import pytz
from datetime import timedelta
from dateutil.parser import parse as dt_parse

from hikvision_isc_client.db import influxdb

tz = pytz.timezone('Asia/Shanghai')


class PreEvent(object):

    def __init__(self, start_time, end_time):
        influxdb.reconnect()
        self.start_time = start_time
        self.end_time = end_time

    def get_alarm_list(self, camera_index):
        sql = '''
            select *
            from "one_week"."event_vss"
            where
                time > $start_time
                and time < $end_time
                and camera_index = $camera_index
        '''
        res = influxdb.query(sql, bind_params={
            'start_time': self.start_time,
            'end_time': self.end_time,
            'camera_index': camera_index
        })
        points = []
        if res and len(res) > 0:
            points = res['event_vss']

        return points

    @staticmethod
    def merge_alarm_to_event(alarm_list):

        events = []
        for alarm_point in alarm_list:
            # 报警时间转换成上海时区
            alarm_time = dt_parse(alarm_point['time']).astimezone(tz)
            if len(events) > 0 \
               and alarm_time - events[-1]['end_time'] < timedelta(seconds=40) \
               and events[-1]['end_time'] - events[-1]['start_time'] < timedelta(hours=0.5):
                events[-1]['end_time'] = alarm_time + timedelta(seconds=10)
                continue

            events.append({
                'start_time': alarm_time - timedelta(seconds=10),
                'end_time': alarm_time + timedelta(seconds=20)
            })

        return events


if __name__ == '__main__':

    from hikvision_isc_client.recorder import recorder

    pre_event = PreEvent('2021-04-26 00:00:00', '2021-04-26 16:00:00')
    alarm_points = pre_event.get_alarm_list('f8a3c4d9b8ae42118b4db9fcf7895031')
    for event in pre_event.merge_alarm_to_event(alarm_points):
        recorder('f8a3c4d9b8ae42118b4db9fcf7895031', event['start_time'], event['end_time'])