from datasets import Dataset


def only_nan(input:list) -> bool:
    #remove nans and whitespaces
    c_input = [e for e in input if e==e and e!=" "]
    if len(c_input) > 0:
        return False
    else:
        return True

def shard_ds(ds:Dataset, size=1000) -> list[Dataset]:
    if len(ds) < 1000:
        ds_list = [ds]
    else:
        ds_list = []
        n_s = round(len(ds)/size)
        indices = [i for i in range(n_s)]
        for i in indices:
            data_shard = ds.shard(num_shards=n_s, index = i)
            ds_list.append(data_shard)
    
    return ds_list


def word_tokenize(text: str) -> list[str]:
    """
    Tokenizes a string into words, splitting on whitespace and punctuation.
    Example:
        >>> word_tokenize("Hello, world!")
        ['Hello', ',', 'world', '!']
        >>> word_tokenize("This is a test.")
        ['This', 'is', 'a', 'test', '.']
        >>> word_tokenize("Many spaces    between words.")
        ['Many', 'spaces', 'between', 'words', '.']
    """

    punkt = [",", ".", "!", "?", ":", ";", "(", ")", "[", "]", "{", "}", '"', "'"]
    for p in punkt:
        text = text.replace(p, f" {p} ")
    t = text.split()
    return t 

def remove_punkt_and_numbers(tokens:list[str]) -> list[str]:
    punkt = [",", ".", "!", "?", ":", ";", "(", ")", "[", "]", "{", "}", '"', "'"]
    tokens = [i.lower() for i in tokens if i not in punkt and i.isalpha()]
    return tokens


def count_tokens_and_words(page:Dataset,colname:str,wordlist:list[str])-> Dataset:
    """returns all token count including numbers and punctuation,
    as well as relation of dictionary items to all tokens (measures general quality),
    and relation of dictionary items to only alphabetic words (measures difference between ocr methods)
    """ 

    toks = word_tokenize(page[colname])
    a_toks = remove_punkt_and_numbers(toks)
    t_length = len(toks)

    punkt = [",", ".", "!", "?", ":", ";", "(", ")", "[", "]", "{", "}", '"', "'"]
    t_punkt = [i for i in toks if i in punkt]
    n_punkt = len(t_punkt)

    word_c = [i for i in a_toks if i in wordlist]
    if len(a_toks) == 0:
        wc_rel = 0.0
        wc_a_rel = 0.0
    else:
        wc_rel = round(len(word_c)/len(toks),4)
        wc_a_rel = round(len(word_c)/len(a_toks),4)

    t_name = colname + "_n_tokens"
    wc_name = colname + "_rel_words"
    wc_a_name = colname + "_rel_a_words"
    p_t_name = colname + "_punkt_tokens"
    a_t_name = colname + "_a_tokens"

    page.update({t_name:t_length,
                 wc_name:wc_rel,
                 wc_a_name:wc_a_rel,
                 p_t_name:n_punkt,
                 a_t_name:len(a_toks)})
    
    return page


def make_year_list(start_year: int, stop_year: int) -> list[str]:
    """make a list of file names based on years"""
    year_list = list(range(start_year, stop_year + 1))
    year_list = [str(i) for i in year_list]
    return year_list