#
# Copyright (C) 2001-2016 NLTK Project
# Author: Masato Hagiwara <hagisan@gmail.com>
# URL: <http://nltk.org/>
# For license information, see LICENSE.TXT

# For more information, see http://lilyx.net/pages/nltkjapanesecorpus.html
from __future__ import print_function

import sys

from nltk.corpus.reader import util

from nltk import compat
from nltk.corpus.reader.util import *
from nltk.corpus.reader.api import *

class ChasenCorpusReader(CorpusReader):

    def __init__(self, root, fileids, encoding='utf8', sent_splitter=None):
        self._sent_splitter = sent_splitter
        CorpusReader.__init__(self, root, fileids, encoding)

    def raw(self, fileids=None):
        if fileids is None: fileids = self._fileids
        elif isinstance(fileids, compat.string_types): fileids = [fileids]
        return concat([self.open(f).read() for f in fileids])

    def words(self, fileids=None):
        return concat([ChasenCorpusView(fileid, enc,
                                        False, False, False, self._sent_splitter)
            for (fileid, enc) in self.abspaths(fileids, True)])

    def tagged_words(self, fileids=None):
        return concat([ChasenCorpusView(fileid, enc,
                                        True, False, False, self._sent_splitter)
            for (fileid, enc) in self.abspaths(fileids, True)])

    def sents(self, fileids=None):
        return concat([ChasenCorpusView(fileid, enc,
                                        False, True, False, self._sent_splitter)
            for (fileid, enc) in self.abspaths(fileids, True)])

    def tagged_sents(self, fileids=None):
        return concat([ChasenCorpusView(fileid, enc,
                                        True, True, False, self._sent_splitter)
            for (fileid, enc) in self.abspaths(fileids, True)])

    def paras(self, fileids=None):
        return concat([ChasenCorpusView(fileid, enc,
                                        False, True, True, self._sent_splitter)
            for (fileid, enc) in self.abspaths(fileids, True)])

    def tagged_paras(self, fileids=None):
        return concat([ChasenCorpusView(fileid, enc,
                                        True, True, True, self._sent_splitter)
            for (fileid, enc) in self.abspaths(fileids, True)])


class ChasenCorpusView(StreamBackedCorpusView):
    """
    A specialized corpus view for ChasenReader. Similar to ``TaggedCorpusView``,
    but this'll use fixed sets of word and sentence tokenizer.
    """

    def __init__(self, corpus_file, encoding,
                 tagged, group_by_sent, group_by_para, sent_splitter=None):
        self._tagged = tagged
        self._group_by_sent = group_by_sent
        self._group_by_para = group_by_para
        self._sent_splitter = sent_splitter
        StreamBackedCorpusView.__init__(self, corpus_file, encoding=encoding)


    def read_block(self, stream):
        """Reads one paragraph at a time."""
        block = []
        for para_str in read_regexp_block(stream, r".", r"^EOS\n"):

            para = []

            sent = []
            for line in para_str.splitlines():

                _eos = line.strip() == 'EOS'
                _cells = line.split('\t')
                w = (_cells[0], '\t'.join(_cells[1:]))
                if not _eos: sent.append(w)

                if _eos or (self._sent_splitter and self._sent_splitter(w)):
                    if not self._tagged:
                        sent = [w for (w,t) in sent]
                    if self._group_by_sent:
                        para.append(sent)
                    else:
                        para.extend(sent)
                    sent = []

            if len(sent)>0:
                if not self._tagged:
                    sent = [w for (w,t) in sent]

                if self._group_by_sent:
                    para.append(sent)
                else:
                    para.extend(sent)

            if self._group_by_para:
                block.append(para)
            else:
                block.extend(para)

        return block

def demo():

    import nltk
    from nltk.corpus.util import LazyCorpusLoader

    jeita = LazyCorpusLoader(
        'jeita', ChasenCorpusReader, r'.*chasen', encoding='utf-8')
    print('/'.join( jeita.words()[22100:22140] ))


    print('\nEOS\n'.join('\n'.join("%s/%s" % (w[0],w[1].split('\t')[2]) for w in sent)
                          for sent in jeita.tagged_sents()[2170:2173]))

def test():

    from nltk.corpus.util import LazyCorpusLoader

    jeita = LazyCorpusLoader(
        'jeita', ChasenCorpusReader, r'.*chasen', encoding='utf-8')

    assert isinstance(jeita.tagged_words()[0][1], compat.string_types)

if __name__ == '__main__':
    demo()
    test()
