#!/usr/bin/env python2
# -*- coding: utf-8 -*-

# SàT plugin for import external blogs
# Copyright (C) 2009-2017 Jérôme Poisson (goffi@goffi.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.

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

from sat.core.i18n import _, D_
from sat.core.constants import Const as C
from sat.core.log import getLogger
log = getLogger(__name__)
from sat.core import exceptions
from sat.tools.common import data_format
from twisted.internet import threads
from collections import OrderedDict
import itertools
import time
import cgi
import os.path


PLUGIN_INFO = {
    C.PI_NAME: "Dotclear import",
    C.PI_IMPORT_NAME: "IMPORT_DOTCLEAR",
    C.PI_TYPE: C.PLUG_TYPE_BLOG,
    C.PI_DEPENDENCIES: ["BLOG_IMPORT"],
    C.PI_MAIN: "DotclearImport",
    C.PI_HANDLER: "no",
    C.PI_DESCRIPTION: _("""Blog importer for Dotclear blog engine.""")
}

SHORT_DESC = D_(u"import posts from Dotclear blog engine")

LONG_DESC = D_(u"""This importer handle Dotclear blog engine.

To use it, you'll need to export your blog to a flat file.
You must go in your admin interface and select Plugins/Maintenance then Backup.
Export only one blog if you have many, i.e. select "Download database of current blog"
Depending on your configuration, your may need to use Import/Export plugin and export as a flat file.

location: you must use the absolute path to your backup for the location parameter
""")
POST_ID_PREFIX = u"SàT_DOTCLEAR_IMPORT_BLOG"
KNOWN_DATA_TYPES = ('link', 'setting', 'post', 'meta', 'media', 'post_media', 'comment', 'captcha')
ESCAPE_MAP = {
    'r': u'\r',
    'n': u'\n',
    '"': u'"',
    '\\': u'\\',
    }


class DotclearParser(object):
    # XXX: we have to parse all file to build data
    #      this can be ressource intensive on huge blogs

    def __init__(self):
        self.posts_data = OrderedDict()
        self.tags = {}

    def getPostId(self, post):
        """Return a unique and constant post id

        @param post(dict): parsed post data
        @return (unicode): post unique item id
        """
        return u"{}_{}_{}_{}:{}".format(POST_ID_PREFIX, post['blog_id'], post['user_id'], post['post_id'], post['post_url'])

    def getCommentId(self, comment):
        """Return a unique and constant comment id

        @param comment(dict): parsed comment
        @return (unicode): comment unique comment id
        """
        post_id = comment['post_id']
        parent_item_id = self.posts_data[post_id]['blog']['id']
        return u"{}_comment_{}".format(parent_item_id, comment['comment_id'])

    def getTime(self, data, key):
        """Parse time as given by dotclear, with timezone handling

        @param data(dict): dotclear data (post or comment)
        @param key(unicode): key to get (e.g. "post_creadt")
        @return (float): Unix time
        """
        return time.mktime(time.strptime(data[key], "%Y-%m-%d %H:%M:%S"))

    def readFields(self, fields_data):
        buf = []
        idx = 0
        while True:
            if fields_data[idx] != '"':
                raise exceptions.ParsingError
            while True:
                idx += 1
                try:
                    char = fields_data[idx]
                except IndexError:
                    raise exceptions.ParsingError("Data was expected")
                if char == '"':
                    # we have reached the end of this field,
                    # we try to parse a new one
                    yield u''.join(buf)
                    buf = []
                    idx += 1
                    try:
                        separator = fields_data[idx]
                    except IndexError:
                        return
                    if separator != u',':
                        raise exceptions.ParsingError("Field separator was expeceted")
                    idx += 1
                    break # we have a new field
                elif char == u'\\':
                    idx += 1
                    try:
                        char = ESCAPE_MAP[fields_data[idx]]
                    except IndexError:
                        raise exceptions.ParsingError("Escaped char was expected")
                    except KeyError:
                        char = fields_data[idx]
                        log.warning(u"Unknown key to escape: {}".format(char))
                buf.append(char)

    def parseFields(self, headers, data):
        return dict(itertools.izip(headers, self.readFields(data)))

    def postHandler(self, headers, data, index):
        post = self.parseFields(headers, data)
        log.debug(u'({}) post found: {}'.format(index, post['post_title']))
        mb_data = {'id': self.getPostId(post),
                   'published': self.getTime(post, 'post_creadt'),
                   'updated': self.getTime(post, 'post_upddt'),
                   'author': post['user_id'], # there use info are not in the archive
                                              # TODO: option to specify user info
                   'content_xhtml': u"{}{}".format(post['post_content_xhtml'], post['post_excerpt_xhtml']),
                   'title': post['post_title'],
                   'allow_comments': C.boolConst(bool(int(post['post_open_comment']))),
                    }
        self.posts_data[post['post_id']] = {'blog': mb_data, 'comments':[[]], 'url': u'/post/{}'.format(post['post_url'])}

    def metaHandler(self, headers, data, index):
        meta = self.parseFields(headers, data)
        if meta['meta_type'] == 'tag':
            tags = self.tags.setdefault(meta['post_id'], set())
            tags.add(meta['meta_id'])

    def metaFinishedHandler(self):
        for post_id, tags in self.tags.iteritems():
            data_format.iter2dict('tag', tags, self.posts_data[post_id]['blog'])
        del self.tags

    def commentHandler(self, headers, data, index):
        comment = self.parseFields(headers, data)
        if comment['comment_site']:
            # we don't use atom:uri because it's used for jid in XMPP
            content = u'{}\n<hr>\n<a href="{}">author website</a>'.format(
                comment['comment_content'],
                cgi.escape(comment['comment_site']).replace('"', u'%22'))
        else:
            content = comment['comment_content']
        mb_data = {'id': self.getCommentId(comment),
                   'published': self.getTime(comment, 'comment_dt'),
                   'updated': self.getTime(comment, 'comment_upddt'),
                   'author': comment['comment_author'],
                   # we don't keep email addresses to avoid the author to be spammed
                   # (they would be available publicly else)
                   # 'author_email': comment['comment_email'],
                   'content_xhtml': content,
                  }
        self.posts_data[comment['post_id']]['comments'][0].append(
            {'blog': mb_data, 'comments': [[]]})

    def parse(self, db_path):
        with open(db_path) as f:
            signature = f.readline().decode('utf-8')
            try:
                version = signature.split('|')[1]
            except IndexError:
                version = None
            log.debug(u"Dotclear version: {}".format(version))
            data_type = None
            data_headers = None
            index = None
            while True:
                buf = f.readline().decode('utf-8')
                if not buf:
                    break
                if buf.startswith('['):
                    header = buf.split(' ', 1)
                    data_type = header[0][1:]
                    if data_type not in KNOWN_DATA_TYPES:
                        log.warning(u"unkown data type: {}".format(data_type))
                    index = 0
                    try:
                        data_headers = header[1].split(',')
                        # we need to remove the ']' from the last header
                        last_header = data_headers[-1]
                        data_headers[-1] = last_header[:last_header.rfind(']')]
                    except IndexError:
                        log.warning(u"Can't read data)")
                else:
                    if data_type is None:
                        continue
                    buf = buf.strip()
                    if not buf and data_type in KNOWN_DATA_TYPES:
                        try:
                            finished_handler = getattr(self, '{}FinishedHandler'.format(data_type))
                        except AttributeError:
                            pass
                        else:
                            finished_handler()
                        log.debug(u"{} data finished".format(data_type))
                        data_type = None
                        continue
                    assert data_type
                    try:
                        fields_handler = getattr(self, '{}Handler'.format(data_type))
                    except AttributeError:
                        pass
                    else:
                        fields_handler(data_headers, buf, index)
                    index += 1
        return (self.posts_data.itervalues(), len(self.posts_data))


class DotclearImport(object):

    def __init__(self, host):
        log.info(_("plugin Dotclear Import initialization"))
        self.host = host
        host.plugins['BLOG_IMPORT'].register('dotclear', self.DcImport, SHORT_DESC, LONG_DESC)

    def DcImport(self, client, location, options=None):
        if not os.path.isabs(location):
            raise exceptions.DataError(u"An absolute path to backup data need to be given as location")
        dc_parser = DotclearParser()
        d = threads.deferToThread(dc_parser.parse, location)
        return d