# importing libraries / dependencies
import os
from selenium import webdriver
from selenium.webdriver.chrome.options import Options
import csv
import time
import datetime
import pytz

starttime = time.time() # get the current time (for interval calculatio)
date = datetime.datetime.now() # get the current date (for filename)

# specify options for google chrome in headless mode (runs without GUI)
chrome_options = Options()
chrome_options.add_argument("--headless")

interval = 2.0  # interval for crawler in seconds
symbol = "NDX"  # symbol that is used in CSV file
market_open_hour = 14  # hour when the market opens (in UTC time)
market_open_minute = 30  # minute when the market opens
market_close_hour = 21  # hour when the market closes (in UTC time)

# run the google chrome driver
driver = webdriver.Chrome(executable_path=os.path.abspath("chromedriver"), chrome_options=chrome_options)
driver.get("https://finance.yahoo.com/quote/%5ENDX?p=&guccounter=1")

# define the filename of the csv file (e.g. NDX-2020-11-26.csv)
csvfile = "{}-{}-{}-{}.csv".format(symbol, date.year, date.month, date.day)

# setting this to false will end the crawling
running = True

# open CSV file
with open(csvfile, 'w') as file:
    writer = csv.writer(file)
    writer.writerow(["symbol", "price", "timestamp"])  # write first line in csv file
    while running:

        # find the element by its xpath on the website
        price = driver.find_element_by_xpath('//div[@id="quote-market-notice"]/preceding-sibling::span[2]').text

        # get the current UTC timestamp
        timestamp = datetime.datetime.now(pytz.utc)

        # only store it, if market is open
        if (timestamp.hour >= market_open_hour) and (timestamp.minute >= market_open_minute) and (timestamp.hour < market_close_hour):
            print("symbol: " + symbol + ",price: " + price + ", timestamp: " + str(timestamp))
            # write it to CSV
            writer.writerow([symbol, price, timestamp])
        elif timestamp.hour > market_close_hour:
            print("market closed, ", str(timestamp))
            # stop crawling
            running = False
        else:
            print("market not opened yet, ", str(timestamp))
        # repeat in the given interval (program will sleep for the interval specified)
        time.sleep(interval - ((time.time() - starttime) % interval))

driver.close()