//! Sala de exposición de los **muebles y objetos de casa**: los 12 modelos
//! ([`Mueble`]) sobre un piso de baldosas, cada uno estampado con [`stamp_mueble`].
//!
//! `cargo run -p llimphi-voxel --example room_demo --release` → `/tmp/room.png`

use std::fs::File;
use std::io::BufWriter;

use llimphi_3d::glam::Vec3;
use llimphi_3d::{Atmosphere, Camera3d, Scene3d, VoxelGrid, VoxelRenderer};
use llimphi_hal::{wgpu, Hal};
use llimphi_raster::peniko::Color;
use llimphi_raster::{vello, Renderer};
use llimphi_voxel::{stamp_mueble, Material, Mueble};

const W: u32 = 1280;
const H: u32 = 620;
const FMT: wgpu::TextureFormat = wgpu::TextureFormat::Rgba8Unorm;

fn main() {
    let cols = 6i32;
    let rows = 12i32;
    let sx = 11i32; // paso en x
    let sz = 15i32; // paso en z
    let margin = 6i32;
    let floor_h = 2i32;
    let dim = [
        (cols * sx + 2 * margin) as u32,
        26,
        (rows * sz + 2 * margin) as u32,
    ];
    let mut g = VoxelGrid::new(dim);

    // Piso de baldosas (cerámica lustrosa + yeso, en damero).
    for x in 0..dim[0] as i32 {
        for z in 0..dim[2] as i32 {
            let tile = ((x / 2 + z / 2) % 2) == 0;
            let m = if tile { Material::Ceramica } else { Material::Yeso };
            for y in 0..floor_h {
                let c = m.color();
                let a = VoxelGrid::shine_to_alpha(if y == floor_h - 1 { m.brillo() } else { 0.0 });
                g.set_rgba(x as u32, y as u32, z as u32, c, a);
            }
        }
    }

    // Los 12 muebles en grilla.
    for (i, m) in Mueble::ALL.iter().enumerate() {
        let c = i as i32 % cols;
        let r = i as i32 / cols;
        let x = margin + c * sx + sx / 2;
        let z = margin + r * sz + sz / 2;
        stamp_mueble(&mut g, *m, x as u32, floor_h as u32, z as u32, 0);
        eprintln!("{:>10} en ({x},{z})", m.label());
    }

    let hal = pollster::block_on(Hal::new(None)).expect("hal");
    let mut renderer = Renderer::new(&hal).expect("renderer");
    let mut vr = VoxelRenderer::new(&hal.device, &hal.queue, FMT, &g);
    vr.sun_dir = [0.4, 0.72, 0.56];
    vr.atmosphere = Atmosphere {
        sky_zenith: [92, 120, 168],
        sky_horizon: [206, 214, 226],
        fog_density: 0.0,
        god_rays: 0.0,
    };
    let camera = Camera3d::orbit(
        Vec3::new(0.0, dim[1] as f32 * 0.02, 0.0),
        14_f32.to_radians(),
        40_f32.to_radians(),
        dim[0].max(dim[2]) as f32 * 0.82,
    );
    let mut scene = Scene3d::new();
    let pixels = render(&hal, &mut renderer, &mut scene, &mut vr, &camera);
    write_png(&pixels, "/tmp/room.png");
    eprintln!("escrito /tmp/room.png — 72 muebles: casa, ciudad, edificios y transporte");
}

fn render(
    hal: &Hal,
    renderer: &mut Renderer,
    scene: &mut Scene3d,
    vr: &mut VoxelRenderer,
    camera: &Camera3d,
) -> Vec<u8> {
    let inter = hal.device.create_texture(&wgpu::TextureDescriptor {
        label: Some("inter"),
        size: wgpu::Extent3d { width: W, height: H, depth_or_array_layers: 1 },
        mip_level_count: 1,
        sample_count: 1,
        dimension: wgpu::TextureDimension::D2,
        format: FMT,
        usage: wgpu::TextureUsages::STORAGE_BINDING
            | wgpu::TextureUsages::TEXTURE_BINDING
            | wgpu::TextureUsages::RENDER_ATTACHMENT
            | wgpu::TextureUsages::COPY_SRC,
        view_formats: &[],
    });
    let view = inter.create_view(&wgpu::TextureViewDescriptor::default());
    renderer
        .render_to_view(hal, &vello::Scene::new(), &view, W, H, Color::from_rgba8(0, 0, 0, 255))
        .expect("base");
    let mut enc = hal
        .device
        .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: Some("room") });
    scene.render(&hal.device, &hal.queue, &mut enc, &view, (W, H), camera, Some(vr), &[]);
    hal.queue.submit(std::iter::once(enc.finish()));
    let _ = hal.device.poll(wgpu::PollType::wait_indefinitely());
    readback(hal, &inter)
}

fn readback(hal: &Hal, target: &wgpu::Texture) -> Vec<u8> {
    let unpadded = (W * 4) as usize;
    let align = wgpu::COPY_BYTES_PER_ROW_ALIGNMENT as usize;
    let padded = unpadded.div_ceil(align) * align;
    let buf = hal.device.create_buffer(&wgpu::BufferDescriptor {
        label: Some("readback"),
        size: (padded * H as usize) as u64,
        usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
        mapped_at_creation: false,
    });
    let mut enc = hal
        .device
        .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
    enc.copy_texture_to_buffer(
        wgpu::TexelCopyTextureInfo {
            texture: target,
            mip_level: 0,
            origin: wgpu::Origin3d::ZERO,
            aspect: wgpu::TextureAspect::All,
        },
        wgpu::TexelCopyBufferInfo {
            buffer: &buf,
            layout: wgpu::TexelCopyBufferLayout {
                offset: 0,
                bytes_per_row: Some(padded as u32),
                rows_per_image: Some(H),
            },
        },
        wgpu::Extent3d { width: W, height: H, depth_or_array_layers: 1 },
    );
    hal.queue.submit(std::iter::once(enc.finish()));
    let slice = buf.slice(..);
    let (tx, rx) = std::sync::mpsc::channel();
    slice.map_async(wgpu::MapMode::Read, move |r| {
        let _ = tx.send(r);
    });
    let _ = hal.device.poll(wgpu::PollType::wait_indefinitely());
    rx.recv().unwrap().unwrap();
    let data = slice.get_mapped_range();
    let mut pixels = Vec::with_capacity((W * H * 4) as usize);
    for row in 0..H as usize {
        let srow = row * padded;
        pixels.extend_from_slice(&data[srow..srow + unpadded]);
    }
    drop(data);
    buf.unmap();
    pixels
}

fn write_png(pixels: &[u8], path: &str) {
    let file = File::create(path).expect("png");
    let mut enc = png::Encoder::new(BufWriter::new(file), W, H);
    enc.set_color(png::ColorType::Rgba);
    enc.set_depth(png::BitDepth::Eight);
    let mut wtr = enc.write_header().unwrap();
    wtr.write_image_data(pixels).unwrap();
}