#!/usr/bin/env python
# Christopher Jones
# 06/16/2013
# getcvn.py
# grabs the cvn when provided the partnumber
import mechanize, cookielib, urllib, urllib2, BeautifulSoup, string, re, sys, getopt


def SetupBrowser():
	## Initialize settings ##
	# Browser
	br = mechanize.Browser()
	# Cookie Jar
	cj = cookielib.LWPCookieJar()
	br.set_cookiejar(cj)
	# Browser options
	br.set_handle_equiv(True)
	#br.set_handle_gzip(True)
	br.set_handle_redirect(True)
	br.set_handle_referer(True)
	br.set_handle_robots(False)
	# Follows refresh 0 but not hangs on refresh > 0
	br.set_handle_refresh(mechanize._http.HTTPRefreshProcessor(), max_time=10)
	# User-Agent (this is cheating, ok?)
	br.addheaders = [('User-agent', 'Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.1) Gecko/2008071615 Fedora/3.0.1-1.fc9 Firefox/3.0.1')]
	###########################
	return br

def ProcessPage(html):
	soup = BeautifulSoup.BeautifulSoup(html)
	return soup

def AppendFile(fileName,DataA,DataB):
	with open(fileName, "a") as myFile:
		myFile.write("\r\n{0}\t{1}".format(DataA,DataB))

def main(argv):
	partNumber = ''
	proxyServer = ''
	outputFile = ''
	verbose = 0
	usage = "Usage: getcvn.py [-p partnumber] [-P proxy server Hostname] [-o Output file]\n\
		 Command Summary:\n\
			-h\t\tHelp (View Usage)\n\
			-o file\t\tSpecify output filename and location*\n\
			-p partnumber\tGM OS Partnumber\n\
			-P addr:port\tSpecify proxy address and port**\n\
			-v\t\tVerbose\n\n\
		 *  If output file is not specified then output will be stdout.\n\
		 ** Proxy-server is optional\n\
		ex: getcvn.py -p 12639835 -P 99.88.250.22:8118 -o /home/out.txt"
	try:
		opts, args = getopt.getopt(argv,"hvp:P:o:",["partNumber=","proxyServer=","outputFile="])
	except getopt.GetoptError:
		print "Invalid arguments!"
		print usage
		sys.exit(1)
	for opt, arg in opts:
		if opt == '-h':
			print usage
			sys.exit()
		elif opt in ("-p", "--partnumber"):
			partNumber = arg
		elif opt in ("-P", "--proxy-server"):
			proxyServer = arg
		elif opt in ("-o", "--ofile"):
			outputFile = arg
		elif opt in ("-v", "--verbose"):
			verbose = 1
	if partNumber == '':
		print "No GM OS Partnumber Supplied!\nPlease Provide a Partnumber"
		print usage
		sys.exit(1)
	br = SetupBrowser()
	if proxyServer != '':
		br.set_proxies({'http': proxyServer})
	if verbose == 1:
		br.set_debug_http(True)
		br.set_debug_redirects(True)
		br.set_debug_responses(True)
	# Open Website
	url = 'http://tis2web.service.gm.com/tis2web'
	try:
		r = br.open(url)
	except IOError, e:
		if hasattr(e, 'reason'):
			if proxyServer:
				print 'We failed to reach a server. Proxy may be down.'
			else:
				print 'We failed to reach a server.'
			print 'Reason: ', e.reason
			sys.exit(3)
		elif hasattr(e, 'code'):
			print 'The server couldn\'t fulfill the request.'
			print 'Error code: ', e.code
			sys.exit(3)
	# Read the Page
	soup = ProcessPage(br.response().read())
	if verbose == 1:
		print soup
	# Get ID Data for Post
	## Pull Form Action
	forms = soup.findAll("form")
	# Validate Data
	if not forms:
		print 'Unable to find: form data for page!'
		sys.exit(3)
	for form in forms:
		if (form['action']):
			postMessage = (form['action'])
	## Pull Input Field IDs
	inputFields = soup.findAll("input")
	# Validate Data
	if not inputFields:
		print 'Unable to find: form input fields for page!'
		sys.exit(3)
	inputFieldIDs = []
	for inputField in inputFields:
		if (inputField['name']):
			inputFieldIDs.append(inputField['name'])
	## Pull Button Data for 'Get CVN'
	formButtons = soup.findAll("button")
	if not formButtons:
		print 'Unable to find: button data for page!'
		sys.exit(3)
	for button in formButtons:
		if (button['onclick']):
			buttonSubmitData = (button['onclick'])
	## Extract ID from Data
	buttonID = re.findall(r"'([A-Z]\w*)'", buttonSubmitData)
	# Setup Post Data
	postURL = "{0}{1}&{2}=1&bm={3}#{3}".format(url,postMessage,buttonID[0],buttonID[1])
	sendData = "{0}=&{1}={2}".format(inputFieldIDs[0],inputFieldIDs[1],partNumber)
	try:
		res = br.open(postURL, sendData)
	except IOError, e:
		if hasattr(e, 'reason'):
			print 'We failed to reach a server.'
			print 'Reason: ', e.reason
		elif hasattr(e, 'code'):
			print 'The server couldn\'t fulfill the request.'
			print 'Error code: ', e.code
	else:
		responseHTML = res.read()
	#	print responseHTML
		soup = ProcessPage(responseHTML)
	# Pull CVN
	CVNData = soup.findAll('br', text = re.compile(r"sps-nao-nao"))
	if not CVNData:
		print 'No CVN Found For {0}'.format(partNumber)
		sys.exit(2)
	else:
		CVNChecksum = re.split(r" ([0-9A-Z]\w*) ", CVNData[0])
		if outputFile != '':
			AppendFile(outputFile,partNumber,CVNChecksum[1])
		else:
			print CVNChecksum[1]
	sys.exit(0)

if __name__ == "__main__":
   main(sys.argv[1:])