"""Mail to news gateway script. Copyright 2000 Cosimo Alfarano

Author: Cosimo Alfarano
Date: September 16 2000

mail2news.py - Copyright 2000 by Cosimo Alfarano <Alfarano@Students.CS.UniBo.It>
You can use this software under the terms of the GPL. If we meet some day,
and you think this stuff is worth it, you can buy me a beer in return.

Thanks to md for this useful formula. Beer is beer.

Gets news email and sends it via SMTP.

class mail2news is  hopefully conform to rfc850.

"""

import sys
from os import unlink, getpid
from socket import gethostbyaddr, gethostname
import string
from re import findall
import time
import nntplib
import pyginfo
import tempfile

class mail2news:
	"""news to mail gateway class"""

	
	reader = None				# mode reader
#	newsgroups = None			# Newsgroups: local.test,local.moderated...
#	approved = None				# Approved: kame@aragorn.lorien.org
	newsserver = 'localhost'	# no comment :)
	port = 119
	user = None
	password = None

	hostname = gethostbyaddr(gethostname())[0]

	heads_dict, smtpheads, nntpheads = {}, {}, {}
	email, headers, body = [], [], []


	def readfile(self):

		for line in sys.stdin.readlines():
			self.email.append(line)
		
		if(len(self.email) == 1 and self.email[0][0] == '/'):
			file = self.email[0][:-1]
			del self.email[0]
			for line in open(file,'r').readlines():
				self.email.append(line)
				
		return 1


	def parseemail(self):
		"""get news email from file or stdin and separate heads from body

		REMEBER: headers value has '\n' as last char.
			Use string[:-1] to ignore newline.
		"""

		try:
			body = 0		# are we in body or in headers?
	
			for line in self.email:
				if not body and len(line) == 1:
					body = 1	# starts email body section

				if not body:
					try:
						# if it is a multi-line header like Received:
						if not line[0] in [' ','\t']:
							try:
								head, value = string.split(line, ' ', 1)
							except string.index_error:
								value = ''
							self.smtpheads[head] = value
						else:
							self.smtpheads[head] = '%s%s' % \
								(self.smtpheads[head], line)
					except (string.index_error), message:
						print 'line: %s' % line
						print '(probably missing couple "Header: value" in %s)' % line
						sys.exit(1)
	
				elif len(line) > 0 and body:
					self.body.append(line)
	
		except (string.index_error), message:
			print message
			sys.exit(1)
	
		return self.smtpheads, self.body

	def puthead(self, dict, list, key):
		"""private, transform dict entries in list entries
		Appends key of dict to list, deleting it from dict.
		"""

		if dict.has_key(key):
			list.append(key + ' ' + dict.get(key))
			del dict[key]
		else:
			return 0
		return 1

	def sortheads(self):
		"""make list sorted by heads: From: To: Subject: first, others, X-*, X-Resent-* last"""

		set = ('Newsgroups:','From:','To:','X-To:','Cc:','Subject:','Date:','Approved:','References:','Message-Id:') # put at top

		for k in set:
			self.puthead(self.heads_dict,self.headers,k)

		for k in self.heads_dict.keys():
			if k[:2] != 'X-' and k[:9] != 'X-Resent-' and k not in set:
				self.puthead(self.heads_dict,self.headers,k)	

		for k in self.heads_dict.keys():
			if k[:2] == 'X-':
				self.puthead(self.heads_dict,self.headers,k)
			
		for k in self.heads_dict.keys():
			if k[:9] == 'X-Resent-':
				self.puthead(self.heads_dict,self.headers,k)
		
		return self.headers
	
	
	def mergeheads(self):
		"""make a unique headers dictionary from NNTP and SMTP 
		single headers dictionaries."""
	
		self.heads_dict = {}

		try:
			for header in self.smtpheads.keys(): # fill it w/ smtp old heads
				self.heads_dict[header] = self.smtpheads[header]
	
			for header in self.nntpheads.keys(): # and replace them w/ nntp new heads
				self.heads_dict[header] = self.nntpheads[header]

		except KeyError, message:
			print message

		return self.heads_dict

	def addheads(self):
		"""add new header like X-Gateway: 
		"""

		info = pyginfo.pygsinfo()

		try:
			self.heads_dict['X-Gateway:'] = info.PROGNAME + ' ' + \
				info.PROGDESC + ' - Mail to News\n'

# it is nntpheads stuff
#			if(self.newsgroups):
#				self.heads_dict['Newsgroups:'] = self.newsgroups
				
#			if(self.approved):
#				self.heads_dict['Approved:'] = self.approved
	
		except KeyError, message:
			print message

		return self.heads_dict

	def renameheads(self):
		"""rename headers such as Resent-*: to X-Resent-*:

		headers renamed are useless or not rfc 977/850 copliant
		handles References/In-Reply-To headers
		"""
		try:

### test 
#			if(post):
#				if(self.heads_dict.has_key(post)):
#					self.heads_dict['X-Original-' + post] = self.heads_dict[post]
#
#				self.heads_dict[post] = self.heads_dict[pre]
#				del(self.heads_dict[pre])
#				
#			else:
#				if(pre[0:2] == 'X-' and self.heads_dict.has_key(pre)):
#					self.heads_dict['X-Original-' + pre] = self.heads_dict[pre]	
#				elif(not pre[0:2] == 'X-' and self.heads_dict.has_key('X-' + pre)):
#					self.heads_dict['X-' + pre] = self.heads_dict[pre]
#				del(self.heads_dict[pre])
### end test

			for key in self.heads_dict.keys():
				if(key[:7] in ['Resent-']):
					if(self.heads_dict.has_key('X-' + key)):
						self.heads_dict[ 'X-Original-' + key ] = self.heads_dict['X-' + key]
					self.heads_dict[ 'X-' + key ] = self.heads_dict[key]
					del self.heads_dict[key]

			
			# In rfc822 References: is considered, but many MUA doen't put it.
			if(not self.heads_dict.has_key('References:') and self.heads_dict.has_key('In-Reply-To:')):
				print self.heads_dict['In-Reply-To:']

				# some MUA uses msgid without '<' '>'
#				ref = findall('([^\s<>\']+@[^\s<>;:\']+)', \
				# but I prefer use RFC standards
				ref = findall('(<[^<>]+@[^<>]+>)', \
					self.heads_dict['In-Reply-To:'])

				# if found, keep first element that seems a Msg-ID.
				if(ref and len(ref)):
					self.heads_dict['References:']  = '%s\n' % ref[0]
			
#			if(self.heads_dict.has_key('To:')):
#				self.heads_dict['X-To:'] = self.heads_dict['To:']
#				del self.heads_dict['To:']

		except KeyError, message:
			print message

		return self.heads_dict

		
	def removeheads(self, heads = None):
		"""remove headers like Xref: Path: Lines:
		"""

		try:
			# removing some others useless headers .... (From is not From:)

			rmheads = ['Received:','From','NNTP-Posting-Host:','X-Trace']
			if(heads):
				rmheads.append(heads)
		
			for head in rmheads:
				if self.heads_dict.has_key(head):
					del self.heads_dict[head]
				
#			if self.heads_dict.has_key('From'): # neither 'From ' nor 'From:'
#				del self.heads_dict['From']

#			if self.heads_dict.has_key('NNTP-Posting-Host:'): # neither 'From ' nor 'From:'
#				del self.heads_dict['']


#			if self.heads_dict.has_key('Lines:'):
#				del self.heads_dict['Lines:']

			# it is usually set by INN, if ng is moderated...
#			if self.heads_dict.has_key('Sender:'):
#				del self.heads_dict['Sender:']

	
			if self.heads_dict.has_key('Message-id:'):
				self.heads_dict['Message-Id:'] = self.heads_dict['Message-id:']
				del(self.heads_dict['Message-id:'])
				
			if self.heads_dict.has_key('Message-ID:'):
				self.heads_dict['Message-Id:'] = self.heads_dict['Message-ID:']
				del(self.heads_dict['Message-ID:'])
		
			# If message-id is not present, I generate it
			if not self.heads_dict.has_key('Message-Id:'):
				msgid = '<pyg.%d@tuchailepuppapera.org>\n' % (getpid())
				self.heads_dict['Message-Id:'] = msgid

		except KeyError, message:
			print message

		return self.heads_dict

	def sendemail(self):
		"""Talk to NNTP server and try to send email."""
		try:
			msglist = []

			n = nntplib.NNTP(self.newsserver, self.port, self.user, self.password)

			if(self.reader):
				n.putline('mode reader')
				resp = n.getline()
				print resp
	
			resp = n.shortcmd('POST')

			# sett RFC977 2.4.2 
			if resp[0] <> '3':
				raise n.error_reply, str(resp)

			for line in self.headers:
				if not line:
					break
				if line[-1] == '\n':
					line = line[:-1]
				if line[:1] == '.':
					line = '.' + line
				n.putline(line)

			for line in self.body:
				if not line:
					break
				if line[-1] == '\n':
					line = line[:-1]
				if line[:1] == '.':
					line = '.' + line
				n.putline(line)

			n.putline('.')
			n.quit()
			return None
		except (nntplib.error_reply, nntplib.error_temp, nntplib.error_perm, nntplib.error_proto, nntplib.error_data), message:
			return  'NNTP: ' + str(message)