# coding=utf-8

#: ## Lab 6 ##
#: 
#: CS-2910 Network Protocols  
#: Dr. Yoder (Original template by Dr. Sebern)  
#: Fall quarter 2014-2015
#: 
#: | Team members (username) |
#: |:------------------------|
#: | Brianna Wu   (wub)      |
#: | Steve Lubitz (lubitzs)  |
#: 
# If you are curious about the names above, look them up!

import imaplib
import base64
import quopri
import email
from email.parser import Parser

# Open a file containing the full text of an email message (headers and all).
# Display the hierarchy of parts in the message.
# Save each "leaf" (non-multipart) part in a file.
def main():
	email_parser = Parser()
	with open('imaplib-mail.txt','rb') as input_file:
		email_message = email.message_from_file(input_file)
	print "Python's default take:"
	email.iterators._structure(email_message) 
	print

	print "Message part hierarchy:"
	# Process the message parts, starting with [1], which is rendered as "1"
	# The first child will be [1 1], rendered as "1.1"
	process_child_parts(email_message,[])

# Recursive function to traverse (depth-first) the message part hierarchy.	
# 
# part_num: An array of integers. e.g. [1 2 3] represents part 1.2.3
def process_child_parts(part,part_num):
	part_type = part.get_content_type();
	# Make the part number in dotted decimal notation
        if len(part_num) > 0:
	   part_num_str = str(part_num[0])
	   for part_num_component in part_num[1:]:
	      part_num_str += '.' + str(part_num_component)
        else: 
           part_num_str = '(top)'
	# print '{0} {1}'.format(part_num_str,part_type)

	# Display the header items for this part
	header_items = part.items()
	for item in part.items():
		print '{0} : Header: {1} = {2}'.format(part_num_str,item[0],item[1])
	params = part.get_params()
	for param in params:
		param_value = '= ' + param[1] if param[1] else ''
		print '{0} : Content-Type: {1} {2}'.format(part_num_str,param[0],param_value)

	# If part is not multipart, it is a leaf part; process it.
	if not part.is_multipart():
		part_payload = part.get_payload()
		transfer_encoding = part.get('Content-Transfer-Encoding')

		# As it is, this code will dump each leaf part into a file named with its number.
		# To get the real data, it is necessary to decode the part_payload value
		# before writing it to the file.

		# This is where the decoding SHOULD happen
		part_payload = process_part(part_payload, transfer_encoding)

		with open('data-'+part_num_str,'wb') as payload_file:
			payload_file.write(part_payload)
	#	print '{0} : Payload:\n--------\n{1}\n--------'.format(part_num_str,part_payload)

	# If part is multipart, recurse to children.
	else:
		children = []
		for child in part.get_payload():
			children.append(child)
		# print "children=",children
		child_num = 1
		for child2 in children[0:]:
			# print "child2=",child2.get_content_type()
			child_part_num = part_num[:]
			child_part_num.append(child_num)
			child_num += 1
			process_child_parts(child2,child_part_num)
	return

# Decode the part_payload value
#	part_payload -- the raw part text
# Return value
#	Decoded part, as a string
def process_part(part_payload,transfer_encoding):
	# Default is to do nothing
	decoded_payload = part_payload
	
	# Modify this method to do the proper decoding.
	return decoded_payload

main()