use crate::harness::Harness;
use bevy::prelude::*;
use bevy_prototype_debug_lines::DebugLines;
use rapier::math::{Point, Real, DIM};
use rapier::pipeline::{
    DebugRenderBackend, DebugRenderMode, DebugRenderObject, DebugRenderPipeline,
};
use std::fmt::Debug;

pub struct RapierDebugRenderPlugin {
    depth_test: bool,
}

impl Default for RapierDebugRenderPlugin {
    fn default() -> Self {
        Self {
            depth_test: cfg!(feature = "dim3"),
        }
    }
}

impl RapierDebugRenderPlugin {
    pub fn with_depth_test(enabled: bool) -> Self {
        Self {
            depth_test: enabled,
        }
    }
}

impl Plugin for RapierDebugRenderPlugin {
    fn build(&self, app: &mut App) {
        app.add_plugin(
            bevy_prototype_debug_lines::DebugLinesPlugin::with_depth_test(self.depth_test),
        )
        .insert_resource(DebugRenderPipeline::new(
            Default::default(),
            !DebugRenderMode::RIGID_BODY_AXES,
        ))
        .add_system_to_stage(CoreStage::Update, debug_render_scene);
    }
}

struct BevyLinesRenderBackend<'a> {
    lines: &'a mut DebugLines,
}

impl<'a> DebugRenderBackend for BevyLinesRenderBackend<'a> {
    #[cfg(feature = "dim2")]
    fn draw_line(&mut self, _: DebugRenderObject, a: Point<Real>, b: Point<Real>, color: [f32; 4]) {
        self.lines.line_colored(
            [a.x, a.y, 1.0e-8].into(),
            [b.x, b.y, 1.0e-8].into(),
            0.0,
            Color::hsla(color[0], color[1], color[2], color[3]),
        )
    }
    #[cfg(feature = "dim3")]
    fn draw_line(&mut self, _: DebugRenderObject, a: Point<Real>, b: Point<Real>, color: [f32; 4]) {
        self.lines.line_colored(
            [a.x, a.y, a.z].into(),
            [b.x, b.y, b.z].into(),
            0.0,
            Color::hsla(color[0], color[1], color[2], color[3]),
        )
    }
}

fn debug_render_scene(
    mut pipeline: ResMut<DebugRenderPipeline>,
    harness: NonSend<Harness>,
    mut lines: ResMut<DebugLines>,
) {
    let mut backend = BevyLinesRenderBackend { lines: &mut *lines };
    pipeline.render(
        &mut backend,
        &harness.physics.bodies,
        &harness.physics.colliders,
        &harness.physics.impulse_joints,
        &harness.physics.multibody_joints,
    );
}