import csv
import datetime
import logging
from io import StringIO
from typing import Generator

from helpers.mongo import mongo


class Events:
    def __init__(self):
        self.collection = mongo.events_collection
        self.metrics = ("launch", "joke", "ping")

    @property
    def today(self):
        date = datetime.datetime.now()
        return datetime.datetime(year=date.year, month=date.month, day=date.day)

    @property
    def date_range(self) -> Generator[datetime.date, None, None]:
        today = self.today
        first = today - datetime.timedelta(days=30)
        while first <= today:
            yield today
            today = today - datetime.timedelta(days=1)

    def inc(self, event: str):
        if event not in self.metrics:
            logging.error("metric is not allowed")
            return
        query = {"date": self.today, "event": event}
        event = self.collection.find_one(query)
        if event is None:
            query["count"] = 1
            self.collection.insert_one(query)
        else:
            self.collection.update_one({"_id": event["_id"]}, {"$inc": {"count": 1}})

    def form_data(self):
        si = StringIO()
        cw = csv.writer(si)
        cw.writerow(["Date"] + list(self.metrics))
        for date in self.date_range:
            row = [date.strftime("%y-%m-%d")]
            for metric in self.metrics:
                data = self.collection.find_one({"date": date, "event": metric}) or {"count": 0}
                row.append(str(data["count"]))
            cw.writerow(row)
        return si.getvalue()

    def today_json(self):
        values = self.collection.find({"date": self.today})
        values = {value['event']: value['count'] for value in values}
        json_data = {}
        for metric in self.metrics:
            json_data[metric] = values.get(metric) or 0
        return json_data


events = Events()