#!/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"INS: {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()