#!/usr/bin/env python
# -*- coding: utf-8 -*-

from email.Utils import parseaddr
from email.Parser import Parser
import os
import os.path
import ConfigParser
from re import compile, IGNORECASE
from stat import ST_MTIME
from string import upper, split, replace
import logging
import sys
import subprocess
from sys import stdin
from time import ctime, sleep, time
from socket import gethostname
from rfc822 import parsedate_tz, mktime_tz

if 'ERESSEA' in os.environ:
    dir = os.environ['ERESSEA']
elif 'HOME' in os.environ:
    dir = os.path.join(os.environ['HOME'], 'eressea')
else: # WTF? No HOME?
    dir = "/home/eressea/eressea"
if not os.path.isdir(dir):
    print "please set the ERESSEA environment variable to the install path"
    sys.exit(1)
rootdir = dir

game = int(sys.argv[1])
gamedir = os.path.join(rootdir, "game-%d" % (game, ))
frommail = 'eressea-server@kn-bremen.de'
gamename = 'Eressea'
sender = '%s Server <%s>' % (gamename, frommail)

inifile = os.path.join(gamedir, 'eressea.ini')
if not os.path.exists(inifile):
    print "no such file: " . inifile
else:
    config = ConfigParser.ConfigParser()
    config.read(inifile)
    if config.has_option('game', 'email'):
        frommail = config.get('game', 'email')
    if config.has_option('game', 'name'):
        gamename = config.get('game', 'name')
    if config.has_option('game', 'sender'):
        sender = config.get('game', 'sender')
    else:
        sender = "%s Server <%s>" % (gamename, frommail)
    config = None
prefix = 'turn-'
hostname = gethostname()
orderbase = "orders.dir"
sendmail = True
# maximum number of reports per sender:
maxfiles = 20
# write headers to file?
writeheaders = True
# reject all html email?
rejecthtml = True

def unlock_file(filename):
    try:
        os.unlink(filename+".lock")
    except:
        print "could not unlock %s.lock, file not found" % filename

def lock_file(filename):
    i = 0
    wait = 1
    if not os.path.exists(filename):
        file=open(filename, "w")
        file.close()
    while True:
        try:
            os.symlink(filename, filename+".lock")
            return
        except:
            i = i+1
            if i == 5: unlock_file(filename)
            sleep(wait)
            wait = wait*2

messages = {
        "multipart-en" :
                "ERROR: The orders you sent contain no plaintext. " \
                "The Eressea server cannot process orders containing HTML " \
                "or invalid attachments, which are the reasons why this " \
                "usually happens. Please change the settings of your mail " \
                "software and re-send the orders.",

        "multipart-de" :
                "FEHLER: Die von dir eingeschickte Mail enthält keinen " \
                "Text. Evtl. hast Du den Zug als HTML oder als anderweitig " \
                "ungültig formatierte Mail ingeschickt. Wir können ihn " \
                "deshalb nicht berücksichtigen. Schicke den Zug nochmals " \
                "als reinen Text ohne Formatierungen ein.",

        "maildate-de":
                "Es erreichte uns bereits ein Zug mit einem späteren " \
                "Absendedatum (%s > %s). Entweder ist deine " \
                "Systemzeit verstellt, oder ein Zug hat einen anderen Zug von " \
                "dir auf dem Transportweg überholt. Entscheidend für die " \
                "Auswertungsreihenfolge ist das Absendedatum, d.h. der Date:-Header " \
                "deiner Mail.",

        "maildate-en":
                "The server already received an order file that was sent at a later " \
                "date (%s > %s). Either your system clock is wrong, or two messages have " \
                "overtaken each other on the way to the server. The order of " \
                "execution on the server is always according to the Date: header in " \
                "your mail.",

        "nodate-en":
                "Your message did not contain a valid Date: header in accordance with RFC2822.",

        "nodate-de":
                "Deine Nachricht enthielt keinen gueltigen Date: header nach RFC2822.",

        "error-de":
                "Fehler",

        "error-en":
                "Error",

        "warning-de":
                "Warnung",

        "warning-en":
                "Warning",

        "subject-de":
                "Befehle angekommen",

        "subject-en":
                "orders received"
}

# return 1 if addr is a valid email address
def valid_email(addr):
    rfc822_specials = '/()<>@,;:\\"[]'
    # First we validate the name portion (name@domain)
    c = 0
    while c < len(addr):
        if addr[c] == '"' and (not c or addr[c - 1] == '.' or addr[c - 1] == '"'):
            c = c + 1
            while c < len(addr):
                if addr[c] == '"': break
                if addr[c] == '\\' and addr[c + 1] == ' ':
                    c = c + 2
                    continue
                if ord(addr[c]) < 32 or ord(addr[c]) >= 127: return 0
                c = c + 1
            else: return 0
            if addr[c] == '@': break
            if addr[c] != '.': return 0
            c = c + 1
            continue
        if addr[c] == '@': break
        if ord(addr[c]) <= 32 or ord(addr[c]) >= 127: return 0
        if addr[c] in rfc822_specials: return 0
        c = c + 1
    if not c or addr[c - 1] == '.': return 0

    # Next we validate the domain portion (name@domain)
    domain = c = c + 1
    if domain >= len(addr): return 0
    count = 0
    while c < len(addr):
        if addr[c] == '.':
            if c == domain or addr[c - 1] == '.': return 0
            count = count + 1
        if ord(addr[c]) <= 32 or ord(addr[c]) >= 127: return 0
        if addr[c] in rfc822_specials: return 0
        c = c + 1
    return count >= 1

# return the replyto or from address in the header
def get_sender(header):
    replyto = header.get("Reply-To")
    if replyto is None:
        replyto = header.get("From")
        if replyto is None: return None
    x = parseaddr(replyto)
    return x[1]

# return first available filename basename,[0-9]+
def available_file(dirname, basename):
    ver = 0
    maxdate = 0
    filename = "%s/%s,%s,%d" % (dirname, basename, hostname, ver)
    while os.path.exists(filename):
        maxdate = max(os.stat(filename)[ST_MTIME], maxdate)
        ver = ver + 1
        filename = "%s/%s,%s,%d" % (dirname, basename, hostname, ver)
    if ver >= maxfiles:
        return None, None
    return maxdate, filename

def formatpar(string, l=76, indent=2):
    words = split(string)
    res = ""
    ll = 0
    first = 1

    for word in words:
        if first == 1:
            res = word
            first = 0
            ll = len(word)
        else:
            if ll + len(word) > l:
                res = res + "\n"+" "*indent+word
                ll = len(word) + indent
            else:
                res = res+" "+word
                ll = ll + len(word) + 1

    return res+"\n"

def store_message(message, filename):
    outfile = open(filename, "w")
    outfile.write(message.as_string())
    outfile.close()
    return

def write_part(outfile, part):
    charset = part.get_content_charset()
    payload = part.get_payload(decode=True)

    if charset is None:
        charset = "latin1"
    try:
        msg = payload.decode(charset, "ignore")
    except:
        msg = payload
        charset = None
    try:
        utf8 = msg.encode("utf-8", "ignore")
        outfile.write(utf8)
    except:
        outfile.write(msg)
        return False
    outfile.write("\n");
    return True

def copy_orders(message, filename, sender):
        # print the header first
    if writeheaders:
        from os.path import split
        dirname, basename = split(filename)
        dirname = dirname + '/headers'
        if not os.path.exists(dirname): os.mkdir(dirname)
        outfile = open(dirname + '/' + basename, "w")
        for name, value in message.items():
            outfile.write(name + ": " + value + "\n")
        outfile.close()

    found = False
    outfile = open(filename, "w")
    if message.is_multipart():
        for part in message.get_payload():
            content_type = part.get_content_type()
            logger.debug("found content type %s for %s" % (content_type, sender))
            if content_type=="text/plain":
                if write_part(outfile, part):
                    found = True
                else:
                    charset = part.get_content_charset()
                    logger.error("could not write text/plain part (charset=%s) for %s" % (charset, sender))

    else:
        if write_part(outfile, message):
            found = True
        else:
            charset = message.get_content_charset()
            logger.error("could not write text/plain message (charset=%s) for %s" % (charset, sender))
    outfile.close()
    return found

# create a file, containing:
# game=0 locale=de file=/path/to/filename email=rcpt@domain.to
def accept(game, locale, stream, extend=None):
    global rootdir, orderbase, gamedir, gamename, sender
    if extend is not None:
        orderbase = orderbase + ".pre-" + extend
    savedir = os.path.join(gamedir, orderbase)
    # check if it's one of the pre-sent orders.
    # create the save-directories if they don't exist
    if not os.path.exists(gamedir): os.mkdir(gamedir)
    if not os.path.exists(savedir): os.mkdir(savedir)
    # parse message
    message = Parser().parse(stream)
    email = get_sender(message)
    logger = logging.getLogger(email)
    # write syslog
    if email is None or valid_email(email)==0:
        logger.warning("invalid email address: " + str(email))
        return -1
    logger.info("received orders from " + email)
    # get an available filename
    lock_file(gamedir + "/orders.queue")
    maxdate, filename = available_file(savedir, prefix + email)
    if filename is None:
        logger.warning("more than " + str(maxfiles) + " orders from " + email)
        return -1
    # copy the orders to the file
    text_ok = copy_orders(message, filename, email)
    unlock_file(gamedir + "/orders.queue")

    warning, msg, fail = None, "", False
    maildate = message.get("Date")
    if maildate != None:
        turndate = mktime_tz(parsedate_tz(maildate))
        os.utime(filename, (turndate, turndate))
        logger.debug("mail date is '%s' (%d)" % (maildate, turndate))
        if False and turndate < maxdate:
            logger.warning("inconsistent message date " + email)
            warning = " (" + messages["warning-" + locale] + ")"
            msg = msg + formatpar(messages["maildate-" + locale] % (ctime(maxdate),ctime(turndate)), 76, 2) + "\n"
    else:
        logger.warning("missing message date " + email)
        warning = " (" + messages["warning-" + locale] + ")"
        msg = msg + formatpar(messages["nodate-" + locale], 76, 2) + "\n"

    if not text_ok:
        warning = " (" + messages["error-" + locale] + ")"
        msg = msg + formatpar(messages["multipart-" + locale], 76, 2) + "\n"
        logger.warning("rejected - no text/plain in orders from " + email)
        os.unlink(filename)
        savedir = savedir + "/rejected"
        if not os.path.exists(savedir): os.mkdir(savedir)
        lock_file(gamedir + "/orders.queue")
        maxdate, filename = available_file(savedir, prefix + email)
        store_message(message, filename)
        unlock_file(gamedir + "/orders.queue")
        fail = True

    if sendmail and warning is not None:
        subject = gamename + " " + messages["subject-"+locale] + warning
        print("mail " + subject)
        ps = subprocess.Popen(['mutt', '-s', subject, email], stdin=subprocess.PIPE)
        ps.communicate(msg)

    if not sendmail:
        print text_ok, fail, email
        print filename

    if not fail:
        lock_file(gamedir + "/orders.queue")
        queue = open(gamedir + "/orders.queue", "a")
        queue.write("email=%s file=%s locale=%s game=%s\n" % (email, filename, locale, game))
        queue.close()
        unlock_file(gamedir + "/orders.queue")

    logger.info("done - accepted orders from " + email)

    return 0

# the main body of the script:
try:
    os.mkdir(os.path.join(rootdir, 'log'))
except:
    pass # already exists?
LOG_FILENAME=os.path.join(rootdir, 'log/orders.log')
logging.basicConfig(level=logging.DEBUG, filename=LOG_FILENAME)
logger = logging
delay = None # TODO: parse the turn delay
locale = sys.argv[2]
infile = stdin
if len(sys.argv)>3:
    infile = open(sys.argv[3], "r")
retval = accept(game, locale, infile, delay)
if infile!=stdin:
    infile.close()
sys.exit(retval)