#
# Copyright 2009 Zuza Software Foundation
#
# This file is part of the Translate Toolkit.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, see <http://www.gnu.org/licenses/>.

"""Manage the OmegaT glossary format

OmegaT glossary format is used by the
`OmegaT <http://www.omegat.org/en/omegat.html>`_ computer aided
translation tool.

It is a bilingual base class derived format with :class:`OmegaTFile`
and :class:`OmegaTUnit` providing file and unit level access.

Format Implementation
    The OmegaT glossary format is a simple Tab Separated Value (TSV) file
    with the columns: source, target, comment.

    The dialect of the TSV files is specified by :class:`OmegaTDialect`.

Encoding
    The files are either UTF-8 or encoded using the system default.  UTF-8
    encoded files use the .utf8 extension while system encoded files use
    the .tab extension.
"""

import csv
import locale

from translate.storage import base


OMEGAT_FIELDNAMES = ["source", "target", "comment"]
"""Field names for an OmegaT glossary unit"""


class OmegaTDialect(csv.Dialect):
    """Describe the properties of an OmegaT generated TAB-delimited glossary
    file.
    """

    delimiter = "\t"
    lineterminator = "\r\n"
    quoting = csv.QUOTE_NONE


csv.register_dialect("omegat", OmegaTDialect)


class OmegaTUnit(base.TranslationUnit):
    """An OmegaT glossary unit"""

    def __init__(self, source=None):
        self._dict = {}
        if source:
            self.source = source
        super().__init__(source)

    def getdict(self):
        """Get the dictionary of values for a OmegaT line"""
        return self._dict

    def setdict(self, newdict):
        """Set the dictionary of values for a OmegaT line

        :param newdict: a new dictionary with OmegaT line elements
        :type newdict: Dict
        """
        # TODO First check that the values are OK
        self._dict = newdict
    dict = property(getdict, setdict)

    def _get_field(self, key):
        if key not in self._dict:
            return None
        elif self._dict[key]:
            return self._dict[key]
        else:
            return ""

    def _set_field(self, key, newvalue):
        if newvalue is None:
            self._dict[key] = None
        if key not in self._dict or newvalue != self._dict[key]:
            self._dict[key] = newvalue

    def getnotes(self, origin=None):
        return self._get_field('comment')

    def addnote(self, text, origin=None, position="append"):
        currentnote = self._get_field('comment')
        if position == "append" and currentnote is not None and currentnote != '':
            self._set_field('comment', currentnote + '\n' + text)
        else:
            self._set_field('comment', text)

    def removenotes(self, origin=None):
        self._set_field('comment', '')

    @property
    def source(self):
        return self._get_field('source')

    @source.setter
    def source(self, source):
        self._rich_source = None
        self._set_field('source', source)

    @property
    def target(self):
        return self._get_field('target')

    @target.setter
    def target(self, target):
        self._rich_target = None
        self._set_field('target', target)

    def settargetlang(self, newlang):
        self._dict['target-lang'] = newlang
    targetlang = property(None, settargetlang)

    def __str__(self):
        return str(self._dict)

    def istranslated(self):
        return bool(self._dict.get('target', None))


class OmegaTFile(base.TranslationStore):
    """An OmegaT glossary file"""

    Name = "OmegaT Glossary"
    Mimetypes = ["application/x-omegat-glossary"]
    Extensions = ["utf8"]
    UnitClass = OmegaTUnit

    def __init__(self, inputfile=None, **kwargs):
        """Construct an OmegaT glossary, optionally reading in from inputfile.
        """
        super().__init__(**kwargs)
        self.filename = ''
        self.extension = ''
        if inputfile is not None:
            self.parse(inputfile)

    def parse(self, input):
        """parsese the given file or file source string"""
        if hasattr(input, 'name'):
            self.filename = input.name
        elif not getattr(self, 'filename', ''):
            self.filename = ''
        if hasattr(input, "read"):
            tmsrc = input.read()
            input.close()
            input = tmsrc
        try:
            input = input.decode(self.encoding)
        except Exception:
            raise ValueError("OmegaT files are either UTF-8 encoded or use the default system encoding")
        lines = csv.DictReader(input.split("\n"), fieldnames=OMEGAT_FIELDNAMES,
                               dialect="omegat")
        for line in lines:
            newunit = OmegaTUnit()
            newunit.dict = line
            self.addunit(newunit)

    def serialize(self, out):
        # Check first if there is at least one translated unit
        translated_units = [u for u in self.units if u.istranslated()]
        if not translated_units:
            return

        output = csv.StringIO()
        writer = csv.DictWriter(output, fieldnames=OMEGAT_FIELDNAMES, dialect="omegat")
        for unit in translated_units:
            writer.writerow(unit.dict)
        out.write(output.getvalue().encode(self.encoding))


class OmegaTFileTab(OmegaTFile):
    """An OmegaT glossary file in the default system encoding"""

    Name = "OmegaT Glossary"
    Mimetypes = ["application/x-omegat-glossary"]
    Extensions = ["tab"]

    @property
    def encoding(self):
        return locale.getdefaultlocale()[1]
