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

# Copyright © 2012-2022 Roberto Alsina and others.

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# person obtaining a copy of this software and associated
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# 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.
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# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
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"""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, bytes):
            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)
