# -*- coding: utf-8 -*-

"""
This file is for Python 2.7.
And all classes are from `Python Official Document`_.

.. _`Python Official Document`: http://docs.python.org/library/csv.html

More sophisticated implementation is available on "csvkit_" module.

.. _csvkit: http://pypi.python.org/pypi/csvkit
"""

import codecs
import csv

from six import PY3
if PY3:
    import io as cStringIO
else:
    import cStringIO


[docs]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

[docs]    def next(self):
        return self.reader.next().encode("utf-8")


[docs]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", **kwds):
        f = UTF8Recoder(f, encoding)
        self.reader = csv.reader(f, dialect=dialect, **kwds)

[docs]    def next(self):
        row = self.reader.next()
        return [unicode(s, "utf-8") for s in row]

    def __iter__(self):
        return self


[docs]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 = cStringIO.StringIO()
        self.writer = csv.writer(self.queue, dialect=dialect, **kwds)
        self.stream = f
        self.encoder = codecs.getincrementalencoder(encoding)()

[docs]    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)

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

# vim: set et ts=4 sw=4 cindent fileencoding=utf-8 :