from hashlib import sha1
from django.conf import settings
from django.http import HttpResponse
from django.utils import simplejson as json

class LayarException(Exception):
    def __init__(self, code, message):
        self.code = code
        self.message = message

class POI(object):

    def __init__(self, id, lat, lon, title, actions=None, image_url=None,
                 line2=None, line3=None, line4=None, type=0, attribution=None):
        self.id = str(id)
        self.lat = lat
        self.lon = lon
        self.title = title          # recommended max len 60
        self.imageURL = image_url
        self.line2 = line2          # recommended max len 35
        self.line3 = line3
        self.line4 = line4
        self.type = type
        self.attribution = attribution  # recommended max len 45
        self.actions = actions

    def to_dict(self):
        d = dict(self.__dict__)

        # do lat/long conversion
        if isinstance(self.lat, float):
            d['lat'] = int(self.lat*1000000)
        if isinstance(self.lon, float):
            d['lon'] = int(self.lon*1000000)

        # convert actions dictionary into expected format
        if self.actions:
            d['actions'] = [{'label':k, 'uri':v} for k,v in self.actions.iteritems()]
        else:
            d['actions'] = []

        return d

class LayarView(object):

    results_per_page = 15
    max_results = 50

    def __init__(self):
        self.developer_key = settings.LAYAR_DEVELOPER_KEY

    def __call__(self, request):
        user_id = request.GET['userId']
        developer_id = request.GET['developerId']
        developer_hash = request.GET['developerHash']
        timestamp = request.GET['timestamp']
        layer_name = request.GET['layerName']
        latitude = request.GET['lat']
        longitude = request.GET['lon']
        accuracy = request.GET['accuracy']
        radius = request.GET['radius']
        radio_option = request.GET.get('RADIOLIST')
        search_query = request.GET.get('SEARCHBOX')
        custom_slider = request.GET.get('CUSTOM_SLIDER')
        page_key = request.GET.get('pageKey')

        # oauth: oauth_consumer_key, oauth_signature_method, oauth_timestamp,
        #   oauth_nonce, oauth_version, oauth_signature

        layar_response = dict(hotspots=[], layer=layer_name, errorCode=0,
                              errorString='ok', nextPageKey=None, morePages=False)

        try:

            # verify hash
            key = self.developer_key + timestamp
            if sha1(key).hexdigest() != developer_hash:
                raise LayarException(20, 'Bad developerHash')

            try:
                poi_func = getattr(self, 'get_%s_pois' % layer_name)
            except AttributeError:
                raise LayarException(21, 'no such layer: %s' % layer_name)

            pois = poi_func(latitude=latitude, longitude=longitude, radius=radius,
                            start_index=0,
                            radio_option=radio_option, search_query=search_query,
                            custom_slider=custom_slider)

            # pagination logic
            if len(pois) > self.max_results:
                pois = pois[:self.max_results]

            layar_response['hotspots'] = [poi.to_dict() for poi in pois]

        except LayarException, e:
            layar_response['errorCode'] = e.code
            layar_response['errorString'] = e.message

        content = json.dumps(layar_response)
        return HttpResponse(content, content_type='application/javascript; charset=utf-8')