use anyhow::*;
use image::GenericImageView;

pub struct Texture {
    pub texture: wgpu::Texture,
    pub view: wgpu::TextureView,
    pub sampler: wgpu::Sampler,
    pub size: wgpu::Extent3d,
}

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

    pub fn create_depth_texture(
        device: &wgpu::Device,
        config: &wgpu::SurfaceConfiguration,
        label: &str,
    ) -> Self {
        let size = wgpu::Extent3d {
            width: config.width,
            height: config.height,
            depth_or_array_layers: 1,
        };
        let desc = 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: &[Self::DEPTH_FORMAT],
        };
        let texture = device.create_texture(&desc);
        let view = texture.create_view(&wgpu::TextureViewDescriptor::default());
        let 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::FilterMode::Nearest,
            compare: Some(wgpu::CompareFunction::LessEqual),
            lod_min_clamp: 0.0,
            lod_max_clamp: 100.0,
            ..Default::default()
        });

        Self {
            texture,
            view,
            sampler,
            size, // NEW!
        }
    }

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

    pub fn from_image(
        device: &wgpu::Device,
        queue: &wgpu::Queue,
        img: &image::DynamicImage,
        label: Option<&str>,
        is_normal_map: bool,
    ) -> Result<Self> {
        let dimensions = img.dimensions();
        let rgba = img.to_rgba8();

        let format = if is_normal_map {
            wgpu::TextureFormat::Rgba8Unorm
        } else {
            wgpu::TextureFormat::Rgba8UnormSrgb
        };
        let usage = wgpu::TextureUsages::TEXTURE_BINDING | wgpu::TextureUsages::COPY_DST;
        let size = wgpu::Extent3d {
            width: img.width(),
            height: img.height(),
            depth_or_array_layers: 1,
        };
        let texture = Self::create_2d_texture(
            device,
            size.width,
            size.height,
            format,
            usage,
            wgpu::FilterMode::Linear,
            label,
        );

        queue.write_texture(
            wgpu::ImageCopyTexture {
                aspect: wgpu::TextureAspect::All,
                texture: &texture.texture,
                mip_level: 0,
                origin: wgpu::Origin3d::ZERO,
            },
            &rgba,
            wgpu::ImageDataLayout {
                offset: 0,
                bytes_per_row: Some(4 * dimensions.0),
                rows_per_image: Some(dimensions.1),
            },
            size,
        );

        Ok(texture)
    }

    pub(crate) fn create_2d_texture(
        device: &wgpu::Device,
        width: u32,
        height: u32,
        format: wgpu::TextureFormat,
        usage: wgpu::TextureUsages,
        mag_filter: wgpu::FilterMode,
        label: Option<&str>,
    ) -> Self {
        let size = wgpu::Extent3d {
            width,
            height,
            depth_or_array_layers: 1,
        };
        Self::create_texture(
            device,
            label,
            size,
            format,
            usage,
            wgpu::TextureDimension::D2,
            mag_filter,
        )
    }

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

        let view = texture.create_view(&wgpu::TextureViewDescriptor::default());
        let 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,
            min_filter: wgpu::FilterMode::Nearest,
            mipmap_filter: wgpu::FilterMode::Nearest,
            ..Default::default()
        });

        Self {
            texture,
            view,
            sampler,
            size, // NEW!
        }
    }
}

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 = device.create_texture(&wgpu::TextureDescriptor {
            label,
            size: wgpu::Extent3d {
                width,
                height,
                // A cube has 6 sides, so we need 6 layers
                depth_or_array_layers: 6,
            },
            mip_level_count,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format,
            usage,
            view_formats: &[],
        });

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

        let 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::Nearest,
            mipmap_filter: wgpu::FilterMode::Nearest,
            ..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 }

}