# OfflineIMAP initialization code
# Copyright (C) 2002-2007 John Goerzen
# <jgoerzen@complete.org>
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA

import os
import sys
import threading
import offlineimap.imaplib2 as imaplib
import signal
import socket
import logging
from optparse import OptionParser
import offlineimap
from offlineimap import accounts, threadutil, syncmaster
from offlineimap.ui import UI_LIST, setglobalui, getglobalui
from offlineimap.CustomConfig import CustomConfigParser


try:
    import fcntl
    hasfcntl = 1
except:
    hasfcntl = 0

lockfd = None

class OfflineImap:
    """The main class that encapsulates the high level use of OfflineImap.

    To invoke OfflineImap you would call it with::

      oi = OfflineImap()
      oi.run()
    """
    def lock(self, config, ui):
        global lockfd, hasfcntl
        if not hasfcntl:
            return
        lockfd = open(config.getmetadatadir() + "/lock", "w")
        try:
            fcntl.flock(lockfd, fcntl.LOCK_EX | fcntl.LOCK_NB)
        except IOError:
            ui.locked()
            ui.terminate(1)
    
    def run(self):
        """Parse the commandline and invoke everything"""

        parser = OptionParser(version=offlineimap.__version__,
                              description="%s.\n\n%s" % 
                              (offlineimap.__copyright__,
                               offlineimap.__license__))
        parser.add_option("-1",
                  action="store_true", dest="singlethreading",
                  default=False,
                  help="Disable all multithreading operations and use "
              "solely a single-thread sync. This effectively sets the "
              "maxsyncaccounts and all maxconnections configuration file "
              "variables to 1.")

        parser.add_option("-P", dest="profiledir", metavar="DIR",
                  help="Sets OfflineIMAP into profile mode. The program "
              "will create DIR (it must not already exist). "
              "As it runs, Python profiling information about each "
              "thread is logged into profiledir. Please note: "
              "This option is present for debugging and optimization "
              "only, and should NOT be used unless you have a "
              "specific reason to do so. It will significantly "
              "decrease program performance, may reduce reliability, "
              "and can generate huge amounts of data. This option "
              "implies the -1 option.")

        parser.add_option("-a", dest="accounts", metavar="ACCOUNTS",
                  help="""Overrides the accounts section in the config file.
              Lets you specify a particular account or set of
              accounts to sync without having to edit the config
              file. You might use this to exclude certain accounts,
              or to sync some accounts that you normally prefer not to.""")

        parser.add_option("-c", dest="configfile", metavar="FILE",
                  default="~/.offlineimaprc",
                  help="Specifies a configuration file to use in lieu of "
                       "%default.")

        parser.add_option("-d", dest="debugtype", metavar="type1,[type2...]",
                  help="""Enables debugging for OfflineIMAP. This is useful
              if you are to track down a malfunction or figure out what is
              going on under the hood. This option requires one or more
              debugtypes, separated by commas. These define what exactly
              will be debugged, and so far include two options: imap, thread,
              maildir or ALL. The imap option will enable IMAP protocol
              stream and parsing debugging. Note that the output may contain
              passwords, so take care to remove that from the debugging
              output before sending it to anyone else. The maildir option
              will enable debugging for certain Maildir operations.
              The use of any debug option (unless 'thread' is included),
              implies the single-thread option -1.""")

        parser.add_option("-l", dest="logfile", metavar="FILE",
                  help="Log to FILE")

        parser.add_option("-f", dest="folders", metavar="folder1,[folder2...]",
                  help=
              "Only sync the specified folders. The folder names "
              "are the *untranslated* foldernames. This "
              "command-line option overrides any 'folderfilter' "
              "and 'folderincludes' options in the configuration " 
              "file.")

        parser.add_option("-k", dest="configoverride",
                  action="append",
                  metavar="[section:]option=value",
                  help=
              """Override configuration file option. If"section" is
              omitted, it defaults to "general". Any underscores
              in the section name are replaced with spaces:
              for instance, to override option "autorefresh" in
              the "[Account Personal]" section in the config file
              one would use "-k Account_Personal:autorefresh=30".""")

        parser.add_option("-o",
                  action="store_true", dest="runonce",
                  default=False,
                  help="Run only once, ignoring any autorefresh setting "
                       "in the configuration file.")

        parser.add_option("-q",
                  action="store_true", dest="quick",
                  default=False,
                  help="Run only quick synchronizations. Ignore any "
              "flag updates on IMAP servers (if a flag on the remote IMAP "
              "changes, and we have the message locally, it will be left "
              "untouched in a quick run.")

        parser.add_option("-u", dest="interface",
                  help="Specifies an alternative user interface to "
              "use. This overrides the default specified in the "
              "configuration file. The UI specified with -u will "
              "be forced to be used, even if checks determine that it is "
              "not usable. Possible interface choices are: %s " %
              ", ".join(UI_LIST.keys()))

        (options, args) = parser.parse_args()

        #read in configuration file
        configfilename = os.path.expanduser(options.configfile)
    
        config = CustomConfigParser()
        if not os.path.exists(configfilename):
            logging.error(" *** Config file '%s' does not exist; aborting!" %
                          configfilename)
            sys.exit(1)
        config.read(configfilename)

        #profile mode chosen?
        if options.profiledir:
            if not options.singlethreading:
                logging.warn("Profile mode: Forcing to singlethreaded.")
                options.singlethreading = True
            profiledir = options.profiledir
            os.mkdir(profiledir)
            threadutil.setprofiledir(profiledir)
            logging.warn("Profile mode: Potentially large data will be "
                         "created in '%s'" % profiledir)

        #override a config value
        if options.configoverride:
            for option in options.configoverride:
                (key, value) = option.split('=', 1)
                if ':' in key:
                    (secname, key) = key.split(':', 1)
                    section = secname.replace("_", " ")
                else:
                    section = "general"
                config.set(section, key, value)

        #which ui to use? cmd line option overrides config file
        ui_type = config.getdefault('general','ui', 'ttyui')
        if options.interface != None:
            ui_type = options.interface
        if '.' in ui_type:
            #transform Curses.Blinkenlights -> Blinkenlights
            ui_type = ui_type.split('.')[-1]
            logging.warning('Using old interface name, consider using one '
                            'of %s' % ', '.join(UI_LIST.keys()))
        try:
            # create the ui class
            ui = UI_LIST[ui_type.lower()](config)
        except KeyError:
            logging.error("UI '%s' does not exist, choose one of: %s" % \
                              (ui_type,', '.join(UI_LIST.keys())))
            sys.exit(1)
        setglobalui(ui)

        #set up additional log files
        if options.logfile:
            ui.setlogfd(open(options.logfile, 'wt'))
    
        #welcome blurb
        ui.init_banner()

        if options.debugtype:
            if options.debugtype.lower() == 'all':
                options.debugtype = 'imap,maildir,thread'
            #force single threading?
            if not ('thread' in options.debugtype.split(',') \
                    and not options.singlethreading):
                ui._msg("Debug mode: Forcing to singlethreaded.")
                options.singlethreading = True

            debugtypes = options.debugtype.split(',') + ['']
            for type in debugtypes:
                type = type.strip()
                ui.add_debug(type)
                if type.lower() == 'imap':
                    imaplib.Debug = 5

        if options.runonce:
            # FIXME: maybe need a better
            for section in accounts.getaccountlist(config):
                config.remove_option('Account ' + section, "autorefresh")

        if options.quick:
            for section in accounts.getaccountlist(config):
                config.set('Account ' + section, "quick", '-1')

        #custom folder list specified?
        if options.folders:
            foldernames = options.folders.split(",")
            folderfilter = "lambda f: f in %s" % foldernames
            folderincludes = "[]"
            for accountname in accounts.getaccountlist(config):
                account_section = 'Account ' + accountname
                remote_repo_section = 'Repository ' + \
                                      config.get(account_section, 'remoterepository')
                local_repo_section = 'Repository ' + \
                                     config.get(account_section, 'localrepository')
                for section in [remote_repo_section, local_repo_section]:
                    config.set(section, "folderfilter", folderfilter)
                    config.set(section, "folderincludes", folderincludes)

        self.lock(config, ui)
        self.config = config
    
        def sigterm_handler(signum, frame):
            # die immediately
            ui = getglobalui()
            ui.terminate(errormsg="terminating...")

        signal.signal(signal.SIGTERM,sigterm_handler)
    
        try:
            pidfd = open(config.getmetadatadir() + "/pid", "w")
            pidfd.write(str(os.getpid()) + "\n")
            pidfd.close()
        except:
            pass
    
        try:
            if options.logfile:
                sys.stderr = ui.logfile
    
            socktimeout = config.getdefaultint("general", "socktimeout", 0)
            if socktimeout > 0:
                socket.setdefaulttimeout(socktimeout)
    
            activeaccounts = config.get("general", "accounts")
            if options.accounts:
                activeaccounts = options.accounts
            activeaccounts = activeaccounts.replace(" ", "")
            activeaccounts = activeaccounts.split(",")
            allaccounts = accounts.AccountHashGenerator(config)
    
            syncaccounts = []
            for account in activeaccounts:
                if account not in allaccounts:
                    if len(allaccounts) == 0:
                        errormsg = 'The account "%s" does not exist because no accounts are defined!'%account
                    else:
                        errormsg = 'The account "%s" does not exist.  Valid accounts are:'%account
                        for name in allaccounts.keys():
                            errormsg += '\n%s'%name
                    ui.terminate(1, errortitle = 'Unknown Account "%s"'%account, errormsg = errormsg)
                if account not in syncaccounts:
                    syncaccounts.append(account)
    
            server = None
            remoterepos = None
            localrepos = None
    
            threadutil.initInstanceLimit('ACCOUNTLIMIT',
                                    config.getdefaultint('general',
                                                         'maxsyncaccounts', 1))
    
            for reposname in config.getsectionlist('Repository'):
                for instancename in ["FOLDER_" + reposname,
                                     "MSGCOPY_" + reposname]:
                    if options.singlethreading:
                        threadutil.initInstanceLimit(instancename, 1)
                    else:
                        threadutil.initInstanceLimit(instancename,
                               config.getdefaultint('Repository ' + reposname,
                                                    'maxconnections', 2))
            def sig_handler(sig, frame):
                if sig == signal.SIGUSR1 or sig == signal.SIGHUP:
                    # tell each account to stop sleeping
                    accounts.Account.set_abort_event(self.config, 1)
                elif sig == signal.SIGUSR2:
                    # tell each account to stop looping
                    accounts.Account.set_abort_event(self.config, 2)
                
            signal.signal(signal.SIGHUP,sig_handler)
            signal.signal(signal.SIGUSR1,sig_handler)
            signal.signal(signal.SIGUSR2,sig_handler)
    
            #various initializations that need to be performed:
            offlineimap.mbnames.init(config, syncaccounts)

            if options.singlethreading:
                #singlethreaded
                self.sync_singlethreaded(syncaccounts, config)
            else:
                # multithreaded
                t = threadutil.ExitNotifyThread(target=syncmaster.syncitall,
                                 name='Sync Runner',
                                 kwargs = {'accounts': syncaccounts,
                                           'config': config})
                t.setDaemon(1)
                t.start()
                threadutil.exitnotifymonitorloop(threadutil.threadexited)

            ui.terminate()
        except KeyboardInterrupt:
            ui.terminate(1, errormsg = 'CTRL-C pressed, aborting...')
            return
        except (SystemExit):
            raise
        except:
            ui.mainException()

    def sync_singlethreaded(self, accs, config):
        """Executed if we do not want a separate syncmaster thread

        :param accs: A list of accounts that should be synced
        :param config: The CustomConfig object
        """
        for accountname in accs:
            account = offlineimap.accounts.SyncableAccount(config, accountname)
            threading.currentThread().name = "Account sync %s" % accountname
            account.syncrunner()
