# -*- coding: utf-8 -*-
from __future__ import print_function, unicode_literals

import copy
import locale
import logging
import os
import re
import sys

import pytz

import six
from six.moves.urllib.parse import urlparse, urlunparse

from pelican import signals
from pelican.settings import DEFAULT_CONFIG
from pelican.utils import (SafeDatetime, deprecated_attribute, memoized,
                           path_to_url, posixize_path,
                           python_2_unicode_compatible, sanitised_join,
                           set_date_tzinfo, slugify, strftime,
                           truncate_html_words)

# Import these so that they're avalaible when you import from pelican.contents.
from pelican.urlwrappers import (Author, Category, Tag, URLWrapper)  # NOQA

logger = logging.getLogger(__name__)


@python_2_unicode_compatible
class Content(object):
    """Represents a content.

    :param content: the string to parse, containing the original content.
    :param metadata: the metadata associated to this page (optional).
    :param settings: the settings dictionary (optional).
    :param source_path: The location of the source of this content (if any).
    :param context: The shared context between generators.

    """
    @deprecated_attribute(old='filename', new='source_path', since=(3, 2, 0))
    def filename():
        return None

    def __init__(self, content, metadata=None, settings=None,
                 source_path=None, context=None):
        if metadata is None:
            metadata = {}
        if settings is None:
            settings = copy.deepcopy(DEFAULT_CONFIG)

        self.settings = settings
        self._content = content
        if context is None:
            context = {}
        self._context = context
        self.translations = []

        local_metadata = dict()
        local_metadata.update(metadata)

        # set metadata as attributes
        for key, value in local_metadata.items():
            if key in ('save_as', 'url'):
                key = 'override_' + key
            setattr(self, key.lower(), value)

        # also keep track of the metadata attributes available
        self.metadata = local_metadata

        # default template if it's not defined in page
        self.template = self._get_template()

        # First, read the authors from "authors", if not, fallback to "author"
        # and if not use the settings defined one, if any.
        if not hasattr(self, 'author'):
            if hasattr(self, 'authors'):
                self.author = self.authors[0]
            elif 'AUTHOR' in settings:
                self.author = Author(settings['AUTHOR'], settings)

        if not hasattr(self, 'authors') and hasattr(self, 'author'):
            self.authors = [self.author]

        # XXX Split all the following code into pieces, there is too much here.

        # manage languages
        self.in_default_lang = True
        if 'DEFAULT_LANG' in settings:
            default_lang = settings['DEFAULT_LANG'].lower()
            if not hasattr(self, 'lang'):
                self.lang = default_lang

            self.in_default_lang = (self.lang == default_lang)

        # create the slug if not existing, generate slug according to
        # setting of SLUG_ATTRIBUTE
        if not hasattr(self, 'slug'):
            if (settings['SLUGIFY_SOURCE'] == 'title' and
                    hasattr(self, 'title')):
                self.slug = slugify(self.title,
                                    settings.get('SLUG_SUBSTITUTIONS', ()))
            elif (settings['SLUGIFY_SOURCE'] == 'basename' and
                    source_path is not None):
                basename = os.path.basename(
                    os.path.splitext(source_path)[0])
                self.slug = slugify(
                    basename, settings.get('SLUG_SUBSTITUTIONS', ()))

        self.source_path = source_path

        # manage the date format
        if not hasattr(self, 'date_format'):
            if hasattr(self, 'lang') and self.lang in settings['DATE_FORMATS']:
                self.date_format = settings['DATE_FORMATS'][self.lang]
            else:
                self.date_format = settings['DEFAULT_DATE_FORMAT']

        if isinstance(self.date_format, tuple):
            locale_string = self.date_format[0]
            if sys.version_info < (3, ) and isinstance(locale_string,
                                                       six.text_type):
                locale_string = locale_string.encode('ascii')
            locale.setlocale(locale.LC_ALL, locale_string)
            self.date_format = self.date_format[1]

        # manage timezone
        default_timezone = settings.get('TIMEZONE', 'UTC')
        timezone = getattr(self, 'timezone', default_timezone)

        if hasattr(self, 'date'):
            self.date = set_date_tzinfo(self.date, timezone)
            self.locale_date = strftime(self.date, self.date_format)

        if hasattr(self, 'modified'):
            self.modified = set_date_tzinfo(self.modified, timezone)
            self.locale_modified = strftime(self.modified, self.date_format)

        # manage status
        if not hasattr(self, 'status'):
            self.status = getattr(self, 'default_status', None)

        # store the summary metadata if it is set
        if 'summary' in metadata:
            self._summary = metadata['summary']

        signals.content_object_init.send(self)

    def __str__(self):
        return self.source_path or repr(self)

    def _has_valid_mandatory_properties(self):
        """Test mandatory properties are set."""
        for prop in self.mandatory_properties:
            if not hasattr(self, prop):
                logger.error(
                    "Skipping %s: could not find information about '%s'",
                    self, prop)
                return False
        return True

    def _has_valid_save_as(self):
        """Return true if save_as doesn't write outside output path, false
        otherwise."""
        try:
            output_path = self.settings["OUTPUT_PATH"]
        except KeyError:
            # we cannot check
            return True

        try:
            sanitised_join(output_path, self.save_as)
        except RuntimeError:  # outside output_dir
            logger.error(
                "Skipping %s: file %r would be written outside output path",
                self,
                self.save_as,
            )
            return False

        return True

    def _has_valid_status(self):
        if hasattr(self, 'allowed_statuses'):
            if self.status not in self.allowed_statuses:
                logger.error(
                    "Unknown status '%s' for file %s, skipping it.",
                    self.status,
                    self
                )
                return False

        # if undefined we allow all
        return True

    def is_valid(self):
        """Validate Content"""
        # Use all() to not short circuit and get results of all validations
        return all([self._has_valid_mandatory_properties(),
                    self._has_valid_save_as(),
                    self._has_valid_status()])

    @property
    def url_format(self):
        """Returns the URL, formatted with the proper values"""
        metadata = copy.copy(self.metadata)
        path = self.metadata.get('path', self.get_relative_source_path())
        metadata.update({
            'path': path_to_url(path),
            'slug': getattr(self, 'slug', ''),
            'lang': getattr(self, 'lang', 'en'),
            'date': getattr(self, 'date', SafeDatetime.now()),
            'author': self.author.slug if hasattr(self, 'author') else '',
            'tag': self.tag.slug if hasattr(self, 'tag') else '',
            'category': self.category.slug if hasattr(self, 'category') else ''
        })
        return metadata

    def _expand_settings(self, key, klass=None):
        if not klass:
            klass = self.__class__.__name__
        fq_key = ('%s_%s' % (klass, key)).upper()
        return self.settings[fq_key].format(**self.url_format)

    def get_url_setting(self, key):
        if hasattr(self, 'override_' + key):
            return getattr(self, 'override_' + key)
        key = key if self.in_default_lang else 'lang_%s' % key
        return self._expand_settings(key)

    def _link_replacer(self, siteurl, m):
        what = m.group('what')
        value = urlparse(m.group('value'))
        path = value.path
        origin = m.group('path')

        # XXX Put this in a different location.
        if what in {'filename', 'attach'}:
            if path.startswith('/'):
                path = path[1:]
            else:
                # relative to the source path of this content
                path = self.get_relative_source_path(
                    os.path.join(self.relative_dir, path)
                )

            if path not in self._context['filenames']:
                unquoted_path = path.replace('%20', ' ')

                if unquoted_path in self._context['filenames']:
                    path = unquoted_path

            linked_content = self._context['filenames'].get(path)
            if linked_content:
                if what == 'attach':
                    if isinstance(linked_content, Static):
                        linked_content.attach_to(self)
                    else:
                        logger.warning(
                            "%s used {attach} link syntax on a "
                            "non-static file. Use {filename} instead.",
                            self.get_relative_source_path())
                origin = '/'.join((siteurl, linked_content.url))
                origin = origin.replace('\\', '/')  # for Windows paths.
            else:
                logger.warning(
                    "Unable to find '%s', skipping url replacement.",
                    value.geturl(), extra={
                        'limit_msg': ("Other resources were not found "
                                      "and their urls not replaced")})
        elif what == 'category':
            origin = '/'.join((siteurl, Category(path, self.settings).url))
        elif what == 'tag':
            origin = '/'.join((siteurl, Tag(path, self.settings).url))
        elif what == 'index':
            origin = '/'.join((siteurl, self.settings['INDEX_SAVE_AS']))
        elif what == 'author':
            origin = '/'.join((siteurl, Author(path, self.settings).url))
        else:
            logger.warning(
                "Replacement Indicator '%s' not recognized, "
                "skipping replacement",
                what)

        # keep all other parts, such as query, fragment, etc.
        parts = list(value)
        parts[2] = origin
        origin = urlunparse(parts)

        return ''.join((m.group('markup'), m.group('quote'), origin,
                        m.group('quote')))

    def _update_content(self, content, siteurl):
        """Update the content attribute.

        Change all the relative paths of the content to relative paths
        suitable for the output content.

        :param content: content resource that will be passed to the templates.
        :param siteurl: siteurl which is locally generated by the writer in
                        case of RELATIVE_URLS.
        """
        if not content:
            return content

        instrasite_link_regex = self.settings['INTRASITE_LINK_REGEX']
        regex = r"""
            (?P<markup><[^\>]+  # match tag with all url-value attributes
                (?:href|src|poster|data|cite|formaction|action)\s*=\s*)

            (?P<quote>["\'])      # require value to be quoted
            (?P<path>{0}(?P<value>.*?))  # the url value
            \2""".format(instrasite_link_regex)
        hrefs = re.compile(regex, re.X)

        return hrefs.sub(lambda m: self._link_replacer(siteurl, m), content)

    def get_siteurl(self):
        return self._context.get('localsiteurl', '')

    @memoized
    def get_content(self, siteurl):
        if hasattr(self, '_get_content'):
            content = self._get_content()
        else:
            content = self._content
        return self._update_content(content, siteurl)

    @property
    def content(self):
        return self.get_content(self.get_siteurl())

    @memoized
    def get_summary(self, siteurl):
        """Returns the summary of an article.

        This is based on the summary metadata if set, otherwise truncate the
        content.
        """
        if hasattr(self, '_summary'):
            return self._update_content(self._summary, siteurl)

        if self.settings['SUMMARY_MAX_LENGTH'] is None:
            return self.content

        return truncate_html_words(self.content,
                                   self.settings['SUMMARY_MAX_LENGTH'])

    @property
    def summary(self):
        return self.get_summary(self.get_siteurl())

    def _get_summary(self):
        """deprecated function to access summary"""

        logger.warning('_get_summary() has been deprecated since 3.6.4. '
                       'Use the summary decorator instead')
        return self.summary

    @summary.setter
    def summary(self, value):
        """Dummy function"""
        pass

    @property
    def status(self):
        return self._status

    @status.setter
    def status(self, value):
        # TODO maybe typecheck
        self._status = value.lower()

    @property
    def url(self):
        return self.get_url_setting('url')

    @property
    def save_as(self):
        return self.get_url_setting('save_as')

    def _get_template(self):
        if hasattr(self, 'template') and self.template is not None:
            return self.template
        else:
            return self.default_template

    def get_relative_source_path(self, source_path=None):
        """Return the relative path (from the content path) to the given
        source_path.

        If no source path is specified, use the source path of this
        content object.
        """
        if not source_path:
            source_path = self.source_path
        if source_path is None:
            return None

        return posixize_path(
            os.path.relpath(
                os.path.abspath(os.path.join(
                    self.settings['PATH'],
                    source_path)),
                os.path.abspath(self.settings['PATH'])
            ))

    @property
    def relative_dir(self):
        return posixize_path(
            os.path.dirname(
                os.path.relpath(
                    os.path.abspath(self.source_path),
                    os.path.abspath(self.settings['PATH']))))


class Page(Content):
    mandatory_properties = ('title',)
    allowed_statuses = ('published', 'hidden')
    default_status = 'published'
    default_template = 'page'


class Article(Content):
    mandatory_properties = ('title', 'date', 'category')
    allowed_statuses = ('published', 'draft')
    default_status = 'published'
    default_template = 'article'

    def __init__(self, *args, **kwargs):
        super(Article, self).__init__(*args, **kwargs)

        # handle WITH_FUTURE_DATES (designate article to draft based on date)
        if not self.settings['WITH_FUTURE_DATES'] and hasattr(self, 'date'):
            if self.date.tzinfo is None:
                now = SafeDatetime.now()
            else:
                now = SafeDatetime.utcnow().replace(tzinfo=pytz.utc)
            if self.date > now:
                self.status = 'draft'

        # if we are a draft and there is no date provided, set max datetime
        if not hasattr(self, 'date') and self.status == 'draft':
            self.date = SafeDatetime.max

    def _expand_settings(self, key):
        klass = 'article' if self.status == 'published' else 'draft'
        return super(Article, self)._expand_settings(key, klass)


@python_2_unicode_compatible
class Static(Page):
    def __init__(self, *args, **kwargs):
        super(Static, self).__init__(*args, **kwargs)
        self._output_location_referenced = False

    @deprecated_attribute(old='filepath', new='source_path', since=(3, 2, 0))
    def filepath():
        return None

    @deprecated_attribute(old='src', new='source_path', since=(3, 2, 0))
    def src():
        return None

    @deprecated_attribute(old='dst', new='save_as', since=(3, 2, 0))
    def dst():
        return None

    @property
    def url(self):
        # Note when url has been referenced, so we can avoid overriding it.
        self._output_location_referenced = True
        return super(Static, self).url

    @property
    def save_as(self):
        # Note when save_as has been referenced, so we can avoid overriding it.
        self._output_location_referenced = True
        return super(Static, self).save_as

    def attach_to(self, content):
        """Override our output directory with that of the given content object.
        """

        # Determine our file's new output path relative to the linking
        # document. If it currently lives beneath the linking
        # document's source directory, preserve that relationship on output.
        # Otherwise, make it a sibling.

        linking_source_dir = os.path.dirname(content.source_path)
        tail_path = os.path.relpath(self.source_path, linking_source_dir)
        if tail_path.startswith(os.pardir + os.sep):
            tail_path = os.path.basename(tail_path)
        new_save_as = os.path.join(
            os.path.dirname(content.save_as), tail_path)

        # We do not build our new url by joining tail_path with the linking
        # document's url, because we cannot know just by looking at the latter
        # whether it points to the document itself or to its parent directory.
        # (An url like 'some/content' might mean a directory named 'some'
        # with a file named 'content', or it might mean a directory named
        # 'some/content' with a file named 'index.html'.) Rather than trying
        # to figure it out by comparing the linking document's url and save_as
        # path, we simply build our new url from our new save_as path.

        new_url = path_to_url(new_save_as)

        def _log_reason(reason):
            logger.warning(
                "The {attach} link in %s cannot relocate "
                "%s because %s. Falling back to "
                "{filename} link behavior instead.",
                content.get_relative_source_path(),
                self.get_relative_source_path(), reason,
                extra={'limit_msg': "More {attach} warnings silenced."})

        # We never override an override, because we don't want to interfere
        # with user-defined overrides that might be in EXTRA_PATH_METADATA.
        if hasattr(self, 'override_save_as') or hasattr(self, 'override_url'):
            if new_save_as != self.save_as or new_url != self.url:
                _log_reason("its output location was already overridden")
            return

        # We never change an output path that has already been referenced,
        # because we don't want to break links that depend on that path.
        if self._output_location_referenced:
            if new_save_as != self.save_as or new_url != self.url:
                _log_reason("another link already referenced its location")
            return

        self.override_save_as = new_save_as
        self.override_url = new_url