use super::{
    super::{Pipeline, TerrainLocals, TgtColorFmt, TgtDepthStencilFmt},
    shadow, Globals, Light, Shadow,
};
use gfx::{
    self, gfx_defines, gfx_impl_struct_meta, gfx_pipeline, gfx_pipeline_inner,
    gfx_vertex_struct_meta, state::ColorMask,
};
use vek::*;

gfx_defines! {
    vertex Vertex {
        pos_norm: u32 = "v_pos_norm",
    }

    pipeline pipe {
        vbuf: gfx::VertexBuffer<Vertex> = (),

        locals: gfx::ConstantBuffer<TerrainLocals> = "u_locals",
        globals: gfx::ConstantBuffer<Globals> = "u_globals",
        lights: gfx::ConstantBuffer<Light> = "u_lights",
        shadows: gfx::ConstantBuffer<Shadow> = "u_shadows",

        point_shadow_maps: gfx::TextureSampler<f32> = "t_point_shadow_maps",
        directed_shadow_maps: gfx::TextureSampler<f32> = "t_directed_shadow_maps",

        alt: gfx::TextureSampler<[f32; 2]> = "t_alt",
        horizon: gfx::TextureSampler<[f32; 4]> = "t_horizon",

        noise: gfx::TextureSampler<f32> = "t_noise",
        waves: gfx::TextureSampler<[f32; 4]> = "t_waves",

        // Shadow stuff
        light_shadows: gfx::ConstantBuffer<shadow::Locals> = "u_light_shadows",

        tgt_color: gfx::BlendTarget<TgtColorFmt> = ("tgt_color", ColorMask::all(), gfx::preset::blend::ALPHA),
        tgt_depth_stencil: gfx::DepthTarget<TgtDepthStencilFmt> = gfx::preset::depth::LESS_EQUAL_TEST,
        // tgt_depth_stencil: gfx::DepthStencilTarget<TgtDepthStencilFmt> = (gfx::preset::depth::LESS_EQUAL_TEST,Stencil::new(Comparison::Always,0xff,(StencilOp::Keep,StencilOp::Keep,StencilOp::Keep))),
    }
}

impl Vertex {
    #[allow(clippy::identity_op)] // TODO: Pending review in #587
    #[allow(clippy::into_iter_on_ref)] // TODO: Pending review in #587
    pub fn new(pos: Vec3<f32>, norm: Vec3<f32>) -> Self {
        let (norm_axis, norm_dir) = norm
            .as_slice()
            .into_iter()
            .enumerate()
            .find(|(_i, e)| **e != 0.0)
            .unwrap_or((0, &1.0));
        let norm_bits = ((norm_axis << 1) | if *norm_dir > 0.0 { 1 } else { 0 }) as u32;

        const EXTRA_NEG_Z: f32 = 65536.0;

        Self {
            pos_norm: 0
                | ((pos.x as u32) & 0x003F) << 0
                | ((pos.y as u32) & 0x003F) << 6
                | (((pos.z + EXTRA_NEG_Z).max(0.0).min((1 << 17) as f32) as u32) & 0x1FFFF) << 12
                | (norm_bits & 0x7) << 29,
        }
    }
}

pub struct FluidPipeline;

impl Pipeline for FluidPipeline {
    type Vertex = Vertex;
}