# Copyright 2010-2015  Lars Wirzenius
#
# 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 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 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/>.
#
# =*= License: GPL-3+ =*=


import os
import re


class DraftsDirectory(object):

    def __init__(self, dirname):
        self.dirname = dirname

    def create_if_missing(self):
        if not os.path.exists(self.dirname):
            os.mkdir(self.dirname)

    def get_draft_pathname(self, draft_id):
        return os.path.join(self.dirname, '%s.mdwn' % draft_id)

    def get_draft_attachments_dirname(self, draft_id):
        return os.path.join(self.dirname, '%s' % draft_id)

    def create_draft(self, content):
        draft_id = self._pick_available_draft_id()
        pathname = self.get_draft_pathname(draft_id)
        with open(pathname, 'w') as f:
            f.write(content)
        return draft_id

    def _pick_available_draft_id(self):
        for i in range(1000):
            pathname = self.get_draft_pathname(i)
            if not os.path.exists(pathname):
                return i
        raise cliapp.AppException('ERROR: too many existing drafts')

    def get_drafts(self):
        for basename in os.listdir(self.dirname):
            # .# is what Emacs autosave files start with.
            if basename.endswith('.mdwn') and not basename.startswith('.#'):
                suffixless = basename[:-len('.mdwn')]
                pathname = os.path.join(self.dirname, basename)
                yield suffixless, pathname

    def remove_draft(self, draft_id):
        filename = self.get_draft_pathname(draft_id)
        os.remove(filename)

        dirname = self.get_draft_attachments_dirname(draft_id)
        if os.path.exists(dirname):
            shutil.rmtree(dirname)

    def get_draft_title(self, draft_id):
        pathname = self.get_draft_pathname(draft_id)
        with open(pathname) as f:
            return self._get_title_from_open_file(f)

    def _get_title_from_open_file(self, f):
        for line in f:
            m = re.match(r'\[\[!meta title="(?P<title>.*)("\]\])$', line)
            if m:
                return m.group('title')
        return None