#!/usr/bin/env python
from __future__ import absolute_import, division, print_function, \
    unicode_literals
import os
import sys
import time
import socket
import six.moves.urllib as urllib
import hashlib
import logging

from zeroconf import ServiceInfo, Zeroconf
from six.moves.BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer

from . import utils
from .utils import _
import argparse

__all__ = ["put"]


def validate_address(address):
    """ Validate IP address
    """
    try:
        socket.inet_aton(address)
        return address
    except socket.error:
        raise argparse.ArgumentTypeError(
            _("%s is not a valid IP address") % address
        )


class StateHTTPServer(HTTPServer):
    """
    HTTP Server that knows a certain filename and can be set to remember if
    that file has been transferred using :class:`FileHandler`
    """
    downloaded = False
    filename = ""
    allowed_basenames = []
    reporthook = None


class FileHandler(BaseHTTPRequestHandler):
    """
    Custom HTTP upload handler that allows one single filename to be requested.

    """

    def do_GET(self):
        if self.path in map(
            lambda x: urllib.request.pathname2url(os.path.join('/', x)),
            self.server.allowed_basenames
        ):
            utils.logger.info(_("Peer found. Uploading..."))
            full_path = os.path.join(os.curdir, self.server.filename)
            with open(full_path, 'rb') as fh:
                maxsize = os.path.getsize(full_path)
                self.send_response(200)
                self.send_header('Content-type', 'application/octet-stream')
                self.send_header(
                    'Content-disposition',
                    'inline; filename="%s"' % os.path.basename(
                        self.server.filename
                    )
                )
                self.send_header('Content-length', maxsize)
                self.end_headers()

                i = 0
                while True:
                    data = fh.read(1024 * 8)  # chunksize taken from urllib
                    if not data:
                        break
                    self.wfile.write(data)
                    if self.server.reporthook is not None:
                        self.server.reporthook(i, 1024 * 8, maxsize)
                    i += 1
            self.server.downloaded = True

        else:
            self.send_response(404)
            self.end_headers()
            raise RuntimeError(_("Invalid request received. Aborting."))

    def log_message(self, format, *args):
        """
        Suppress log messages by overloading this function

        """
        return


def cli(inargs=None):
    """
    Commandline interface for sending files

    """
    parser = argparse.ArgumentParser()

    parser.add_argument(
        '--port', '-p',
        type=int, nargs='?', metavar=_("PORT"),
        help=_("The port to share the file on")
    )
    parser.add_argument(
        '--address', '-a', nargs='?',
        type=validate_address, metavar=_("ADDRESS"),
        help=_("The address to share the file on")
    )
    parser.add_argument(
        '--interface', '-i', nargs='?', metavar=_("INTERFACE"),
        help=_("The interface to share the file on")
    )
    parser.add_argument(
        '--verbose', '-v',
        action='count', default=0,
        help=_("Verbose mode. Multiple -v options increase the verbosity")
    )
    parser.add_argument(
        '--quiet', '-q',
        action='count', default=0,
        help=_("Quiet mode. Hides progess bar")
    )
    parser.add_argument(
        '--timeout', '-t',
        type=int, metavar=_("SECONDS"),
        help=_("Set timeout after which program aborts transfer")
    )
    parser.add_argument(
        '--version', '-V',
        action='version',
        version='%%(prog)s %s' % utils.__version__
    )
    parser.add_argument(
        'input', metavar=_("input"),
        help=_("The file to share on the network")
    )
    parser.add_argument(
        'output',
        nargs='?',
        help="The share alias on the network"
    )
    args = parser.parse_args(inargs)

    utils.enable_logger(args.verbose)

    try:
        if not os.path.isfile(args.input):
            raise ValueError(
                _("File %s does not exist") % args.input
            )
        if args.interface and args.address:
            raise ValueError(
                _("You may only provide one of --address "
                  "or --interface")
            )

        if args.output is None:
            args.output = utils.generate_alias()

        if not args.quiet:
            print(_(
                "Download this file using `zget %(f)s` or `zget %(o)s`"
            ) % {'f': os.path.basename(args.input), 'o': args.output})

        with utils.Progresshook(args.input) as progress:
            put(
                args.input,
                output=args.output,
                interface=args.interface,
                address=args.address,
                port=args.port,
                reporthook=progress if args.quiet == 0 else None,
                timeout=args.timeout,
            )
    except Exception as e:
        if args.verbose:
            raise
        utils.logger.error(unicode(e))
        utils.logger.error(
            _("An Error occurred. For a full traceback try running zget "
              "again with enabled verbosity (-vvv).")
        )
        sys.exit(1)


def put(
    filename,
    output=None,
    interface=None,
    address=None,
    port=None,
    reporthook=None,
    timeout=None,
):
    """Send a file using the zget protocol.

    Parameters
    ----------
    filename : string
        The filename to be transferred
    output : string
        The alias to share on the network. Optional. If empty, the input
        filename will be used.
    interface : string
        The network interface to use. Optional.
    address : string
        The network address to use. Optional.
    port : int
        The network port to use. Optional.
    reporthook : callable
        A hook that will be called during transfer. Handy for watching the
        transfer. See :code:`urllib.urlretrieve` for callback parameters.
        Optional.
    timeout : int
        Seconds to wait until process is aborted. A running transfer is not
        aborted even when timeout was hit. Optional.

    Raises
    -------
    TimeoutException
        When a timeout occurred.

    """
    if port is None:
        port = utils.config().getint('DEFAULT', 'port')

    if interface is None:
        interface = utils.config().get('DEFAULT', 'interface')

    if not 0 <= port <= 65535:
        raise ValueError(_("Port %d exceeds allowed range") % port)

    basename = os.path.basename(filename)

    filehashes = []
    filehashes.append(hashlib.sha1(basename.encode('utf-8')).hexdigest())
    if output is not None:
        filehashes.append(hashlib.sha1(output.encode('utf-8')).hexdigest())

    if interface is None:
        interface = utils.default_interface()

    if address is None:
        address = utils.ip_addr(interface)

    server = StateHTTPServer((address, port), FileHandler)
    server.timeout = timeout
    server.filename = filename
    server.allowed_basenames.append(basename)
    if output is not None:
        server.allowed_basenames.append(output)
    server.reporthook = reporthook

    port = server.server_port

    utils.logger.debug(
        _("Using interface %s") % interface
    )

    utils.logger.debug(
        _("Listening on %(a)s:%(p)d \n"
          "you may change address using --address and "
          "port using --port") % {'a': address, 'p': port}
    )

    zeroconf = Zeroconf()

    infos = []
    for filehash in filehashes:
        utils.logger.debug(
            _("Broadcasting as %s._zget._http._tcp.local.") % filehash
        )
        infos.append(ServiceInfo(
            "_zget._http._tcp.local.",
            "%s._zget._http._tcp.local." % filehash,
            socket.inet_aton(address), port, 0, 0,
            {'path': None}
        ))

    try:
        for info in infos:
            zeroconf.register_service(info)
        server.handle_request()
    except KeyboardInterrupt:
        pass

    server.socket.close()
    for info in infos:
        zeroconf.unregister_service(info)
    zeroconf.close()

    if timeout is not None and not server.downloaded:
        raise utils.TimeoutException()
    else:
        utils.logger.info(_("Done."))

if __name__ == '__main__':
    cli(sys.argv[1:])
