#![allow(non_upper_case_globals)]

#[derive(Clone, Copy)]
pub struct Reg(u8);

/// hard wired 0
pub const zero: Reg = Reg(0);
/// return address
pub const ra: Reg = Reg(1);
/// stack pointer
pub const sp: Reg = Reg(2);
/// global pointer
pub const gp: Reg = Reg(3);
/// thread pointer
pub const tp: Reg = Reg(4);
/// temp / alternate link
pub const t0: Reg = Reg(5);
pub const t1: Reg = Reg(6);
pub const t2: Reg = Reg(7);

pub const fp: Reg = Reg(8);
pub const s0: Reg = Reg(8);
pub const s1: Reg = Reg(9);

pub const a0: Reg = Reg(10);
pub const a1: Reg = Reg(11);
pub const a2: Reg = Reg(12);
pub const a3: Reg = Reg(13);
pub const a4: Reg = Reg(14);
pub const a5: Reg = Reg(15);
pub const a6: Reg = Reg(16);
pub const a7: Reg = Reg(17);

pub const s2: Reg = Reg(18);
pub const s3: Reg = Reg(19);
pub const s4: Reg = Reg(20);
pub const s5: Reg = Reg(21);
pub const s6: Reg = Reg(22);
pub const s7: Reg = Reg(23);
pub const s8: Reg = Reg(24);
pub const s9: Reg = Reg(25);
pub const s10: Reg = Reg(26);
pub const s11: Reg = Reg(27);

pub const t3: Reg = Reg(28);
pub const t4: Reg = Reg(29);
pub const t5: Reg = Reg(30);
pub const t6: Reg = Reg(31);

impl Reg {
    #[inline]
    pub const fn val(&self) -> u32 {
        self.0 as u32
    }
}

impl Reg {
    pub fn from_str(str: &str) -> Option<Self> {
        Some(match str {
            "zero" => zero,
            "ra" => ra,
            "sp" => sp,
            "gp" => gp,
            "tp" => tp,
            "t0" => t0,
            "t1" => t1,
            "t2" => t2,
            "fp" => fp,
            "s0" => s0,
            "s1" => s1,
            "a0" => a0,
            "a1" => a1,
            "a2" => a2,
            "a3" => a3,
            "a4" => a4,
            "a5" => a5,
            "a6" => a6,
            "a7" => a7,
            "s2" => s2,
            "s3" => s3,
            "s4" => s4,
            "s5" => s5,
            "s6" => s6,
            "s7" => s7,
            "s8" => s8,
            "s9" => s9,
            "s10" => s10,
            "s11" => s11,
            "t3" => t3,
            "t4" => t4,
            "t5" => t5,
            "t6" => t6,
            _ => {
                return None;
            }
        })
    }
}

impl std::fmt::Debug for Reg {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(
            f,
            "{}",
            match self.0 {
                0 => "zero",
                1 => "ra",
                2 => "sp",
                3 => "gp",
                4 => "tp",
                5 => "t0",
                6 => "t1",
                7 => "t2",
                8 => "fp",
                9 => "s1",
                10 => "a0",
                11 => "a1",
                12 => "a2",
                13 => "a3",
                14 => "a4",
                15 => "a5",
                16 => "a6",
                17 => "a7",
                18 => "s2",
                19 => "s3",
                20 => "s4",
                21 => "s5",
                22 => "s6",
                23 => "s7",
                24 => "s8",
                25 => "s9",
                26 => "s10",
                27 => "s11",
                28 => "t3",
                29 => "t4",
                30 => "t5",
                31 => "t6",
                _ => "unknown",
            }
        )
    }
}

// pub const ft0: Reg = Reg(0);
// pub const ft1: Reg = Reg(1);
// pub const ft2: Reg = Reg(2);
// pub const ft3: Reg = Reg(3);
// pub const ft4: Reg = Reg(4);
// pub const ft5: Reg = Reg(5);
// pub const ft6: Reg = Reg(6);
// pub const ft7: Reg = Reg(7);
//
// pub const fs0: Reg = Reg(8);
// pub const fs1: Reg = Reg(9);
//
// pub const fa0: Reg = Reg(10);
// pub const fa1: Reg = Reg(11);
// pub const fa2: Reg = Reg(12);
// pub const fa3: Reg = Reg(13);
// pub const fa4: Reg = Reg(14);
// pub const fa5: Reg = Reg(15);
// pub const fa6: Reg = Reg(16);
// pub const fa7: Reg = Reg(17);
//
// pub const fs2: Reg = Reg(18);
// pub const fs3: Reg = Reg(19);
// pub const fs4: Reg = Reg(20);
// pub const fs5: Reg = Reg(21);
// pub const fs6: Reg = Reg(22);
// pub const fs7: Reg = Reg(23);
// pub const fs8: Reg = Reg(24);
// pub const fs9: Reg = Reg(25);
// pub const fs10: Reg = Reg(26);
// pub const fs11: Reg = Reg(27);
//
// pub const ft8: Reg = Reg(28);
// pub const ft9: Reg = Reg(29);
// pub const ft10: Reg = Reg(30);
// pub const ft11: Reg = Reg(31);