use std::fmt::Debug;

use dyn_clonable::*;
use sexp::Sexp;

use crate::asm::data::{
    literal::DebugMsg, literal::Label,
    literal::RoutineName,
    Rd,
    Wr,
};
use crate::asm::error::Error;
use crate::asm::instr::Cond;
use crate::runtime::fault::Fault;
use crate::runtime::frame::{CallStack, StackFrame};
use crate::runtime::program::Program;
use crate::asm::parse::arg_parser::ArgParser;

/// A higher level simple opration
#[derive(Clone, Debug)]
pub enum OpWrapper {
    /// 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
    Op(Op),
}

/// A low level instruction
#[derive(Clone, Debug)]
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>),
    /// Copy value
    Move { dst: Wr, src: Rd },
    /// Store runtime status to a register
    StoreStatus { dst: Wr },
    /// Load runtime status from a register
    LoadStatus { src: Rd },

    Extension(Box<dyn OpTrait>),
}

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

#[clonable]
pub trait OpTrait: Clone + Debug + Send + 'static {
    fn execute(&self, program: &Program, call_stack: &mut CallStack, frame: &mut StackFrame) -> Result<(), Fault>;
}

pub enum ParseOpResult {
    Parsed(Box<dyn OpTrait>),
    Unknown(ArgParser),
}

#[clonable]
pub trait AsmModule: Clone + Debug + Send + 'static {
    /// Get name of the module
    fn name(&self) -> &'static str;

    /// Parse an op.
    /// If the keyword matches and the function decides to parse the instruction, it must consume
    /// the argument list and either return Ok or Err.
    ///
    /// If the instruction keyword is not recognized, return Unknown with the unchanged argument list.
    fn parse_op(&self, keyword: &str, arg_tokens: ArgParser) -> Result<ParseOpResult, Error>;
}