from pathlib import Path
from . import about
from . import util
from .download import download


def read_lang_data(package):
    tokenization = package.load_json(('tokenizer', 'specials.json'))
    with package.open(('tokenizer', 'prefix.txt'), default=None) as file_:
        prefix = read_prefix(file_) if file_ is not None else None
    with package.open(('tokenizer', 'suffix.txt'), default=None) as file_:
        suffix = read_suffix(file_) if file_ is not None else None
    with package.open(('tokenizer', 'infix.txt'), default=None) as file_:
        infix = read_infix(file_) if file_ is not None else None
    return tokenization, prefix, suffix, infix


def align_tokens(ref, indices): # Deprecated, surely?
    start = 0
    queue = list(indices)
    for token in ref:
        end = start + len(token)
        emit = []
        while queue and queue[0][1] <= end:
            emit.append(queue.pop(0))
        yield token, emit
        start = end
    assert not queue


def detokenize(token_rules, words): # Deprecated?
    """To align with treebanks, return a list of "chunks", where a chunk is a
    sequence of tokens that are separated by whitespace in actual strings. Each
    chunk should be a tuple of token indices, e.g.

    >>> detokenize(["ca<SEP>n't", '<SEP>!'], ["I", "ca", "n't", "!"])
    [(0,), (1, 2, 3)]
    """
    string = ' '.join(words)
    for subtoks in token_rules:
        # Algorithmically this is dumb, but writing a little list-based match
        # machine? Ain't nobody got time for that.
        string = string.replace(subtoks.replace('<SEP>', ' '), subtoks)
    positions = []
    i = 0
    for chunk in string.split():
        subtoks = chunk.split('<SEP>')
        positions.append(tuple(range(i, i+len(subtoks))))
        i += len(subtoks)
    return positions


def fix_glove_vectors_loading(overrides):
    """Special-case hack for loading the GloVe vectors, to support deprecated
    <1.0 stuff. Phase this out once the data is fixed."""

    if 'data_dir' in overrides and 'path' not in overrides:
        raise ValueError("The argument 'data_dir' has been renamed to 'path'")
    if overrides.get('path') is False:
        return overrides
    if overrides.get('path') in (None, True):
        data_path = util.get_data_path()
    else:
        path = overrides['path']
        if isinstance(path, basestring):
            path = Path(path)
        data_path = path.parent
    vec_path = None
    if 'add_vectors' not in overrides:
        if 'vectors' in overrides:
            vec_path = util.match_best_version(overrides['vectors'], None, data_path)
            if vec_path is None:
                return overrides
        else:
            vec_path = util.match_best_version('en_glove_cc_300_1m_vectors', None, data_path)
        if vec_path is not None:
            vec_path = vec_path / 'vocab' / 'vec.bin'
    if vec_path is not None:
        overrides['add_vectors'] = lambda vocab: vocab.load_vectors_from_bin_loc(vec_path)
    return overrides


class ModelDownload():
    """Replace download modules within en and de with deprecation warning and
    download default language model (using shortcut). Use classmethods to allow
    importing ModelDownload as download and calling download.en() etc."""

    @classmethod
    def load(self, lang):
        util.print_msg(
            "The spacy.{l}.download command is now deprecated. Please use "
            "spacy.download [model name or shortcut] instead. For more "
            "info and available models, see the documentation: {d}. "
            "Downloading default '{l}' model now...".format(d=about.__docs__, l=lang),
            title="Warning: deprecated command")
        download(lang)

    @classmethod
    def en(cls, *args, **kwargs):
        cls.load('en')

    @classmethod
    def de(cls, *args, **kwargs):
        cls.load('de')