use std::str::FromStr;
use crate::vm::{
    syn::ast::*,
    reg::*,
    inst::Inst,
};

grammar;

LabelDef: String = {
    <Label> ":" => <>
}

Value: Value = {
    <Label> => Value::Label(<>),
    <Number> => Value::Number(<>),
}

Label: String = {
    "[a-zA-Z]+" => String::from(<>),
}

Number: u64 = {
    <s:r"\$[0-9]+"> => u64::from_str(s).unwrap(),
    <s:r"\$0x[0-9a-fA-F]+"> => u64::from_str_radix(s, 16).unwrap()
}

Reg: Reg = {
    "%ip" => IP,
    "%sp" => SP,
    "%fp" => FP,
    "%flags" => FLAGS,
    "%status" => STATUS,
    "%r[0-9]{2}" => {
        let offset = (&<>[2..]).parse::<u8>().unwrap();
        let reg = R00 + offset;
        assert!(reg < LAST_REG, "invalid register");
        reg
    }
}

Inst: Inst = {
    "add" <d:Reg> "," <s:Reg> => Inst::Add(d, s),
    "mul" <d:Reg> "," <s:Reg> => Inst::Mul(d, s),
    "div" <d:Reg> "," <s:Reg> =>Inst::Div(d, s),
    "mod" <d:Reg> "," <s:Reg> => Inst::Mod(d, s),
    "ineg" <d:Reg> => Inst::INeg(d),
    "and" <d:Reg> "," <s:Reg> => Inst::And(d, s),
    "or" <d:Reg> "," <s:Reg> => Inst::Or(d, s),
    "xor" <d:Reg> "," <s:Reg> => Inst::Xor(d, s),
    "shl" <d:Reg> "," <s:Reg> => Inst::Shl(d, s),
    "shr" <d:Reg> "," <s:Reg> => Inst::Shr(d, s),
    "cmpeq" <d:Reg> "," <s:Reg> => Inst::CmpEq(d, s),
    "cmplt" <d:Reg> "," <s:Reg> => Inst::CmpLt(d, s),
    "jz" <d:Reg> => Inst::Jz(d),
    "jnz" <d:Reg> => Inst::Jnz(d),
    "load" <d:Reg> "," <s:Reg> => Inst::Load(d, s),
    "store" <d:Reg> "," <s:Reg> => Inst::Store(d, s),
    "storeimm" <d:Reg> "," <s:Number> => {
        if s > u32::max_value() as u64 {
            eprintln!("WARNING: number {} is too large. It will be truncated to 32 bits.", s);
        }
        Inst::StoreImm(d, (s & 0xFFFF_FFFF) as u32)
    },
    "memcopy" <d:Reg> "," <s:Reg> => Inst::MemCopy(d, s),
    "regcopy" <d:Reg> "," <s:Reg> => Inst::RegCopy(d, s),
    "nop" => Inst::Nop,
    "halt" => Inst::Halt,
}

Directive: Directive = {
    ".section" <s:Label> => Directive::Section(s.to_string()),
}

pub Line: Line = {
    <Directive> => Line::Directive(<>),
    <Inst> => Line::Inst(<>),
    <LabelDef> => Line::LabelDef(<>),
}