import json
from collections import Counter
from datetime import datetime, timedelta

import pytz
import tornado

from core.prometheus_metrics_handler import api_requests_counter

CONTINENTS = ["EU", "NA", "SA", "AS", "AF", "OC", "AN"]
BANDS = ["160m", "80m", "60m", "40m", "30m", "20m", "17m", "15m", "12m", "10m", "6m"]
CONTINENTS_SET = frozenset(CONTINENTS)
BANDS_SET = frozenset(BANDS)


class APIDxStatsHandler(tornado.web.RequestHandler):
    """API request handler for /api/v1/dxstats"""

    def initialize(self, spots, web_server_metrics):
        self._spots = spots
        self._web_server_metrics = web_server_metrics

    def get(self):
        self._web_server_metrics["last_api_access_time"] = datetime.now(pytz.UTC)
        self._web_server_metrics["api_access_counter"] += 1
        self._web_server_metrics["status"] = "OK"
        api_requests_counter.inc()

        one_hour_ago = (datetime.now(pytz.UTC) - timedelta(hours=1)).timestamp()
        counts = Counter()

        for key in self._spots.iterkeys():
            spot = self._spots.get(key)
            if spot is None:
                continue
            if not spot.time or spot.time < one_hour_ago:
                continue
            if spot.de_continent in CONTINENTS_SET and spot.dx_continent in CONTINENTS_SET and spot.band in BANDS_SET:
                counts[spot.de_continent, spot.dx_continent, spot.band] += 1

        result = {
            de: {dx: {band: counts[de, dx, band] for band in BANDS} for dx in CONTINENTS}
            for de in CONTINENTS
        }

        self.write(json.dumps(result))
        self.set_status(200)
        self.set_header("Cache-Control", "no-store")
        self.set_header("Content-Type", "application/json")