import sys
import os
import hashlib
import Queue
import random
import select
import time
import threading

import OpenSSL.crypto

from netlib import tcp, http, certutils, websockets
import netlib.utils

import language
import utils


class PathocError(Exception):
    pass


class SSLInfo:
    def __init__(self, certchain, cipher):
        self.certchain, self.cipher = certchain, cipher

    def __str__(self):
        parts = [
            "Cipher: %s, %s bit, %s"%self.cipher,
            "SSL certificate chain:"
        ]
        for i in self.certchain:
            parts.append("\tSubject: ")
            for cn in i.get_subject().get_components():
                parts.append("\t\t%s=%s"%cn)
            parts.append("\tIssuer: ")
            for cn in i.get_issuer().get_components():
                parts.append("\t\t%s=%s"%cn)
            parts.extend(
                [
                    "\tVersion: %s"%i.get_version(),
                    "\tValidity: %s - %s"%(
                        i.get_notBefore(), i.get_notAfter()
                    ),
                    "\tSerial: %s"%i.get_serial_number(),
                    "\tAlgorithm: %s"%i.get_signature_algorithm()
                ]
            )
            pk = i.get_pubkey()
            types = {
                OpenSSL.crypto.TYPE_RSA: "RSA",
                OpenSSL.crypto.TYPE_DSA: "DSA"
            }
            t = types.get(pk.type(), "Uknown")
            parts.append("\tPubkey: %s bit %s"%(pk.bits(), t))
            s = certutils.SSLCert(i)
            if s.altnames:
                parts.append("\tSANs: %s"%" ".join(s.altnames))
            return "\n".join(parts)


class Response:
    def __init__(
        self,
        httpversion,
        status_code,
        msg,
        headers,
        content,
        sslinfo
    ):
        self.httpversion, self.status_code = httpversion, status_code
        self.msg = msg
        self.headers, self.content = headers, content
        self.sslinfo = sslinfo

    def __repr__(self):
        return "Response(%s - %s)"%(self.status_code, self.msg)


class WebsocketFrameReader(threading.Thread):
    def __init__(self, rfile, callback, ws_read_limit):
        threading.Thread.__init__(self)
        self.ws_read_limit = ws_read_limit
        self.rfile, self.callback = rfile, callback
        self.terminate = Queue.Queue()
        self.is_done = Queue.Queue()

    def run(self):
        while 1:
            if self.ws_read_limit == 0:
                break
            r, _, _ = select.select([self.rfile], [], [], 0.05)
            try:
                self.terminate.get_nowait()
                break
            except Queue.Empty:
                pass
            for rfile in r:
                print websockets.Frame.from_file(self.rfile).human_readable()
                if self.ws_read_limit is not None:
                    self.ws_read_limit -= 1
        self.is_done.put(None)


class Pathoc(tcp.TCPClient):
    def __init__(
            self,
            address,

            # SSL
            ssl=None,
            sni=None,
            sslversion=4,
            clientcert=None,
            ciphers=None,

            # Websockets
            ws_read_limit = None,

            # Output control
            showreq = False,
            showresp = False,
            explain = False,
            hexdump = False,
            ignorecodes = (),
            ignoretimeout = False,
            showsummary = False,
            fp = sys.stderr
    ):
        """
            spec: A request specification
            showreq: Print requests
            showresp: Print responses
            explain: Print request explanation
            showssl: Print info on SSL connection
            hexdump: When printing requests or responses, use hex dump output
            showsummary: Show a summary of requests
            ignorecodes: Sequence of return codes to ignore
        """
        tcp.TCPClient.__init__(self, address)
        self.settings = language.Settings(
            staticdir = os.getcwd(),
            unconstrained_file_access = True,
            request_host = self.address.host
        )
        self.ssl, self.sni = ssl, sni
        self.clientcert = clientcert
        self.sslversion = utils.SSLVERSIONS[sslversion]
        self.ciphers = ciphers
        self.sslinfo = None

        self.ws_read_limit = ws_read_limit

        self.showreq = showreq
        self.showresp = showresp
        self.explain = explain
        self.hexdump = hexdump
        self.ignorecodes = ignorecodes
        self.ignoretimeout = ignoretimeout
        self.showsummary = showsummary
        self.fp = fp

        self.ws_framereader = None

    def http_connect(self, connect_to):
        self.wfile.write(
            'CONNECT %s:%s HTTP/1.1\r\n'%tuple(connect_to) +
            '\r\n'
        )
        self.wfile.flush()
        l = self.rfile.readline()
        if not l:
            raise PathocError("Proxy CONNECT failed")
        parsed = http.parse_response_line(l)
        if not parsed[1] == 200:
            raise PathocError(
                "Proxy CONNECT failed: %s - %s"%(parsed[1], parsed[2])
            )
        http.read_headers(self.rfile)

    def connect(self, connect_to=None, showssl=False, fp=sys.stdout):
        """
            connect_to: A (host, port) tuple, which will be connected to with
            an HTTP CONNECT request.
        """
        tcp.TCPClient.connect(self)
        if connect_to:
            self.http_connect(connect_to)
        self.sslinfo = None
        if self.ssl:
            try:
                self.convert_to_ssl(
                    sni=self.sni,
                    cert=self.clientcert,
                    method=self.sslversion,
                    cipher_list = self.ciphers
                )
            except tcp.NetLibError, v:
                raise PathocError(str(v))
            self.sslinfo = SSLInfo(
                self.connection.get_peer_cert_chain(),
                self.get_current_cipher()
            )
            if showssl:
                print >> fp, str(self.sslinfo)

    def _show_summary(self, fp, resp):
        print >> fp, "<< %s %s: %s bytes"%(
            resp.status_code, utils.xrepr(resp.msg), len(resp.content)
        )

    def _show(self, fp, header, data, hexdump):
        if hexdump:
            print >> fp, "%s (hex dump):"%header
            for line in netlib.utils.hexdump(data):
                print >> fp, "\t%s %s %s"%line
        else:
            print >> fp, "%s (unprintables escaped):"%header
            print >> fp, netlib.utils.cleanBin(data)

    def stop(self):
        self.ws_framereader.terminate.put(None)

    def wait(self):
        if self.ws_framereader:
            while 1:
                try:
                    self.ws_framereader.is_done.get(timeout=0.05)
                    self.ws_framereader.join()
                    return
                except Queue.Empty:
                    pass

    def websocket_get_frame(self, frame):
        """
            Called when a frame is received from the server.
        """
        pass

    def websocket_send_frame(self, r):
        """
            Sends a single websocket frame.
        """
        req = None
        if isinstance(r, basestring):
            r = language.parse_requests(r)[0]
        if self.showreq:
            self.wfile.start_log()
        try:
            req = language.serve(r, self.wfile, self.settings)
            self.wfile.flush()
        except tcp.NetLibTimeout:
            if self.ignoretimeout:
                return None
            if self.showsummary:
                print >> self.fp, "<<", "Timeout"
            raise
        except tcp.NetLibDisconnect: # pragma: nocover
            if self.showsummary:
                print >> self.fp, "<<", "Disconnect"
            raise
        finally:
            if req:
                if self.explain:
                    print >> self.fp, ">> Spec:", r.spec()
                if self.showreq:
                    self._show(
                        self.fp, ">> Websocket Frame",
                        self.wfile.get_log(),
                        self.hexdump
                    )

    def websocket_start(self, r, callback=None, limit=None):
        """
            Performs an HTTP request, and attempts to drop into websocket
            connection.

            callback: A callback called within the websocket thread for every
            server frame.
            limit: Disconnect after receiving N server frames.
        """
        resp = self.http(r)
        if resp.status_code == 101:
            if self.showsummary:
                print >> self.fp, "<< websocket connection established..."
            self.ws_framereader = WebsocketFrameReader(
                self.rfile,
                self.websocket_get_frame,
                self.ws_read_limit
            )
            self.ws_framereader.start()
        return resp

    def http(self, r):
        """
            Performs a single request.

            r: A language.Request object, or a string representing one request.

            Returns Response if we have a non-ignored response.

            May raise http.HTTPError, tcp.NetLibError
        """
        if isinstance(r, basestring):
            r = language.parse_requests(r)[0]
        resp, req = None, None
        if self.showreq:
            self.wfile.start_log()
        if self.showresp:
            self.rfile.start_log()
        try:
            req = language.serve(r, self.wfile, self.settings)
            self.wfile.flush()
            resp = list(
                http.read_response(
                    self.rfile,
                    req["method"],
                    None
                )
            )
            resp.append(self.sslinfo)
            resp = Response(*resp)
        except http.HttpError, v:
            if self.showsummary:
                print >> self.fp, "<< HTTP Error:", v.message
            raise
        except tcp.NetLibTimeout:
            if self.ignoretimeout:
                return None
            if self.showsummary:
                print >> self.fp, "<<", "Timeout"
            raise
        except tcp.NetLibDisconnect: # pragma: nocover
            if self.showsummary:
                print >> self.fp, "<<", "Disconnect"
            raise
        finally:
            if req:
                if resp and resp.status_code in self.ignorecodes:
                    resp = None
                else:
                    if self.explain:
                        print >> self.fp, ">> Spec:", r.spec()

                    if self.showreq:
                        self._show(
                            self.fp, ">> Request",
                            self.wfile.get_log(),
                            self.hexdump
                        )

                    if self.showsummary and resp:
                        self._show_summary(self.fp, resp)
                    if self.showresp:
                        self._show(
                            self.fp,
                            "<< Response",
                            self.rfile.get_log(),
                            self.hexdump
                        )
        return resp

    def request(self, r):
        """
            Performs a single request.

            r: A language.Request object, or a string representing one request.

            Returns Response if we have a non-ignored response.

            May raise http.HTTPError, tcp.NetLibError
        """
        if isinstance(r, basestring):
            r = language.parse_requests(r)[0]
        if isinstance(r, language.Request):
            if r.ws:
                return self.websocket_start(r, self.websocket_get_frame)
            else:
                return self.http(r)
        elif isinstance(r, language.WebsocketFrame):
            self.websocket_send_frame(r)


def main(args): # pragma: nocover
    memo = set([])
    trycount = 0
    p = None
    try:
        cnt = 0
        while 1:
            if cnt == args.repeat and args.repeat != 0:
                break
            if trycount > args.memolimit:
                print >> sys.stderr, "Memo limit exceeded..."
                return
            if args.wait and cnt != 0:
                time.sleep(args.wait)

            cnt += 1
            if args.random:
                playlist = [random.choice(args.requests)]
            else:
                playlist = args.requests
            p = Pathoc(
                (args.host, args.port),
                ssl = args.ssl,
                sni = args.sni,
                sslversion = args.sslversion,
                clientcert = args.clientcert,
                ciphers = args.ciphers,
                showreq = args.showreq,
                showresp = args.showresp,
                explain = args.explain,
                hexdump = args.hexdump,
                ignorecodes = args.ignorecodes,
                ignoretimeout = args.ignoretimeout,
                showsummary = True
            )
            if args.explain or args.memo:
                playlist = [
                    i.freeze(p.settings) for i in playlist
                ]
            if args.memo:
                newlist = []
                for spec in playlist:
                    h = hashlib.sha256(spec.spec()).digest()
                    if h not in memo:
                        memo.add(h)
                        newlist.append(spec)
                playlist = newlist
            if not playlist:
                trycount += 1
                continue

            trycount = 0
            try:
                p.connect(args.connect_to, args.showssl)
            except tcp.NetLibError, v:
                print >> sys.stderr, str(v)
                continue
            except PathocError, v:
                print >> sys.stderr, str(v)
                sys.exit(1)
            if args.timeout:
                p.settimeout(args.timeout)
            for spec in playlist:
                try:
                    ret = p.request(spec)
                    sys.stdout.flush()
                    if ret and args.oneshot:
                        return
                except (http.HttpError, tcp.NetLibError), v:
                    pass
            p.wait()
    except KeyboardInterrupt:
        pass
    if p:
        p.stop()
        p.wait()