )
                    .child(
                        div().flex_1().rounded_xl().bg(linear_gradient(
                            180.,
                            linear_color_stop(gpui::green(), 0.),
                            linear_color_stop(gpui::blue(), 0.5),
                        )
                        .color_space(color_space)),
                    ),
            )
            .child(div().h_24().child(canvas(
                move |_, _| {},
                move |bounds, _, cx| {
                    let size = size(bounds.size.width * 0.8, px(80.));
                    let square_bounds = Bounds {
                        origin: point(
                            bounds.size.width.half() - size.width.half(),
                            bounds.origin.y,
                        ),
                        size,
                    };
                    let height = square_bounds.size.height;
                    let horizontal_offset = height;
                    let vertical_offset = px(30.);
                    let mut path = gpui::Path::new(square_bounds.bottom_left());
                    path.line_to(square_bounds.origin + point(horizontal_offset, vertical_offset));
                    path.line_to(
                        square_bounds.top_right() + point(-horizontal_offset, vertical_offset),
                    );
                    path.line_to(square_bounds.bottom_right());
                    path.line_to(square_bounds.bottom_left());
                    cx.paint_path(
                        path,
                        linear_gradient(
                            180.,
                            linear_color_stop(gpui::red(), 0.),
                            linear_color_stop(gpui::blue(), 1.),
                        )
                        .color_space(color_space),
                    );
                },
            )))
    }
}

fn main() {
    App::new().run(|cx: &mut AppContext| {
        cx.open_window(
            WindowOptions {
                focus: true,
                ..Default::default()
            },
            |cx| cx.new_view(|_| GradientViewer::new()),
        )
        .unwrap();
        cx.activate(true);
    });
}