import csv
from csv import DictReader
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import datetime as dt


def backtest():
    TQQQsharePrice = 100
    investment = 10000
    invested = investment
    TQQQreturns = []
    TQQQcloses = []
    QQQreturns = []
    increment = 2500

    dates = []

    period = 1

    with open("QQQ.csv", newline="") as file:
        reader = DictReader(file)
        next(reader, None)
        data = [row for row in reader]

    target = dt.date(2015, 9, 17)
    for index, day in enumerate(data):
        if dt.datetime.strptime(day["Date"], '%Y-%m-%d').date() == target:
            period = index
            print(target)
            break

    last = float(data[period - 1]["Close"])
    startDay = dt.datetime.strptime(data[period - 1]["Date"], '%Y-%m-%d').date()
    TQQQshares = investment / TQQQsharePrice
    QQQshares = investment / last


    for day in data[period:]:
        percentPL = ((float(day["Close"]) - last) / last) * 3
        date = dt.datetime.strptime(day["Date"], '%Y-%m-%d').date()
        TQQQsharePrice = TQQQsharePrice + (TQQQsharePrice * percentPL)

        if (date - startDay).days > 30:
            startDay = date
            TQQQshares += increment / TQQQsharePrice
            QQQshares += increment / float(day["Close"])
            invested += increment
        # TQQQshares += increment / TQQQsharePrice
        # QQQshares += increment / float(day["Close"])
        # invested += increment

        dates.append(date)
        TQQQreturns.append(TQQQshares * TQQQsharePrice)
        QQQreturns.append(QQQshares * float(day["Close"]))

        last = float(day["Close"])


    plt.gca().xaxis.set_major_formatter(mdates.DateFormatter('%Y-%m-%d'))
    plt.gca().xaxis.set_major_locator(mdates.DayLocator(interval=1000))
    plt.title("3X DAILY LEVERAGED $QQQ \n FIVE YEAR PERIOD 10K THEN $1500 A MONTH (30 DAYS) \n AUGUST 19 2015 - AUGUST 25 2020")
    plt.plot(dates, TQQQreturns, label="3X $QQQ\n FINAL:${:,.2f}\n INVESTED:${:,.2f}".format((int(TQQQsharePrice * TQQQshares)), invested))
    plt.plot(dates, QQQreturns, label="$QQQ\n FINAL:${:,.2f}\n INVESTED:${:,.2f}".format((int(QQQshares * last)), invested))
    plt.legend()
    plt.show()


if __name__ == '__main__':
    backtest()