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

import itertools
import logging
import os
import pprint
import re
import sys
import multiprocessing

from pelican.generators import ArticlesGenerator
from pelican.generators import PagesGenerator
from pelican.settings import DEFAULT_CONFIG
from pelican import signals
from pelican.utils import pelican_open

logger = logging.getLogger(__name__)


try:
    from PIL import ExifTags
    from PIL import Image
    from PIL import ImageDraw
    from PIL import ImageEnhance
    from PIL import ImageFont
except ImportError:
    raise Exception('PIL/Pillow not found')


def initialized(pelican):

    p = os.path.expanduser('~/Pictures')

    DEFAULT_CONFIG.setdefault('PHOTO_LIBRARY', p)
    DEFAULT_CONFIG.setdefault('PHOTO_GALLERY', (1024, 768, 80))
    DEFAULT_CONFIG.setdefault('PHOTO_ARTICLE', (760, 506, 80))
    DEFAULT_CONFIG.setdefault('PHOTO_THUMB', (192, 144, 60))
    DEFAULT_CONFIG.setdefault('PHOTO_GALLERY_TITLE', '')
    DEFAULT_CONFIG.setdefault('PHOTO_WATERMARK', 'False')
    DEFAULT_CONFIG.setdefault('PHOTO_WATERMARK_TEXT', DEFAULT_CONFIG['SITENAME'])
    DEFAULT_CONFIG.setdefault('PHOTO_WATERMARK_IMG', '')
    DEFAULT_CONFIG.setdefault('PHOTO_WATERMARK_IMG_SIZE', (64, 64))
    DEFAULT_CONFIG.setdefault('PHOTO_RESIZE_JOBS', 1)

    DEFAULT_CONFIG['queue_resize'] = {}
    DEFAULT_CONFIG['created_galleries'] = {}

    if pelican:
        pelican.settings.setdefault('PHOTO_LIBRARY', p)
        pelican.settings.setdefault('PHOTO_GALLERY', (1024, 768, 80))
        pelican.settings.setdefault('PHOTO_ARTICLE', (760, 506, 80))
        pelican.settings.setdefault('PHOTO_THUMB', (192, 144, 60))
        pelican.settings.setdefault('PHOTO_GALLERY_TITLE', '')
        pelican.settings.setdefault('PHOTO_WATERMARK', 'False')
        pelican.settings.setdefault('PHOTO_WATERMARK_TEXT', pelican.settings['SITENAME'])
        pelican.settings.setdefault('PHOTO_WATERMARK_IMG', '')
        pelican.settings.setdefault('PHOTO_WATERMARK_IMG_SIZE', (64, 64))
        pelican.settings.setdefault('PHOTO_RESIZE_JOBS', 1)


def read_notes(filename, msg=None):
    notes = {}
    try:
        with pelican_open(filename) as text:
            for line in text.splitlines():
                if line.startswith('#'):
                    continue

                m = line.split(':', 1)
                if len(m) > 1:
                    pic = m[0].strip()
                    note = m[1].strip()
                    if pic and note:
                        notes[pic] = note
                else:
                    notes[line] = ''
    except Exception as e:
        if msg:
            logger.warning('{} at file {}'.format(msg, filename))
        logger.debug('read_notes issue: {} at file {}. Debug message:{}'.format(msg, filename, e))
    return notes


def enqueue_resize(orig, resized, spec=(640, 480, 80)):

    if resized not in DEFAULT_CONFIG['queue_resize']:
        DEFAULT_CONFIG['queue_resize'][resized] = (orig, spec)
    elif DEFAULT_CONFIG['queue_resize'][resized] != (orig, spec):
        logger.error('photos: resize conflict for {}, {}-{} is not {}-{}'.format(resized, DEFAULT_CONFIG['queue_resize'][resized][0], DEFAULT_CONFIG['queue_resize'][resized][1], orig, spec))


def isalpha(img):
    return True if img.mode in ('RGBA', 'LA') or (img.mode == 'P' and 'transparency' in img.info) else False


def ReduceOpacity(im, opacity):
    """Reduces Opacity

    Returns an image with reduced opacity.
    Taken from http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/362879
    """

    assert opacity >= 0 and opacity <= 1
    if isalpha(im):
        im = im.copy()
    else:
        im = im.convert('RGBA')

    alpha = im.split()[3]
    alpha = ImageEnhance.Brightness(alpha).enhance(opacity)
    im.putalpha(alpha)
    return im


def watermark_photo(image, watermark_text, watermark_image, watermark_image_size):

    margin = [10, 10]
    opacity = 0.6

    watermark_layer = Image.new("RGBA", image.size, (0, 0, 0, 0))
    draw_watermark = ImageDraw.Draw(watermark_layer)
    text_reducer = 32
    image_reducer = 8
    text_size = [0, 0]
    mark_size = [0, 0]
    font_height = 0
    text_position = [0, 0]

    if watermark_text:
        font_name = 'SourceCodePro-Bold.otf'

        plugin_dir = os.path.dirname(os.path.realpath(__file__))
        default_font = os.path.join(plugin_dir, font_name)
        font = ImageFont.FreeTypeFont(default_font, watermark_layer.size[0] // text_reducer)
        text_size = draw_watermark.textsize(watermark_text, font)
        text_position = [image.size[i] - text_size[i] - margin[i] for i in [0, 1]]
        draw_watermark.text(text_position, watermark_text, (255, 255, 255), font=font)

    if watermark_image:
        mark_image = Image.open(watermark_image)
        mark_image_size = [ watermark_layer.size[0] // image_reducer for size in mark_size]
        mark_image.thumbnail(mark_image_size, Image.ANTIALIAS)
        mark_position = [watermark_layer.size[i] - mark_image.size[i] - margin[i] for i in [0, 1]]
        mark_position = tuple([mark_position[0] - (text_size[0] // 2) + (mark_image_size[0] // 2), mark_position[1] - text_size[1]])

        if not isalpha(mark_image):
            mark_image = mark_image.convert('RGBA')

        watermark_layer.paste(mark_image, mark_position, mark_image)

    watermark_layer = ReduceOpacity(watermark_layer, opacity)
    image.paste(watermark_layer, (0, 0), watermark_layer)

    return image


def resize_worker(orig, resized, spec, wm, wm_text, wm_img, wm_img_size):
    logger.info('photos: make photo {} -> {}'.format(orig, resized))
    im = Image.open(orig)
    try:
        exif = im._getexif()
    except:
        exif = None

    icc_profile = im.info.get("icc_profile", None)

    if exif:
        for tag, value in exif.items():
            decoded = ExifTags.TAGS.get(tag, tag)
            if decoded == 'Orientation':
                if value == 3:
                    im = im.rotate(180)
                elif value == 6:
                    im = im.rotate(270)
                elif value == 8:
                    im = im.rotate(90)
                break
    im.thumbnail((spec[0], spec[1]), Image.ANTIALIAS)
    try:
        os.makedirs(os.path.split(resized)[0])
    except:
        pass

    if wm:
        im = watermark_photo(im, wm_text, wm_img, wm_img_size)

    im.save(resized, 'JPEG', quality=spec[2], icc_profile=icc_profile)


def resize_photos(generator, writer):
    logger.info('photos: {} photo resizes to consider.'.format(len(DEFAULT_CONFIG['queue_resize'].items())))
    pool = multiprocessing.Pool(generator.settings['PHOTO_RESIZE_JOBS'])
    for resized, what in DEFAULT_CONFIG['queue_resize'].items():
        resized = os.path.join(generator.output_path, resized)
        orig, spec = what
        if (not os.path.isfile(resized) or
                os.path.getmtime(orig) > os.path.getmtime(resized)):
            pool.apply_async(resize_worker, args=(
                orig,
                resized,
                spec,
                generator.settings['PHOTO_WATERMARK'],
                generator.settings['PHOTO_WATERMARK_TEXT'],
                generator.settings['PHOTO_WATERMARK_IMG'],
                generator.settings['PHOTO_WATERMARK_IMG_SIZE']
            ))

    pool.close()
    pool.join()


def detect_content(content):

    hrefs = None

    def replacer(m):
        what = m.group('what')
        value = m.group('value')
        origin = m.group('path')

        if what == 'photo':
            if value.startswith('/'):
                value = value[1:]
            path = os.path.join(
                os.path.expanduser(settings['PHOTO_LIBRARY']),
                value)
            if not os.path.isfile(path):
                logger.error('photos: No photo %s', path)
            else:
                photo = os.path.splitext(value)[0].lower() + 'a.jpg'
                origin = os.path.join(settings['SITEURL'], 'photos', photo)
                enqueue_resize(
                    path,
                    os.path.join('photos', photo),
                    settings['PHOTO_ARTICLE'])
        return ''.join((m.group('markup'), m.group('quote'), origin,
                        m.group('quote')))

    if hrefs is None:
        regex = r"""
            (?P<markup><\s*[^\>]*  # match tag with src and href attr
                (?:href|src)\s*=)

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

    if content._content and '{photo}' in content._content:
        settings = content.settings
        content._content = hrefs.sub(replacer, content._content)


def galleries_string_decompose(gallery_string):
    splitter_regex = re.compile(r'[\s,]*?({photo}|{filename})')
    title_regex = re.compile(r'{(.+)}')
    galleries = map(unicode.strip if sys.version_info.major == 2 else str.strip, filter(None, splitter_regex.split(gallery_string)))
    galleries = [gallery[1:] if gallery.startswith('/') else gallery for gallery in galleries]
    if len(galleries) % 2 == 0 and u' ' not in galleries:
        galleries = zip(zip(['type'] * len(galleries[0::2]), galleries[0::2]), zip(['location'] * len(galleries[0::2]), galleries[1::2]))
        galleries = [dict(gallery) for gallery in galleries]
        for gallery in galleries:
            title = re.search(title_regex, gallery['location'])
            if title:
                gallery['title'] = title.group(1)
                gallery['location'] = re.sub(title_regex, '', gallery['location']).strip()
            else:
                gallery['title'] = DEFAULT_CONFIG['PHOTO_GALLERY_TITLE']
        return galleries
    else:
        logger.critical('Unexpected gallery location format! \n{}'.format(pprint.pformat(galleries)))
        raise Exception


def process_gallery(generator, content, location):

    content.photo_gallery = []

    galleries = galleries_string_decompose(location)

    for gallery in galleries:

        if gallery['location'] in DEFAULT_CONFIG['created_galleries']:
            content.photo_gallery.append((gallery['location'], DEFAULT_CONFIG['created_galleries'][gallery]))
            continue

        if gallery['type'] == '{photo}':
            dir_gallery = os.path.join(os.path.expanduser(generator.settings['PHOTO_LIBRARY']), gallery['location'])
            rel_gallery = gallery['location']
        elif gallery['type'] == '{filename}':
            base_path = os.path.join(generator.path, content.relative_dir)
            dir_gallery = os.path.join(base_path, gallery['location'])
            rel_gallery = os.path.join(content.relative_dir, gallery['location'])

        if os.path.isdir(dir_gallery):
            logger.info('photos: Gallery detected: {}'.format(rel_gallery))
            dir_photo = os.path.join('photos', rel_gallery.lower())
            dir_thumb = os.path.join('photos', rel_gallery.lower())
            exifs = read_notes(os.path.join(dir_gallery, 'exif.txt'),
                               msg='photos: No EXIF for gallery')
            captions = read_notes(os.path.join(dir_gallery, 'captions.txt'), msg='photos: No captions for gallery')
            blacklist = read_notes(os.path.join(dir_gallery, 'blacklist.txt'), msg='photos: No blacklist for gallery')
            content_gallery = []

            title = gallery['title']
            for pic in sorted(os.listdir(dir_gallery)):
                if pic.startswith('.'):
                    continue
                if pic.endswith('.txt'):
                    continue
                if pic in blacklist:
                    continue
                photo = os.path.splitext(pic)[0].lower() + '.jpg'
                thumb = os.path.splitext(pic)[0].lower() + 't.jpg'
                content_gallery.append((
                    pic,
                    os.path.join(dir_photo, photo),
                    os.path.join(dir_thumb, thumb),
                    exifs.get(pic, ''),
                    captions.get(pic, '')))

                enqueue_resize(
                    os.path.join(dir_gallery, pic),
                    os.path.join(dir_photo, photo),
                    generator.settings['PHOTO_GALLERY'])
                enqueue_resize(
                    os.path.join(dir_gallery, pic),
                    os.path.join(dir_thumb, thumb),
                    generator.settings['PHOTO_THUMB'])

            content.photo_gallery.append((title, content_gallery))
            logger.debug('Gallery Data: '.format(pprint.pformat(content.photo_gallery)))
            DEFAULT_CONFIG['created_galleries']['gallery'] = content_gallery
        else:
            logger.critical('photos: Gallery does not exist: {} at {}'.format(gallery['location'], dir_gallery))
            raise Exception


def detect_gallery(generator, content):
    if 'gallery' in content.metadata:
        gallery = content.metadata.get('gallery')
        if gallery.startswith('{photo}') or gallery.startswith('{filename}'):
            process_gallery(generator, content, gallery)
        elif gallery:
            logger.error('photos: Gallery tag not recognized: {}'.format(gallery))


def process_image(generator, content, image):

    image_clipper = lambda x: x[8:] if x[8] == '/' else x[7:]
    file_clipper = lambda x: x[11:] if x[10] == '/' else x[10:]

    if image.startswith('{photo}'):
        path = os.path.join(os.path.expanduser(generator.settings['PHOTO_LIBRARY']), image_clipper(image))
        image = image_clipper(image)
    elif image.startswith('{filename}'):
        path = os.path.join(content.relative_dir, file_clipper(image))
        image = file_clipper(image)

    if os.path.isfile(path):
        photo = os.path.splitext(image)[0].lower() + 'a.jpg'
        thumb = os.path.splitext(image)[0].lower() + 't.jpg'
        content.photo_image = (
            os.path.basename(image).lower(),
            os.path.join('photos', photo),
            os.path.join('photos', thumb))
        enqueue_resize(
            path,
            os.path.join('photos', photo),
            generator.settings['PHOTO_ARTICLE'])
        enqueue_resize(
            path,
            os.path.join('photos', thumb),
            generator.settings['PHOTO_THUMB'])
    else:
        logger.error('photo: No photo for {} at {}'.format(content.source_path, path))


def detect_image(generator, content):
        image = content.metadata.get('image', None)
        if image:
            if image.startswith('{photo}') or image.startswith('{filename}'):
                process_image(generator, content, image)
            else:
                logger.error('photos: Image tag not recognized: {}'.format(image))


def detect_images_and_galleries(generators):
    """Runs generator on both pages and articles. """
    for generator in generators:
        if isinstance(generator, ArticlesGenerator):
            for article in itertools.chain(generator.articles, generator.translations, generator.drafts):
                detect_image(generator, article)
                detect_gallery(generator, article)
        elif isinstance(generator, PagesGenerator):
            for page in itertools.chain(generator.pages, generator.translations, generator.hidden_pages):
                detect_image(generator, page)
                detect_gallery(generator, page)


def register():
    """Uses the new style of registration based on GitHub Pelican issue #314. """
    signals.initialized.connect(initialized)
    try:
        signals.content_object_init.connect(detect_content)
        signals.all_generators_finalized.connect(detect_images_and_galleries)
        signals.article_writer_finalized.connect(resize_photos)
    except Exception as e:
        logger.exception('Plugin failed to execute: {}'.format(pprint.pformat(e)))