import requests


class Fetcher:
    def __init__(self, URL, token):
        self.URL = URL
        self.token = token
        self.headers = {"Authorization": "GoogleLogin auth="+token}
        self.getUnreadCounts()
        self.getSubscriptions()
        self.articles = {}

    def getUnreadCounts(self):
        response = requests.get(self.URL+"/reader/api/0/unread-count?output=json", headers=self.headers)
        result = dict([(item["id"], (item["count"], item["newestItemTimestampUsec"])) for item in response.json()["unreadcounts"]])
        self.unreadCounts = result
        self.categories = [{"id": item, "name": item[13:], "count": self.unreadCounts[item][0]}
                           for item in self.unreadCounts.keys() if item[0:13] == "user/-/label/"]

    def getSubscriptions(self):
        response = requests.get(self.URL+"/reader/api/0/subscription/list?output=json", headers=self.headers)
        self.feeds = response.json()["subscriptions"]

    def feedsFromCategory(self, category):
        return [item for item in self.feeds if item["categories"][0]["id"] == category and self.unreadCounts[item["id"]][0] != 0]

    def articlesFromCategory(self, category, number):
        if category not in self.articles:
            response = requests.get(self.URL+"/reader/api/0/stream/contents?n="+number+"&s=user/-/label/"+category, headers=self.headers)
            self.articles[category] = response.json()["items"]

    def articlesFromFeed(self, feed, category):
        return [article for article in self.articles[category] if article["origin"]["streamId"] == feed]

    def fetch(self):
        for category in self.categories:
            yield "Fetching category " + category["name"]
            self.articlesFromCategory(category["name"], str(self.unreadCounts[category["id"]][0]))