#!/usr/bin/env python

import os, re, sys

# check command-line arguments
if len(sys.argv) < 4:
	print "usage: " + sys.argv[0] + " <template file> <data file> <output file>";
	sys.exit()

# xml output header (created here to keep the template creation simple)
xml_header = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"

# xml output footer
xml_footer = "\n"

# read in the template file (1st command-line argument)
try:
	tmplif = open(sys.argv[1], 'r')
	try:
		template = tmplif.readlines()
	finally:
		tmplif.close()
except IOError:
	print "Failed to open template file " + sys.argv[1] + "!"
	sys.exit()

# read in the data file, using the first line as a header to define template
# replacement values. If the header line contains
# "Term","Section_Name","Person_ID","Campus_User_Name" then any occurences of
# #Term, #Section_Name, #Person_ID, or #Campus_User_Name will be replaced with
# the appropriate value from the csv data file in the resulting xml output.
try:
	dataif = open(sys.argv[2], 'r')
	try:
		# read all lines in the file into a list
		datafile = dataif.readlines()
		# use the first line to get column names (and remove trailing newline)
		colnames = re.sub('\n$', '', datafile[0])
		# remove quotation marks
		colnames = re.sub('"', '', colnames)
		# make a list of the column names
		columns = colnames.split(',')
		# remove the header from the data list now that column names are stored
		datafile.reverse()
		datafile.pop()
		datafile.reverse()
	finally:
		dataif.close()
except IOError:
	print "Failed to open data file " + sys.argv[2] + "!"
	sys.exit

# all the necessary data is gathered now, try to open the output file (if it
# exists it will be overwritten!)
try:
	xmlof = open(sys.argv[3], 'w')
	try:
		# write the xml header
		xmlof.write(xml_header)
		# for each entry in the data list, make an appropriate xml entry
		# with template placeholders replaced by values from the data list
		for line in datafile:
			#print "Line: %d" % datafile.index(line)
			# remove trailing newline
			line = re.sub('\n$', '', line)
			# remove quotation marks
			line = re.sub('"', '', line)
			print "\nCurrent entry: [%s]" % line
			#continue
			# split the line into a list of columns
			linelist = line.split(',')
			#print "Items on line: %d" % len(linelist)
			#print "[%s] [%s] [%s] [%s]\n" % (linelist[0], linelist[1], linelist[2], linelist[3]),
			skipline = 0
			for line in linelist:
				if len(line) == 0:
					skipline = 1
			if skipline == 1:
				skipline = 0
				break

			# create a new xml entry from the template
			for entry in template:
				print "%s" % entry,
			newxmlentry = template
			for entry in newxmlentry:
				print "%s" % entry,

			print ""

			# for each item in each datafile line
			for item in linelist:
				print "Current item: %s" % item
				# now try to replace it in every line of the template
				for tmplline in newxmlentry:
					tmpindex = newxmlentry.index(tmplline)
					#print "Index (newxmlentry line): %d" % tmpindex
					#print "Template line: %s" % tmplline,
					srchstr = "#" + columns[linelist.index(item)]
					#print "Search string: %s" % srchstr
					newline = tmplline.replace(srchstr, item)
					newxmlentry[tmpindex] = newline
					#print "New entry: %s" % newxmlentry[tmpindex],

			for line in newxmlentry:
				print line,
				
			for newline in newxmlentry:
				xmlof.write(newline)

		# write the xml footer
		xmlof.write(xml_footer)
	finally:
		xmlof.close()
except IOError:
	print "Failed to open output file " + sys.argv[3] + "!"
	sys.exit()