/*************************************************************************
 *
 * HTCd - Copyright (C) 1998-2006 Henrik Rydberg
 *
 * 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 2 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; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <net/isocket.h>
#include <mail/res.h>
#include <http/http.h>
#include <mt/lookup.h>
#include <mt/lock.h>
#include <sys/utsname.h>
#include <signal.h>

static fp_stream merr(stderr);
static IPnode NODE;
static int PORT;
static mstring URL,PATH,SERVER,URL1,URL2;
static int volatile RUNNING;

const mstring REDIRECT="/tmp/redirect.";
const int BACKLOG=4;
const int SNDBUFSIZE=16384;
const int RCVBUFSIZE=16384;
const int MAXHEAD=16384;
const int SAFEZONE=4096;

static void BreakURL()
{
  static const mstring pre="//";
  int p=URL.find(pre);
  if(p>=0) {
    p+=pre.size();
    int q=p+URL.right(p).find('/');
    if(q>=p) {
      URL1=URL.left(q);
      URL2=URL.right(q);
    }
    else {
      URL1=URL;
      URL2.clear();
    }
  }
  else throw(0);
}

static mstring Combine(const sref& uri)
{
  const int ncvt=3;
  static const mstring cvt[ncvt]={"/BODY","/en","/sv"};
  mstring d=uri;
  mstring s=URL1;
  for(int i=0;i<ncvt;i++) {
    int p=d.find(cvt[i]);
    if(p>=0) {
      d.erase(p,cvt[i].size());
      s+=cvt[i];
    }
  }
  s+=URL2;
  s+=d;
  return s;
}

static int Handle(isocket& sock)
{
  mstring buffer(MAXHEAD+SAFEZONE);
  int nhead=sock.gethead(buffer.data(),MAXHEAD);
  if(nhead<=0) return 0;
  httpReq req(sref(buffer.data(),nhead));
  httpResp resp;
  resp.status=HTTP_301;
  //resp.location=URL+req.uri;
  resp.location=Combine(req.uri);
  if(req.arg.nempty()) { resp.location.append(1,'?'); resp.location+=req.arg; }
  resp.putHead(sock);
  putend(sock);
  sock.close();
  return 1;
}

///////////////////////////////////////////////////////////////

extern "C" {
  static void onTERM(int sig) { RUNNING=0; }
  typedef void (*disp_t)(int);
}

static void MainProc(isocket& sock)
{
  RUNNING=1;
  while(RUNNING) {
    int test=sock.test();
    if(test>0) {
      try {
        isocket* s=sock.accept();
        if(s) Handle(*s);
      }
      catch(const merror_t& e) {
        merr<<"SOCKET: "<<e.desc<<"\n";
      }
    }
    else if(test<0) RUNNING=0;
  }
}

///////////////////////////////////////////////////////////////

static void httpServer()
{
  isocket sock(NODE.addr,PORT,BACKLOG);
  sock.keepalive(1);
  sock.sendbufsize(SNDBUFSIZE);
  sock.recvbufsize(RCVBUFSIZE);
  sigignore(SIGPIPE);
  disp_t onterm=signal(SIGTERM,onTERM);
  disp_t onint=signal(SIGINT,onTERM);
  MainProc(sock);
  signal(SIGINT,onint);
  signal(SIGTERM,onterm);
}

static void Daemon() try
{
  PROCLOCK(PATH);
  merr<<"redirect: "<<SERVER<<" -> "<<URL<<" started\n";
  httpServer();
}
catch(const merror_t& e) {
  if(First(e.desc)!=sref("proclock:")) merr<<e.desc<<"\n";
}
catch(...) {
  merr<<"FATAL\n";
}

main(int argc,char* argv[]) try
{
  if(argc<3) {
    merr<<"Usage: "<<argv[0]<<" [host:]<port> <url> [-1|0|1]\n";
    return -1;
  }
  sref s(argv[1]);
  mstring host=s.left_last(':');
  mstring sport=s.past_last(':');
  if(sport.empty()) {
    sport=host;
    host.clear();
  }
  PORT=atoi(sport);
  URL=argv[2];
  if(URL.back()=='/') URL=URL.popb();
  BreakURL();
  if(host.empty()) {
    struct utsname u; uname(&u);
    host=u.nodename;
  }
  Lookup(NODE,host);
  SERVER=NODE.name; SERVER.append(1,'-'); SERVER+=itoa(PORT);
  PATH=REDIRECT; PATH+=SERVER;  
  int cmd=argc>3?atoi(argv[3]):0;
  if(cmd) ProcTerminate(PATH);
  if(cmd>=0) { if(fork()==0) Daemon(); }
  return 0;
}
catch(const merror_t& e) {
  merr<<"ERROR: ["<<e.desc<<"]\n";
  return -1;
}
catch(...) {
  merr<<"ERROR: [FATAL]\n";
  return -1;
}