#!/usr/bin/python3
#
# Hippotat - Asinine IP Over HTTP program
# ./hippotat - client main program
#
# Copyright 2017 Ian Jackson
#
# GPLv3+
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program, in the file GPLv3.  If not,
#    see <http://www.gnu.org/licenses/>.

#@ import sys; sys.path.append('@PYBUILD_INSTALL_DIR@')
from hippotatlib import *

import twisted.web
import twisted.web.client

import io

class GeneralResponseConsumer(twisted.internet.protocol.Protocol):
  def __init__(self, cl, req, desc):
    self._cl = cl
    self._req = req
    self._desc = desc

  def _log(self, dflag, msg, **kwargs):
    self._cl.log(dflag, '%s: %s' % (self._desc, msg), idof=self._req, **kwargs)

  def connectionMade(self):
    self._log(DBG.HTTP_CTRL, 'connectionMade')

class ResponseConsumer(GeneralResponseConsumer):
  def __init__(self, cl, req):
    super().__init__(cl, req, 'RC')
    ssddesc = '[%s] %s' % (id(req), self._desc)
    self._ssd = SlipStreamDecoder(ssddesc, partial(queue_inbound, cl.ipif))
    self._log(DBG.HTTP_CTRL, '__init__')

  def dataReceived(self, data):
    self._log(DBG.HTTP, 'dataReceived', d=data)
    try:
      self._ssd.inputdata(data)
    except Exception as e:
      self._handleexception()

  def connectionLost(self, reason):
    self._log(DBG.HTTP_CTRL, 'connectionLost ' + str(reason))
    if not reason.check(twisted.web.client.ResponseDone):
      self.latefailure()
      return
    try:
      self._log(DBG.HTTP, 'ResponseDone')
      self._ssd.flush()
      self._cl.req_fin(self._req)
    except Exception as e:
      self._handleexception()
    self._cl.report_running()

  def _handleexception(self):
    self._latefailure(traceback.format_exc())

  def _latefailure(self, reason):
    self._log(DBG.HTTP_CTRL, '_latefailure ' + str(reason))
    self._cl.req_err(self._req, reason)

class ErrorResponseConsumer(GeneralResponseConsumer):
  def __init__(self, cl, req, resp):
    super().__init__(cl, req, 'ERROR-RC')
    self._resp = resp
    self._m = b''
    try:
      self._phrase = resp.phrase.decode('utf-8')
    except Exception:
      self._phrase = repr(resp.phrase)
    self._log(DBG.HTTP_CTRL, '__init__ %d %s' % (resp.code, self._phrase))

  def dataReceived(self, data):
    self._log(DBG.HTTP_CTRL, 'dataReceived ' + repr(data))
    self._m += data

  def connectionLost(self, reason):
    try:
      mbody = self._m.decode('utf-8')
    except Exception:
      mbody = repr(self._m)
    if not reason.check(twisted.web.client.ResponseDone):
      mbody += ' || ' + str(reason)
    self._cl.req_err(self._req,
            "FAILED %d %s | %s"
            % (self._resp.code, self._phrase, mbody))

class Client():
  def __init__(cl, c,ss,cs):
    cl.c = c
    cl.outstanding = { }
    cl.desc = '[%s %s] ' % (ss,cs)
    cl.running_reported = False
    cl.log_info('setting up')

  def log_info(cl, msg):
    log.info(cl.desc + msg, dflag=False)

  def report_running(cl):
    if not cl.running_reported:
      cl.log_info('running OK')
      cl.running_reported = True

  def log(cl, dflag, msg, **kwargs):
    log_debug(dflag, cl.desc + msg, **kwargs)

  def log_outstanding(cl):
    cl.log(DBG.CTRL_DUMP, 'OS %s' % cl.outstanding)

  def start(cl):
    cl.queue = PacketQueue('up', cl.c.max_queue_time)
    cl.agent = twisted.web.client.Agent(
      reactor, connectTimeout = cl.c.http_timeout)

  def outbound(cl, packet, saddr, daddr):
    #print('OUT ', saddr, daddr, repr(packet))
    cl.queue.append(packet)
    cl.check_outbound()

  def req_ok(cl, req, resp):
    cl.log(DBG.HTTP_CTRL,
            'req_ok %d %s %s' % (resp.code, repr(resp.phrase), str(resp)),
            idof=req)
    if resp.code == 200:
      rc = ResponseConsumer(cl, req)
    else:
      rc = ErrorResponseConsumer(cl, req, resp)

    resp.deliverBody(rc)
    # now rc is responsible for calling req_fin

  def req_err(cl, req, err):
    # called when the Deferred fails, or (if it completes),
    # later, by ResponsConsumer or ErrorResponsConsumer
    try:
      cl.log(DBG.HTTP_CTRL, 'req_err ' + str(err), idof=req)
      if isinstance(err, twisted.python.failure.Failure):
        err = err.getTraceback()
      print('[%#x] %s' % (id(req), err), file=sys.stderr)
      if not isinstance(cl.outstanding[req], int):
        raise RuntimeError('[%#x] previously %s' %
                           (id(req), cl.outstanding[req]))
      cl.outstanding[req] = err
      cl.log_outstanding()
      reactor.callLater(cl.c.http_retry, partial(cl.req_fin, req))
    except Exception as e:
      crash(traceback.format_exc() + '\n----- handling -----\n' + err)

  def req_fin(cl, req):
    del cl.outstanding[req]
    cl.log(DBG.HTTP_CTRL, 'req_fin OS=%d' % len(cl.outstanding), idof=req)
    cl.check_outbound()

  def check_outbound(cl):
    while True:
      if len(cl.outstanding) >= cl.c.max_outstanding:
        break

      if (not cl.queue.nonempty() and
          len(cl.outstanding) >= cl.c.target_requests_outstanding):
        break

      d = b''
      def moredata(s): nonlocal d; d += s
      cl.queue.process((lambda: len(d)),
                    moredata,
                    cl.c.max_batch_up)

      d = mime_translate(d)

      crlf = b'\r\n'
      lf   =   b'\n'
      mime = (b'--b'                                        + crlf +
              b'Content-Type: text/plain; charset="utf-8"'  + crlf +
              b'Content-Disposition: form-data; name="m"'   + crlf + crlf +
              str(cl.c.client)            .encode('ascii')  + crlf +
              cl.c.password                                 + crlf +
              str(cl.c.target_requests_outstanding)
                                          .encode('ascii')  + crlf +
              str(cl.c.http_timeout)      .encode('ascii')  + crlf +
            ((
              b'--b'                                        + crlf +
              b'Content-Type: application/octet-stream'     + crlf +
              b'Content-Disposition: form-data; name="d"'   + crlf + crlf +
              d                                             + crlf
             ) if len(d) else b'')                               +
              b'--b--'                                      + crlf)

      #df = open('data.dump.dbg', mode='wb')
      #df.write(mime)
      #df.close()
      # POST -use -c 'multipart/form-data; boundary="b"' http://localhost:8099/ <data.dump.dbg

      cl.log(DBG.HTTP_FULL, 'requesting: ' + str(mime))

      hh = { 'User-Agent': ['hippotat'],
             'Content-Type': ['multipart/form-data; boundary="b"'],
             'Content-Length': [str(len(mime))] }

      bytesreader = io.BytesIO(mime)
      producer = twisted.web.client.FileBodyProducer(bytesreader)

      req = cl.agent.request(b'POST',
                          cl.c.url,
                          twisted.web.client.Headers(hh),
                          producer)

      cl.outstanding[req] = len(d)
      cl.log(DBG.HTTP_CTRL,
             'request OS=%d' % len(cl.outstanding),
             idof=req, d=d)
      req.addTimeout(cl.c.http_timeout, reactor)
      req.addCallback(partial(cl.req_ok, req))
      req.addErrback(partial(cl.req_err, req))

    cl.log_outstanding()

clients = [ ]

def process_cfg(_opts, putative_servers, putative_clients):
  global clients

  for ss in putative_servers.values():
    for (ci,cs) in putative_clients.items():
      c = ConfigResults()

      sections = cfg_process_client_common(c,ss,cs,ci)
      if not sections: continue

      log_debug_config('processing client [%s %s]' % (ss, cs))

      def srch(getter,key): return cfg_search(getter,key,sections)

      c.http_timeout   += srch(cfg.getint, 'http_timeout_grace')
      c.max_outstanding = srch(cfg.getint, 'max_requests_outstanding')
      c.max_batch_up    = srch(cfg.getint, 'max_batch_up')
      c.http_retry      = srch(cfg.getint, 'http_retry')
      c.max_queue_time  = srch(cfg.getint, 'max_queue_time')
      c.vroutes         = srch(cfg.get,    'vroutes')

      try: c.ifname     = srch(cfg_get_raw, 'ifname_client')
      except NoOptionError: pass

      try: c.url = srch(cfg.get,'url')
      except NoOptionError:
        cfg_process_saddrs(c, ss)
        c.url = c.saddrs[0].url()

      c.client = ci

      cfg_process_vaddr(c,ss)

      cfg_process_ipif(c,
                       sections,
                       (('local','client'),
                        ('peer', 'vaddr'),
                        ('rnets','vroutes')))

      clients.append(Client(c,ss,cs))

common_startup(process_cfg)

for cl in clients:
  cl.start()
  cl.ipif = start_ipif(cl.c.ipif_command, cl.outbound)
  cl.check_outbound()

common_run()