#!/usr/bin/env python3

import sys

import ply.yacc as yacc
from ply.lex import LexToken

# Get the token map from the lexer.  This is required.
from lexer import tokens

# Error rule for syntax errors


def p_error(p: LexToken):
    if p:
        print(f"Unexpected {repr(p.value)} on line {p.lineno}")
    else:
        print("Unexpected end of file.")


def p_program(p):
    """program : instruction_list
               | empty
    """
    pass


def p_empty(p):
    """empty :"""
    pass


def p_inss(p):
    """instruction_list : instruction_list line
                        | line
    """
    if len(p) == 2:
        p[0] = [p[1]]
    else:
        p[0] = p[1] + [p[2]]

    # print(f"INSes: {len(p)}")
    # print(f"    {p[1]}")
    # if len(p) > 2:
    #     print(f"    {p[2]}")
    pass


def p_inss2(p):
    """instruction_list2 : line instruction_list2
                         | line
    """
    if len(p) == 2:
        p[0] = [p[1]]
    else:
        p[0] = [p[1]] + p[2]

    print(f"INSes2: {len(p)}")
    print(f"    {p[1]}")
    if len(p) > 2:
        print(f"    {p[2]}")
    pass


def p_line(p):
    """line : instruction NL
            | NL
    """
    if len(p) == 2:
        pass
    else:
        p[0] = p[1]


def p_instruction(p):
    """instruction : noarg
                   | onearg
                   | twoarg
                   | jumpdest
                   | invalid_arg
    """
    print(f"Item: {p[1]}")
    p[0] = p[1]
    pass


def p_jumpdest(p):
    """jumpdest : SYMBOL COLON"""
    p[0] = (p[1],)


def p_twoarg(p):
    """twoarg : op REG COMMA argument COMMA argument"""
    p[0] = (*p[1], p[2], p[4], p[6])
    pass


def p_argument(p):
    """argument : number
                | REG
                | SYMBOL
    """
    pass


def p_onearg(p):
    """onearg : op REG COMMA argument"""
    p[0] = (*p[1], p[2], p[4], None)
    pass


def p_noarg(p):
    """noarg : op"""
    p[0] = (*p[1], None, None, None)
    pass


def p_invalid_arg(p):
    """invalid_arg : op argument"""
    print(f"Invalid opcode, destination missing: {p[1:]}")
    sys.exit(1)
    pass


def p_op(p):
    """op : OP DOT JUMP
          | OP
    """
    if len(p) == 2:
        p[0] = (p[1], None)
    else:
        p[0] = (p[1], p[3])


def p_number(p):
    """number : NUMBER
              | HEXNUMBER
    """
    p[0] = p[1]


parser = yacc.yacc()