from string import punctuation
from collections import Counter
from nltk import bigrams, trigrams, NaiveBayesClassifier, classify
from nltk.corpus import PlaintextCorpusReader, stopwords


def load_corpus(corpus_root):
    '''Tar inn rotmappen av et korpus.
    Returnerer NLTK-korpus.'''
    return PlaintextCorpusReader(corpus_root, '.*\.txt')


def clean_words(words):
    '''Tar inn en liste med token.
    Returnerer listen uten tegnsetting og stoppord'''
    stopwords_nor = stopwords.words('norwegian')
    return [word.lower() for word in words if word not in punctuation and word not in stopwords_nor]


def split_data(pos_feats, neg_feats):
    '''Tar inn lister med hhv. positive og negative trekk.
    Returnerer listene satt sammen og delt inn i train_set, dev_set, test_set.'''
    test_set = pos_feats[:122] + neg_feats[:122]
    dev_set = pos_feats[122:182] + neg_feats[122:182]
    train_set = pos_feats[182:] + neg_feats[182:]
    
    return train_set, dev_set, test_set




# OPPGAVE 4.2
def feature_extractor_top_1000(document):
    features = {}

    # din kode her...

    return features


# OPPGAVE 4.3.1
def feature_extractor_bow(document):
    features = {}

    # din kode her...
        
    return features


# OPPGAVE 4.3.2
def feature_extractor_bow_bigrams(document):
    features = {}

    # din kode her...
    
    return features


# OPPGAVE 4.3.3
def feature_extractor_bow_bigrams_trigrams(document):
    features = {}

    # din kode her...
    
    return features



def main():
    # OPPGAVE 4.1
    # din kode her...

    # OPPGAVE 4.2
    print('1000 MEST FREKVENTE ORD =========================================')
    # din kode her...

    # svar p? teorisp?rsm?l her...

    # OPPGAVE 4.3.1
    print('\nBAG OF WORDS ==================================================')
    # din kode her...

    # OPPGAVE 4.3.2
    print('\nBAG OF WORDS + BIGRAM =========================================')
    # din kode her...

    # OPPGAVE 4.3.3
    print('\nBAG OF WORDS + BIGRAM + TRIGRAM ===============================')
    # din kode her...

    # OPPGAVE 4.4
    print('\nModellen med ... gir h?yest n?yaktighet p? dev_set.')
    # din kode her...

    # forslag til forbedring her...


if __name__ == '__main__':
    main()