from __future__ import absolute_import
import re
import argparse
from argparse import ArgumentTypeError
from netlib import http
from . import filt, utils
from .proxy import config

APP_HOST = "mitm.it"
APP_PORT = 80


class ParseException(Exception):
    pass


def _parse_hook(s):
    sep, rem = s[0], s[1:]
    parts = rem.split(sep, 2)
    if len(parts) == 2:
        patt = ".*"
        a, b = parts
    elif len(parts) == 3:
        patt, a, b = parts
    else:
        raise ParseException("Malformed hook specifier - too few clauses: %s" % s)

    if not a:
        raise ParseException("Empty clause: %s" % str(patt))

    if not filt.parse(patt):
        raise ParseException("Malformed filter pattern: %s" % patt)

    return patt, a, b


def parse_replace_hook(s):
    """
        Returns a (pattern, regex, replacement) tuple.

        The general form for a replacement hook is as follows:

            /patt/regex/replacement

        The first character specifies the separator. Example:

            :~q:foo:bar

        If only two clauses are specified, the pattern is set to match
        universally (i.e. ".*"). Example:

            /foo/bar/

        Clauses are parsed from left to right. Extra separators are taken to be
        part of the final clause. For instance, the replacement clause below is
        "foo/bar/":

            /one/two/foo/bar/

        Checks that pattern and regex are both well-formed. Raises
        ParseException on error.
    """
    patt, regex, replacement = _parse_hook(s)
    try:
        re.compile(regex)
    except re.error, e:
        raise ParseException("Malformed replacement regex: %s" % str(e.message))
    return patt, regex, replacement


def parse_setheader(s):
    """
        Returns a (pattern, header, value) tuple.

        The general form for a replacement hook is as follows:

            /patt/header/value

        The first character specifies the separator. Example:

            :~q:foo:bar

        If only two clauses are specified, the pattern is set to match
        universally (i.e. ".*"). Example:

            /foo/bar/

        Clauses are parsed from left to right. Extra separators are taken to be
        part of the final clause. For instance, the value clause below is
        "foo/bar/":

            /one/two/foo/bar/

        Checks that pattern and regex are both well-formed. Raises
        ParseException on error.
    """
    return _parse_hook(s)


def parse_server_spec(url):
    normalized_url = re.sub("^https?2", "", url)

    p = http.parse_url(normalized_url)
    if not p or not p[1]:
        raise ArgumentTypeError("Invalid server specification: %s" % url)

    if url.lower().startswith("https2http"):
        ssl = [True, False]
    elif url.lower().startswith("http2https"):
        ssl = [False, True]
    elif url.lower().startswith("https"):
        ssl = [True, True]
    else:
        ssl = [False, False]

    return ssl + list(p[1:3])


def get_common_options(options):
    stickycookie, stickyauth = None, None
    if options.stickycookie_filt:
        stickycookie = options.stickycookie_filt

    if options.stickyauth_filt:
        stickyauth = options.stickyauth_filt

    stream_large_bodies = utils.parse_size(options.stream_large_bodies)

    reps = []
    for i in options.replace:
        try:
            p = parse_replace_hook(i)
        except ParseException, e:
            raise ArgumentTypeError(e.message)
        reps.append(p)
    for i in options.replace_file:
        try:
            patt, rex, path = parse_replace_hook(i)
        except ParseException, e:
            raise ArgumentTypeError(e.message)
        try:
            v = open(path, "rb").read()
        except IOError, e:
            raise ArgumentTypeError("Could not read replace file: %s" % path)
        reps.append((patt, rex, v))

    setheaders = []
    for i in options.setheader:
        try:
            p = parse_setheader(i)
        except ParseException, e:
            raise ArgumentTypeError(e.message)
        setheaders.append(p)

    return dict(
        app=options.app,
        app_host=options.app_host,
        app_port=options.app_port,

        anticache=options.anticache,
        anticomp=options.anticomp,
        client_replay=options.client_replay,
        kill=options.kill,
        no_server=options.no_server,
        refresh_server_playback=not options.norefresh,
        rheaders=options.rheaders,
        rfile=options.rfile,
        replacements=reps,
        setheaders=setheaders,
        server_replay=options.server_replay,
        scripts=options.scripts,
        stickycookie=stickycookie,
        stickyauth=stickyauth,
        stream_large_bodies=stream_large_bodies,
        showhost=options.showhost,
        wfile=options.wfile,
        verbosity=options.verbose,
        nopop=options.nopop,
    )


def common_options(parser):
    parser.add_argument(
        "--anticache",
        action="store_true", dest="anticache", default=False,
        help="Strip out request headers that might cause the server to return 304-not-modified."
    )
    parser.add_argument(
        "--confdir",
        action="store", type=str, dest="confdir", default='~/.mitmproxy',
        help="Configuration directory. (~/.mitmproxy)"
    )
    parser.add_argument(
        "--host",
        action="store_true", dest="showhost", default=False,
        help="Use the Host header to construct URLs for display."
    )
    parser.add_argument(
        "-q",
        action="store_true", dest="quiet",
        help="Quiet."
    )
    parser.add_argument(
        "-r",
        action="store", dest="rfile", default=None,
        help="Read flows from file."
    )
    parser.add_argument(
        "-s",
        action="append", type=str, dest="scripts", default=[],
        metavar='"script.py --bar"',
        help="Run a script. Surround with quotes to pass script arguments. Can be passed multiple times."
    )
    parser.add_argument(
        "-t",
        action="store", dest="stickycookie_filt", default=None, metavar="FILTER",
        help="Set sticky cookie filter. Matched against requests."
    )
    parser.add_argument(
        "-u",
        action="store", dest="stickyauth_filt", default=None, metavar="FILTER",
        help="Set sticky auth filter. Matched against requests."
    )
    parser.add_argument(
        "-v",
        action="store_const", dest="verbose", default=1, const=2,
        help="Increase event log verbosity."
    )
    parser.add_argument(
        "-w",
        action="store", dest="wfile", default=None,
        help="Write flows to file."
    )
    parser.add_argument(
        "-z",
        action="store_true", dest="anticomp", default=False,
        help="Try to convince servers to send us un-compressed data."
    )
    parser.add_argument(
        "-Z",
        action="store", dest="body_size_limit", default=None,
        metavar="SIZE",
        help="Byte size limit of HTTP request and response bodies." \
             " Understands k/m/g suffixes, i.e. 3m for 3 megabytes."
    )
    parser.add_argument(
        "--stream",
        action="store", dest="stream_large_bodies", default=None,
        metavar="SIZE",
        help="Stream data to the client if response body exceeds the given threshold. "
             "If streamed, the body will not be stored in any way. Understands k/m/g suffixes, i.e. 3m for 3 megabytes."
    )

    group = parser.add_argument_group("Proxy Options")
    # We could make a mutually exclusive group out of -R, -U, -T, but we don't do that because
    #  - --upstream-server should be in that group as well, but it's already in a different group.
    #  - our own error messages are more helpful
    group.add_argument(
        "-b",
        action="store", type=str, dest="addr", default='',
        help="Address to bind proxy to (defaults to all interfaces)"
    )
    group.add_argument(
        "-I", "--ignore",
        action="append", type=str, dest="ignore", default=[],
        metavar="HOST",
        help="Ignore host and forward all traffic without processing it. "
             "In transparent mode, it is recommended to use an IP address (range), not the hostname. "
             "In regular mode, only SSL traffic is ignored and the hostname should be used. "
             "The supplied value is interpreted as a regular expression and matched on the ip or the hostname. "
             "Can be passed multiple times. "
    )
    group.add_argument(
        "-n",
        action="store_true", dest="no_server",
        help="Don't start a proxy server."
    )
    group.add_argument(
        "-p",
        action="store", type=int, dest="port", default=8080,
        help="Proxy service port."
    )
    group.add_argument(
        "-R",
        action="store", type=parse_server_spec, dest="reverse_proxy", default=None,
        help="Forward all requests to upstream HTTP server: http[s][2http[s]]://host[:port]"
    )
    group.add_argument(
        "-T",
        action="store_true", dest="transparent_proxy", default=False,
        help="Set transparent proxy mode."
    )
    group.add_argument(
        "-U",
        action="store", type=parse_server_spec, dest="upstream_proxy", default=None,
        help="Forward all requests to upstream proxy server: http://host[:port]"
    )

    group = parser.add_argument_group(
        "Advanced Proxy Options",
        """
            The following options allow a custom adjustment of the proxy behavior.
            Normally, you don't want to use these options directly and use the provided wrappers instead (-R, -U, -T).
        """.strip()
    )
    group.add_argument(
        "--http-form-in", dest="http_form_in", default=None,
        action="store", choices=("relative", "absolute"),
        help="Override the HTTP request form accepted by the proxy"
    )
    group.add_argument(
        "--http-form-out", dest="http_form_out", default=None,
        action="store", choices=("relative", "absolute"),
        help="Override the HTTP request form sent upstream by the proxy"
    )

    group = parser.add_argument_group("Web App")
    group.add_argument(
        "-a",
        action="store_false", dest="app", default=True,
        help="Disable the mitmproxy web app."
    )
    group.add_argument(
        "--app-host",
        action="store", dest="app_host", default=APP_HOST, metavar="host",
        help="Domain to serve the app from. For transparent mode, use an IP when\
                a DNS entry for the app domain is not present. Default: %s" % APP_HOST

    )
    group.add_argument(
        "--app-port",
        action="store", dest="app_port", default=APP_PORT, type=int, metavar="80",
        help="Port to serve the app from."
    )

    group = parser.add_argument_group("Client Replay")
    group.add_argument(
        "-c",
        action="store", dest="client_replay", default=None, metavar="PATH",
        help="Replay client requests from a saved file."
    )

    group = parser.add_argument_group("Server Replay")
    group.add_argument(
        "-S",
        action="store", dest="server_replay", default=None, metavar="PATH",
        help="Replay server responses from a saved file."
    )
    group.add_argument(
        "-k",
        action="store_true", dest="kill", default=False,
        help="Kill extra requests during replay."
    )
    group.add_argument(
        "--rheader",
        action="append", dest="rheaders", type=str,
        help="Request headers to be considered during replay. "
             "Can be passed multiple times."
    )
    group.add_argument(
        "--norefresh",
        action="store_true", dest="norefresh", default=False,
        help="Disable response refresh, "
             "which updates times in cookies and headers for replayed responses."
    )
    group.add_argument(
        "--no-pop",
        action="store_true", dest="nopop", default=False,
        help="Disable response pop from response flow. "
             "This makes it possible to replay same response multiple times."
    )

    group = parser.add_argument_group(
        "Replacements",
        """
            Replacements are of the form "/pattern/regex/replacement", where
            the separator can be any character. Please see the documentation
            for more information.
        """.strip()
    )
    group.add_argument(
        "--replace",
        action="append", type=str, dest="replace", default=[],
        metavar="PATTERN",
        help="Replacement pattern."
    )
    group.add_argument(
        "--replace-from-file",
        action="append", type=str, dest="replace_file", default=[],
        metavar="PATH",
        help="Replacement pattern, where the replacement clause is a path to a file."
    )

    group = parser.add_argument_group(
        "Set Headers",
        """
            Header specifications are of the form "/pattern/header/value",
            where the separator can be any character. Please see the
            documentation for more information.
        """.strip()
    )
    group.add_argument(
        "--setheader",
        action="append", type=str, dest="setheader", default=[],
        metavar="PATTERN",
        help="Header set pattern."
    )

    group = parser.add_argument_group(
        "Proxy Authentication",
        """
            Specify which users are allowed to access the proxy and the method
            used for authenticating them.
        """
    )
    user_specification_group = group.add_mutually_exclusive_group()
    user_specification_group.add_argument(
        "--nonanonymous",
        action="store_true", dest="auth_nonanonymous",
        help="Allow access to any user long as a credentials are specified."
    )

    user_specification_group.add_argument(
        "--singleuser",
        action="store", dest="auth_singleuser", type=str,
        metavar="USER",
        help="Allows access to a a single user, specified in the form username:password."
    )
    user_specification_group.add_argument(
        "--htpasswd",
        action="store", dest="auth_htpasswd", type=str,
        metavar="PATH",
        help="Allow access to users specified in an Apache htpasswd file."
    )

    config.ssl_option_group(parser)