/*
 *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef WEBRTC_P2P_BASE_TRANSPORTCHANNELIMPL_H_
#define WEBRTC_P2P_BASE_TRANSPORTCHANNELIMPL_H_

#include <string>
#include "webrtc/p2p/base/transport.h"
#include "webrtc/p2p/base/transportchannel.h"

namespace buzz { class XmlElement; }

namespace cricket {

class Candidate;

// Base class for real implementations of TransportChannel.  This includes some
// methods called only by Transport, which do not need to be exposed to the
// client.
class TransportChannelImpl : public TransportChannel {
 public:
  explicit TransportChannelImpl(const std::string& content_name, int component)
      : TransportChannel(content_name, component) {}

  // Returns the transport that created this channel.
  virtual Transport* GetTransport() = 0;

  // For ICE channels.
  virtual IceRole GetIceRole() const = 0;
  virtual void SetIceRole(IceRole role) = 0;
  virtual void SetIceTiebreaker(uint64 tiebreaker) = 0;
  // To toggle G-ICE/ICE.
  virtual bool GetIceProtocolType(IceProtocolType* type) const = 0;
  virtual void SetIceProtocolType(IceProtocolType type) = 0;
  // SetIceCredentials only need to be implemented by the ICE
  // transport channels. Non-ICE transport channels can just ignore.
  // The ufrag and pwd should be set before the Connect() is called.
  virtual void SetIceCredentials(const std::string& ice_ufrag,
                                 const std::string& ice_pwd)  = 0;
  // SetRemoteIceCredentials only need to be implemented by the ICE
  // transport channels. Non-ICE transport channels can just ignore.
  virtual void SetRemoteIceCredentials(const std::string& ice_ufrag,
                                       const std::string& ice_pwd) = 0;

  // SetRemoteIceMode must be implemented only by the ICE transport channels.
  virtual void SetRemoteIceMode(IceMode mode) = 0;

  // Begins the process of attempting to make a connection to the other client.
  virtual void Connect() = 0;

  // Resets this channel back to the initial state (i.e., not connecting).
  virtual void Reset() = 0;

  // Allows an individual channel to request signaling and be notified when it
  // is ready.  This is useful if the individual named channels have need to
  // send their own transport-info stanzas.
  sigslot::signal1<TransportChannelImpl*> SignalRequestSignaling;
  virtual void OnSignalingReady() = 0;

  // Handles sending and receiving of candidates.  The Transport
  // receives the candidates and may forward them to the relevant
  // channel.
  //
  // Note: Since candidates are delivered asynchronously to the
  // channel, they cannot return an error if the message is invalid.
  // It is assumed that the Transport will have checked validity
  // before forwarding.
  sigslot::signal2<TransportChannelImpl*,
                   const Candidate&> SignalCandidateReady;
  virtual void OnCandidate(const Candidate& candidate) = 0;

  // DTLS methods
  // Set DTLS local identity.  The identity object is not copied, but the caller
  // retains ownership and must delete it after this TransportChannelImpl is
  // destroyed.
  // TODO(bemasc): Fix the ownership semantics of this method.
  virtual bool SetLocalIdentity(rtc::SSLIdentity* identity) = 0;

  // Set DTLS Remote fingerprint. Must be after local identity set.
  virtual bool SetRemoteFingerprint(const std::string& digest_alg,
    const uint8* digest,
    size_t digest_len) = 0;

  virtual bool SetSslRole(rtc::SSLRole role) = 0;

  // TransportChannel is forwarding this signal from PortAllocatorSession.
  sigslot::signal1<TransportChannelImpl*> SignalCandidatesAllocationDone;

  // Invoked when there is conflict in the ICE role between local and remote
  // agents.
  sigslot::signal1<TransportChannelImpl*> SignalRoleConflict;

  // Emitted whenever the number of connections available to the transport
  // channel decreases.
  sigslot::signal1<TransportChannelImpl*> SignalConnectionRemoved;

 private:
  DISALLOW_EVIL_CONSTRUCTORS(TransportChannelImpl);
};

}  // namespace cricket

#endif  // WEBRTC_P2P_BASE_TRANSPORTCHANNELIMPL_H_