#!/bin/env python
# -*- coding: utf-8 -*-
# Copyright (C) 2022  Iván Alejandro Ávalos Díaz <avalos@disroot.org>
#                     Edgar Alexis López Martínez <edgarmlmp@gmail.com>
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
from enum import Enum
from tabla import LexToken, TablaLex, tokens
from shared import Control
from pprint import pprint
from errors import Error
from typing import NoReturn
from more_itertools import seekable

from nanoiter import NanoIter
from tabla import TablaLex, Token
from errors import Error

class BaseParser:
    def __init__(self, iterador: NanoIter):
        self.iterador: NanoIter = iterador

    def want(self, *want: Token) -> (LexToken | Error):
        '''Requires the next token to have a matching ltok. Returns
        that token, or an error.

        '''
        tok: LexToken = self.lex()
        if len(want) == 0:
            return tok
        for w in want:
            if tok.tipo == w:
                return tok

        return Error.syntax(tok.tipo, want, tok.numlinea)

    def _try(self, *want: Token) -> (LexToken | NoReturn):
        '''Looks for a matching ltok from the lexer, and if not
        present, unlexes the token and returns void. If found, the
        token is consumed from the lexer and is returned.

        '''
        tok: LexToken = self.lex()
        if len(want) == 0:
            return tok
        for w in want:
            if tok.tipo == w:
                return tok
        self.unlex()

    def peek(self, *want: Token) -> (LexToken | NoReturn):
        '''Looks for a matching ltok from the lexer, unlexes the
        token, and returns it; or void if it was not an ltok.

        '''
        tok: LexToken = self.iterador.peek()
        if len(want) == 0:
            return tok
        for w in want:
            if tok.tipo == w:
                return tok

    def lex(self):
        return self.iterador.next()

    def unlex(self):
        self.iterador.back()

    def synassert(self, cond: bool, msg: str, numlinea: int) -> (Error | NoReturn):
        '''Returns a syntax error if cond is false and void
        otherwise.

        '''
        if not cond:
            return Error(msg = msg, numlinea = numlinea)