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

# Copyright © 2012-2020 Roberto Alsina and others.

# Permission is hereby granted, free of charge, to any
# person obtaining a copy of this software and associated
# documentation files (the "Software"), to deal in the
# Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the
# Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice
# shall be included in all copies or substantial portions of
# the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
# PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
# OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
# OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

"""Mixin for importer plugins."""

import io
import csv
import datetime
import os
from urllib.parse import urlparse

from lxml import etree, html
from mako.template import Template
from pkg_resources import resource_filename

from nikola import utils

links = {}


class ImportMixin(object):
    """Mixin with common used methods."""

    name = "import_mixin"
    needs_config = False
    doc_usage = "[options] export_file"
    doc_purpose = "import a dump from a different engine."
    cmd_options = [
        {
            'name': 'output_folder',
            'long': 'output-folder',
            'short': 'o',
            'default': 'new_site',
            'help': 'Location to write imported content.'
        },
    ]

    def _execute(self, options={}, args=[]):
        """Import a blog from an export into a Nikola site."""
        raise NotImplementedError("Must be implemented by a subclass.")

    @classmethod
    def get_channel_from_file(cls, filename):
        """Get channel from XML file."""
        tree = etree.fromstring(cls.read_xml_file(filename))
        channel = tree.find('channel')
        return channel

    @staticmethod
    def configure_redirections(url_map, base_dir=''):
        """Configure redirections from an url_map."""
        index = base_dir + 'index.html'
        if index.startswith('/'):
            index = index[1:]
        redirections = []
        for k, v in url_map.items():
            if not k[-1] == '/':
                k = k + '/'

            # remove the initial "/" because src is a relative file path
            src = (urlparse(k).path + 'index.html')[1:]
            dst = (urlparse(v).path)
            if src == index:
                utils.LOGGER.warning("Can't do a redirect for: {0!r}".format(k))
            else:
                redirections.append((src, dst))
        return redirections

    def generate_base_site(self):
        """Generate a base Nikola site."""
        if not os.path.exists(self.output_folder):
            os.system('nikola init -q ' + self.output_folder)
        else:
            self.import_into_existing_site = True
            utils.LOGGER.warning('The folder {0} already exists - assuming that this is a '
                                 'already existing Nikola site.'.format(self.output_folder))

        filename = resource_filename('nikola', 'conf.py.in')
        # The 'strict_undefined=True' will give the missing symbol name if any,
        # (ex: NameError: 'THEME' is not defined )
        # for other errors from mako/runtime.py, you can add format_extensions=True ,
        # then more info will be writen to *somefile* (most probably conf.py)
        conf_template = Template(filename=filename, strict_undefined=True)

        return conf_template

    @staticmethod
    def populate_context(channel):
        """Populate context with settings."""
        raise NotImplementedError("Must be implemented by a subclass.")

    @classmethod
    def transform_content(cls, content):
        """Transform content to a Nikola-friendly format."""
        return content

    @classmethod
    def write_content(cls, filename, content, rewrite_html=True):
        """Write content to file."""
        if rewrite_html:
            try:
                doc = html.document_fromstring(content)
                doc.rewrite_links(replacer)
                content = html.tostring(doc, encoding='utf8')
            except etree.ParserError:
                content = content.encode('utf-8')
        else:
            content = content.encode('utf-8')

        utils.makedirs(os.path.dirname(filename))
        with open(filename, "wb+") as fd:
            fd.write(content)

    @classmethod
    def write_post(cls, filename, content, headers, compiler, rewrite_html=True):
        """Ask the specified compiler to write the post to disk."""
        if rewrite_html:
            try:
                doc = html.document_fromstring(content)
                doc.rewrite_links(replacer)
                content = html.tostring(doc, encoding='utf8')
            except etree.ParserError:
                pass
        if isinstance(content, utils.bytes_str):
            content = content.decode('utf-8')
        compiler.create_post(
            filename,
            content=content,
            onefile=True,
            **headers)

    def write_metadata(self, filename, title, slug, post_date, description, tags, **kwargs):
        """Write metadata to meta file."""
        if not description:
            description = ""

        utils.makedirs(os.path.dirname(filename))
        with io.open(filename, "w+", encoding="utf8") as fd:
            data = {'title': title, 'slug': slug, 'date': post_date, 'tags': ','.join(tags), 'description': description}
            data.update(kwargs)
            fd.write(utils.write_metadata(data, site=self.site, comment_wrap=False))

    @staticmethod
    def write_urlmap_csv(output_file, url_map):
        """Write urlmap to csv file."""
        utils.makedirs(os.path.dirname(output_file))
        fmode = 'w+'
        with io.open(output_file, fmode) as fd:
            csv_writer = csv.writer(fd)
            for item in url_map.items():
                csv_writer.writerow(item)

    def get_configuration_output_path(self):
        """Get path for the output configuration file."""
        if not self.import_into_existing_site:
            filename = 'conf.py'
        else:
            filename = 'conf.py.{name}-{time}'.format(
                time=datetime.datetime.now().strftime('%Y%m%d_%H%M%S'),
                name=self.name)
        config_output_path = os.path.join(self.output_folder, filename)
        utils.LOGGER.info('Configuration will be written to: {0}'.format(config_output_path))

        return config_output_path

    @staticmethod
    def write_configuration(filename, rendered_template):
        """Write the configuration file."""
        utils.makedirs(os.path.dirname(filename))
        with io.open(filename, 'w+', encoding='utf8') as fd:
            fd.write(rendered_template)


def replacer(dst):
    """Replace links."""
    return links.get(dst, dst)
