ferrum-wgpu 0.1.1

use {
    anyhow::{Ok, Result},
    image::{DynamicImage, ImageBuffer},
    wgpu::{Extent3d, Sampler, TextureView},
};

pub struct Texture {
    pub texture: wgpu::Texture,
    pub view: wgpu::TextureView,
    pub sampler: wgpu::Sampler,
}

impl Texture {
    pub const DEPTH_FORMAT: wgpu::TextureFormat = wgpu::TextureFormat::Depth32Float;

    pub fn create_2d_texture(
        device: &wgpu::Device,
        width: u32,
        height: u32,
        format: wgpu::TextureFormat,
        usage: wgpu::TextureUsages,
        filter: wgpu::FilterMode,
        label: Option<&str>,
    ) -> Self {
        let size: Extent3d = wgpu::Extent3d {
            width: width.max(1),
            height: height.max(1),
            depth_or_array_layers: 1,
        };

        let label_texture: Option<String> = label.map(|l| format!("Texture::{}", l));
        let texture: wgpu::Texture = device.create_texture(&wgpu::TextureDescriptor {
            label: label_texture.as_deref(),
            size,
            mip_level_count: 1,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format,
            usage,
            view_formats: &[],
        });

        let view: wgpu::TextureView = texture.create_view(&wgpu::TextureViewDescriptor::default());

        let label_sampler: Option<String> = label.map(|l| format!("Sampler::{}", l));
        let sampler: Sampler = device.create_sampler(&wgpu::SamplerDescriptor {
            label: label_sampler.as_deref(),
            address_mode_u: wgpu::AddressMode::ClampToEdge,
            address_mode_v: wgpu::AddressMode::ClampToEdge,
            address_mode_w: wgpu::AddressMode::ClampToEdge,
            mag_filter: filter,
            min_filter: filter,
            mipmap_filter: wgpu::MipmapFilterMode::Nearest,
            lod_min_clamp: 0.0,
            lod_max_clamp: 100.0,
            ..Default::default()
        });

        Self {
            texture,
            view,
            sampler,
        }
    }

    pub fn from_bytes(
        device: &wgpu::Device,
        queue: &wgpu::Queue,
        bytes: &[u8],
        label: &str,
        is_normal_map: bool,
    ) -> Result<Self> {
        let img: DynamicImage = image::load_from_memory(bytes)?;
        Self::from_image(device, queue, img, label, is_normal_map)
    }

    pub fn from_image(
        device: &wgpu::Device,
        queue: &wgpu::Queue,
        img: DynamicImage,
        label: &str,
        is_normal_map: bool,
    ) -> Result<Self> {
        let diffuse_rgba: ImageBuffer<image::Rgba<u8>, Vec<u8>> = img.to_rgba8();

        use image::GenericImageView;
        let dimensions: (u32, u32) = img.dimensions();

        let texture_size: Extent3d = wgpu::Extent3d {
            width: dimensions.0,
            height: dimensions.1,
            depth_or_array_layers: 1,
        };

        // Normal maps store XYZ vectors, not colors → must be linear (no sRGB curve).
        // Diffuse / albedo maps store visible colors → sRGB.
        let format = if is_normal_map {
            wgpu::TextureFormat::Rgba8Unorm
        } else {
            wgpu::TextureFormat::Rgba8UnormSrgb
        };

        let texture: wgpu::Texture = device.create_texture(&wgpu::TextureDescriptor {
            label: Some(label),
            size: texture_size,
            mip_level_count: 1,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format,
            usage: wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::COPY_DST,
            view_formats: &[],
        });

        queue.write_texture(
            wgpu::TexelCopyTextureInfo {
                texture: &texture,
                mip_level: 0,
                origin: wgpu::Origin3d::ZERO,
                aspect: wgpu::TextureAspect::All,
            },
            &diffuse_rgba,
            wgpu::TexelCopyBufferLayout {
                offset: 0,
                bytes_per_row: Some(4 * dimensions.0),
                rows_per_image: Some(dimensions.1),
            },
            texture_size,
        );

        let view: TextureView = texture.create_view(&wgpu::TextureViewDescriptor::default());

        let sampler: Sampler = device.create_sampler(&wgpu::SamplerDescriptor {
            label: Some("sampler"),
            address_mode_u: wgpu::AddressMode::ClampToEdge,
            address_mode_v: wgpu::AddressMode::ClampToEdge,
            address_mode_w: wgpu::AddressMode::ClampToEdge,
            mag_filter: wgpu::FilterMode::Linear,
            min_filter: wgpu::FilterMode::Linear,
            mipmap_filter: wgpu::MipmapFilterMode::Linear,
            ..Default::default()
        });

        Ok(Self {
            texture,
            view,
            sampler,
        })
    }

    /// Crea una normal map plana de 1x1 con el valor `(128, 128, 255)`, que
    /// decodifica a `(0, 0, 1)` en espacio tangente: una normal perpendicular a
    /// la superficie, sin relieve.
    ///
    /// Se usa como respaldo para materiales sin normal map (p. ej. el suelo). Sin
    /// esto, el `load_model` caía a la textura de color como si fuera de normales,
    /// produciendo direcciones erróneas que dejaban la superficie sin iluminar.
    pub fn default_normal(device: &wgpu::Device, queue: &wgpu::Queue) -> Self {
        let texture: wgpu::Texture = device.create_texture(&wgpu::TextureDescriptor {
            label: Some("default_normal"),
            size: Extent3d {
                width: 1,
                height: 1,
                depth_or_array_layers: 1,
            },
            mip_level_count: 1,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format: wgpu::TextureFormat::Rgba8Unorm,
            usage: wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::COPY_DST,
            view_formats: &[],
        });

        queue.write_texture(
            wgpu::TexelCopyTextureInfo {
                texture: &texture,
                mip_level: 0,
                origin: wgpu::Origin3d::ZERO,
                aspect: wgpu::TextureAspect::All,
            },
            &[128u8, 128, 255, 255],
            wgpu::TexelCopyBufferLayout {
                offset: 0,
                bytes_per_row: Some(4),
                rows_per_image: Some(1),
            },
            Extent3d {
                width: 1,
                height: 1,
                depth_or_array_layers: 1,
            },
        );

        let view: TextureView = texture.create_view(&wgpu::TextureViewDescriptor::default());
        let sampler: Sampler = device.create_sampler(&wgpu::SamplerDescriptor::default());

        Self {
            texture,
            view,
            sampler,
        }
    }

    pub fn create_depth_texture(
        device: &wgpu::Device,
        config: &wgpu::SurfaceConfiguration,
        label: &str,
    ) -> Self {
        let size: Extent3d = wgpu::Extent3d {
            width: config.width.max(1),
            height: config.height.max(1),
            depth_or_array_layers: 1,
        };

        let texture: wgpu::Texture = device.create_texture(&wgpu::TextureDescriptor {
            label: Some(label),
            size,
            mip_level_count: 1,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format: Self::DEPTH_FORMAT,
            usage: wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::TEXTURE_BINDING,
            view_formats: &[],
        });

        let view: TextureView = texture.create_view(&wgpu::TextureViewDescriptor::default());

        let sampler: Sampler = device.create_sampler(&wgpu::SamplerDescriptor {
            address_mode_u: wgpu::AddressMode::ClampToEdge,
            address_mode_v: wgpu::AddressMode::ClampToEdge,
            address_mode_w: wgpu::AddressMode::ClampToEdge,
            mag_filter: wgpu::FilterMode::Linear,
            min_filter: wgpu::FilterMode::Linear,
            mipmap_filter: wgpu::MipmapFilterMode::Nearest,
            lod_min_clamp: 0.0,
            lod_max_clamp: 100.0,
            ..Default::default()
        });

        Self {
            texture,
            view,
            sampler,
        }
    }

    pub fn create_shadow_map(device: &wgpu::Device, size: u32, label: &str) -> Self {
        let size: Extent3d = wgpu::Extent3d {
            width: size,
            height: size,
            depth_or_array_layers: 1,
        };

        let texture: wgpu::Texture = device.create_texture(&wgpu::TextureDescriptor {
            label: Some(&(label.to_owned() + " texture")),
            size,
            mip_level_count: 1,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format: Self::DEPTH_FORMAT,
            usage: wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::TEXTURE_BINDING,
            view_formats: &[],
        });

        let view: TextureView = texture.create_view(&wgpu::TextureViewDescriptor::default());

        let sampler: Sampler = device.create_sampler(&wgpu::SamplerDescriptor {
            label: Some(&(label.to_owned() + " sampler")),
            address_mode_u: wgpu::AddressMode::ClampToEdge,
            address_mode_v: wgpu::AddressMode::ClampToEdge,
            address_mode_w: wgpu::AddressMode::ClampToEdge,
            mag_filter: wgpu::FilterMode::Linear,
            min_filter: wgpu::FilterMode::Linear,
            mipmap_filter: wgpu::MipmapFilterMode::Nearest,
            lod_min_clamp: 0.0,
            lod_max_clamp: 100.0,
            compare: Some(wgpu::CompareFunction::LessEqual),
            ..Default::default()
        });

        Self {
            texture,
            view,
            sampler,
        }
    }
}

pub struct CubeTexture {
    texture: wgpu::Texture,
    sampler: wgpu::Sampler,
    view: wgpu::TextureView,
}

impl CubeTexture {
    pub fn create_2d(
        device: &wgpu::Device,
        width: u32,
        height: u32,
        format: wgpu::TextureFormat,
        mip_level_count: u32,
        usage: wgpu::TextureUsages,
        mag_filter: wgpu::FilterMode,
        label: Option<&str>,
    ) -> Self {
        let texture: wgpu::Texture = device.create_texture(&wgpu::TextureDescriptor {
            label,
            size: wgpu::Extent3d {
                width,
                height,
                depth_or_array_layers: 6,
            },
            mip_level_count,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format,
            usage,
            view_formats: &[],
        });

        let view: TextureView = texture.create_view(&wgpu::TextureViewDescriptor {
            label,
            dimension: Some(wgpu::TextureViewDimension::Cube),
            array_layer_count: Some(6),
            ..Default::default()
        });

        let sampler: Sampler = device.create_sampler(&wgpu::SamplerDescriptor {
            label,
            address_mode_u: wgpu::AddressMode::ClampToEdge,
            address_mode_v: wgpu::AddressMode::ClampToEdge,
            address_mode_w: wgpu::AddressMode::ClampToEdge,
            mag_filter,
            min_filter: wgpu::FilterMode::Linear,
            mipmap_filter: wgpu::MipmapFilterMode::Linear,
            ..Default::default()
        });

        Self {
            texture,
            sampler,
            view,
        }
    }

    pub fn texture(&self) -> &wgpu::Texture {
        &self.texture
    }

    pub fn view(&self) -> &wgpu::TextureView {
        &self.view
    }

    pub fn sampler(&self) -> &wgpu::Sampler {
        &self.sampler
    }
}