use crate::data::{
    literal::DebugMsg, literal::Label,
    literal::RoutineName,
    Rd,
    Wr,
};
use crate::instr::Cond;

/// A higher level simple opration
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum HLOp {
    /// Mark a jump target.
    Label(Label),
    /// Jump to a label
    Jump(Label),
    /// Jump to a label if a flag is set
    JumpIf(Cond, Label),
    /// Low level op
    L(Op),
}

/// A low level instruction
#[derive(Clone, Debug, Eq, PartialEq)]
pub enum Op {
    /// Do nothing
    Nop,
    /// Mark a far jump target (can be jumped to from another routine).
    /// This label is preserved in optimized code.
    FarLabel(Label),
    /// Jump to a label that can be in another function
    FarJump(Label),
    /// Call a routine with arguments.
    /// The arguments are passed as argX. Return values are stored in resX registers.
    Call(RoutineName, Vec<Rd>),
    /// Exit the current routine with return values
    Ret(Vec<Rd>),
    /// Mark a routine entry point (call target).
    /// Kept in the low level instruction file for position-independent code
    Routine(RoutineName),
    /// Skip backward or forward
    Skip(Rd),
    /// Skip if a flag is set
    SkipIf(Cond, Rd),
    /// Deny jumps, skips and run across this address, producing a run-time fault with a message.
    Barrier(Option<DebugMsg>),
    /// Generate a run-time fault with a debugger message
    Fault(Option<DebugMsg>),

    Move { dst: Wr, src: Rd },
    Test { a: Rd },
    Compare { a: Rd, b: Rd },
    StoreStatus { dst: Wr },
    LoadStatus { src: Rd },

    Add { dst: Wr, a: Rd, b: Rd },
    Sub { dst: Wr, a: Rd, b: Rd },
    Mul { dst: Wr, a: Rd, b: Rd },
    Div { dst: Wr, rem: Wr, a: Rd, div: Rd },
    // "Mod" is functionally equivalent to "Div" with the result discarded,
    // but status flags are updated by the remainder
    Mod { dst: Wr, a: Rd, div: Rd },

    And { dst: Wr, a: Rd, b: Rd },
    Or { dst: Wr, a: Rd, b: Rd },
    Xor { dst: Wr, a: Rd, b: Rd },
    Cpl { dst: Wr, a: Rd },
    Rol { dst: Wr, a: Rd, n: Rd },
    // Rotate (with wrap-around)
    Ror { dst: Wr, a: Rd, n: Rd },
    Lsl { dst: Wr, a: Rd, n: Rd },
    // Shift
    Lsr { dst: Wr, a: Rd, n: Rd },
    Asr { dst: Wr, a: Rd, n: Rd },
}

/// Make "into" work
impl From<Op> for HLOp {
    fn from(op: Op) -> Self {
        HLOp::L(op)
    }
}