import datetime
import logging

from aiohttp import ClientSession


log = logging.getLogger(__name__)


class DiscordAlert:
    def __init__(self, alert_name: str, alert: dict):
        self.name = alert_name
        self.url = alert['url']
        self.session = ClientSession()

    def _make_payload(self, worker, status: dict):
        service = worker.service

        serv_name = service['name']
        is_up = status['status']

        err = status.get('error', 'No error provided')
        color = 0x00ff00 if is_up else 0xff0000

        ts = status['timestamp'] / 1000
        dt_iso = datetime.datetime.utcfromtimestamp(ts).isoformat()
        embed = {
            'title': serv_name,
            'color': color,
            'timestamp': dt_iso
        }

        if not is_up:
            embed['description'] = f'error: {err}'
        else:
            # calculate downtime here

            # first we need to find the work that had a success
            # before the current one
            conn = worker.manager.conn
            cur = conn.cursor()

            # find the last work that had a success
            cur.execute(f"""
            SELECT timestamp FROM {worker.name}
            WHERE timestamp < ? AND status = 1
            ORDER BY timestamp DESC
            LIMIT 1
            """, (status['timestamp'], ))

            row = cur.fetchone()
            ts_success = row[0]

            # now we fetch all the downtime after that ts_success
            cur.execute(f"""
            SELECT COUNT(*) FROM {worker.name}
            WHERE timestamp > ? AND status = 0
            """, (ts_success,))

            row = cur.fetchone()
            count = row[0]

            downtime_msec = count * worker.service['poll'] * 1000
            downtime_sec = downtime_msec / 1000
            downtime_min = round(downtime_sec / 60, 3)

            embed['footer'] = {
                'text': f'down for {downtime_min} minutes '
                        f'({downtime_sec} seconds)'
            }

        return {
            'content': '',
            'embeds': [embed],
        }

    async def post(self, service: dict, status: dict):
        payload = self._make_payload(service, status)

        log.warning(f'Posting an alert! {status.get("error")}')
        async with self.session.post(self.url, json=payload) as resp:
            return resp