import io
import codecs
import csv
"""Copyright 2012-2013
Eindhoven University of Technology
Bogdan Vasilescu

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>."""


'''Based on http://stackoverflow.com/questions/3085263/create-an-utf-8-csv-file-in-python'''


class UTF8Recoder:
    """
    Iterator that reads an encoded stream and reencodes the input to UTF-8
    """

    def __init__(self, f, encoding):
        self.reader = codecs.getreader(encoding)(f)

    def __iter__(self):
        return self

    def __next__(self):
        return next(self.reader)


class UnicodeReader:
    """
    A CSV reader which will iterate over lines in the CSV file "f",
    which is encoded in the given encoding.
    """

    def __init__(self, f, dialect=csv.excel, encoding="utf-8", delimiter=';', **kwds):
        f = UTF8Recoder(f, encoding)
        self.reader = csv.reader(f, delimiter=delimiter, dialect=dialect, **kwds)

    def __next__(self):
        row = next(self.reader)
        return [s for s in row]

    def __iter__(self):
        return self


class UnicodeWriter:
    """
    A CSV writer which will write rows to CSV file "f",
    which is encoded in the given encoding.
    """

    def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds):
        # Redirect output to a queue
        self.queue = io.StringIO()
        self.writer = csv.writer(self.queue, delimiter=';', dialect=dialect, **kwds)
        self.stream = f
        self.encoder = codecs.getincrementalencoder(encoding)()

    def writerow(self, row):
        self.writer.writerow([s.encode("utf-8") for s in row])
        # Fetch UTF-8 output from the queue ...
        data = self.queue.getvalue()
        data = data.decode("utf-8")
        # ... and reencode it into the target encoding
        data = self.encoder.encode(data)
        # write to the target stream
        self.stream.write(data)
        # empty queue
        self.queue.truncate(0)

    def writerows(self, rows):
        for row in rows:
            self.writerow(row)
