#!/usr/bin/python
# 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/>.


import cliapp
import os
import re
import shutil
import string
import time


__version__ = '0.5'


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


class Command(object):

    def __init__(self, app):
        self._app = app

    def run(self, args):
        raise NotImplementedError()


class NewCommand(Command):

    _default_new_note_template = '''\
[[!meta title="%(title)s"]]
[[!tag ]]
[[!meta date="%(date)s"]]
%(topiclink)s

'''

    def run(self, args):
        self._check_args_and_settings(args)

        topic = self._app.settings['topic']
        values = {
            'title': args[0],
            'date': time.strftime('%Y-%m-%d %H:%M', self._app.now_tuple),
            'topiclink': self._get_topic_link(topic),
        }

        drafts_dir = DraftsDirectory(self._app.drafts_dir())
        drafts_dir.create_if_missing()
        draft_id = drafts_dir.create_draft(
            self._get_new_note_template() % values)
        self._app.edit_file(drafts_dir.get_draft_pathname(draft_id))

    def _check_args_and_settings(self, args):
        if not args:
            raise cliapp.AppException('Usage: journal-note new TITLE')

        self._app.settings.require('source')
        topic = self._app.settings['topic']
        if topic and not self._topic_page_exists(topic):
            raise cliapp.AppException('Topic %s does not exist yet' % topic)

    def _topic_page_exists(self, topic):
        pathname = os.path.join(self._app.settings['source'], topic + '.mdwn')
        return os.path.exists(pathname)

    def _get_topic_link(self, topic):
        if topic:
            return '[[!meta link="%s"]]' % topic
        else:
            return ''

    def _get_new_note_template(self):
        filename = self._app.settings['new-note-template']
        if filename:
            with open(filename) as f:
                return f.read()
        else:
            return self._default_new_note_template


class ListCommand(Command):

    def run(self, args):
        drafts_dir = DraftsDirectory(self._app.drafts_dir())
        for draft_id, _ in drafts_dir.get_drafts():
            print draft_id, drafts_dir.get_draft_title(draft_id)


class EditCommand(Command):

    def run(self, args):
        if len(args) > 1:
            raise cliapp.AppException('Must be given at most one draft ID')
        drafts_dir = DraftsDirectory(self._app.drafts_dir())
        _, pathname = self._app.choose_draft(drafts_dir, args)
        self._app.edit_file(pathname)


class AttachCommand(Command):

    def run(self, args):
        if len(args) < 2:
            raise cliapp.AppException('Usage: journal-note attach ID file...')

        drafts_dir = DraftsDirectory(self._app.draft_dir())
        dirname = drafts_dir.get_draft_attachments_dirname(args[0])
        if not os.path.exists(dirname):
            os.mkdir(dirname)
        for filename in args[1:]:
            shutil.copy(filename, dirname)


class RemoveCommand(Command):

    def run(self, args):
        if not args:
            raise cliapp.AppException('Usage: journal-note remove ID')
        drafts_dir = DraftsDirectory(self._app.drafts_dir())
        drafts_dir.remove_draft(args[0])


class FinishCommand(Command):

    def run(self, args):
        drafts_dir = DraftsDirectory(self._app.drafts_dir())

        draft_id, draft_mdwn = self._app.choose_draft(drafts_dir, args)
        draft_attch = drafts_dir.get_draft_attachments_dirname(draft_id)

        title = drafts_dir.get_draft_title(draft_id)
        if not title:
            raise Exception("%s has no title" % draft_mdwn)

        pub_attch = os.path.join(
            self._published_dir(),
            self._summarise_title(title))
        pub_mdwn = pub_attch + '.mdwn'

        if os.path.exists(pub_mdwn):
            raise cliapp.AppException('%s already exists' % pub_mdwn)

        self._publish_draft(draft_mdwn, draft_attch, pub_mdwn, pub_attch)

        if self._app.settings['git']:
            if os.path.exists(pub_attch):
                self._commit_to_git([pub_mdwn, pub_attch])
            else:
                self._commit_to_git([pub_mdwn])
            if self._app.settings['push']:
                self._push_git()

    def _published_dir(self):
        subdir = time.strftime('notes/%Y/%m/%d', self._app.now_tuple)
        return os.path.join(self._app.settings['source'], subdir)

    def _summarise_title(self, title):
        basename = ''
        acceptable = set(string.ascii_letters + string.digits + '-_')
        for c in title.lower():
            if c in acceptable:
                basename += c
            elif not basename.endswith('_'):
                basename += '_'
        return basename

    def _publish_draft(self, draft_mdwn, draft_attch, pub_mdwn, pub_attch):
        parent_dir = os.path.dirname(pub_mdwn)
        if not os.path.exists(parent_dir):
            os.makedirs(parent_dir)
        os.rename(draft_mdwn, pub_mdwn)
        if os.path.exists(draft_attch):
            os.rename(draft_attch, pub_attch)

    def _commit_to_git(self, pathnames):
        cliapp.runcmd(
            ['git', 'add'] + pathnames,
            cwd=self._app.settings['source'])

        cliapp.runcmd(
            ['git', 'commit', '-m', 'Publish log entry'],
            cwd=self._app.settings['source'])

    def _push_git(self):
        cliapp.runcmd(
            ['git', 'push', 'origin', 'HEAD'],
            cwd=self._app.settings['source'])


class NewTopicCommand(Command):

    def run(self, args):
        if len(args) != 2:
            raise cliapp.AppException(
                'Must be given two args (page path, title) (%r)' % args)

        pathname = self._topic_pathname(args[0])
        self._create_topic_page(pathname, args[1])
        self._app.edit_file(pathname)

    def _topic_pathname(self, page_path):
        return os.path.join(self._app.settings['source'], page_path + '.mdwn')

    def _create_topic_page(self, pathname, title):
        dirname = os.path.dirname(pathname)
        if not os.path.exists(dirname):
            os.makedirs(dirname)

            template = '''\
[[!meta title="%(title)s"]]
[[!inline pages="link(.)" archive=yes reverse=yes trail=yes]]
'''

        with open(pathname, 'w') as f:
            f.write(template % {'title': title})


class NewPersonCommand(Command):

    def run(self, args):
        if len(args) != 1:
            raise cliapp.AppException(
                'Need the name of a person (in Last, First form)')

        def normalise(name):
            s = name.lower()
            s = ' '.join(s.split(','))
            s = '.'.join(s.split())
            return s

        name = args[0]
        basename = normalise(name)
        pathname = os.path.join(
            self._app.settings['source'], 'people', basename + '.mdwn')

        if os.path.exists(pathname):
            raise cliapp.AppException('File %s already exists' % pathname)

        template = '''\
[[!meta title="%(name)s"]]

[[!inline archive=yes pages="link(.)"]]
'''

        with open(pathname, 'w') as f:
            f.write(
                template %
                {
                    'name': name,
                    'basename': basename,
                })


class JournalTool(cliapp.Application):

    cmd_synopsis = {
        'attach': 'DRAFT-ID [FILE]...',
        'edit': '[DRAFT-ID]',
        'finish': '[DRAFT-ID]',
        'list': '',
        'new': 'TITLE',
        'remove': 'DRAFT-ID',
        }

    def add_settings(self):
        self.settings.string(
            ['source'],
            'use journal source tree in DIR',
            metavar='DIR')

        self.settings.boolean(
            ['git'],
            'add entries to git automatically',
            default=True)

        self.settings.string(
            ['editor'],
            'editor to launch for journal entries. Must include %s to '
            'indicate where the filename goes',
            default='sensible-editor %s')

        self.settings.boolean(
            ['push'],
            'push finished articles with git?')

        self.settings.string(
            ['topic'],
            'new entry belongs to TOPIC',
            metavar='TOPIC')

        self.settings.string(
            ['new-note-template'],
            'use FILE as the template for new journal notes',
            metavar='FILE')

        self.settings.string(
            ['pretend-time'],
            'pretend that the time is NOW (form: YYYY-MM-DD HH:MM:DD form)',
            metavar='NOW')

    def process_args(self, args):
        if self.settings['pretend-time']:
            self.now_tuple = time.strptime(
                self.settings['pretend-time'], '%Y-%m-%d %H:%M:%S')
        else:
            self.now_tuple = time.localtime()
        cliapp.Application.process_args(self, args)

    def cmd_new(self, args):
        '''Create a new journal entry draft.'''
        NewCommand(self).run(args)

    def cmd_list(self, args):
        '''List journal entry drafts.'''
        ListCommand(self).run(args)

    def cmd_edit(self, args):
        '''Edit a draft journal entry.'''
        EditCommand(self).run(args)

    def cmd_attach(self, args):
        '''Attach files to a journal entry draft.'''
        AttachCommand(self).run(args)

    def cmd_remove(self, args):
        '''Remove a draft.'''
        RemoveCommand(self).run(args)

    def cmd_finish(self, args):
        '''Publish a draft journal entry.'''
        FinishCommand(self).run(args)

    def cmd_new_topic(self, args):
        '''Create a new topic page.'''
        NewTopicCommand(self).run(args)

    def cmd_new_person(self, args):
        '''Create a page to list all notes referring to a person.

        This is probably only useful to Lars's personal journal.

        '''

        NewPersonCommand(self).run(args)

    def drafts_dir(self):
        return os.path.join(self.settings['source'], 'drafts')

    def edit_file(self, pathname):
        safe_pathname = cliapp.shell_quote(pathname)
        cmdline = ['sh', '-c', self.settings['editor'] % safe_pathname]
        self.runcmd(cmdline, stdin=None, stdout=None, stderr=None)

    def choose_draft(self, drafts_dir, args):
        if len(args) == 0:
            drafts = list(drafts_dir.get_drafts())
            if len(drafts) == 1:
                draft_id, filename = drafts[0]
                return draft_id, filename
            elif len(drafts) == 0:
                raise cliapp.AppException('No drafts to choose from')
            else:
                raise cliapp.AppException(
                    'Cannot choose entry draft automatically')
        elif len(args) == 1:
            pathname = drafts_dir.get_draft_pathname(args[0])
            if not os.path.exists(pathname):
                raise cliapp.AppException('draft %s does not exist' % args[0])
            return args[0], pathname
        elif len(args) > 1:
            raise cliapp.AppException('Must give at most one draft number')


JournalTool(version=__version__).run()