use anyhow::Result;

#[cfg(all(feature = "with-image", feature = "with-nalgebra"))]
mod example {
    use anyhow::Result;
    use crossbeam::channel;
    use image::ImageFormat;
    use kiss3d::{
        light::Light,
        window::{State, Window},
    };
    use nalgebra::Point3;
    use realsense_rust::{
        prelude::*, Config, Format, Pipeline, PointCloud, Resolution, StreamKind,
    };
    use std::time::Duration;

    #[derive(Debug)]
    struct PointWithColor {
        vertex: Point3<f32>,
        color: Point3<f32>,
    }

    #[derive(Debug)]
    struct PcdVizState {
        rx: channel::Receiver<Vec<PointWithColor>>,
        points: Option<Vec<PointWithColor>>,
    }

    impl PcdVizState {
        pub fn new(rx: channel::Receiver<Vec<PointWithColor>>) -> Self {
            let state = Self { rx, points: None };
            state
        }
    }

    impl State for PcdVizState {
        fn step(&mut self, window: &mut Window) {
            // try to receive recent points
            if let Ok(points) = self.rx.try_recv() {
                self.points = Some(points);
            };

            // draw axis
            window.draw_line(
                &Point3::origin(),
                &Point3::new(1.0, 0.0, 0.0),
                &Point3::new(1.0, 0.0, 0.0),
            );
            window.draw_line(
                &Point3::origin(),
                &Point3::new(0.0, 1.0, 0.0),
                &Point3::new(0.0, 1.0, 0.0),
            );
            window.draw_line(
                &Point3::origin(),
                &Point3::new(0.0, 0.0, 1.0),
                &Point3::new(0.0, 0.0, 1.0),
            );

            // draw points
            if let Some(points) = &self.points {
                for point in points.iter() {
                    window.draw_point(&point.vertex, &point.color);
                }
            }
        }
    }

    pub fn main() -> Result<()> {
        let (tx, rx) = channel::unbounded();

        std::thread::spawn(move || {
            let state = PcdVizState::new(rx);
            let mut window = Window::new("point cloud");
            window.set_light(Light::StickToCamera);
            window.render_loop(state);
        });

        // init pipeline
        let pipeline = Pipeline::new()?;
        let config = Config::new()?
            .enable_stream(StreamKind::Depth, 0, 640, 0, Format::Z16, 30)?
            .enable_stream(StreamKind::Color, 0, 640, 0, Format::Rgb8, 30)?;
        let mut pipeline = pipeline.start(&config)?;
        let profile = pipeline.profile();

        // pointcloud filter
        let mut pointcloud = PointCloud::create()?;

        // show stream info
        for (idx, stream_result) in profile.streams()?.try_into_iter()?.enumerate() {
            let stream = stream_result?;
            println!("stream data {}: {:#?}", idx, stream.get_data()?);
        }

        // process frames
        for _ in 0..1000 {
            let timeout = Duration::from_millis(1000);
            let frames = match pipeline.wait(timeout)? {
                Some(frame) => frame,
                None => {
                    println!("timeout error");
                    continue;
                }
            };

            println!("frame number = {}", frames.number()?);

            let color_frame = frames.color_frame()?.unwrap();
            let depth_frame = frames.depth_frame()?.unwrap();

            // save video frame
            {
                let image = color_frame.owned_image()?;
                image.save_with_format(
                    format!("sync-video-example-{}.png", color_frame.number()?),
                    ImageFormat::Png,
                )?;
            }

            // save depth frame
            {
                let Resolution { width, height } = depth_frame.resolution()?;
                let distance = depth_frame.distance(width / 2, height / 2)?;
                println!("distance = {}", distance);

                let image = depth_frame.owned_image()?;
                image.save_with_format(
                    format!("sync-depth-example-{}.png", depth_frame.number()?),
                    ImageFormat::Png,
                )?;
            }

            // access texture data
            let pixel_data = color_frame.data()?;
            let frame_width = color_frame.width()? as f32;
            let frame_height = color_frame.height()? as f32;
            let bytes_per_pixel = color_frame.bits_per_pixel()? / 8;
            let pixel_stride = color_frame.stride_in_bytes()?;

            // compute point cloud
            pointcloud.map_to(color_frame.clone())?;
            let points_frame = pointcloud.calculate(depth_frame.clone())?;
            let points = points_frame
                .vertices()?
                .iter()
                .zip(points_frame.texture_coordinates()?)
                .map(|(vertex, tex_coord)| {
                    let [x, y, z] = vertex.xyz;

                    let mut color = Point3::new(0f32, 0f32, 0f32);
                    let (u, v) = (tex_coord.u, tex_coord.v);
                    if u >= 0f32 && u < 1f32 && v >= 0f32 && v < 1f32 {
                        let x = (u * frame_width) as usize;
                        let y = (v * frame_height) as usize;
                        let idx = x * bytes_per_pixel + y * pixel_stride;

                        let r = pixel_data[idx] as f32;
                        let g = pixel_data[idx + 1] as f32;
                        let b = pixel_data[idx + 2] as f32;
                        color = Point3::new(r, g, b) / 255f32;
                    }

                    PointWithColor {
                        vertex: Point3::new(x, y, z),
                        color,
                    }
                })
                .collect::<Vec<_>>();

            if let Err(_) = tx.send(points) {
                break;
            }
        }

        Ok(())
    }
}

#[cfg(all(feature = "with-image", feature = "with-nalgebra"))]
fn main() -> Result<()> {
    example::main()
}

#[cfg(not(all(feature = "with-image", feature = "with-nalgebra")))]
fn main() {
    panic!("please enable with-image and with-nalgebra features to run this example");
}
