import asyncio
import time
from datetime import timedelta, timezone, datetime
from gql import Client, gql
from gql.transport.aiohttp import AIOHTTPTransport
from base.orm import local_session
from sqlalchemy import func
from orm.shout import ShoutTopic
from orm.viewed import ViewedEntry
from ssl import create_default_context
from os import environ, path

load_facts = gql("""
query getDomains {
    domains {
        id
        title
        facts {
            activeVisitors
            viewsToday
            viewsMonth
            viewsYear
        }
    }
}
""")

load_pages = gql("""
query getDomains {
    domains {
    title
    statistics {
        pages(sorting: TOP) {
                # id
                count
                # created
                value
            }
        }
    }
}
""")
schema_str = open(path.dirname(__file__) + '/ackee.graphql').read()
token = environ.get("ACKEE_TOKEN", "")


def create_client(headers=None, schema=None):
    return Client(
        schema=schema,
        transport=AIOHTTPTransport(
            url="https://ackee.discours.io/api",
            ssl=create_default_context(),
            headers=headers
        )
    )


class ViewedStorage:
    lock = asyncio.Lock()
    by_shouts = {}
    by_topics = {}
    views = None
    pages = None
    domains = None
    period = 24 * 60 * 60  # one time a day
    client = None
    auth_result = None
    disabled = False

    @staticmethod
    async def init():
        """ graphql client connection using permanent token """
        self = ViewedStorage
        async with self.lock:
            if token:
                self.client = create_client({
                    "Authorization": "Bearer %s" % str(token)
                }, schema=schema_str)
                print("[stat.viewed] * authorized permanentely by ackee.discours.io: %s" % token)
            else:
                print("[stat.viewed] * please set ACKEE_TOKEN")
                self.disabled = True

    @staticmethod
    async def update_pages():
        """ query all the pages from ackee sorted by views count """
        start = time.time()
        self = ViewedStorage
        try:
            self.pages = await self.client.execute_async(load_pages)
            self.pages = self.pages["domains"][0]["statistics"]["pages"]
            print("[stat.viewed] ⎪ ackee pages updated")
            shouts = {}
            try:
                for page in self.pages:
                    p = page["value"].split("?")[0]
                    slug = p.split('discours.io/')[-1]
                    shouts[slug] = page["count"]
                for slug, v in shouts:
                    await ViewedStorage.increment(slug, v)
            except Exception:
                pass
            print("[stat.viewed] ⎪ %d pages collected " % len(shouts.keys()))
        except Exception as e:
            raise e

        end = time.time()
        print("[stat.viewed] ⎪ update_pages took %fs " % (end - start))

    @staticmethod
    async def get_facts():
        self = ViewedStorage
        async with self.lock:
            return self.client.execute_async(load_facts)

    @staticmethod
    async def get_shout(shout_slug):
        """ getting shout views metric by slug """
        self = ViewedStorage
        async with self.lock:
            shout_views = self.by_shouts.get(shout_slug)
            if not shout_views:
                shout_views = 0
                with local_session() as session:
                    try:
                        shout_views = session.query(func.sum(ViewedEntry.amount)).where(
                            ViewedEntry.shout == shout_slug
                        ).all()[0][0]
                        self.by_shouts[shout_slug] = shout_views
                        self.update_topics(session, shout_slug)
                    except Exception as e:
                        raise e

            return shout_views

    @staticmethod
    async def get_topic(topic_slug):
        """ getting topic views value summed """
        self = ViewedStorage
        topic_views = 0
        async with self.lock:
            for shout_slug in self.by_topics.get(topic_slug, {}).keys():
                topic_views += self.by_topics[topic_slug].get(shout_slug, 0)
        return topic_views

    @staticmethod
    def update_topics(session, shout_slug):
        """ updates topics counters by shout slug """
        self = ViewedStorage
        for t in session.query(ShoutTopic).where(ShoutTopic.shout == shout_slug).all():
            tpc = t.topic
            if not self.by_topics.get(tpc):
                self.by_topics[tpc] = {}
            self.by_topics[tpc][shout_slug] = self.by_shouts[shout_slug]

    @staticmethod
    async def increment(shout_slug, amount=1, viewer='anonymous'):
        """ the only way to change views counter """
        self = ViewedStorage
        async with self.lock:
            with local_session() as session:
                viewed = ViewedEntry.create(**{
                    "viewer": viewer,
                    "shout": shout_slug,
                    "amount": amount
                })
                session.add(viewed)
                session.commit()
                self.by_shouts[shout_slug] = self.by_shouts.get(shout_slug, 0) + amount
                self.update_topics(session, shout_slug)

    @staticmethod
    async def worker():
        """ async task worker """
        failed = 0
        self = ViewedStorage
        if self.disabled:
            return
        async with self.lock:
            while True:
                try:
                    print("[stat.viewed] ⎧ updating views...")
                    await self.update_pages()
                    failed = 0
                except Exception:
                    failed += 1
                    print("[stat.viewed] ⎩ update failed #%d, wait 10 seconds" % failed)
                    if failed > 3:
                        print("[stat.viewed] ⎩ not trying to update anymore")
                        break
                if failed == 0:
                    when = datetime.now(timezone.utc) + timedelta(seconds=self.period)
                    t = format(when.astimezone().isoformat())
                    print("[stat.viewed] ⎩ next update: %s" % (
                        t.split("T")[0] + " " + t.split("T")[1].split(".")[0]
                    ))
                    await asyncio.sleep(self.period)
                else:
                    await asyncio.sleep(10)
                    print("[stat.viewed] ⎧ trying to update data again...")