#!/usr/bin/env python

from __future__ import absolute_import, print_function

__doc__ = """Tiny HTTP Proxy.

This module implements GET, HEAD, POST, PUT and DELETE methods

on BaseHTTPServer, and behaves as an HTTP proxy.  The CONNECT

method is also implemented experimentally, but has not been

tested yet.

Any help will be greatly appreciated.           SUZUKI Hisao

"""

__version__ = "0.2.1"

import optparse

import os

import select

import socket

import sys

from mercurial import util

httpserver = util.httpserver

socketserver = util.socketserver

urlreq = util.urlreq

if os.environ.get('HGIPV6', '0') == '1':

    family = socket.AF_INET6

else:

    family = socket.AF_INET

class ProxyHandler (httpserver.basehttprequesthandler):

    __base = httpserver.basehttprequesthandler

    __base_handle = __base.handle

    server_version = "TinyHTTPProxy/" + __version__

    rbufsize = 0                        # self.rfile Be unbuffered

    def handle(self):

        (ip, port) = self.client_address

        allowed = getattr(self, 'allowed_clients', None)

        if allowed is not None and ip not in allowed:

            self.raw_requestline = self.rfile.readline()

            if self.parse_request():

                self.send_error(403)

        else:

            self.__base_handle()

    def log_request(self, code='-', size='-'):

        xheaders = [h for h in self.headers.items() if h[0].startswith('x-')]

        self.log_message('"%s" %s %s%s',

                         self.requestline, str(code), str(size),

                         ''.join([' %s:%s' % h for h in sorted(xheaders)]))

        # Flush for Windows, so output isn't lost on TerminateProcess()

        sys.stderr.flush()

    def _connect_to(self, netloc, soc):

        i = netloc.find(':')

        if i >= 0:

            host_port = netloc[:i], int(netloc[i + 1:])

        else:

            host_port = netloc, 80

        print("\t" "connect to %s:%d" % host_port)

        try: soc.connect(host_port)

        except socket.error as arg:

            try: msg = arg[1]

            except (IndexError, TypeError): msg = arg

            self.send_error(404, msg)

            return 0

        return 1

    def do_CONNECT(self):

        soc = socket.socket(family, socket.SOCK_STREAM)

        try:

            if self._connect_to(self.path, soc):

                self.log_request(200)

                self.wfile.write(self.protocol_version +

                                 " 200 Connection established\r\n")

                self.wfile.write("Proxy-agent: %s\r\n" % self.version_string())

                self.wfile.write("\r\n")

                self._read_write(soc, 300)

        finally:

            print("\t" "bye")

            soc.close()

            self.connection.close()

    def do_GET(self):

        (scm, netloc, path, params, query, fragment) = urlreq.urlparse(

            self.path, 'http')

        if scm != 'http' or fragment or not netloc:

            self.send_error(400, "bad url %s" % self.path)

            return

        soc = socket.socket(family, socket.SOCK_STREAM)

        try:

            if self._connect_to(netloc, soc):

                self.log_request()

                soc.send("%s %s %s\r\n" % (

                    self.command,

                    urlreq.urlunparse(('', '', path, params, query, '')),

                    self.request_version))

                self.headers['Connection'] = 'close'

                del self.headers['Proxy-Connection']

                for key_val in self.headers.items():

                    soc.send("%s: %s\r\n" % key_val)

                soc.send("\r\n")

                self._read_write(soc)

        finally:

            print("\t" "bye")

            soc.close()

            self.connection.close()

    def _read_write(self, soc, max_idling=20):

        iw = [self.connection, soc]

        ow = []

        count = 0

        while True:

            count += 1

            (ins, _, exs) = select.select(iw, ow, iw, 3)

            if exs:

                break

            if ins:

                for i in ins:

                    if i is soc:

                        out = self.connection

                    else:

                        out = soc

                    try:

                        data = i.recv(8192)

                    except socket.error:

                        break

                    if data:

                        out.send(data)

                        count = 0

            else:

                print("\t" "idle", count)

            if count == max_idling:

                break

    do_HEAD = do_GET

    do_POST = do_GET

    do_PUT  = do_GET

    do_DELETE = do_GET

class ThreadingHTTPServer (socketserver.ThreadingMixIn,

                           httpserver.httpserver):

    def __init__(self, *args, **kwargs):

        httpserver.httpserver.__init__(self, *args, **kwargs)

        a = open("proxy.pid", "w")

        a.write(str(os.getpid()) + "\n")

        a.close()

def runserver(port=8000, bind=""):

    server_address = (bind, port)

    ProxyHandler.protocol_version = "HTTP/1.0"

    httpd = ThreadingHTTPServer(server_address, ProxyHandler)

    sa = httpd.socket.getsockname()

    print("Serving HTTP on", sa[0], "port", sa[1], "...")

    try:

        httpd.serve_forever()

    except KeyboardInterrupt:

        print("\nKeyboard interrupt received, exiting.")

        httpd.server_close()

        sys.exit(0)

if __name__ == '__main__':

    argv = sys.argv

    if argv[1:] and argv[1] in ('-h', '--help'):

        print(argv[0], "[port [allowed_client_name ...]]")

    else:

        if argv[2:]:

            allowed = []

            for name in argv[2:]:

                client = socket.gethostbyname(name)

                allowed.append(client)

                print("Accept: %s (%s)" % (client, name))

            ProxyHandler.allowed_clients = allowed

            del argv[2:]

        else:

            print("Any clients will be served...")

        parser = optparse.OptionParser()

        parser.add_option('-b', '--bind', metavar='ADDRESS',

                          help='Specify alternate bind address '

                               '[default: all interfaces]', default='')

        (options, args) = parser.parse_args()

        port = 8000

        if len(args) == 1:

            port = int(args[0])

        runserver(port, options.bind)