import operator

from folkugat_web.config import search as config
from folkugat_web.utils import groupby


def get_all_ngrams(text):
    return [(m, text[i:i+m])
            for m in range(config.MIN_NGRAM_LENGTH, len(text) + 1)
            for i in range(len(text) - m + 1)
            if m > 0]

def get_text_ngrams(*texts):
    texts = [word.lower() for text in texts for word in text.split()]
    word_ngrams = [ngram for ngrams in map(get_all_ngrams, texts) for ngram in ngrams]
    result = dict(groupby(word_ngrams,
                          key_fn=operator.itemgetter(0),
                          group_fn=lambda gr: list(set(map(operator.itemgetter(1), gr)))))
    return result