import hashlib
import pickle
import re
import socket
import ssl
from .compat import get_charset
from .compat import HTTPError
from .compat import OrderedDict
from .compat import Request
from .compat import urlencode
from .compat import URLError
from .compat import urlopen
try:
    import simplejson as json
    try:
        InvalidJson = json.JSONDecodeError
    except AttributeError:
        InvalidJson = ValueError
except ImportError:
    import json
    InvalidJson = ValueError

from micawber.exceptions import InvalidResponseException
from micawber.exceptions import ProviderException
from micawber.exceptions import ProviderNotFoundException


class Provider(object):
    def __init__(self, endpoint, timeout=3.0, user_agent=None, **kwargs):
        self.endpoint = endpoint
        self.socket_timeout = timeout
        self.user_agent = user_agent or 'python-micawber'
        self.base_params = {'format': 'json'}
        self.base_params.update(kwargs)

    def fetch(self, url):
        req = Request(url, headers={'User-Agent': self.user_agent})
        try:
            resp = fetch(req, self.socket_timeout)
        except URLError:
            return False
        except HTTPError:
            return False
        except socket.timeout:
            return False
        except ssl.SSLError:
            return False
        return resp

    def encode_params(self, url, **extra_params):
        params = dict(self.base_params)
        params.update(extra_params)
        params['url'] = url
        return urlencode(sorted(params.items()))

    def request(self, url, **extra_params):
        encoded_params = self.encode_params(url, **extra_params)

        endpoint_url = self.endpoint
        if '?' in endpoint_url:
            endpoint_url = '%s&%s' % (endpoint_url.rstrip('&'), encoded_params)
        else:
            endpoint_url = '%s?%s' % (endpoint_url, encoded_params)

        response = self.fetch(endpoint_url)
        if response:
            return self.handle_response(response, url)
        else:
            raise ProviderException('Error fetching "%s"' % endpoint_url)

    def handle_response(self, response, url):
        try:
            json_data = json.loads(response)
        except InvalidJson as exc:
            try:
                msg = exc.message
            except AttributeError:
                msg = exc.args[0]
            raise InvalidResponseException(msg)

        if 'url' not in json_data:
            json_data['url'] = url
        if 'title' not in json_data:
            json_data['title'] = json_data['url']

        return json_data


def make_key(*args, **kwargs):
    return hashlib.md5(pickle.dumps((args, kwargs))).hexdigest()


def url_cache(fn):
    def inner(self, url, **params):
        if self.cache is not None:
            key = make_key(url, params)
            data = self.cache.get(key)
            if not data:
                data = fn(self, url, **params)
                self.cache.set(key, data)
            return data
        return fn(self, url, **params)
    return inner


def fetch(request, timeout=None):
    urlopen_params = {}
    if timeout:
        urlopen_params['timeout'] = timeout
    resp = urlopen(request, **urlopen_params)
    if resp.code < 200 or resp.code >= 300:
        return False

    # by RFC, default HTTP charset is ISO-8859-1
    charset = get_charset(resp) or 'iso-8859-1'

    content = resp.read().decode(charset)
    resp.close()
    return content


class ProviderRegistry(object):
    def __init__(self, cache=None):
        self._registry = OrderedDict()
        self.cache = cache

    def register(self, regex, provider):
        self._registry[regex] = provider

    def unregister(self, regex):
        del self._registry[regex]

    def __iter__(self):
        return iter(reversed(list(self._registry.items())))

    def provider_for_url(self, url):
        for regex, provider in self:
            if re.match(regex, url):
                return provider

    @url_cache
    def request(self, url, **params):
        provider = self.provider_for_url(url)
        if provider:
            return provider.request(url, **params)
        raise ProviderNotFoundException('Provider not found for "%s"' % url)


def bootstrap_basic(cache=None, registry=None):
    # complements of oembed.com#section7
    pr = registry or ProviderRegistry(cache)

    # c
    pr.register(r'http://chirb\.it/\S+', Provider('http://chirb.it/oembed.json'))
    pr.register(r'https?://www\.circuitlab\.com/circuit/\S+', Provider('https://www.circuitlab.com/circuit/oembed'))

    # d
    pr.register(r'https?://(?:www\.)?dailymotion\.com/\S+', Provider('http://www.dailymotion.com/services/oembed'))

    # f
    pr.register(r'https?://\S*?flickr\.com/\S+', Provider('https://www.flickr.com/services/oembed/'))
    pr.register(r'https?://flic\.kr/\S*', Provider('https://www.flickr.com/services/oembed/'))
    pr.register(r'https?://(?:www\.)?funnyordie\.com/videos/\S+', Provider('http://www.funnyordie.com/oembed'))

    # g
    pr.register(r'https?://gist\.github\.com/\S*', Provider('https://github.com/api/oembed'))

    # h
    pr.register(r'http://(?:www\.)hulu\.com/watch/\S+', Provider('http://www.hulu.com/api/oembed.json'))

    # i
    pr.register(r'https?://\S*imgur\.com/\S+', Provider('https://api.imgur.com/oembed')),
    pr.register(r'https?://(www\.)?instagr(\.am|am\.com)/p/\S+', Provider('http://api.instagram.com/oembed'))

    # m
    pr.register(r'http://www\.mobypicture\.com/user/\S*?/view/\S*', Provider('http://api.mobypicture.com/oEmbed'))
    pr.register(r'http://moby\.to/\S*', Provider('http://api.mobypicture.com/oEmbed'))

    # p
    pr.register(r'http://i\S*\.photobucket\.com/albums/\S+', Provider('http://photobucket.com/oembed'))
    pr.register(r'http://gi\S*\.photobucket\.com/groups/\S+', Provider('http://photobucket.com/oembed'))
    pr.register(r'http://www\.polleverywhere\.com/(polls|multiple_choice_polls|free_text_polls)/\S+', Provider('http://www.polleverywhere.com/services/oembed/'))
    pr.register(r'https?://(.+\.)?polldaddy\.com/\S*', Provider('http://polldaddy.com/oembed/'))

    # s
    pr.register(r'https?://(?:www\.)?slideshare\.net/[^\/]+/\S+', Provider('http://www.slideshare.net/api/oembed/2'))
    pr.register(r'https?://slidesha\.re/\S*', Provider('http://www.slideshare.net/api/oembed/2'))
    pr.register(r'http://\S*\.smugmug\.com/\S*', Provider('http://api.smugmug.com/services/oembed/'))
    pr.register(r'https://\S*?soundcloud\.com/\S+', Provider('http://soundcloud.com/oembed'))
    pr.register(r'https?://speakerdeck\.com/\S*', Provider('https://speakerdeck.com/oembed.json')),
    pr.register(r'https?://(?:www\.)?scribd\.com/\S*', Provider('http://www.scribd.com/services/oembed'))

    # t
    pr.register(r'https?://(www\.)?twitter\.com/\S+/status(es)?/\S+', Provider('https://api.twitter.com/1/statuses/oembed.json'))

    # v
    pr.register(r'http://vimeo\.com/\S+', Provider('http://vimeo.com/api/oembed.json'))
    pr.register(r'https://vimeo\.com/\S+', Provider('https://vimeo.com/api/oembed.json'))

    # w
    pr.register(r'http://\S+\.wordpress\.com/\S+', Provider('http://public-api.wordpress.com/oembed/'))
    pr.register(r'https?://wordpress\.tv/\S+', Provider('http://wordpress.tv/oembed/'))

    # y
    pr.register(r'http://(\S*\.)?youtu(\.be/|be\.com/watch)\S+', Provider('http://www.youtube.com/oembed'))
    pr.register(r'https://(\S*\.)?youtu(\.be/|be\.com/watch)\S+', Provider('http://www.youtube.com/oembed?scheme=https&'))

    return pr


def bootstrap_embedly(cache=None, registry=None, **params):
    endpoint = 'http://api.embed.ly/1/oembed'
    schema_url = 'http://api.embed.ly/1/services/python'

    pr = registry or ProviderRegistry(cache)

    # fetch the schema
    contents = fetch(schema_url)
    json_data = json.loads(contents)

    for provider_meta in json_data:
        for regex in provider_meta['regex']:
            pr.register(regex, Provider(endpoint, **params))
    return pr


def bootstrap_noembed(cache=None, registry=None, **params):
    endpoint = 'http://noembed.com/embed'
    schema_url = 'http://noembed.com/providers'

    pr = registry or ProviderRegistry(cache)

    # fetch the schema
    contents = fetch(schema_url)
    json_data = json.loads(contents)

    for provider_meta in json_data:
        for regex in provider_meta['patterns']:
            pr.register(regex, Provider(endpoint, **params))
    return pr


def bootstrap_oembed(cache=None, registry=None, **params):
    schema_url = 'https://oembed.com/providers.json'
    pr = registry or ProviderRegistry(cache)

    # Fetch schema.
    contents = fetch(schema_url)
    json_data = json.loads(contents)

    for item in json_data:
        for endpoint in item['endpoints']:
            # Possibly this provider only supports discovery via <link> tags,
            # which is not supported by micawber.
            if 'schemes' not in endpoint:
                continue

            # Consists of one or more schemes, a destination URL and optionally
            # a format, e.g. "json".
            url = endpoint['url']
            if '{format}' in url:
                url = url.replace('{format}', 'json')

            provider = Provider(url, **params)
            for scheme in endpoint['schemes']:
                # Transform the raw pattern into a reasonable regex. Match one
                # or more of any character that is not a slash, whitespace, or
                # a parameter used for separating querystring/url params.
                pattern = scheme.replace('*', r'[^\/\s\?&]+?')
                pr.register(pattern, provider)

    # Currently oembed.com does not provide patterns for YouTube, so we'll add
    # these ourselves.
    pr.register(r'http://(\S*\.)?youtu(\.be/|be\.com/watch)\S+',
                Provider('http://www.youtube.com/oembed'))
    pr.register(r'https://(\S*\.)?youtu(\.be/|be\.com/watch)\S+',
                Provider('http://www.youtube.com/oembed?scheme=https&'))

    return pr
