import smtplib, string, regex, regsub, pwd, os, socket, rfc822, time
import helpers, StringIO
from ui_config import config

draft_txt = """From: %s
Reply-to: %s
To: 
Cc: 
Subject: 

%s"""

reply_txt = """From: %s
Reply-to: %s
To: %s
Cc: %s
Subject: %s%s
In-Reply-To: %s
References: %s

%s:
%s

%s"""

_user_address = None

def deduce_user_address():
	global _user_address
	if config["from-address"]:
		return config["from-address"]
	if _user_address is None:
		userinfo = pwd.getpwuid(os.getuid())
		host = socket.gethostname()
		ip = socket.gethostbyname(host)
		fqdn = socket.gethostbyaddr(ip)[0]
		_user_address = "%s@%s" % (userinfo[0], fqdn)
		if userinfo[4]:
			x = regsub.sub(",*$", "", userinfo[4])
			_user_address = "%s <%s>" % (x, _user_address)
	return _user_address

def get_signature_text():
	try:
		pathname = os.path.expanduser(config["signature-file"])
		sig = "-- \n" + helpers.read_text_from_named_file(pathname)
	except IOError:
		sig = ""
	return sig

def make_new_message_text():
	return draft_txt % (deduce_user_address(), config["reply-to"], 
				get_signature_text())

def remove_duplicate_addrs(recipients, used_addrs):
	result = []
	for recipient in string.split(recipients, ","):
		name, addr = rfc822.parseaddr(recipient)
		if not addr in used_addrs:
			result.append(recipient)
			used_addrs.append(addr)
	return string.join(result, ","), used_addrs

def make_reply_message_text(msg):
	user_addr = deduce_user_address()
	reply_to = config["reply-to"]
	to_addrs = msg["to"]
	if to_addrs:
		to_addrs = msg["from"] + ", " + to_addrs
	else:
		to_addrs = msg["from"]
	cc_addrs = msg["cc"]
	
	user_addr_name, user_addr_addr = rfc822.parseaddr(user_addr)
	reply_to_name, reply_to_addr = rfc822.parseaddr(reply_to)

	if user_addr_addr and reply_to_addr:
		used_addrs = [user_addr_addr, reply_to_addr]
	elif user_addr_addr:
		used_addrs = [user_addr_addr]
	elif reply_to_addr:
		used_addrs = [reply_to_addr]
	else:
		used_addrs = []
	to_addrs, used_addrs = remove_duplicate_addrs(to_addrs, used_addrs)
	cc_addrs, used_addrs = remove_duplicate_addrs(cc_addrs, used_addrs)

	subject = msg["subject"]
	if string.lower(subject[:3]) == "re:":
		re = ""
	else:
		re = "Re: "

	msgid = msg["message-id"]
	refs = msg["references"] + " " + msgid
	while len(refs) > config["max-references-length"]:
		new_refs = regsub.sub("[^ ]* ", "", refs)
		if len(new_refs) == refs:
			break
		refs = new_refs

	quoted_author = msg["from"]
	quoted = msg.getbodytext()
	quoted = regsub.gsub("^", "> ", quoted)
	if quoted and quoted[-1] != "\n":
		quoted = quoted + "\n"
	
	return reply_txt % (user_addr, reply_to, to_addrs, 
				cc_addrs, re, subject, msgid, refs, 
				quoted_author, quoted, get_signature_text())

empty_trans = string.maketrans("", "")
sevenbit_chars = None

def deduce_charset(str):
	"""Deduce the character set used in a string."""
	global sevenbit_chars
	if not sevenbit_chars:
		list = []
		for code in range(128):
			list.append(chr(code))
		sevenbit_chars = string.join(list, "")
	if string.translate(str, empty_trans, sevenbit_chars):
		return "ISO-8859-1"
	return "us-ascii"

empty_header = regex.compile("^[^:][^:]*:[ \t]*$")
date_header = regex.compile("^Date:", regex.casefold)

def prepare_for_send(msg):
	nonempty = []
	hit = 0
	for line in string.split(msg.getheadertext(), "\n"):
		if line and not line[0] in string.whitespace:
			if date_header.match(line) == -1:
				hit = (empty_header.match(line) == -1)
			else:
				hit = 0
		if line and hit:
			nonempty.append(line)
	nonempty.append("Date: %s" % helpers.rfc822_date())
	nonempty.append("")
	headers = string.join(nonempty, "\n")

	msg.change_text(StringIO.StringIO(headers + "\n" + msg.getbodytext(0)))

def send_msg(msg):
	name, sender = msg.getaddr("from")
	receivers = []
	for header in ["to", "cc"]:
		if msg[header]:
			for name, addr in msg.getaddrlist(header):
				receivers.append(addr)

	smtp = smtplib.SMTP(config["smtp-server"])
	smtp.helo()
	smtp.mail_from(sender)
	for receiver in receivers:
		smtp.rcpt_to(receiver)
	text = string.split(msg.getfulltext(), "\n")
	smtp.data(text)
	smtp.quit()

def main():
	print deduce_user_address()
	print rfc822_date()
	print deduce_charset("this is us-ascii")
	print deduce_charset("tämä on latin1:tä")

if __name__ == "__main__":
	main()