#!/usr/bin/env python

import sys
import os
import optparse
import pwd, grp
from quixote.util import import_object

def drop_root(user):
    # drop root if necessary
    if os.getuid() == 0:
        uid, gid = pwd.getpwnam(user)[2:4]
        os.setgid(gid)
        os.setuid(uid)

def fork_background():
    pid = os.fork()
    if pid != 0:
        sys.exit(0)
    os.chdir('/')
    os.setsid()
    os.umask(0)
    pid = os.fork()
    if pid != 0:
        sys.exit(0)

def redirect_output(filename):
    sys.stdout = sys.stderr = open(filename, 'a', 1)
    os.dup2(sys.stdout.fileno(), 1)
    os.dup2(sys.stderr.fileno(), 2)
    os.close(0)

def write_pid(filename):
    fp = open(filename, 'w')
    fp.write(str(os.getpid()))
    fp.close()

def main():
    parser = optparse.OptionParser()
    parser.add_option('--factory', default='quixote.demo.create_publisher',
                      help='Path to factory function to create the site '
                           'publisher.')
    parser.add_option('--pidfile', default=None,
                      help='If provided, the PID of the server process will '
                           'be written to this file.')
    parser.add_option('--background', action='store_true', default=False,
                      help='Fork server process into the background.')
    parser.add_option('--server-type', default='simple',
                      choices=['simple', 'scgi'],
                      help='Type of server to run ("simple" or "scgi")')
    parser.add_option('--host', dest="host", default='localhost',
                      help="Host interface to listen on.")
    parser.add_option('--port', dest="port", default=None, type="int",
                      help="Port to listen on.")
    parser.add_option('--user', default='web',
                      help='If started as root, use setuid to run as the '
                           'specified user.')
    parser.add_option('--logfile', default=None,
                      help='If specified, stderr and stdout will be redirected '
                           'to the file.')
    options, args = parser.parse_args()
    if options.background:
        fork_background()
    if options.pidfile:
        write_pid(options.pidfile)
    drop_root(options.user)
    if options.logfile:
        redirect_output(options.logfile)
    create_publisher = import_object(options.factory)
    if options.server_type == 'simple':
        from quixote.server.simple_server import run
        run(create_publisher, host=options.host, port=options.port or 8080)
    elif options.server_type == 'scgi':
        from quixote.server.scgi_server import run
        run(create_publisher, host=options.host, port=options.port or 3000)
    else:
        assert 0


if __name__ == '__main__':
    main()