#!/usr/bin/env python

import sys
from BaseHTTPServer import HTTPServer, BaseHTTPRequestHandler
from optparse import OptionParser
from cgi import FieldStorage
import os
import errno
import signal

__version__ = '0.1'

ADDR = '0.0.0.0'
PORT = 8080
OUTPUT = '/tmp'

class DropletHandler(BaseHTTPRequestHandler):

    def do_POST(self):
        try:
            fields = FieldStorage(self.rfile, self.headers,
                                  environ={'REQUEST_METHOD': 'POST'})
        except Exception, error:
            return self.response(500, error)
        try:
            file = fields['file']
        except KeyError:
            return self.response(500, 'No file')
        path = os.path.join(self.server.output, file.filename)
        if os.path.exists(path):
            return self.response(500, 'File exists')
        with open(path, 'wb') as fp:
            fp.write(file.value)
        os.chmod(path, 0644)
        self.log_message('Saved %d bytes to %s', len(file.value), path)
        return self.response(200, 'OK')

    def response(self, *args):
        self.send_response(*args)
        self.end_headers()


def daemonize():
    if os.fork():
        os._exit(0)
    os.setsid()
    if os.fork():
        os._exit(0)
    for fd in xrange(os.sysconf('SC_OPEN_MAX')):
        try:
            os.close(fd)
        except OSError, error:
            if error.errno != errno.EBADF:
                raise
    fd = os.open(os.devnull, os.O_RDWR)
    os.dup(fd)
    os.dup(fd)
    os.umask(027)
    os.chdir('/')
    signal.signal(signal.SIGCHLD, signal.SIG_IGN)


def main():
    optparse = OptionParser('%prog [opts]', version=__version__,
                            description='servlet for Droplet.app')
    optparse.add_option('-d', dest='daemon', default=False, action='store_true',
                        help='launch as a daemon')
    optparse.add_option('-a', dest='addr', metavar='<address>', default=ADDR,
                        help='ip/host to bind to (default: all)')
    optparse.add_option('-p', dest='port', metavar='<port>', default=PORT,
                        help='listener port (default: %default)')
    optparse.add_option('-o', dest='output', metavar='<dir>', default=OUTPUT,
                        help='dir to save to (default: %default)')
    opts, args = optparse.parse_args()
    if opts.daemon:
        daemonize()
    server = HTTPServer((opts.addr, opts.port), DropletHandler)
    server.output = opts.output
    server.serve_forever()
    return 0

if __name__ == '__main__':
    sys.exit(main())