use crate::error;
use bytemuck::offset_of;
use windows::core::PCSTR;
use windows::Win32::Graphics::Direct3D::D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP;
use windows::Win32::Graphics::Direct3D11::{
    ID3D11Buffer, ID3D11Device, ID3D11DeviceContext, D3D11_BIND_VERTEX_BUFFER, D3D11_BUFFER_DESC,
    D3D11_INPUT_ELEMENT_DESC, D3D11_INPUT_PER_VERTEX_DATA, D3D11_SUBRESOURCE_DATA,
    D3D11_USAGE_IMMUTABLE,
};
use windows::Win32::Graphics::Direct3D12::{D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, D3D12_INPUT_ELEMENT_DESC};
use windows::Win32::Graphics::Dxgi::Common::DXGI_FORMAT_R32G32_FLOAT;

#[repr(C)]
#[derive(Debug, Copy, Clone, Default)]
struct D3D12Vertex {
    position: [f32; 2],
    texcoord: [f32; 2],
    color: [f32; 4],
}

const CLEAR: [f32; 4] = [1.0, 1.0, 1.0, 1.0];

static QUAD_VBO_DATA: &[D3D12Vertex; 4] = &[
    D3D12Vertex {
        position: [0.0, 0.0],
        texcoord: [0.0, 1.0],
        color: CLEAR,
    },
    D3D12Vertex {
        position: [0.0, 1.0],
        texcoord: [0.0, 0.0],
        color: CLEAR,
    },
    D3D12Vertex {
        position: [1.0, 0.0],
        texcoord: [1.0, 1.0],
        color: CLEAR,
    },
    D3D12Vertex {
        position: [1.0, 1.0],
        texcoord: [1.0, 0.0],
        color: CLEAR,
    },
];

pub(crate) struct DrawQuad {
    buffer: ID3D11Buffer,
    context: ID3D11DeviceContext,
    offset: u32,
    stride: u32,
}

impl DrawQuad {
    // pub fn new(device: &ID3D11Device, context: &ID3D11DeviceContext) -> error::Result<DrawQuad> {
    //     unsafe {
    //         let mut buffer = None;
    //         device.CreateBuffer(
    //             &D3D11_BUFFER_DESC {
    //                 ByteWidth: std::mem::size_of::<[D3D11Vertex; 4]>() as u32,
    //                 Usage: D3D11_USAGE_IMMUTABLE,
    //                 BindFlags: D3D11_BIND_VERTEX_BUFFER,
    //                 CPUAccessFlags: Default::default(),
    //                 MiscFlags: Default::default(),
    //                 StructureByteStride: 0,
    //             },
    //             Some(&D3D11_SUBRESOURCE_DATA {
    //                 pSysMem: QUAD_VBO_DATA.as_ptr().cast(),
    //                 SysMemPitch: 0,
    //                 SysMemSlicePitch: 0,
    //             }),
    //             Some(&mut buffer),
    //         )?;
    //         assume_d3d11_init!(buffer, "CreateBuffer");
    //
    //         Ok(DrawQuad {
    //             buffer,
    //             context: context.clone(),
    //             offset: 0,
    //             stride: std::mem::size_of::<D3D11Vertex>() as u32,
    //         })
    //     }
    // }
    //
    // pub fn bind_vertices(&self) {
    //     unsafe {
    //         self.context
    //             .IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);
    //         self.context.IASetVertexBuffers(
    //             0,
    //             1,
    //             Some(&Some(self.buffer.clone())),
    //             Some(&self.stride),
    //             Some(&self.offset),
    //         );
    //     }
    // }

    pub fn get_spirv_cross_vbo_desc() -> [D3D12_INPUT_ELEMENT_DESC; 2] {
        [
            D3D12_INPUT_ELEMENT_DESC {
                SemanticName: PCSTR(b"TEXCOORD\0".as_ptr()),
                SemanticIndex: 0,
                Format: DXGI_FORMAT_R32G32_FLOAT,
                InputSlot: 0,
                AlignedByteOffset: offset_of!(D3D12Vertex, position) as u32,
                InputSlotClass: D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
                InstanceDataStepRate: 0,
            },
            D3D12_INPUT_ELEMENT_DESC {
                SemanticName: PCSTR(b"TEXCOORD\0".as_ptr()),
                SemanticIndex: 1,
                Format: DXGI_FORMAT_R32G32_FLOAT,
                InputSlot: 0,
                AlignedByteOffset: offset_of!(D3D12Vertex, texcoord) as u32,
                InputSlotClass: D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA,
                InstanceDataStepRate: 0,
            },
        ]
    }
}