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#![feature(portable_simd)]

use std::simd::cmp::SimdOrd;
use std::simd::u8x8;
use std::simd::u8x16;

pub struct Cube3 {
    edges: u8x16,
    corners: u8x8,
}

const EDGE_ORI_MASK: u8x16 = u8x16::splat(0b0001_0000);
const EDGE_PERM_MASK: u8x16 = u8x16::splat(0b0000_1111);
const CORNER_ORI_MASK: u8x8 = u8x8::splat(0b0011_0000);
const CORNER_PERM_MASK: u8x8 = u8x8::splat(0b0000_0111);
const CO_INV_SWIZZLE: u8x8 = u8x8::from_array([0, 2, 1, 0, 0, 0, 0, 0]);

impl Cube3 {
    /// Compose two Rubik's cube states (apply `b` to `a`)
    pub fn replace_compose(&mut self, a: &Self, b: &Self) {
        let mut edges_composed = a.edges.swizzle_dyn(b.edges & EDGE_PERM_MASK);
        edges_composed ^= b.edges & EDGE_ORI_MASK;

let mut corners_composed = a.corners.swizzle_dyn(b.corners & CORNER_PERM_MASK);
        corners_composed += b.corners & CORNER_ORI_MASK;
        corners_composed = corners_composed.simd_min(corners_composed - CORNER_ORI_MASK);

self.edges = edges_composed;
        self.corners = corners_composed;
    }

/// Inverse a Rubik's cube state
    pub fn replace_inverse(&mut self, a: &Self) {
        let ep = a.edges & EDGE_PERM_MASK;

let pow_3_ep = ep.swizzle_dyn(ep).swizzle_dyn(ep);
        let mut inverse_ep = pow_3_ep.swizzle_dyn(pow_3_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep).swizzle_dyn(pow_3_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep).swizzle_dyn(ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep).swizzle_dyn(pow_3_ep);
        inverse_ep = inverse_ep.swizzle_dyn(inverse_ep).swizzle_dyn(ep);
        let mut inverse_eo = a.edges & EDGE_ORI_MASK;
        inverse_eo = inverse_eo.swizzle_dyn(inverse_ep);
        self.edges = inverse_eo | inverse_ep;

let cp = a.corners & CORNER_PERM_MASK;

let pow_3_cp = cp.swizzle_dyn(cp).swizzle_dyn(cp);
        let pow_6_cp = pow_3_cp.swizzle_dyn(pow_3_cp);
        let pow_7_cp = pow_6_cp.swizzle_dyn(cp);
        let mut inverse_cp = pow_7_cp.swizzle_dyn(pow_6_cp);
        inverse_cp = inverse_cp.swizzle_dyn(inverse_cp);
        inverse_cp = inverse_cp.swizzle_dyn(inverse_cp);
        inverse_cp = inverse_cp.swizzle_dyn(inverse_cp);
        inverse_cp = inverse_cp.swizzle_dyn(inverse_cp);
        inverse_cp = inverse_cp.swizzle_dyn(inverse_cp);
        inverse_cp = inverse_cp.swizzle_dyn(inverse_cp).swizzle_dyn(pow_7_cp);

let mut inverse_co = a.corners >> 3;
        inverse_co = CO_INV_SWIZZLE
            .swizzle_dyn(inverse_co)
            .swizzle_dyn(inverse_cp);
        inverse_co <<= 3;
        self.corners = inverse_co | inverse_cp;
    }
}