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

# Copyright © 2013-2016 Udo Spallek, 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.
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# 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
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# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

"""Post list directive for reStructuredText."""

from __future__ import unicode_literals

import os
import uuid
import natsort

from docutils import nodes
from docutils.parsers.rst import Directive, directives

from nikola import utils
from nikola.plugin_categories import RestExtension

# WARNING: the directive name is post-list
#          (with a DASH instead of an UNDERSCORE)


class Plugin(RestExtension):
    """Plugin for reST post-list directive."""

    name = "rest_post_list"

    def set_site(self, site):
        """Set Nikola site."""
        self.site = site
        self.site.register_shortcode('post-list', _do_post_list)
        directives.register_directive('post-list', PostList)
        PostList.site = site
        return super(Plugin, self).set_site(site)


class PostList(Directive):
    """Provide a reStructuredText directive to create a list of posts.

    Post List
    =========
    :Directive Arguments: None.
    :Directive Options: lang, start, stop, reverse, sort, tags, categories, slugs, post_type, all, template, id
    :Directive Content: None.

    The posts appearing in the list can be filtered by options.
    *List slicing* is provided with the *start*, *stop* and *reverse* options.

    The following not required options are recognized:

    ``start`` : integer
        The index of the first post to show.
        A negative value like ``-3`` will show the *last* three posts in the
        post-list.
        Defaults to None.

    ``stop`` : integer
        The index of the last post to show.
        A value negative value like ``-1`` will show every post, but not the
        *last* in the post-list.
        Defaults to None.

    ``reverse`` : flag
        Reverse the order of the post-list.
        Defaults is to not reverse the order of posts.

    ``sort``: string
        Sort post list by one of each post's attributes, usually ``title`` or a
        custom ``priority``.  Defaults to None (chronological sorting).

    ``tags`` : string [, string...]
        Filter posts to show only posts having at least one of the ``tags``.
        Defaults to None.

    ``categories`` : string [, string...]
        Filter posts to show only posts having one of the ``categories``.
        Defaults to None.

    ``slugs`` : string [, string...]
        Filter posts to show only posts having at least one of the ``slugs``.
        Defaults to None.

    ``post_type`` : string
        Show only ``posts``, ``pages`` or ``all``.
        Replaces ``all``. Defaults to ``posts``.

    ``all`` : flag
        Shows all posts and pages in the post list.
        Defaults to show only posts with set *use_in_feeds*.

    ``lang`` : string
        The language of post *titles* and *links*.
        Defaults to default language.

    ``template`` : string
        The name of an alternative template to render the post-list.
        Defaults to ``post_list_directive.tmpl``

    ``id`` : string
        A manual id for the post list.
        Defaults to a random name composed by 'post_list_' + uuid.uuid4().hex.
    """

    option_spec = {
        'start': int,
        'stop': int,
        'reverse': directives.flag,
        'sort': directives.unchanged,
        'tags': directives.unchanged,
        'categories': directives.unchanged,
        'slugs': directives.unchanged,
        'post_type': directives.unchanged,
        'all': directives.flag,
        'lang': directives.unchanged,
        'template': directives.path,
        'id': directives.unchanged,
    }

    def run(self):
        """Run post-list directive."""
        start = self.options.get('start')
        stop = self.options.get('stop')
        reverse = self.options.get('reverse', False)
        tags = self.options.get('tags')
        tags = [t.strip().lower() for t in tags.split(',')] if tags else []
        categories = self.options.get('categories')
        categories = [c.strip().lower() for c in categories.split(',')] if categories else []
        slugs = self.options.get('slugs')
        slugs = [s.strip() for s in slugs.split(',')] if slugs else []
        post_type = self.options.get('post_type')
        show_all = self.options.get('all', False)
        lang = self.options.get('lang', utils.LocaleBorg().current_lang)
        template = self.options.get('template', 'post_list_directive.tmpl')
        sort = self.options.get('sort')

        output = _do_post_list(start, stop, reverse, tags, categories, slugs, post_type,
                               show_all, lang, template, sort, state=self.state, site=self.site)
        self.state.document.settings.record_dependencies.add("####MAGIC####TIMELINE")
        return [nodes.raw('', output, format='html')]


def _do_post_list(start=None, stop=None, reverse=False, tags=None, categories=None,
                  slugs=None, post_type='post', show_all=False, lang=None,
                  template='post_list_directive.tmpl', sort=None, id=None,
                  data=None, state=None, site=None):
    if lang is None:
        lang = utils.LocaleBorg().current_lang
    if site.invariant:  # for testing purposes
        post_list_id = id or 'post_list_' + 'fixedvaluethatisnotauuid'
    else:
        post_list_id = id or 'post_list_' + uuid.uuid4().hex

    filtered_timeline = []
    posts = []
    step = -1 if reverse is None else None

    # TODO: remove in v8
    if show_all is None:
        timeline = [p for p in site.timeline]
    elif post_type == 'page':
        timeline = [p for p in site.timeline if not p.use_in_feeds]
    elif post_type == 'all':
        timeline = [p for p in site.timeline]
    else:  # post
        timeline = [p for p in site.timeline if p.use_in_feeds]

    # TODO: replaces show_all, uncomment in v8
    # if post_type == 'page':
    #    timeline = [p for p in site.timeline if not p.use_in_feeds]
    # elif post_type == 'all':
    #    timeline = [p for p in site.timeline]
    # else: # post
    #    timeline = [p for p in site.timeline if p.use_in_feeds]

    if categories:
        timeline = [p for p in timeline if p.meta('category', lang=lang).lower() in categories]

    for post in timeline:
        if tags:
            cont = True
            tags_lower = [t.lower() for t in post.tags]
            for tag in tags:
                if tag in tags_lower:
                    cont = False

            if cont:
                continue

        filtered_timeline.append(post)

    if sort:
        filtered_timeline = natsort.natsorted(filtered_timeline, key=lambda post: post.meta[lang][sort], alg=natsort.ns.F | natsort.ns.IC)

    for post in filtered_timeline[start:stop:step]:
        if slugs:
            cont = True
            for slug in slugs:
                if slug == post.meta('slug'):
                    cont = False

            if cont:
                continue

        bp = post.translated_base_path(lang)
        if os.path.exists(bp) and state:
            state.document.settings.record_dependencies.add(bp)

        posts += [post]

    if not posts:
        return []

    template_data = {
        'lang': lang,
        'posts': posts,
        # Need to provide str, not TranslatableSetting (Issue #2104)
        'date_format': site.GLOBAL_CONTEXT.get('date_format')[lang],
        'post_list_id': post_list_id,
        'messages': site.MESSAGES,
    }
    output = site.template_system.render_template(
        template, None, template_data)
    return output
