//! Casita de voxels construida con los **materiales de casa**: muros de ladrillo,
//! piso y puerta de madera, ventanas de **vidrio** (lustroso → glasean al sol),
//! techo a dos aguas de teja y una chimenea de pizarra. Verifica la tanda de
//! materiales de obra *en contexto* y el brillo de los materiales (no sólo minerales).
//!
//! `cargo run -p llimphi-voxel --example house_demo --release` → `/tmp/house.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::Material;

const W: u32 = 1180;
const H: u32 = 700;
const FMT: wgpu::TextureFormat = wgpu::TextureFormat::Rgba8Unorm;

/// Coloca un voxel del material `m`, llevando su brillo en el alpha (los lustrosos
/// como el vidrio glasean; los mate quedan en 255).
fn put(g: &mut VoxelGrid, x: i32, y: i32, z: i32, m: Material) {
    if x < 0 || y < 0 || z < 0 {
        return;
    }
    let a = VoxelGrid::shine_to_alpha(m.brillo());
    g.set_rgba(x as u32, y as u32, z as u32, m.color(), a);
}

fn main() {
    let dim = [56u32, 44, 52];
    let mut g = VoxelGrid::new(dim);

    // Césped.
    let gh = 4i32;
    for x in 0..dim[0] as i32 {
        for z in 0..dim[2] as i32 {
            for y in 0..gh {
                let t = ((x * 5 + z * 7 + y) % 9) as i32 - 4;
                let base = Material::Grass.color();
                let c = |v: u8| (v as i32 + t).clamp(0, 255) as u8;
                g.set(x as u32, y as u32, z as u32, [c(base[0]), c(base[1]), c(base[2])]);
            }
        }
    }

    // Footprint de la casa.
    let (x0, z0) = (12i32, 12i32);
    let (wd, dp) = (26i32, 22i32); // ancho (x), profundidad (z)
    let wh = 9i32; // alto de muros
    let (x1, z1) = (x0 + wd - 1, z0 + dp - 1);

    // Piso de madera.
    for x in x0..=x1 {
        for z in z0..=z1 {
            put(&mut g, x, gh, z, Material::Madera);
        }
    }

    // Muros de ladrillo (perímetro).
    for yy in 0..wh {
        let y = gh + 1 + yy;
        for x in x0..=x1 {
            put(&mut g, x, y, z0, Material::Ladrillo);
            put(&mut g, x, y, z1, Material::Ladrillo);
        }
        for z in z0..=z1 {
            put(&mut g, x0, y, z, Material::Ladrillo);
            put(&mut g, x1, y, z, Material::Ladrillo);
        }
    }

    // Vigas de acero en las esquinas (lustrosas).
    for yy in 0..wh {
        let y = gh + 1 + yy;
        for (cx, cz) in [(x0, z0), (x1, z0), (x0, z1), (x1, z1)] {
            put(&mut g, cx, y, cz, Material::Acero);
        }
    }

    // Puerta de madera (pared frontal z0, centrada).
    let dcx = x0 + wd / 2;
    for yy in 0..5 {
        for dx in -1..=1 {
            put(&mut g, dcx + dx, gh + 1 + yy, z0, Material::Madera);
        }
    }

    // Ventanas de vidrio (3×3) en las cuatro paredes.
    let ventana = |g: &mut VoxelGrid, cx: i32, cz: i32, along_x: bool| {
        for a in -1..=1 {
            for b in 0..3 {
                let y = gh + 3 + b;
                if along_x {
                    put(g, cx + a, y, cz, Material::Vidrio);
                } else {
                    put(g, cx, y, cz + a, Material::Vidrio);
                }
            }
        }
    };
    // Frontal: dos ventanas flanqueando la puerta.
    ventana(&mut g, x0 + 4, z0, true);
    ventana(&mut g, x1 - 4, z0, true);
    // Trasera.
    ventana(&mut g, x0 + wd / 3, z1, true);
    ventana(&mut g, x1 - wd / 3, z1, true);
    // Laterales.
    ventana(&mut g, x0, z0 + dp / 2, false);
    ventana(&mut g, x1, z0 + dp / 2, false);

    // Techo a dos aguas de teja (cumbrera a lo largo de x), con alero de 1.
    let roof_base = gh + 1 + wh;
    let half = (dp + 1) / 2;
    for r in 0..half {
        let y = roof_base + r;
        let za = z0 - 1 + r; // agua norte
        let zb = z1 + 1 - r; // agua sur
        for x in (x0 - 1)..=(x1 + 1) {
            put(&mut g, x, y, za, Material::Teja);
            put(&mut g, x, y, zb, Material::Teja);
        }
    }

    // Chimenea de pizarra (sobresale del techo).
    let (chx, chz) = (x1 - 3, z0 + 3);
    for y in (gh + 1)..(roof_base + half + 2) {
        for dx in 0..2 {
            for dz in 0..2 {
                put(&mut g, chx + dx, y, chz + dz, Material::Pizarra);
            }
        }
    }

    // --- Render ---
    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 = [0.42, 0.66, 0.62]; // sol alto-frontal → las ventanas glasean
    vr.atmosphere = Atmosphere {
        sky_zenith: [96, 146, 208],
        sky_horizon: [206, 220, 232],
        fog_density: 0.0,
        god_rays: 0.0,
    };
    let camera = Camera3d::orbit(
        Vec3::new(0.0, dim[1] as f32 * 0.06, 0.0),
        34_f32.to_radians(),
        20_f32.to_radians(),
        dim[0] as f32 * 1.15,
    );
    let mut scene = Scene3d::new();
    let pixels = render(&hal, &mut renderer, &mut scene, &mut vr, &camera);
    write_png(&pixels, "/tmp/house.png");
    eprintln!("escrito /tmp/house.png — casita con materiales de obra (vidrio/acero lustrosos)");
}

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("house") });
    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();
}