import re
import jsgf

class Nlu:
    def __init__(self):
        self.rules_grammar = jsgf.parse_grammar_file('rules.jsgf')
        self.acts = {
            "request": {
                'triggers': ['jak', 'kiedy'],
                'parameters': ['imie']
            }
        }


    def get_slots(self, expansion, slots):
        if expansion.tag != '':
            slots.append((expansion.tag, expansion.current_match))
            return

        for child in expansion.children:
            self.get_slots(child, slots)

        if not expansion.children and isinstance(expansion, jsgf.NamedRuleRef):
            self.get_slots(expansion.referenced_rule.expansion, slots)
    
    def get_dialog_act(self, rule):
        slots = []
        self.get_slots(rule.expansion, slots)
        return {'act': rule.grammar.name, 'slots': slots}


    def tokenize(self, string):
        clean_string = self.get_str_cleaned(string)

        matched = self.rules_grammar.find_matching_rules(clean_string)

        if matched:
            return self.get_dialog_act(matched[0])
        else:
            return {'act': 'null', 'slots': []}


    def get_str_cleaned(self, str_dirty):
        punctuation = '!"#$%&\'()*+,-./:;<=>?@[\\\\]^_`{|}~'
        new_str = str_dirty.lower()
        new_str = re.sub(' +', ' ', new_str)

        for char in punctuation:
            new_str = new_str.replace(char,'')

        return new_str

    def parse(self, message):
        tokens = self.tokenize(message)
        act = None
        param = []

        for k, v in self.acts.items():
            if any(t in v['triggers'] for t in tokens):
                act = k
            
                for t in tokens:
                    if t in v['parameters']:
                        param.append(t)

    # TODO: Refactor


        return (act, param)

nlu = Nlu()
print(nlu.parse('chciałbym kupić bilet do Krakow'))