/*
 *parse or be parsed
 */


#include <stdio.h>
#include <fcntl.h>
#include <assert.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include "AmConfig.h"
#include "AmSdp.h"
#include "AmUtils.h"
#include "AmPlugIn.h"
#include "AmSession.h"

#include "amci/amci.h"
#include "log.h"

#include <stdexcept>

#include <string>
#include <map>
using std::string;
using std::map;

#include <cctype>
#include <algorithm>

// Not on Solaris!
#if !defined (__SVR4) && !defined (__sun)
#include "strings.h"
#endif

#define CR   '\r'
#define LF   '\n'
#define CRLF "\r\n"

static void parse_session_attr(AmSdp* sdp_msg, char* s, char** next);
static bool parse_sdp_line_ex(AmSdp* sdp_msg, char*& s);
static char* parse_sdp_connection(AmSdp* sdp_msg, char* s, char t);
static void parse_sdp_media(AmSdp* sdp_msg, char* s);
static char* parse_sdp_attr(AmSdp* sdp_msg, char* s);
static void parse_sdp_origin(AmSdp* sdp_masg, char* s);

inline char* get_next_line(char* s);
inline char* skip_till_next_line(char* s, size_t& line_len);
static char* is_eql_next(char* s);
static char* parse_until(char* s, char end);
static char* parse_until(char* s, char* end, char c);
static bool contains(char* s, char* next_line, char c);
static bool is_wsp(char s);

static MediaType media_type(std::string media);
static TransProt transport_type(std::string transport);
static bool attr_check(std::string attr);

enum parse_st {SDP_DESCR, SDP_MEDIA};
enum sdp_connection_st {NET_TYPE, ADDR_TYPE, IP4, IP6};
enum sdp_media_st {MEDIA, PORT, PROTO, FMT}; 
enum sdp_attr_rtpmap_st {TYPE, ENC_NAME, CLK_RATE, ENC_PARAM};
enum sdp_attr_fmtp_st {FORMAT, FORMAT_PARAM};
enum sdp_origin_st {USER, ID, VERSION_ST, NETTYPE, ADDR, UNICAST_ADDR};

// inline functions

inline string net_t_2_str(int nt)
{
  switch(nt){
  case NT_IN: return "IN";
  default: return "<unknown network type>";
  }
}

inline string addr_t_2_str(int at)
{
  switch(at){
  case AT_V4: return "IP4";
  case AT_V6: return "IP6";
  default: return "<unknown address type>";
  }
}


inline string media_t_2_str(int mt)
{
  switch(mt){
  case MT_AUDIO: return "audio";
  case MT_VIDEO: return "video";
  case MT_APPLICATION: return "application";
  case MT_TEXT: return "text";
  case MT_MESSAGE: return "message";
  case MT_IMAGE: return "image";
  default: return "<unknown media type>";
  }
}

inline string transport_p_2_str(int tp)
{
  switch(tp){
  case TP_RTPAVP: return "RTP/AVP";
  case TP_RTPAVPF: return "RTP/AVPF";
  case TP_UDP: return "udp";
  case TP_RTPSAVP: return "RTP/SAVP";
  case TP_RTPSAVPF: return "RTP/SAVPF";
  case TP_UDPTLSRTPSAVP: return "UDP/TLS/RTP/SAVP";
  case TP_UDPTLSRTPSAVPF: return "UDP/TLS/RTP/SAVPF";
  case TP_UDPTL: return "udptl";
  default: return "<unknown media type>";
  }
}

bool SdpConnection::operator == (const SdpConnection& other) const
{
  return network == other.network && addrType == other.addrType 
    && address == other.address;
}

bool SdpOrigin::operator == (const SdpOrigin& other) const
{
  return user == other.user && sessId == other.sessId 
    && sessV == other.sessV && conn == other.conn;
}

bool SdpPayload::operator == (const SdpPayload& other) const
{
  return payload_type == other.payload_type && encoding_name == other.encoding_name 
    && clock_rate == other.clock_rate && encoding_param == other.encoding_param;
}

string SdpConnection::debugPrint() const {
  return addr_t_2_str(addrType) + " " + address;
}

string SdpMedia::debugPrint() const {
  string payload_list;
  for(std::vector<SdpPayload>::const_iterator it=
	payloads.begin(); it!= payloads.end(); it++) {
    if (it != payloads.begin())
      payload_list+=" ";
    payload_list+=int2str(it->payload_type);
  }
  return "port "+int2str(port) + ", payloads: "+payload_list;
}

string SdpMedia::type2str(int type)
{
  return media_t_2_str(type);
}

bool SdpPayload::operator == (int r)
{
  DBG("pl == r: payload_type = %i; r = %i\n", payload_type, r);
  return payload_type == r;
}

string SdpAttribute::print() const
{
  if (value.empty())
    return "a="+attribute+CRLF;
  else
    return "a="+attribute+":"+value+CRLF;
}

bool SdpAttribute::operator==(const SdpAttribute& other) const
{
  return attribute==other.attribute && (value.empty() || (value==other.value));
}

bool SdpMedia::operator == (const SdpMedia& other) const
{
  if (payloads.empty()) {
    if (!other.payloads.empty())
      return false;

  } else if (other.payloads.empty()) {
    return false;

  } else {    
    std::pair<vector<SdpPayload>::const_iterator, vector<SdpPayload>::const_iterator> pl_mismatch 
      = std::mismatch(payloads.begin(), payloads.end(), other.payloads.begin());

    if (pl_mismatch.first != payloads.end() || pl_mismatch.second != other.payloads.end())
      return false;
  }

  if (attributes.empty()) {
    if (!other.attributes.empty()) {
      return false;
    }
  } else {
    std::pair<vector<SdpAttribute>::const_iterator, vector<SdpAttribute>::const_iterator> a_mismatch 
      = std::mismatch(attributes.begin(), attributes.end(), other.attributes.begin());

    if (a_mismatch.first != attributes.end() || a_mismatch.second != other.attributes.end())
      return false;
  }

  return type == other.type && port == other.port && nports == other.nports 
    && transport == other.transport && conn == other.conn && dir == other.dir
    && send == other.send && recv == other.recv;
}

//
// class RtcpAddress: Methods
//
bool RtcpAddress::parse(const string &src)
{
  port = 0;
  nettype.clear();
  addrtype.clear();
  address.clear();

  int len = src.size();
  if (len < 1) return false;

  enum { PORT, NET_TYPE, ADDR_TYPE, ADDR } s = PORT;

  // parsing (somehow) according to RFC 3605
  //    rtcp-attribute =  "a=rtcp:" port  [nettype space addrtype space
  //                             connection-address] CRLF
  // nettype, addrtype is ignored
  for (int i = 0; i < len; ++i) {
    switch (s) {

      case (PORT):
        if (src[i] >= '0' && src[i] <= '9') port = port * 10 + (src[i] - '0');
        else if (src[i] == ' ') s = NET_TYPE;
        else return false; // error
        break;

      case NET_TYPE:
          if (src[i] == ' ') s = ADDR_TYPE;
          else nettype += src[i];
          break;

      case ADDR_TYPE:
          if (src[i] == ' ') s = ADDR;
          else addrtype += src[i];
          break;

      case ADDR:
          address += src[i];
          break;
    }
  }
  return s == PORT ||
    (s == ADDR && !address.empty()); 
  // FIXME: nettype, addrtype and addr should be verified
}

string RtcpAddress::print()
{
  string s(int2str(port));
  if (!address.empty())
    s += " IN " + addrtype + " " + address;
  return s;
}

RtcpAddress::RtcpAddress(const string &attr_value): port(0)
{
  if (!parse(attr_value)) 
    throw std::runtime_error("can't parse rtcp attribute value");
}


//
// class AmSdp: Methods
//
AmSdp::AmSdp()
  : origin(),
    sessionName(),
    conn(),
    media(),
    version(0)
{
  origin.user = "sems";
  origin.sessId = get_random();
  origin.sessV = get_random();
}

AmSdp::AmSdp(const AmSdp& p_sdp_msg)
  : version(p_sdp_msg.version),
    origin(p_sdp_msg.origin),
    sessionName(p_sdp_msg.sessionName),
    conn(p_sdp_msg.conn),
    media(p_sdp_msg.media),
    attributes(p_sdp_msg.attributes)
{
}

int AmSdp::parse(const char* _sdp_msg)
{
  char* s = (char*)_sdp_msg;
  clear();

  bool ret = parse_sdp_line_ex(this,s);
  
  if(!ret && conn.address.empty()){
    for(vector<SdpMedia>::iterator it = media.begin();
	!ret && (it != media.end()); ++it)
      ret = it->conn.address.empty();
    
    if(ret){
      ERROR("A connection field must be field must be present in every\n");
      ERROR("media description or at the session level.\n");
    }
  }
  
    
  return ret;
}

void AmSdp::print(string& body) const
{
  string out_buf = "v="+int2str(version)+"\r\n"
    "o="+origin.user+" "+uint128ToStr(origin.sessId)+" "+
    uint128ToStr(origin.sessV)+" IN ";

  if (!origin.conn.address.empty())
    if (origin.conn.address.find(".") != std::string::npos)
      out_buf += "IP4 " + origin.conn.address + "\r\n";
    else
      out_buf += "IP6 " + origin.conn.address + "\r\n";
  else if (!conn.address.empty())
    if (conn.address.find(".") != std::string::npos)
      out_buf += "IP4 " + conn.address + "\r\n";
    else
      out_buf += "IP6 " + conn.address + "\r\n";
  else if (media.size() && !media[0].conn.address.empty())
    if (media[0].conn.address.find(".") != std::string::npos)
      out_buf += "IP4 " + media[0].conn.address + "\r\n";
    else
      out_buf += "IP6 " + media[0].conn.address + "\r\n";
  else
    out_buf += "IP4 0.0.0.0\r\n";

  out_buf +=
    "s="+sessionName+"\r\n";
  if (!conn.address.empty()) {
    if (conn.address.find(".") != std::string::npos)
      out_buf += "c=IN IP4 ";
    else
      out_buf += "c=IN IP6 ";
    out_buf += conn.address + "\r\n";
  }

  out_buf += "t=0 0\r\n";

  // add attributes (session level)
  for (std::vector<SdpAttribute>::const_iterator a_it=
	 attributes.begin(); a_it != attributes.end(); a_it++) {
    out_buf += a_it->print();
  }

  for(std::vector<SdpMedia>::const_iterator media_it = media.begin();
      media_it != media.end(); media_it++) {
      
      out_buf += "m=" + media_t_2_str(media_it->type) + " " + int2str(media_it->port) + " " + transport_p_2_str(media_it->transport);

      string options;

      if (media_it->transport == TP_RTPAVP || media_it->transport == TP_RTPAVPF || media_it->transport == TP_RTPSAVP || media_it->transport == TP_RTPSAVPF || media_it->transport == TP_UDPTLSRTPSAVP || media_it->transport == TP_UDPTLSRTPSAVPF) {
	for(std::vector<SdpPayload>::const_iterator pl_it = media_it->payloads.begin();
	    pl_it != media_it->payloads.end(); pl_it++) {

	  out_buf += " " + int2str(pl_it->payload_type);

	  // "a=rtpmap:" line
	  if (!pl_it->encoding_name.empty()) {
	    options += "a=rtpmap:" + int2str(pl_it->payload_type) + " "
	      + pl_it->encoding_name + "/" + int2str(pl_it->clock_rate);

	    if(pl_it->encoding_param > 0){
	      options += "/" + int2str(pl_it->encoding_param);
	    }

	    options += "\r\n";
	  }
	  
	  // "a=fmtp:" line
	  if(pl_it->sdp_format_parameters.size()){
	    options += "a=fmtp:" + int2str(pl_it->payload_type) + " "
	      + pl_it->sdp_format_parameters + "\r\n";
	  }
	  
	}
      }
      else {
        // for other transports (UDP/UDPTL) just print out fmt
        out_buf += " " + media_it->fmt;
        // ... and continue with c=, attributes, ...
      }

      if (!media_it->conn.address.empty())
        out_buf += "\r\nc=IN " + addr_t_2_str(media_it->conn.addrType) + 
		" " + media_it->conn.address;

      out_buf += "\r\n" + options;

      if(media_it->send){
	if(media_it->recv){
	  out_buf += "a=sendrecv\r\n";
	}
	else {
	  out_buf += "a=sendonly\r\n";
	}
      }
      else {
	if(media_it->recv){
	  out_buf += "a=recvonly\r\n";
	}
	else {
	  out_buf += "a=inactive\r\n";
	}
      }

      // add attributes (media level)
      for (std::vector<SdpAttribute>::const_iterator a_it=
	     media_it->attributes.begin(); a_it != media_it->attributes.end(); a_it++) {
	out_buf += a_it->print();
      }

      switch (media_it->dir) {
      case SdpMedia::DirActive:  out_buf += "a=direction:active\r\n"; break;
      case SdpMedia::DirPassive: out_buf += "a=direction:passive\r\n"; break;
      case SdpMedia::DirBoth:  out_buf += "a=direction:both\r\n"; break;
      case SdpMedia::DirUndefined: break;
      }
  }

  body = out_buf;
}

const SdpPayload* AmSdp::telephoneEventPayload() const
{
  return findPayload("telephone-event");
}

const SdpPayload *AmSdp::findPayload(const string& name) const
{
  vector<SdpMedia>::const_iterator m_it;

  for (m_it = media.begin(); m_it != media.end(); ++m_it)
    {
      vector<SdpPayload>::const_iterator it = m_it->payloads.begin();
      for(; it != m_it->payloads.end(); ++it)

	{
	  if (it->encoding_name == name)
	    {
	      return new SdpPayload(*it);
	    }
	}
    }
  return NULL;
}

bool AmSdp::operator == (const AmSdp& other) const
{
  if (attributes.empty()) {
    if (!other.attributes.empty())
      return false;

  } else if (other.attributes.empty()) {
    return false;

  } else {
    std::pair<vector<SdpAttribute>::const_iterator, vector<SdpAttribute>::const_iterator> a_mismatch
      = std::mismatch(attributes.begin(), attributes.end(), other.attributes.begin());

    if (a_mismatch.first != attributes.end() || a_mismatch.second != other.attributes.end())
      return false;
  }
   
  if (media.empty()) {
    if (!other.media.empty())
      return false;

  } else if (other.media.empty()) {
    return false;

  } else {
    std::pair<vector<SdpMedia>::const_iterator, vector<SdpMedia>::const_iterator> m_mismatch
      = std::mismatch(media.begin(), media.end(), other.media.begin());

    if (m_mismatch.first != media.end() || m_mismatch.second != other.media.end())
      return false;
  }

  return version == other.version && origin == other.origin 
    && sessionName == other.sessionName && uri == other.uri && conn == other.conn;
}

void AmSdp::clear()
{
  version = 0;
  origin  = SdpOrigin();
  sessionName.clear();
  uri.clear();
  conn = SdpConnection();
  attributes.clear();
  media.clear();
  l_origin = SdpOrigin();
}

void SdpMedia::calcAnswer(const AmPayloadProvider* payload_prov,
			  SdpMedia& answer) const
{
  if (!recv) answer.send = false;
  if (!send) answer.recv = false;

  switch (dir)
  {
    case SdpMedia::DirBoth:
      answer.dir = SdpMedia::DirBoth;
      break;
    case SdpMedia::DirActive:
      answer.dir = SdpMedia::DirPassive;
      break;
    case SdpMedia::DirPassive:
      answer.dir = SdpMedia::DirActive;
      break;
    case SdpMedia::DirUndefined:
      answer.dir = SdpMedia::DirUndefined;
      break;
  }

  /* Calculate the intersection with the offered set of payloads */
  vector<SdpPayload>::const_iterator it = payloads.begin();
  for(; it!= payloads.end(); ++it)
  {
    amci_payload_t* a_pl = NULL;
    if (it->payload_type < DYNAMIC_PAYLOAD_TYPE_START) {
      /* try static payloads */
      a_pl = payload_prov->payload(it->payload_type);
    }

    if (a_pl) {
      answer.payloads.push_back(SdpPayload(a_pl->payload_id,
                                a_pl->name,
                                a_pl->advertised_sample_rate,
                                0));
    } else {
      /* Try dynamic payloads
       * and give a chance to broken
       * implementation using a static payload number
       * for dynamic ones. */

      int int_pt = payload_prov->getDynPayload(it->encoding_name,
                                              it->clock_rate,
                                              it->encoding_param);
      if (int_pt != -1)
        answer.payloads.push_back(*it);
    }
  }
}

/**
 * SDP body parser
 */
static bool parse_sdp_line_ex(AmSdp* sdp_msg, char*& s)
{
  /* SDP can't be empty, return error (true really used for failure?) */
  if (!s)
    return true;

  char* next=0;
  size_t line_len = 0;
  parse_st state;

  /* default state */
  state=SDP_DESCR;
  DBG("Parsing SDP message...\n");

  while (*s != '\0')
  {
    switch (state) {

      case SDP_DESCR:
        switch(*s) {
          case 'v':
          {
            s = is_eql_next(s);
            next = skip_till_next_line(s, line_len);
            if (line_len) {
              string version(s, line_len);
              str2i(version, sdp_msg->version);
              // DBG("parse_sdp_line_ex: found version '%s'\n", version.c_str());
            } else {
              sdp_msg->version = 0;
            }
            s = next;
            state = SDP_DESCR;
            break;
          }

          case 'o':
            //DBG("parse_sdp_line_ex: found origin\n");
            s = is_eql_next(s);
            parse_sdp_origin(sdp_msg, s);
            s = get_next_line(s);
            state = SDP_DESCR;
            break;

          case 's':
          {
            s = is_eql_next(s);
            next = skip_till_next_line(s, line_len);
            if (line_len) {
              sdp_msg->sessionName = string(s, line_len);
            } else {
              sdp_msg->sessionName.clear();
            }
            s = next;
            break;
          }

          case 'u':
          {
            s = is_eql_next(s);
            next = skip_till_next_line(s, line_len);
            if (line_len) {
              sdp_msg->uri = string(s, line_len);
            } else {
              sdp_msg->uri.clear();
            }
            s = next;
          }
          break;

          case 'i':
          case 'e':
          case 'p':
          case 'b':
          case 't':
          case 'k':
            s = is_eql_next(s);
            s = skip_till_next_line(s, line_len);
            state = SDP_DESCR;
            break;

          case 'a':
            s = is_eql_next(s);
            parse_session_attr(sdp_msg, s, &next);
            // next = get_next_line(s);
            // parse_sdp_attr(sdp_msg, s);
            s = next;
            state = SDP_DESCR;
            break;

          case 'c':
            s = is_eql_next(s);
            s = parse_sdp_connection(sdp_msg, s, 'd');
            state = SDP_DESCR;
            break;

          case 'm':
            //DBG("parse_sdp_line_ex: found media\n");
            state = SDP_MEDIA;	
            break;

          default:
          {
            next = skip_till_next_line(s, line_len);
            if (line_len) {
              sdp_msg->uri = string(s, line_len);
            } else {
              sdp_msg->uri.clear();
            }
            next = skip_till_next_line(s, line_len);

            if (line_len) {
              DBG("parse_sdp_line: skipping unknown Session description %s=\n",
              string(s, line_len).c_str());
            }
            s = next;
            break;
          }
        }
        break;

      case SDP_MEDIA:
        switch(*s) {
          case 'm':
            s = is_eql_next(s);
            parse_sdp_media(sdp_msg, s);
            s = skip_till_next_line(s, line_len);
            state = SDP_MEDIA;
            break;

          case 'i':
            s = is_eql_next(s);
            s = skip_till_next_line(s, line_len);
            state = SDP_MEDIA;
            break;

          case 'c':
            s = is_eql_next(s);
            //DBG("parse_sdp_line: found media connection\n");
            s = parse_sdp_connection(sdp_msg, s, 'm');
            state = SDP_MEDIA;
            break;

          case 'b':
            s = is_eql_next(s);
            s = skip_till_next_line(s, line_len);
            state = SDP_MEDIA;
            break;

          case 'k':
            s = is_eql_next(s);
            s = skip_till_next_line(s, line_len);
            state = SDP_MEDIA;
            break;

          case 'a':
            s = is_eql_next(s);
            s = parse_sdp_attr(sdp_msg, s);
            state = SDP_MEDIA;
            break;

          default:
          {
            next = skip_till_next_line(s, line_len);
            if (line_len) {
              DBG("parse_sdp_line: skipping unknown Media description '%.*s'\n",
              (int)line_len, s);
            }
            s = next;
            break;
          }
        }
        break;
    }
  }
  return false;
}

static char* parse_sdp_connection(AmSdp* sdp_msg, char* s, char t)
{
  char* connection_line=s;
  char* next=0;
  char* next_line=0;
  size_t line_len = 0;
  int parsing=1;

  SdpConnection c;

  next_line = skip_till_next_line(s, line_len);
  if (line_len <= 7) { /* should be at least c=IN IP4 ... */
    DBG("short connection line '%.*s'\n", (int)line_len, s);
    return next_line;
  }

  sdp_connection_st state;
  state = NET_TYPE;

  /* DBG("parse_sdp_line_ex: parse_sdp_connection: parsing sdp connection\n"); */

  while (parsing)
  {
    switch(state) {
      case NET_TYPE:
        //Ignore NET_TYPE since it is always IN, fixme
        c.network = NT_IN; // fixme
        connection_line +=3; // fixme
        state = ADDR_TYPE;
        break;

      case ADDR_TYPE:
      {
        string addr_type(connection_line,3);

        string addr_type_uc = addr_type;
        std::transform(addr_type_uc.begin(), addr_type_uc.end(), addr_type_uc.begin(), toupper);
        connection_line +=4;

        if (addr_type_uc == "IP4") {
          c.addrType = AT_V4;
          state = IP4;
        } else if (addr_type_uc == "IP6") {
          c.addrType = AT_V6;
          state = IP6;
        } else {
          DBG("parse_sdp_connection: Unknown addr_type in c-line: '%s'\n", addr_type.c_str());
          c.addrType = AT_NONE;
          parsing = 0; /* ??? */
        }
        break;
      }

      case IP4:
      {
        if (contains(connection_line, next_line, '/')) {
          next = parse_until(s, '/');
          c.address = string(connection_line,int(next-connection_line)-2);
        } else {
          c.address = string(connection_line, line_len-7);
        }
        parsing = 0;
        break;
      }

      case IP6:
      {
        if (contains(connection_line, next_line, '/')) {
          next = parse_until(s, '/');
          c.address = string(connection_line, int(next-connection_line)-2);
        } else {
          c.address = string(connection_line, line_len-7);
        }
        parsing = 0;
        break;
      }
    }
  }

  if (t == 'd') {
    sdp_msg->conn = c;
    DBG("SDP: got session level connection: %s\n", c.debugPrint().c_str());

  } else if(t == 'm') {
    SdpMedia& media = sdp_msg->media.back();
    media.conn = c;
    DBG("SDP: got media level connection: %s\n", c.debugPrint().c_str());
  }

  /* DBG("parse_sdp_line_ex: parse_sdp_connection: done parsing sdp connection\n"); */
  return next_line;
}

static void parse_sdp_media(AmSdp* sdp_msg, char* s)
{
  SdpMedia m;
  
  sdp_media_st state;
  state = MEDIA;
  int parsing = 1;
  char* media_line=s;
  char* next=0;
  char* line_end=0;
  line_end = get_next_line(media_line);
  SdpPayload payload;
  unsigned int payload_type;

  /* DBG("parse_sdp_line_ex: parse_sdp_media: parsing media description...\n"); */
  m.dir = SdpMedia::DirBoth;

  while (parsing)
  {
    switch (state) {
      case MEDIA:
      {
        next = parse_until(media_line, ' ');
        string media;
        if (next > media_line)
          media = string(media_line, int(next-media_line) - 1);

        m.type = media_type(media);

        if (m.type == MT_NONE) {
          ERROR("parse_sdp_media: Unknown media type\n");
        }
        media_line = next;
        state = PORT;
        break;
      }

      case PORT:
      {
        next = parse_until(media_line, ' ');
        /* check for multiple ports */
        if (contains(media_line, next, '/')) {
          /* port number */
          next = parse_until(media_line, '/');

          string port;
          if (next > media_line)
            port = string(media_line, int(next-media_line)-1);

          str2i(port, m.port);

          /* number of ports */
          media_line = next;
          next = parse_until(media_line, ' ');
          string nports;
          if (next > media_line)
            nports = string(media_line, int(next-media_line)-1);

          str2i(nports, m.nports);

        } else {
          /* port number */
          next = parse_until(media_line, ' ');
          string port;
          if (next > media_line)
            port = string(media_line, int(next-media_line)-1);
          str2i(port, m.port);
          media_line = next;
        }

        state = PROTO;
        break;
      }

      case PROTO:
      {
        next = parse_until(media_line, ' ');
        string proto;
        if (next > media_line)
          proto = string(media_line, int(next-media_line)-1);
        /* if(transport_type(proto) < 0){
            ERROR("parse_sdp_media: Unknown transport protocol\n");
            state = FMT;
            break;
          } */

        m.transport = transport_type(proto);
        if (m.transport == TP_NONE)
          DBG("Unknown transport protocol: %s\n",proto.c_str());

        media_line = next;
        state = FMT;
        break;
      }

      case FMT:
      {
        if (m.transport == TP_RTPAVP ||
            m.transport  == TP_RTPAVPF ||
            m.transport == TP_RTPSAVP ||
            m.transport == TP_RTPSAVPF ||
            m.transport == TP_UDPTLSRTPSAVP ||
            m.transport == TP_UDPTLSRTPSAVPF)
        {
          if (contains(media_line, line_end, ' ')) {
            next = parse_until(media_line, ' ');
            string value;
            if (next > media_line)
              value = string(media_line, int(next-media_line)-1);

            if (!value.empty()) {
              payload.type = m.type;
              str2i(value, payload_type);
              payload.payload_type = payload_type;
              m.payloads.push_back(payload);
            }
            media_line = next;

          } else {
            string last_value;
            if (line_end>media_line) {
              if (*line_end == '\0') {
                /* last line in message */
                last_value = string(media_line, int(line_end-media_line));
              } else {
                last_value = string(media_line, int(line_end-media_line)-1);
              }
            }
            if (!last_value.empty()) {
              payload.type = m.type;
              str2i(last_value, payload_type);
              payload.payload_type = payload_type;
              m.payloads.push_back(payload);
            }
            parsing = 0;
          }

        } else {
          line_end--;
          while (line_end > media_line && (*line_end == '\r' || *line_end == '\n'))
            line_end--;

          if (line_end>media_line)
              m.fmt = string(media_line, line_end-media_line+1);

          DBG("set media fmt to '%s'\n", m.fmt.c_str());
          parsing = 0;
        }
      }
      break;
    }
  }
  sdp_msg->media.push_back(m);

  DBG("SDP: got media: %s\n", m.debugPrint().c_str());
  /* DBG("parse_sdp_line_ex: parse_sdp_media: done parsing media description \n"); */
  return;
}

/* session level attribute */
static void parse_session_attr(AmSdp* sdp_msg, char* s, char** next) {
  size_t line_len = 0;
  *next = skip_till_next_line(s, line_len);

  if (*next == s) {
    WARN("premature end of SDP in session attr\n");
    while (**next != '\0') (*next)++;
    return;
  }

  char* attr_end = *next-1;
  while (attr_end >= s && ((*attr_end == LF) || (*attr_end == CR)))
    attr_end--;

  if (*attr_end == ':') {
    WARN("incorrect SDP: value attrib without value: '%s'\n", string(s, attr_end-s+1).c_str());
    return;
  }

  char* col = parse_until(s, attr_end, ':');

  if (col == attr_end) {
    /* property attribute */
    sdp_msg->attributes.push_back(SdpAttribute(string(s, attr_end-s+1)));
    /* DBG("got session attribute '%.*s\n", (int)(attr_end-s+1), s); */
  } else {
    /* value attribute */
    sdp_msg->attributes.push_back(SdpAttribute(string(s, col-s-1), string(col, attr_end-col+1)));
    /* DBG("got session attribute '%.*s:%.*s'\n", (int)(col-s-1), s, (int)(attr_end-col+1), col); */
  }
}

/* media level attribute */
static char* parse_sdp_attr(AmSdp* sdp_msg, char* s)
{
  if (sdp_msg->media.empty()) {
    ERROR("While parsing media options: no actual media !\n");
    return s;
  }

  SdpMedia& media = sdp_msg->media.back();

  SdpPayload payload;

  sdp_attr_rtpmap_st rtpmap_st;
  sdp_attr_fmtp_st fmtp_st;
  rtpmap_st = TYPE;
  fmtp_st = FORMAT;
  char* attr_line=s;
  char* next=0;
  char* line_end=0;
  size_t line_len = 0;
  int parsing = 1;
  line_end = skip_till_next_line(attr_line, line_len);

  unsigned int payload_type, clock_rate, encoding_param = 0;
  string encoding_name, params;

  string attr;
  if (!contains(attr_line, line_end, ':')) {
    attr = string(attr_line, line_len);
    attr_check(attr);
    parsing = 0;
  } else {
    next = parse_until(attr_line, ':');
    attr = string(attr_line, int(next-attr_line)-1);
    attr_line = next;
  }

  /* rtpmap */
  if (attr == "rtpmap") {
    while (parsing)
    {
      switch (rtpmap_st) {
        case TYPE:
        {
          next = parse_until(attr_line, ' ');
          string type(attr_line, int(next-attr_line)-1);
          str2i(type,payload_type);
          attr_line = next;
          rtpmap_st = ENC_NAME;
          break;
        }

        case ENC_NAME:
        {
          if(contains(s, line_end, '/')){
            next = parse_until(attr_line, '/');
            string enc_name(attr_line, int(next-attr_line)-1);
            encoding_name = enc_name;
            attr_line = next;
            rtpmap_st = CLK_RATE;
            break;
          } else {
            rtpmap_st = ENC_PARAM;
            break;
          }
        }

        case CLK_RATE:
        {
          /* check for posible encoding parameters after clock rate */
          if(contains(attr_line, line_end, '/')){
            next = parse_until(attr_line, '/');
            string clk_rate(attr_line, int(next-attr_line)-1);
            str2i(clk_rate, clock_rate);
            attr_line = next;
            rtpmap_st = ENC_PARAM;
            /* last line check */
          }else if (*line_end == '\0') {
            string clk_rate(attr_line, int(line_end-attr_line));
            str2i(clk_rate, clock_rate);
            parsing = 0;
            /* more lines to come */
          }else{
            string clk_rate(attr_line, int(line_end-attr_line)-1);
            str2i(clk_rate, clock_rate);
            parsing=0;
          }
          break;
        }

        case ENC_PARAM:
        {
          next = parse_until(attr_line, ' ');
          if(next < line_end){
            string value(attr_line, int(next-attr_line)-1);
            str2i(value, encoding_param);
            attr_line = next;
            rtpmap_st = ENC_PARAM;
          }else{
            string last_value(attr_line, int(line_end-attr_line)-1);
            str2i(last_value, encoding_param);
            parsing = 0;
          }
          break;
        }
        break;
      }
    }

    /* DBG("found media attr 'rtpmap' type '%d'\n", payload_type); */

    vector<SdpPayload>::iterator pl_it;

    /* find needed SDP payload type (one from m= line list) and point to it */
    for(pl_it=media.payloads.begin();
        (pl_it != media.payloads.end()) && (pl_it->payload_type != int(payload_type));
        ++pl_it);

    if (pl_it != media.payloads.end()) {
      *pl_it = SdpPayload(int(payload_type),
                          encoding_name,
                          int(clock_rate),
                          int(encoding_param));
    }

  } else if(attr == "fmtp") {
    while(parsing)
    {
      switch(fmtp_st) { /* fixme */
        case FORMAT:
        {
          next = parse_until(attr_line, line_end, ' ');
          string fmtp_format(attr_line, int(next-attr_line)-1);
          str2i(fmtp_format, payload_type);
          attr_line = next;
          fmtp_st = FORMAT_PARAM;
          break;
        }

        case FORMAT_PARAM:
        {
          char* param_end = line_end - 1;
          while (is_wsp(*param_end))
            param_end--;

          params = string(attr_line, param_end-attr_line+1);
          parsing = 0;
        }
        break;
      }
    }

    /* DBG("found media attr 'fmtp' for payload '%d': '%s'\n",
       payload_type, params.c_str()); */

    vector<SdpPayload>::iterator pl_it;

    /* find needed SDP payload type (one from m= line list) and point to it */
    for (pl_it=media.payloads.begin();
        (pl_it != media.payloads.end()) && (pl_it->payload_type != int(payload_type));
        pl_it++);

    if(pl_it != media.payloads.end())
      pl_it->sdp_format_parameters = params;

  /* direction */
  } else if (attr == "direction") {
    if (parsing) {
      size_t dir_len = 0;
      next = skip_till_next_line(attr_line, dir_len);
      string value(attr_line, dir_len);
      if (value == "active") {
        media.dir=SdpMedia::DirActive;
        // DBG("found media attr 'direction' value '%s'\n", (char*)value.c_str());
      } else if (value == "passive") {
        media.dir=SdpMedia::DirPassive;
        //DBG("found media attr 'direction' value '%s'\n", (char*)value.c_str());
      } else if (attr == "both") {
        media.dir=SdpMedia::DirBoth;
        //DBG("found media attr 'direction' value '%s'\n", (char*)value.c_str());
      } else {
        DBG("found unknown value for media attribute 'direction'\n");
      }
    } else {
      DBG("ignoring direction attribute without value\n");
    }

  /* sendrecv/sendonly/recvonly/inactive */
  } else if (attr == "sendrecv") {
    media.send = true;
    media.recv = true;
  } else if (attr == "sendonly") {
    media.send = true;
    media.recv = false;
  } else if (attr == "recvonly") {
    media.send = false;
    media.recv = true;
  } else if (attr == "inactive") {
    media.send = false;
    media.recv = false;
  } else {
    attr_check(attr);
    string value;
    if (parsing) {
      size_t attr_len = 0;
      next = skip_till_next_line(attr_line, attr_len);
      value = string (attr_line, attr_len);
    }

    /* if (value.empty()) {
         DBG("got media attribute '%s'\n", attr.c_str());
       } else {
         DBG("got media attribute '%s':'%s'\n", attr.c_str(), value.c_str());
       } */
    media.attributes.push_back(SdpAttribute(attr, value));
  }
  return line_end;
}

static void parse_sdp_origin(AmSdp* sdp_msg, char* s)
{
  char* origin_line = s;
  char* next=0;
  char* line_end=0;
  size_t line_len=0;
  line_end = skip_till_next_line(s, line_len);

  sdp_origin_st origin_st;
  origin_st = USER;
  int parsing = 1;

  SdpOrigin origin;

  /* DBG("parse_sdp_line_ex: parse_sdp_origin: parsing sdp origin\n"); */

  while (parsing)
  {
    switch(origin_st) {
      case USER:
      {
        next = parse_until(origin_line, ' ');
        if (next > line_end) {
          DBG("parse_sdp_origin: ST_USER: Incorrect number of value in o=\n");
          origin_st = UNICAST_ADDR;
          break;
        }
        string user(origin_line, int(next-origin_line)-1);
        origin.user = user;
        origin_line = next;
        origin_st = ID;
        break;
      }

      case ID:
      {
        next = parse_until(origin_line, ' ');
        if (next > line_end) {
          DBG("parse_sdp_origin: ST_ID: Incorrect number of value in o=\n");
          origin_st = UNICAST_ADDR;
          break;
        }
        string id(origin_line, int(next-origin_line)-1);
        str2uint128(id, origin.sessId);
        origin_line = next;
        origin_st = VERSION_ST;
        break;
      }

      case VERSION_ST:
      {
        next = parse_until(origin_line, ' ');
        if(next > line_end){
          DBG("parse_sdp_origin: ST_VERSION: Incorrect number of value in o=\n");
          origin_st = UNICAST_ADDR;
          break;
        }
        string version(origin_line, int(next-origin_line)-1);
        str2uint128(version, origin.sessV);
        origin_line = next;
        origin_st = NETTYPE;
        break;
      }

      case NETTYPE:
      {
        next = parse_until(origin_line, ' ');
        if (next > line_end) {
          DBG("parse_sdp_origin: ST_NETTYPE: Incorrect number of value in o=\n");
          origin_st = UNICAST_ADDR;
          break;
        }
        string net_type(origin_line, int(next-origin_line)-1);
        origin.conn.network = NT_IN; // fixme
        origin_line = next;
        origin_st = ADDR;
        break;
      }

      case ADDR:
      {
        next = parse_until(origin_line, ' ');
        if (next > line_end) {
          DBG("parse_sdp_origin: ST_ADDR: Incorrect number of value in o=\n");
          origin_st = UNICAST_ADDR;
          break;
        }

        string addr_type(origin_line, int(next-origin_line)-1);
        if (addr_type == "IP4") {
          origin.conn.addrType = AT_V4;
        } else if (addr_type == "IP6") {
          origin.conn.addrType = AT_V6;
        } else {
          DBG("parse_sdp_connection: Unknown addr_type in o line: '%s'\n", addr_type.c_str());
          origin.conn.addrType = AT_NONE;
        }

        origin_line = next;
        origin_st = UNICAST_ADDR;
        break;
      }

      case UNICAST_ADDR:
      {
        next = parse_until(origin_line, ' ');
        if (next != origin_line) {
          /* check if line contains more values than allowed */
          if (next > line_end) {
            size_t addr_len = 0;
            skip_till_next_line(origin_line, addr_len);
            origin.conn.address = string(origin_line, addr_len);
          } else {
            DBG("parse_sdp_origin: 'o=' contains more values than allowed; these values will be ignored\n");
            origin.conn.address = string(origin_line, int(next-origin_line)-1);
          }
        } else {
          origin.conn.address = "";
        }
        parsing = 0;
        break;
      }
    }
  }

  sdp_msg->origin = origin;

  /* DBG("parse_sdp_line_ex: parse_sdp_origin: done parsing sdp origin\n"); */
  return;
}

/*
 *HELPER FUNCTIONS
 */

static bool contains(char* s, char* next_line, char c)
{
  char* line=s;
  while((line != next_line-1) && (*line)){
    if(*line == c)
      return true;
    line++;
  }
  return false;
}

static bool is_wsp(char s) {
  return s==' ' || s == '\r' || s == '\n' || s == '\t';
}

static char* parse_until(char* s, char end)
{
  char* line=s;
  while(*line && *line != end ){
    line++;
  }
  line++;
  return line;
}

static char* parse_until(char* s, char* end, char c)
{
  char* line=s;
  while(line<end && *line && *line != c ){
    line++;
  }
  if (line<end)
    line++;
  return line;
}

static size_t len_till_eol(char* s, char* end)
{
  size_t res=0;
  char* line=s;
  while(line<end && *line && *line != '\r' && *line != '\n'){
    line++;
    res++;
  }
  return res;
}

static size_t len_till_char_or_eol(char* s, char* end, char c)
{
  size_t res=0;
  char* line=s;
  while(line<end && *line && *line !=  c && *line != '\r' && *line != '\n'){
    line++;
    res++;
  }
  return res;
}

static char* is_eql_next(char* s)
{
  char* current_line=s;
  if(*(++current_line) != '='){
    DBG("parse_sdp_line: expected '=' but found <%c> \n", *current_line);
  }
  current_line +=1;
  return current_line;
}

inline char* get_next_line(char* s)
{
  char* next_line=s;
  //search for next line
 while( *next_line != '\0') {
    if(*next_line == CR){
      next_line++;
      if (*next_line == LF) {
	next_line++;
	break;
      } else {
	continue;
      }
    } else if (*next_line == LF){	
      next_line++;
      break;
    }
    next_line++;
 }

  return next_line; 
}

/* skip to 0, CRLF or LF;
   @return line_len length of current line
   @return start of next line 
*/
inline char* skip_till_next_line(char* s, size_t& line_len)
{
  char* next_line=s;
  line_len = 0;

  //search for next line
  while( *next_line != '\0') {
    if (*next_line == CR) {
      next_line++;
      if (*next_line == LF) {
	next_line++;
	break;
      } else {
	continue;
      }
    } else if (*next_line == LF){	
      next_line++;
      break;
    }
    line_len++;
    next_line++;
 }

  return next_line; 
}

/*
 *Check if known media type is used
 */
static MediaType media_type(std::string media)
{
  if(media == "audio")
    return MT_AUDIO;
  else if(media == "video")
    return MT_VIDEO;
  else if(media == "application")
    return MT_APPLICATION;
  else if(media == "text")
    return MT_TEXT;
  else if(media == "message")
    return MT_MESSAGE;
  else if(media == "image")
    return MT_IMAGE;
  else 
    return MT_NONE;
}

static TransProt transport_type(string transport)
{
  string transport_uc = transport;
  std::transform(transport_uc.begin(), transport_uc.end(), transport_uc.begin(), toupper);

  if(transport_uc == "RTP/AVP")
    return TP_RTPAVP;
  else if(transport_uc == "RTP/AVPF")
    return TP_RTPAVPF;
  else if(transport_uc == "UDP")
    return TP_UDP;
  else if(transport_uc == "RTP/SAVP")
    return TP_RTPSAVP;
  else if(transport_uc == "RTP/SAVPF")
    return TP_RTPSAVPF;
  else if(transport_uc == "UDP/TLS/RTP/SAVP")
    return TP_UDPTLSRTPSAVP;
  else if(transport_uc == "UDP/TLS/RTP/SAVPF")
    return TP_UDPTLSRTPSAVPF;
  else if(transport_uc == "UDPTL")
    return TP_UDPTL;
  else 
    return TP_NONE;
}

/*
*Check if known attribute name is used
*/
static bool attr_check(std::string attr)
{
  if(attr == "cat")
    return true;
  else if(attr == "keywds")
    return true;
  else if(attr == "tool")
    return true;
  else if(attr == "ptime")
    return true;
  else if(attr == "maxptime")
    return true;
  else if(attr == "recvonly")
    return true;
  else if(attr == "sendrecv")
    return true;
  else if(attr == "sendonly")
    return true;
  else if(attr == "inactive")
    return true;
  else if(attr == "orient")
    return true;
  else if(attr == "type")
    return true;
  else if(attr == "charset")
    return true;
  else if(attr == "sdplang")
    return true;
  else if(attr == "lang")
    return true;
  else if(attr == "framerate")
    return true;
  else if(attr == "quality")
    return true;
  else if(attr == "both")
    return true;
  else if(attr == "active")
    return true;
  else if(attr == "passive")
    return true;
  else {
    DBG("unknown attribute: %s\n", (char*)attr.c_str());
    return false;
  }
}