import urllib
import string
import rfc822
import cStringIO
import time

def make_xlatter():
	alphanumeric=string.letters+string.digits
	source_string=""
	destination_string=""
	for i in range(256):
		source_string=source_string+chr(i)
		if chr(i) in alphanumeric:
			destination_string=destination_string+string.upper(chr(i))
		else:
			destination_string=destination_string+' '
	return string.maketrans(source_string,destination_string)

def simpleParser(text):
	global xlatter
	filtered_text=string.translate(text,xlatter)
	tokens=string.split(filtered_text,' ')
	symbols={}
	for token in tokens:
		if len(token)>0:
			if symbols.has_key(token):
				symbols[token]=symbols[token]+1
			else:
				symbols[token]=1
	return symbols

class Document:
	def __init__(self,name,data=None):
		self.name=name
		self.attributes={'doctype':'basic'}
		self.terms={}
		self.data=data
		if self.data:
			self.parse()

	def parse(self):
		pass

class TextDocument(Document):
	def __init__(self,name,data):
		Document.__init__(self,name,data)
		self.attributes['doctype']='text'
		
	def parse(self):
		self.terms=simpleParser(self.data)

class RFC822Document(Document):
	def __init__(self,name,data=None):
		Document.__init__(self,name,data)
		self.attributes['doctype']='rfc822'

	def parse(self):
		S=cStringIO.StringIO(self.data)
		S.seek(0)
		M=rfc822.Message(S)

		#-- Get the interesting rfc822 attributes.
		subject=M.getheader('subject')
		date=M.getheader('date')
		to_list=M.getaddrlist('to')
		sender_name,sender_address=M.getaddr('from')
		if subject:
			self.attributes['subject']=subject
		if date:
			self.attributes['date']=date
			xdate=M.getdate('date')
			self.attributes['xdate']=time.strftime('%Y%m%d', xdate)
		if len(to_list)>0:
			self.attributes['to']="%s,%s"%(to_list[0])
		if sender_name or sender_address:
			self.attributes['from']="%s,%s"%(sender_name,sender_address)

		#-- Now read the body.
		M.rewindbody()
		body_text=M.fp.read()
		self.terms=simpleParser(body_text)

#-- Factory function to create a new document of the appropriate type.
def newDocument(doctype,name,data):
	if doctype=='rfc822':
		return RFC822Document(name,data)
	if doctype=='text':
		return TextDocument(name,data)
	if doctype=='basic':
		return Document(name,data)

xlatter=make_xlatter()