# Copyright (c) 2009-2018 - Simon Conseil
# Copyright (c) 2013      - Christophe-Marie Duquesne
# Copyright (c) 2014      - Jonas Kaufmann
# Copyright (c) 2015      - François D.
# Copyright (c) 2017      - Mate Lakat
# Copyright (c) 2018      - Edwin Steele

# 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.

import fnmatch
import locale
import logging
import multiprocessing
import os
import pickle
import random
import sys
import zipfile

from click import progressbar, get_terminal_size
from collections import defaultdict
from datetime import datetime
from itertools import cycle
from os.path import isfile, join, splitext
from urllib.parse import quote as url_quote

from . import image, video, signals
from .image import (process_image, get_exif_tags, get_exif_data, get_size,
                    get_iptc_data)
from .settings import get_thumb
from .utils import (Devnull, copy, check_or_create_dir, url_from_path,
                    read_markdown, cached_property, is_valid_html5_video,
                    get_mime)
from .video import process_video
from .writer import AlbumPageWriter, AlbumListPageWriter


class Media:
    """Base Class for media files.

    Attributes:

    - ``type``: ``"image"`` or ``"video"``.
    - ``filename``: Filename of the resized image.
    - ``thumbnail``: Location of the corresponding thumbnail image.
    - ``big``: If not None, location of the unmodified image.
    - ``big_url``: If not None, url of the unmodified image.
    - ``exif``: If not None contains a dict with the most common tags. For more
        information, see :ref:`simple-exif-data`.
    - ``raw_exif``: If not ``None``, it contains the raw EXIF tags.

    """

    type = ''

    def __init__(self, filename, path, settings):
        self.src_filename = self.filename = filename
        self.path = path
        self.settings = settings
        self.ext = os.path.splitext(filename)[1].lower()

        self.src_path = join(settings['source'], path, filename)
        self.dst_path = join(settings['destination'], path, filename)

        self.thumb_name = get_thumb(self.settings, self.filename)
        self.thumb_path = join(settings['destination'], path, self.thumb_name)

        self.logger = logging.getLogger(__name__)
        self._get_metadata()
        # default: title is the filename
        if not self.title:
            self.title = self.filename
        signals.media_initialized.send(self)

    def __repr__(self):
        return "<%s>(%r)" % (self.__class__.__name__, str(self))

    def __str__(self):
        return join(self.path, self.filename)

    @property
    def url(self):
        """URL of the media."""
        return url_from_path(self.filename)

    @property
    def big(self):
        """Path to the original image, if ``keep_orig`` is set (relative to the
        album directory). Copy the file if needed.
        """
        if self.settings['keep_orig']:
            s = self.settings
            if s['use_orig']:
                # The image *is* the original, just use it
                return self.filename
            orig_path = join(s['destination'], self.path, s['orig_dir'])
            check_or_create_dir(orig_path)
            big_path = join(orig_path, self.src_filename)
            if not isfile(big_path):
                copy(self.src_path, big_path, symlink=s['orig_link'])
            return join(s['orig_dir'], self.src_filename)

    @property
    def big_url(self):
        """URL of the original media."""
        if self.big is not None:
            return url_from_path(self.big)

    @property
    def thumbnail(self):
        """Path to the thumbnail image (relative to the album directory)."""

        if not isfile(self.thumb_path):
            self.logger.debug('Generating thumbnail for %r', self)
            path = (self.dst_path if os.path.exists(self.dst_path)
                    else self.src_path)
            try:
                # if thumbnail is missing (if settings['make_thumbs'] is False)
                s = self.settings
                if self.type == 'image':
                    image.generate_thumbnail(
                        path, self.thumb_path, s['thumb_size'],
                        fit=s['thumb_fit'])
                elif self.type == 'video':
                    video.generate_thumbnail(
                        path, self.thumb_path, s['thumb_size'],
                        s['thumb_video_delay'], fit=s['thumb_fit'],
                        converter=s['video_converter'])
            except Exception as e:
                self.logger.error('Failed to generate thumbnail: %s', e)
                return
        return url_from_path(self.thumb_name)

    def _get_metadata(self):
        """ Get image metadata from filename.md: title, description, meta."""
        self.description = ''
        self.meta = {}
        self.title = ''

        descfile = splitext(self.src_path)[0] + '.md'
        if isfile(descfile):
            meta = read_markdown(descfile)
            for key, val in meta.items():
                setattr(self, key, val)

    def _get_file_date(self):
        stat = os.stat(self.src_path)
        return datetime.fromtimestamp(stat.st_mtime)


class Image(Media):
    """Gather all informations on an image file."""

    type = 'image'

    @cached_property
    def date(self):
        return (self.exif and self.exif.get('dateobj', None) or
                self._get_file_date())

    @cached_property
    def exif(self):
        datetime_format = self.settings['datetime_format']
        return (get_exif_tags(self.raw_exif, datetime_format=datetime_format)
                if self.raw_exif and self.ext in ('.jpg', '.jpeg') else None)

    def _get_metadata(self):
        super(Image, self)._get_metadata()
        # If a title or description hasn't been obtained by other means, look
        #  for the information in IPTC fields
        if self.title and self.description:
            # Nothing to do - we already have title and description
            return

        try:
            iptc_data = get_iptc_data(self.src_path)
        except Exception as e:
            self.logger.warning('Could not read IPTC data from %s: %s',
                                self.src_path, e)
        else:
            if not self.title and iptc_data.get('title'):
                self.title = iptc_data['title']
            if not self.description and iptc_data.get('description'):
                self.description = iptc_data['description']

    @cached_property
    def raw_exif(self):
        try:
            return (get_exif_data(self.src_path)
                    if self.ext in ('.jpg', '.jpeg') else None)
        except Exception as e:
            self.logger.warning('Could not read EXIF data from %s: %s',
                                self.src_path, e)

    @cached_property
    def size(self):
        return get_size(self.dst_path)

    @cached_property
    def thumb_size(self):
        return get_size(self.thumb_path)

    def has_location(self):
        return self.exif is not None and 'gps' in self.exif


class Video(Media):
    """Gather all informations on a video file."""

    type = 'video'

    def __init__(self, filename, path, settings):
        super(Video, self).__init__(filename, path, settings)
        base, ext = splitext(filename)
        self.src_filename = filename
        self.date = self._get_file_date()
        if not settings['use_orig'] or not is_valid_html5_video(ext):
            video_format = settings['video_format']
            ext = '.' + video_format
            self.filename = base + ext
            self.mime = get_mime(ext)
            self.dst_path = join(settings['destination'], path, base + ext)
        else:
            self.mime = get_mime(ext)


class Album:
    """Gather all informations on an album.

    Attributes:

    :var description_file: Name of the Markdown file which gives information
        on an album
    :ivar index_url: URL to the index page.
    :ivar output_file: Name of the output HTML file
    :ivar meta: Meta data from the Markdown file.
    :ivar description: description from the Markdown file.

    For details how to annotate your albums with meta data, see
    :doc:`album_information`.

    """

    description_file = "index.md"

    def __init__(self, path, settings, dirnames, filenames, gallery):
        self.path = path
        self.name = path.split(os.path.sep)[-1]
        self.gallery = gallery
        self.settings = settings
        self.subdirs = dirnames
        self.output_file = settings['output_filename']
        self._thumbnail = None

        if path == '.':
            self.src_path = settings['source']
            self.dst_path = settings['destination']
        else:
            self.src_path = join(settings['source'], path)
            self.dst_path = join(settings['destination'], path)

        self.logger = logging.getLogger(__name__)
        self._get_metadata()

        # optionally add index.html to the URLs
        self.url_ext = self.output_file if settings['index_in_url'] else ''

        self.index_url = url_from_path(os.path.relpath(
            settings['destination'], self.dst_path)) + '/' + self.url_ext

        #: List of all medias in the album (:class:`~sigal.gallery.Image` and
        #: :class:`~sigal.gallery.Video`).
        self.medias = medias = []
        self.medias_count = defaultdict(int)

        for f in filenames:
            ext = splitext(f)[1]
            if ext.lower() in settings['img_extensions']:
                media = Image(f, self.path, settings)
            elif ext.lower() in settings['video_extensions']:
                media = Video(f, self.path, settings)
            else:
                continue

            self.medias_count[media.type] += 1
            medias.append(media)

        signals.album_initialized.send(self)

    def __repr__(self):
        return "<%s>(path=%r, title=%r)" % (self.__class__.__name__, self.path,
                                            self.title)

    def __str__(self):
        return ('{} : '.format(self.path) +
                ', '.join('{} {}s'.format(count, _type)
                          for _type, count in self.medias_count.items()))

    def __len__(self):
        return len(self.medias)

    def __iter__(self):
        return iter(self.medias)

    def _get_metadata(self):
        """Get album metadata from `description_file` (`index.md`):

        -> title, thumbnail image, description

        """
        descfile = join(self.src_path, self.description_file)
        self.description = ''
        self.meta = {}
        # default: get title from directory name
        self.title = os.path.basename(self.path if self.path != '.'
                                      else self.src_path)

        if isfile(descfile):
            meta = read_markdown(descfile)
            for key, val in meta.items():
                setattr(self, key, val)

        try:
            self.author = self.meta['author'][0]
        except KeyError:
            self.author = self.settings.get('author')

    def create_output_directories(self):
        """Create output directories for thumbnails and original images."""
        check_or_create_dir(self.dst_path)

        if self.medias:
            check_or_create_dir(join(self.dst_path,
                                     self.settings['thumb_dir']))

        if self.medias and self.settings['keep_orig']:
            self.orig_path = join(self.dst_path, self.settings['orig_dir'])
            check_or_create_dir(self.orig_path)

    def sort_subdirs(self, albums_sort_attr):
        if self.subdirs:
            if albums_sort_attr:
                root_path = self.path if self.path != '.' else ''
                if albums_sort_attr.startswith("meta."):
                    meta_key = albums_sort_attr.split(".", 1)[1]
                    key = lambda s: locale.strxfrm(
                        self.gallery.albums[join(root_path, s)].meta.get(meta_key, [''])[0])
                else:
                    key = lambda s: locale.strxfrm(
                        getattr(self.gallery.albums[join(root_path, s)],
                                albums_sort_attr))
            else:
                key = locale.strxfrm

            self.subdirs.sort(key=key,
                              reverse=self.settings['albums_sort_reverse'])

        signals.albums_sorted.send(self)

    def sort_medias(self, medias_sort_attr):
        if self.medias:
            if medias_sort_attr == 'date':
                key = lambda s: s.date or datetime.now()
            elif medias_sort_attr.startswith('meta.'):
                meta_key = medias_sort_attr.split(".", 1)[1]
                key = lambda s: locale.strxfrm(s.meta.get(meta_key, [''])[0])
            else:
                key = lambda s: locale.strxfrm(getattr(s, medias_sort_attr))

            self.medias.sort(key=key,
                             reverse=self.settings['medias_sort_reverse'])

        signals.medias_sorted.send(self)

    @property
    def images(self):
        """List of images (:class:`~sigal.gallery.Image`)."""
        for media in self.medias:
            if media.type == 'image':
                yield media

    @property
    def videos(self):
        """List of videos (:class:`~sigal.gallery.Video`)."""
        for media in self.medias:
            if media.type == 'video':
                yield media

    @property
    def albums(self):
        """List of :class:`~sigal.gallery.Album` objects for each
        sub-directory.
        """
        root_path = self.path if self.path != '.' else ''
        return [self.gallery.albums[join(root_path, path)]
                for path in self.subdirs]

    @property
    def url(self):
        """URL of the album, relative to its parent."""
        url = self.name.encode('utf-8')
        return url_quote(url) + '/' + self.url_ext

    @property
    def thumbnail(self):
        """Path to the thumbnail of the album."""

        if self._thumbnail:
            # stop if it is already set
            return self._thumbnail

        # Test the thumbnail from the Markdown file.
        thumbnail = self.meta.get('thumbnail', [''])[0]

        if thumbnail and isfile(join(self.src_path, thumbnail)):
            self._thumbnail = url_from_path(join(
                self.name, get_thumb(self.settings, thumbnail)))
            self.logger.debug("Thumbnail for %r : %s", self, self._thumbnail)
            return self._thumbnail
        else:
            # find and return the first landscape image
            for f in self.medias:
                ext = splitext(f.filename)[1]
                if ext.lower() in self.settings['img_extensions']:
                    # Use f.size if available as it is quicker (in cache), but
                    # fallback to the size of src_path if dst_path is missing
                    size = f.size
                    if size is None:
                        size = get_size(f.src_path)

                    if size['width'] > size['height']:
                        self._thumbnail = (url_quote(self.name) + '/' +
                                           f.thumbnail)
                        self.logger.debug(
                            "Use 1st landscape image as thumbnail for %r : %s",
                            self, self._thumbnail)
                        return self._thumbnail

            # else simply return the 1st media file
            if not self._thumbnail and self.medias:
                for media in self.medias:
                    if media.thumbnail is not None:
                        self._thumbnail = (url_quote(self.name) + '/' +
                                           media.thumbnail)
                        break
                else:
                    self.logger.warning("No thumbnail found for %r", self)
                    return None

                self.logger.debug("Use the 1st image as thumbnail for %r : %s",
                                  self, self._thumbnail)
                return self._thumbnail

            # use the thumbnail of their sub-directories
            if not self._thumbnail:
                for path, album in self.gallery.get_albums(self.path):
                    if album.thumbnail:
                        self._thumbnail = (url_quote(self.name) + '/' +
                                           album.thumbnail)
                        self.logger.debug(
                            "Using thumbnail from sub-directory for %r : %s",
                            self, self._thumbnail)
                        return self._thumbnail

        self.logger.error('Thumbnail not found for %r', self)
        return None

    @property
    def random_thumbnail(self):
        try:
            return url_from_path(join(self.name,
                                      random.choice(self.medias).thumbnail))
        except IndexError:
            return self.thumbnail

    @property
    def breadcrumb(self):
        """List of ``(url, title)`` tuples defining the current breadcrumb
        path.
        """
        if self.path == '.':
            return []

        path = self.path
        breadcrumb = [((self.url_ext or '.'), self.title)]

        while True:
            path = os.path.normpath(os.path.join(path, '..'))
            if path == '.':
                break

            url = (url_from_path(os.path.relpath(path, self.path)) + '/' +
                   self.url_ext)
            breadcrumb.append((url, self.gallery.albums[path].title))

        breadcrumb.reverse()
        return breadcrumb

    @property
    def show_map(self):
        """Check if we have at least one photo with GPS location in the album
        """
        return any(image.has_location() for image in self.images)

    @cached_property
    def zip(self):
        """Make a ZIP archive with all media files and return its path.

        If the ``zip_gallery`` setting is set,it contains the location of a zip
        archive with all original images of the corresponding directory.

        """
        zip_gallery = self.settings['zip_gallery']

        if zip_gallery and len(self) > 0:
            zip_gallery = zip_gallery.format(album=self)
            archive_path = join(self.dst_path, zip_gallery)
            if (self.settings.get('zip_skip_if_exists', False) and
                    isfile(archive_path)):
                self.logger.debug("Archive %s already created, passing",
                                  archive_path)
                return zip_gallery

            archive = zipfile.ZipFile(archive_path, 'w', allowZip64=True)
            attr = ('src_path' if self.settings['zip_media_format'] == 'orig'
                    else 'dst_path')

            for p in self:
                path = getattr(p, attr)
                try:
                    archive.write(path, os.path.split(path)[1])
                except OSError as e:
                    self.logger.warn('Failed to add %s to the ZIP: %s', p, e)

            archive.close()
            self.logger.debug('Created ZIP archive %s', archive_path)
            return zip_gallery


class Gallery(object):

    def __init__(self, settings, ncpu=None):
        self.settings = settings
        self.logger = logging.getLogger(__name__)
        self.stats = defaultdict(int)
        self.init_pool(ncpu)
        check_or_create_dir(settings['destination'])

        # Build the list of directories with images
        albums = self.albums = {}
        src_path = self.settings['source']

        ignore_dirs = settings['ignore_directories']
        ignore_files = settings['ignore_files']

        progressChars = cycle(["/", "-", "\\", "|"])
        show_progress = (self.logger.getEffectiveLevel() >= logging.WARNING and
                         os.isatty(sys.stdout.fileno()))
        self.progressbar_target = None if show_progress else Devnull()

        for path, dirs, files in os.walk(src_path, followlinks=True,
                                         topdown=False):
            if show_progress:
                print("\rCollecting albums " + next(progressChars), end="")
            relpath = os.path.relpath(path, src_path)

            # Test if the directory match the ignore_dirs settings
            if ignore_dirs and any(fnmatch.fnmatch(relpath, ignore)
                                   for ignore in ignore_dirs):
                self.logger.info('Ignoring %s', relpath)
                continue

            # Remove files that match the ignore_files settings
            if ignore_files:
                files_path = {join(relpath, f) for f in files}
                for ignore in ignore_files:
                    files_path -= set(fnmatch.filter(files_path, ignore))

                self.logger.debug('Files before filtering: %r', files)
                files = [os.path.split(f)[1] for f in files_path]
                self.logger.debug('Files after filtering: %r', files)

            # Remove sub-directories that have been ignored in a previous
            # iteration (as topdown=False, sub-directories are processed before
            # their parent
            for d in dirs[:]:
                path = join(relpath, d) if relpath != '.' else d
                if path not in albums.keys():
                    dirs.remove(d)

            album = Album(relpath, settings, dirs, files, self)

            if not album.medias and not album.albums:
                self.logger.info('Skip empty album: %r', album)
            else:
                album.create_output_directories()
                albums[relpath] = album

        print("\rCollecting albums, done.")

        with progressbar(albums.values(), label="%16s" % "Sorting albums",
                         file=self.progressbar_target) as progress_albums:
            for album in progress_albums:
                album.sort_subdirs(settings['albums_sort_attr'])

        with progressbar(albums.values(), label="%16s" % "Sorting media",
                         file=self.progressbar_target) as progress_albums:
            for album in progress_albums:
                album.sort_medias(settings['medias_sort_attr'])

        self.logger.debug('Albums:\n%r', albums.values())
        signals.gallery_initialized.send(self)

    @property
    def title(self):
        """Title of the gallery."""
        return self.settings['title'] or self.albums['.'].title

    def init_pool(self, ncpu):
        try:
            cpu_count = multiprocessing.cpu_count()
        except NotImplementedError:
            cpu_count = 1

        if ncpu is None:
            ncpu = cpu_count
        else:
            try:
                ncpu = int(ncpu)
            except ValueError:
                self.logger.error('ncpu should be an integer value')
                ncpu = cpu_count

        self.logger.info("Using %s cores", ncpu)
        if ncpu > 1:
            self.pool = multiprocessing.Pool(processes=ncpu)
        else:
            self.pool = None

    def get_albums(self, path):
        """Return the list of all sub-directories of path."""

        for name in self.albums[path].subdirs:
            subdir = os.path.normpath(join(path, name))
            yield subdir, self.albums[subdir]
            for subname, album in self.get_albums(subdir):
                yield subname, self.albums[subdir]

    def build(self, force=False):
        "Create the image gallery"

        if not self.albums:
            self.logger.warning("No albums found.")
            return

        def log_func(x):
            # 63 is the total length of progressbar, label, percentage, etc
            available_length = get_terminal_size()[0] - 64
            if x and available_length > 10:
                return x.name[:available_length]
            else:
                return ""

        try:
            with progressbar(self.albums.values(), label="Collecting files",
                             item_show_func=log_func, show_eta=False,
                             file=self.progressbar_target) as albums:
                media_list = [f for album in albums
                              for f in self.process_dir(album, force=force)]
        except KeyboardInterrupt:
            sys.exit('Interrupted')

        bar_opt = {'label': "Processing files",
                   'show_pos': True,
                   'file': self.progressbar_target}
        failed_files = []

        if self.pool:
            try:
                with progressbar(length=len(media_list), **bar_opt) as bar:
                    for res in self.pool.imap_unordered(worker, media_list):
                        if res:
                            failed_files.append(res)
                        bar.update(1)
                self.pool.close()
                self.pool.join()
            except KeyboardInterrupt:
                self.pool.terminate()
                sys.exit('Interrupted')
            except pickle.PicklingError:
                self.logger.critical(
                    "Failed to process files with the multiprocessing feature."
                    " This can be caused by some module import or object "
                    "defined in the settings file, which can't be serialized.",
                    exc_info=True)
                sys.exit('Abort')
        else:
            with progressbar(media_list, **bar_opt) as medias:
                for media_item in medias:
                    res = process_file(media_item)
                    if res:
                        failed_files.append(res)

        if failed_files:
            self.remove_files(failed_files)

        if self.settings['write_html']:
            album_writer = AlbumPageWriter(self.settings,
                                           index_title=self.title)
            album_list_writer = AlbumListPageWriter(self.settings,
                                                    index_title=self.title)
            with progressbar(self.albums.values(),
                             label="%16s" % "Writing files",
                             item_show_func=log_func, show_eta=False,
                             file=self.progressbar_target) as albums:
                for album in albums:
                    if album.albums:
                        if album.medias:
                            self.logger.warning(
                                "Album %s contains sub-albums and images. "
                                "Please move images to their own sub-album. "
                                "Images in album %s will not be visible.",
                                album.title, album.title
                            )
                        album_list_writer.write(album)
                    else:
                        album_writer.write(album)
        print('')

        signals.gallery_build.send(self)

    def remove_files(self, files):
        self.logger.error('Some files have failed to be processed:')
        for path, filename in files:
            self.logger.error('  - %s/%s', path, filename)
            album = self.albums[path]
            for f in album.medias:
                if f.filename == filename:
                    self.stats[f.type + '_failed'] += 1
                    album.medias.remove(f)
                    break
        self.logger.error('You can run "sigal build" in verbose (--verbose) or'
                          ' debug (--debug) mode to get more details.')

    def process_dir(self, album, force=False):
        """Process a list of images in a directory."""
        for f in album:
            if isfile(f.dst_path) and not force:
                self.logger.info("%s exists - skipping", f.filename)
                self.stats[f.type + '_skipped'] += 1
            else:
                self.stats[f.type] += 1
                yield (f.type, f.path, f.filename, f.src_path, album.dst_path,
                       self.settings)


def process_file(args):
    # args => ftype, path, filename, src_path, dst_path, settings
    processor = process_image if args[0] == 'image' else process_video
    ret = processor(*args[3:])
    # If the processor return an error (ret != 0), then we return the path and
    # filename of the failed file to the parent process.
    return args[1:3] if ret else None


def worker(args):
    try:
        return process_file(args)
    except KeyboardInterrupt:
        pass
