from __future__ import absolute_import

import abc
import logging
import numbers
import os
import re
from copy import deepcopy
from math import ceil

import certifi
from six import python_2_unicode_compatible, add_metaclass

logger = logging.getLogger("Cloudinary")
ch = logging.StreamHandler()
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
ch.setFormatter(formatter)
logger.addHandler(ch)

from cloudinary import utils
from cloudinary.exceptions import GeneralError
from cloudinary.cache import responsive_breakpoints_cache
from cloudinary.http_client import HttpClient
from cloudinary.compat import urlparse, parse_qs

from platform import python_version, platform

CERT_KWARGS = {
    'cert_reqs': 'CERT_REQUIRED',
    'ca_certs': certifi.where(),
}

CF_SHARED_CDN = "d3jpl91pxevbkh.cloudfront.net"
OLD_AKAMAI_SHARED_CDN = "cloudinary-a.akamaihd.net"
AKAMAI_SHARED_CDN = "res.cloudinary.com"
SHARED_CDN = AKAMAI_SHARED_CDN
CL_BLANK = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7"
URI_SCHEME = "cloudinary"
API_VERSION = "v1_1"

VERSION = "1.44.1"

_USER_PLATFORM_DETAILS = "; ".join((platform(), "Python {}".format(python_version())))

USER_AGENT = "CloudinaryPython/{} ({})".format(VERSION, _USER_PLATFORM_DETAILS)
""" :const: USER_AGENT """

USER_PLATFORM = ""
"""
Additional information to be passed with the USER_AGENT, e.g. "CloudinaryCLI/1.2.3".
This value is set in platform-specific implementations that use pycloudinary.

The format of the value should be <ProductName>/Version[ (comment)].
@see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.43

**Do not set this value in application code!**
"""


def get_user_agent():
    """
    Provides the `USER_AGENT` string that is passed to the Cloudinary servers.
    Prepends  `USER_PLATFORM` if it is defined.

    :returns: the user agent
    :rtype: str
    """

    if USER_PLATFORM == "":
        return USER_AGENT
    else:
        return USER_PLATFORM + " " + USER_AGENT


def import_django_settings():
    try:
        from django.core.exceptions import ImproperlyConfigured

        try:
            from django.conf import settings as _django_settings

            # We can get a situation when Django module is installed in the system, but not initialized,
            # which means we are running not in a Django process.
            # In this case the following line throws ImproperlyConfigured exception
            if 'cloudinary' in _django_settings.INSTALLED_APPS:
                from django import get_version as _get_django_version
                global USER_PLATFORM
                USER_PLATFORM = "Django/{django_version}".format(django_version=_get_django_version())

            if 'CLOUDINARY' in dir(_django_settings):
                return _django_settings.CLOUDINARY
            else:
                return None

        except ImproperlyConfigured:
            return None

    except ImportError:
        return None


@add_metaclass(abc.ABCMeta)
class BaseConfig(object):
    def __init__(self):
        django_settings = import_django_settings()
        if django_settings:
            self.update(**django_settings)

        self._load_config_from_env()

    def __getattr__(self, i):
        return self.__dict__.get(i)

    @staticmethod
    def _is_nested_key(key):
        return re.match(r'\w+\[\w+\]', key)

    def _put_nested_key(self, key, value):
        chain = re.split(r'[\[\]]+', key)
        chain = [k for k in chain if k]
        outer = self.__dict__
        last_key = chain.pop()
        for inner_key in chain:
            if inner_key in outer:
                inner = outer[inner_key]
            else:
                inner = dict()
                outer[inner_key] = inner
            outer = inner
        if isinstance(value, list):
            value = value[0]
        outer[last_key] = value

    def _is_url_scheme_valid(self, url):
        """
        Helper function. Validates url scheme

        :param url: A named tuple containing URL components

        :return: bool True on success or False on failure
        """
        return url.scheme.lower() == self._uri_scheme

    @staticmethod
    def _parse_cloudinary_url(cloudinary_url):
        return urlparse(cloudinary_url)

    @abc.abstractmethod
    def _config_from_parsed_url(self, parsed_url):
        """Extract additional config from the parsed URL."""
        raise NotImplementedError()

    def _setup_from_parsed_url(self, parsed_url):
        config_from_parsed_url = self._config_from_parsed_url(parsed_url)
        self.update(**config_from_parsed_url)

        for k, v in parse_qs(parsed_url.query).items():
            if self._is_nested_key(k):
                self._put_nested_key(k, v)
            else:
                self.__dict__[k] = v[0]

    def _load_from_url(self, url):
        parsed_url = self._parse_cloudinary_url(url)

        return self._setup_from_parsed_url(parsed_url)

    @abc.abstractmethod
    def _load_config_from_env(self):
        """Load config from environment variables or URL."""
        raise NotImplementedError()

    def update(self, **keywords):
        for k, v in keywords.items():
            self.__dict__[k] = v


class Config(BaseConfig):
    def __init__(self):
        self._uri_scheme = URI_SCHEME

        super(Config, self).__init__()

        if not self.signature_algorithm:
            self.signature_algorithm = utils.SIGNATURE_SHA1
        if not self.signature_version:
            self.signature_version = 2

    def _config_from_parsed_url(self, parsed_url):
        if not self._is_url_scheme_valid(parsed_url):
            raise ValueError("Invalid CLOUDINARY_URL scheme. Expecting to start with 'cloudinary://'")

        is_private_cdn = parsed_url.path != ""
        result = {
            "cloud_name": parsed_url.hostname,
            "api_key": parsed_url.username,
            "api_secret": parsed_url.password,
            "private_cdn": is_private_cdn,
        }
        if is_private_cdn:
            result.update({"secure_distribution": parsed_url.path[1:]})

        return result

    def _load_config_from_env(self):
        if os.environ.get("CLOUDINARY_CLOUD_NAME"):
            config_keys = [key for key in os.environ.keys()
                           if key.startswith("CLOUDINARY_") and key != "CLOUDINARY_URL"]

            for full_key in config_keys:
                conf_key = full_key[len("CLOUDINARY_"):].lower()
                conf_val = os.environ[full_key]
                if conf_val in ["true", "false"]:
                    conf_val = conf_val == "true"

                self.update(**{conf_key: conf_val})
        elif os.environ.get("CLOUDINARY_URL"):
            self._load_from_url(os.environ.get("CLOUDINARY_URL"))


_config = Config()


def config(**keywords):
    global _config
    _config.update(**keywords)
    return _config


def reset_config():
    global _config
    _config = Config()


_http_client = HttpClient()

# FIXME: circular import issue
from cloudinary.search import Search
from cloudinary.search_folders import SearchFolders


@python_2_unicode_compatible
class CloudinaryResource(object):
    """
    Recommended sources for video tag
    """
    default_video_sources = [
        {
            "type": "mp4",
            "codecs": "hev1",
            "transformations": {"video_codec": "h265"}
        }, {
            "type": "webm",
            "codecs": "vp9",
            "transformations": {"video_codec": "vp9"}
        }, {
            "type": "mp4",
            "transformations": {"video_codec": "auto"}
        }, {
            "type": "webm",
            "transformations": {"video_codec": "auto"}
        },
    ]

    def __init__(self, public_id=None, format=None, version=None,
                 signature=None, url_options=None, metadata=None, type=None, resource_type=None,
                 default_resource_type=None):
        self.metadata = metadata
        metadata = metadata or {}
        self.public_id = public_id or metadata.get('public_id')
        self.format = format or metadata.get('format')
        self.version = version or metadata.get('version')
        self.signature = signature or metadata.get('signature')
        self.type = type or metadata.get('type') or "upload"
        self.resource_type = resource_type or metadata.get('resource_type') or default_resource_type
        self.url_options = url_options or {}

    def __str__(self):
        return self.public_id

    def __len__(self):
        return len(self.public_id) if self.public_id is not None else 0

    def validate(self):
        return utils.verify_api_response_signature(self.public_id, self.version, self.signature)

    def get_prep_value(self):
        if None in [self.public_id,
                    self.type,
                    self.resource_type]:
            return None
        prep = ''
        prep = prep + self.resource_type + '/' + self.type + '/'
        if self.version:
            prep = prep + 'v' + str(self.version) + '/'
        prep = prep + self.public_id
        if self.format:
            prep = prep + '.' + self.format
        return prep

    def get_presigned(self):
        return self.get_prep_value() + '#' + self.get_expected_signature()

    def get_expected_signature(self):
        return utils.api_sign_request({"public_id": self.public_id, "version": self.version}, config().api_secret,
                                      config().signature_algorithm, signature_version=1)

    @property
    def url(self):
        return self.build_url(**self.url_options)

    def __build_url(self, **options):
        combined_options = dict(format=self.format, version=self.version, type=self.type,
                                resource_type=self.resource_type or "image")
        combined_options.update(options)
        public_id = combined_options.get('public_id') or self.public_id
        return utils.cloudinary_url(public_id, **combined_options)

    def build_url(self, **options):
        return self.__build_url(**options)[0]

    @staticmethod
    def default_poster_options(options):
        options["format"] = options.get("format", "jpg")

    @staticmethod
    def default_source_types():
        return ['webm', 'mp4', 'ogv']

    @staticmethod
    def _validate_srcset_data(srcset_data):
        """
        Helper function. Validates srcset_data parameters

        :param srcset_data: A dictionary containing the following keys:
                breakpoints A list of breakpoints.
                min_width   Minimal width of the srcset images
                max_width   Maximal width of the srcset images.
                max_images  Number of srcset images to generate.

        :return: bool True on success or False on failure
        """
        if not all(k in srcset_data and isinstance(srcset_data[k], numbers.Number) for k in ("min_width", "max_width",
                                                                                             "max_images")):
            logger.warning("Either valid (min_width, max_width, max_images)" +
                           "or breakpoints must be provided to the image srcset attribute")
            return False

        if srcset_data["min_width"] > srcset_data["max_width"]:
            logger.warning("min_width must be less than max_width")
            return False

        if srcset_data["max_images"] <= 0:
            logger.warning("max_images must be a positive integer")
            return False

        return True

    def _generate_breakpoints(self, srcset_data):
        """
        Helper function. Calculates static responsive breakpoints using provided parameters.

        Either the breakpoints or min_width, max_width, max_images must be provided.

        :param srcset_data: A dictionary containing the following keys:
                                breakpoints A list of breakpoints.
                                min_width   Minimal width of the srcset images
                                max_width   Maximal width of the srcset images.
                                max_images  Number of srcset images to generate.

        :return: A list of breakpoints

        :raises ValueError: In case of invalid or missing parameters
        """
        breakpoints = srcset_data.get("breakpoints", list())

        if breakpoints:
            return breakpoints

        if not self._validate_srcset_data(srcset_data):
            return None

        min_width, max_width, max_images = srcset_data["min_width"], srcset_data["max_width"], srcset_data["max_images"]

        if max_images == 1:
            # if user requested only 1 image in srcset, we return max_width one
            min_width = max_width

        step_size = int(ceil(float(max_width - min_width) / (max_images - 1 if max_images > 1 else 1)))

        curr_breakpoint = min_width

        while curr_breakpoint < max_width:
            breakpoints.append(curr_breakpoint)
            curr_breakpoint += step_size

        breakpoints.append(max_width)

        return breakpoints

    def _fetch_breakpoints(self, srcset_data=None, **options):
        """
        Helper function. Retrieves responsive breakpoints list from cloudinary server

        When passing special string to transformation `width` parameter of form `auto:breakpoints{parameters}:json`,
        the response contains JSON with data of the responsive breakpoints

        :param srcset_data: A dictionary containing the following keys:
                                min_width   Minimal width of the srcset images
                                max_width   Maximal width of the srcset images
                                bytes_step  Minimal bytes step between images
                                max_images  Number of srcset images to generate
        :param options: Additional options

        :return: Resulting breakpoints
        """
        if srcset_data is None:
            srcset_data = dict()

        min_width = srcset_data.get("min_width", 50)
        max_width = srcset_data.get("max_width", 1000)
        bytes_step = srcset_data.get("bytes_step", 20000)
        max_images = srcset_data.get("max_images", 20)
        transformation = srcset_data.get("transformation")

        kbytes_step = int(ceil(float(bytes_step) / 1024))

        breakpoints_width_param = "auto:breakpoints_{min_width}_{max_width}_{kbytes_step}_{max_images}:json".format(
            min_width=min_width, max_width=max_width, kbytes_step=kbytes_step, max_images=max_images)
        breakpoints_url = utils.cloudinary_scaled_url(self.public_id, breakpoints_width_param, transformation, options)

        return _http_client.get_json(breakpoints_url).get("breakpoints", None)

    def _get_or_generate_breakpoints(self, srcset_data, **options):
        """
        Helper function. Gets from cache or calculates srcset breakpoints using provided parameters

        :param srcset_data: A dictionary containing the following keys:
                                breakpoints A list of breakpoints.
                                min_width   Minimal width of the srcset images
                                max_width   Maximal width of the srcset images
                                max_images  Number of srcset images to generate
        :param options: Additional options

        :return: Resulting breakpoints
        """

        breakpoints = srcset_data.get("breakpoints")

        if breakpoints:
            return breakpoints

        if srcset_data.get("use_cache"):
            breakpoints = responsive_breakpoints_cache.instance.get(self.public_id, **options)
            if not breakpoints:
                try:
                    breakpoints = self._fetch_breakpoints(srcset_data, **options)
                except GeneralError as e:
                    logger.warning("Failed getting responsive breakpoints: {error}".format(error=e.message))

                if breakpoints:
                    responsive_breakpoints_cache.instance.set(self.public_id, breakpoints, **options)

        if not breakpoints:
            # Static calculation if cache is not enabled or we failed to fetch breakpoints
            breakpoints = self._generate_breakpoints(srcset_data)

        return breakpoints

    def _generate_srcset_attribute(self, breakpoints, transformation=None, **options):
        """
        Helper function. Generates srcset attribute value of the HTML img tag.

        :param breakpoints: A list of breakpoints.
        :param transformation: Custom transformation
        :param options:     Additional options

        :return:  Resulting srcset attribute value

        :raises ValueError: In case of invalid or missing parameters
        """
        if not breakpoints:
            return None

        if transformation is None:
            transformation = dict()

        return ", ".join(["{0} {1}w".format(utils.cloudinary_scaled_url(
            self.public_id, w, transformation, options), w) for w in breakpoints])

    @staticmethod
    def _generate_sizes_attribute(breakpoints):
        """
        Helper function. Generates sizes attribute value of the HTML img tag.

        :param breakpoints: A list of breakpoints.

        :return: Resulting 'sizes' attribute value
        """
        if not breakpoints:
            return None

        return ", ".join("(max-width: {bp}px) {bp}px".format(bp=bp) for bp in breakpoints)

    def _generate_image_responsive_attributes(self, attributes, srcset_data, **options):
        """
        Helper function. Generates srcset and sizes attributes of the image tag

        Create both srcset and sizes here to avoid fetching breakpoints twice

        :param attributes: Existing attributes
        :param srcset_data: A dictionary containing the following keys:
                                breakpoints     A list of breakpoints.
                                min_width       Minimal width of the srcset images
                                max_width       Maximal width of the srcset images.
                                max_images      Number of srcset images to generate.
        :param options:     Additional options

        :return: The responsive attributes
        """
        responsive_attributes = dict()

        if not srcset_data:
            return responsive_attributes

        breakpoints = None

        if "srcset" not in attributes:
            breakpoints = self._get_or_generate_breakpoints(srcset_data, **options)
            transformation = srcset_data.get("transformation")
            srcset_attr = self._generate_srcset_attribute(breakpoints, transformation, **options)
            if srcset_attr:
                responsive_attributes["srcset"] = srcset_attr

        if "sizes" not in attributes and srcset_data.get("sizes") is True:
            if not breakpoints:
                breakpoints = self._get_or_generate_breakpoints(srcset_data, **options)
            sizes_attr = self._generate_sizes_attribute(breakpoints)
            if sizes_attr:
                responsive_attributes["sizes"] = sizes_attr

        return responsive_attributes

    def image(self, **options):
        """
        Generates HTML img tag

        :param options: Additional options

        :return: Resulting img tag
        """
        if options.get("resource_type", self.resource_type) == "video":
            self.default_poster_options(options)

        custom_attributes = options.pop("attributes", dict())

        srcset_option = options.pop("srcset", dict())
        srcset_data = dict()

        if isinstance(srcset_option, dict):
            srcset_data = config().srcset or dict()
            srcset_data = srcset_data.copy()
            srcset_data.update(srcset_option)
        else:
            if "srcset" not in custom_attributes:
                custom_attributes["srcset"] = srcset_option

        src, attrs = self.__build_url(**options)

        client_hints = attrs.pop("client_hints", config().client_hints)
        responsive = attrs.pop("responsive", False)
        hidpi = attrs.pop("hidpi", False)

        if (responsive or hidpi) and not client_hints:
            attrs["data-src"] = src

            classes = "cld-responsive" if responsive else "cld-hidpi"
            if "class" in attrs:
                classes += " " + attrs["class"]
            attrs["class"] = classes

            src = attrs.pop("responsive_placeholder", config().responsive_placeholder)
            if src == "blank":
                src = CL_BLANK

        responsive_attrs = self._generate_image_responsive_attributes(custom_attributes, srcset_data, **options)

        if responsive_attrs:
            # width and height attributes override srcset behavior, they should be removed from html attributes.
            for key in {"width", "height"}:
                attrs.pop(key, None)

        attrs.update(responsive_attrs)
        # Explicitly provided attributes override options
        attrs.update(custom_attributes)

        if src:
            attrs["src"] = src

        return u"<img {0}/>".format(utils.html_attrs(attrs))

    def video_thumbnail(self, **options):
        self.default_poster_options(options)
        return self.build_url(**options)

    @staticmethod
    def _video_mime_type(video_type, codecs=None):
        """
        Helper function for video(), generates video MIME type string from video_type and codecs.
        Example: video/mp4; codecs=mp4a.40.2

        :param video_type: mp4, webm, ogg etc.
        :param codecs: List or string of codecs. E.g.: "avc1.42E01E" or "avc1.42E01E, mp4a.40.2" or
                       ["avc1.42E01E", "mp4a.40.2"]

        :return: Resulting mime type
        """

        video_type = 'ogg' if video_type == 'ogv' else video_type

        if not video_type:
            return ""

        codecs_str = ", ".join(codecs) if isinstance(codecs, (list, tuple)) else codecs
        codecs_attr = "; codecs={codecs_str}".format(codecs_str=codecs_str) if codecs_str else ""

        return "video/{}{}".format(video_type, codecs_attr)

    @staticmethod
    def _collect_video_tag_attributes(video_options):
        """
        Helper function for video tag, collects remaining options and returns them as attributes

        :param video_options: Remaining options

        :return: Resulting attributes
        """
        attributes = video_options.copy()

        if 'html_width' in attributes:
            attributes['width'] = attributes.pop('html_width')
        if 'html_height' in attributes:
            attributes['height'] = attributes.pop('html_height')

        if "poster" in attributes and not attributes["poster"]:
            attributes.pop("poster", None)

        return attributes

    def _generate_video_poster_attr(self, source, video_options):
        """
        Helper function for video tag, generates video poster URL

        :param source: The public ID of the resource
        :param video_options: Additional options

        :return: Resulting video poster URL
        """
        if 'poster' not in video_options:
            return self.video_thumbnail(public_id=source, **video_options)

        poster_options = video_options['poster']

        if not isinstance(poster_options, dict):
            return poster_options

        if 'public_id' not in poster_options:
            return self.video_thumbnail(public_id=source, **poster_options)

        return utils.cloudinary_url(poster_options['public_id'], **poster_options)[0]

    def _populate_video_source_tags(self, source, options):
        """
        Helper function for video tag, populates source tags from provided options.

        source_types and sources are mutually exclusive, only one of them can be used.
        If both are not provided, source types are used (for backwards compatibility)

        :param source: The public ID of the video
        :param options: Additional options

        :return: Resulting source tags (may be empty)
        """
        source_tags = []

        # Consume all relevant options, otherwise they are left and passed as attributes
        video_sources = options.pop('sources', [])
        source_types = options.pop('source_types', [])
        source_transformation = options.pop('source_transformation', {})

        if video_sources and isinstance(video_sources, list):
            # processing new source structure with codecs
            for source_data in video_sources:
                transformation = options.copy()
                transformation.update(source_data.get("transformations", {}))
                source_type = source_data.get("type", '')
                src = utils.cloudinary_url(source, format=source_type, **transformation)[0]
                codecs = source_data.get("codecs", [])
                source_tags.append("<source {attributes}>".format(
                    attributes=utils.html_attrs({'src': src, 'type': self._video_mime_type(source_type, codecs)})))

            return source_tags

        # processing old source_types structure with out codecs
        if not source_types:
            source_types = self.default_source_types()

        if not isinstance(source_types, (list, tuple)):
            return source_tags

        for source_type in source_types:
            transformation = options.copy()
            transformation.update(source_transformation.get(source_type, {}))
            src = utils.cloudinary_url(source, format=source_type, **transformation)[0]
            source_tags.append("<source {attributes}>".format(
                attributes=utils.html_attrs({'src': src, 'type': self._video_mime_type(source_type)})))

        return source_tags

    def video(self, **options):
        """
        Creates an HTML video tag for the provided +source+

        Examples:
           CloudinaryResource("mymovie.mp4").video()
           CloudinaryResource("mymovie.mp4").video(source_types = 'webm')
           CloudinaryResource("mymovie.ogv").video(poster = "myspecialplaceholder.jpg")
           CloudinaryResource("mymovie.webm").video(source_types = ['webm', 'mp4'], poster = {'effect': 'sepia'})

        :param options:
         * <tt>source_types</tt>            - Specify which source type the tag should include.
                                              defaults to webm, mp4 and ogv.
         * <tt>sources</tt>                 - Similar to source_types, but may contain codecs list.
                                              source_types and sources are mutually exclusive, only one of
                                              them can be used. If both are not provided, default source types
                                              are used.
         * <tt>source_transformation</tt>   - specific transformations to use
                                              for a specific source type.
         * <tt>poster</tt>                  - override default thumbnail:
           * url: provide an ad hoc url
           * options: with specific poster transformations and/or Cloudinary +:public_id+

        :return: Video tag
        """
        public_id = options.get('public_id', self.public_id)
        use_fetch_format = options.get('use_fetch_format', config().use_fetch_format)
        if not use_fetch_format:
            source = re.sub(r"\.({0})$".format("|".join(self.default_source_types())), '', public_id)
        else:
            source = public_id

        custom_attributes = options.pop("attributes", dict())

        fallback = options.pop('fallback_content', '')

        # Save source types for a single video source handling (it can be a single type)
        source_types = options.get('source_types', "")

        poster_options = options.copy()
        if "poster" not in custom_attributes:
            options["poster"] = self._generate_video_poster_attr(source, poster_options)

        if "resource_type" not in options:
            options["resource_type"] = self.resource_type or "video"

        # populate video source tags
        source_tags = self._populate_video_source_tags(source, options)

        if not source_tags:
            source = source + '.' + utils.build_array(source_types)[0]

        video_url, video_options = utils.cloudinary_url(source, **options)

        if not source_tags:
            custom_attributes['src'] = video_url

        attributes = self._collect_video_tag_attributes(video_options)
        attributes.update(custom_attributes)

        sources_str = ''.join(str(x) for x in source_tags)
        html = "<video {attributes}>{sources}{fallback}</video>".format(
            attributes=utils.html_attrs(attributes), sources=sources_str, fallback=fallback)

        return html

    @staticmethod
    def __generate_media_attr(**media_options):
        media_query_conditions = []
        if "min_width" in media_options:
            media_query_conditions.append("(min-width: {}px)".format(media_options["min_width"]))
        if "max_width" in media_options:
            media_query_conditions.append("(max-width: {}px)".format(media_options["max_width"]))

        return " and ".join(media_query_conditions)

    def source(self, **options):
        attrs = options.get("attributes") or {}

        srcset_data = config().srcset or dict()
        srcset_data = srcset_data.copy()
        srcset_data.update(options.pop("srcset", dict()))

        responsive_attrs = self._generate_image_responsive_attributes(attrs, srcset_data, **options)

        attrs.update(responsive_attrs)

        # `source` tag under `picture` tag uses `srcset` attribute for both `srcset` and `src` urls
        if "srcset" not in attrs:
            attrs["srcset"], _ = self.__build_url(**options)

        if "media" not in attrs:
            media_attr = self.__generate_media_attr(**(options.get("media", {})))
            if media_attr:
                attrs["media"] = media_attr

        return u"<source {0}>".format(utils.html_attrs(attrs))

    def picture(self, **options):
        sub_tags = []
        sources = options.pop("sources") or list()
        for source in sources:
            curr_options = deepcopy(options)

            if "transformation" in source:
                curr_options = utils.chain_transformations(curr_options, source["transformation"])

            curr_options["media"] = dict((k, source[k]) for k in ['min_width', 'max_width'] if k in source)

            sub_tags.append(self.source(**curr_options))

        sub_tags.append(self.image(**options))

        return u"<picture>{}</picture>".format("".join(sub_tags))


class CloudinaryImage(CloudinaryResource):
    def __init__(self, public_id=None, **kwargs):
        super(CloudinaryImage, self).__init__(public_id=public_id, default_resource_type="image", **kwargs)


class CloudinaryVideo(CloudinaryResource):
    def __init__(self, public_id=None, **kwargs):
        super(CloudinaryVideo, self).__init__(public_id=public_id, default_resource_type="video", **kwargs)