# (SS,7/4/14) Python script to lookup EUR and USD exchanges rates from Yahoo and save to HyperFlight currency tables

import urllib2
import datetime
from BeautifulSoup import BeautifulSoup
import MySQLdb
import sys
import smtplib
from email.mime.text import MIMEText
import email.utils

def fetch_page(AURL): 
  print AURL
  req = urllib2.Request(AURL, '',  {'User-Agent' : 'Mozilla/5.0 (Windows NT 6.3; WOW64)'})
  response = urllib2.urlopen(req)
  the_page = response.read()
  return the_page      
      
def get_currency_yahoo(AFromCurrency, AToCurrency):
    LToken = AFromCurrency.lower() + AToCurrency.lower() # e.g. gbpusd
    LURL = 'http://uk.finance.yahoo.com/q?s=' + LToken + '=x'
    html = fetch_page(LURL)
    
    soup = BeautifulSoup(html)
    
    # find the exchange rate which is in a span e.g. <span id="yfs_l10_gbpusd=x">1.6592</span>
    spans = soup.findAll('span', {"id" : "yfs_l10_" + LToken + "=x"})
    LExchangeRate = 0
    if len(spans) > 0:
        try:
            LExchangeRate = float(spans[0].text.strip())
        except ValueError, e:
            print 'ValueError: %s' % (e)
    else:
        print 'Exchange rate not found'
        
    return LExchangeRate
    
def get_currency(AFromCurrency, AToCurrency):
    print
    LExchangeRate = get_currency_yahoo(AFromCurrency, AToCurrency); 
    print 'Exchange rate %s to %s: %s' % (AFromCurrency, AToCurrency, LExchangeRate)
    
    # save in history table
    LSQL = 'INSERT INTO currency_history SET \
        ExchangeRateDateTime = NOW(), Currency = "%s", \
        ExchangeRate = %0.4f' % (AToCurrency, LExchangeRate)
    cur.execute(LSQL)
    
    # update currencies table if <> 0
    if LExchangeRate != 0:
        LSQL = 'UPDATE currencies SET \
            ExchangeRate = %0.4f \
            WHERE Currency = "%s"' % (LExchangeRate, AToCurrency)
        cur.execute(LSQL)
    else:
        set_alert(True) # signal alert if exchange is 0

def set_alert(AAlert):
    global FAlert # required to modify a global 
    FAlert = AAlert
      
def get_alert():
    return FAlert
      
def send_email_file(AFileName, ASubject, AFrom, ATo, ABcc):
    # Open a plain text file for reading.  For this example, assume that
    # the text file contains only ASCII characters.
    fp = open(AFileName, 'rb')
    # Create a text/plain message
    msg = MIMEText(fp.read())
    fp.close()

    # header    
    if get_alert():
        msg['Subject'] = 'ALERT!!! ' + ASubject
    else:
        msg['Subject'] = ASubject
    msg['From'] = AFrom
    msg['To'] = ATo
    msg['Date'] = email.utils.formatdate(localtime=True)
    if get_alert():       
        msg['X-Priority'] = '2'
            
    # send the messsage using localhost
    s = smtplib.SMTP('localhost')
    s.sendmail(AFrom, [ATo, ABcc], msg.as_string())
    s.quit()
     
LOG_FILE = 'get_currency_exchange_rates.log'
 
FAlert = False  # global used to set alert
 
# output all prints to file
f = open(LOG_FILE, 'w')
sys.stdout = f 
        
start = datetime.datetime.now()
print('Started: ' + start.strftime('%Y-%m-%d %H:%M:%S'))
filename_date_suffix = start.strftime('%Y-%m-%d')

con = MySQLdb.connect(host='localhost', user='hyperflight', passwd='b747', db='hyperflight')
cur = con.cursor()

# fetch all (non GBP) currencies from currencies table
cur.execute("SELECT Currency FROM currencies WHERE Currency <> 'GBP' ORDER BY Currency")
rows = cur.fetchall()
for row in rows:
    get_currency('GBP', row[0]) # e.g. get_currency('GBP', 'EUR')

cur.close()
con.close()

finish = datetime.datetime.now()
time_taken = finish - start
print
print('Finished: ' + finish.strftime('%Y-%m-%d %H:%M:%S'))
print('Time taken: %0.3f seconds' % (time_taken.seconds + time_taken.microseconds / 1E6))

# set back to default out and close the opened log file
sys.stdout = sys.__stdout__
f.close()

# send the file as an email
send_email_file(LOG_FILE, 'HyperFlight Exchange Rate Result', 'exchange_rate@hyperflight.co.uk', 'sales@hyperflight.co.uk', 'contactforms@itpartnership.com')