/**
 * Copyright (C) 2013 Regents of the University of California.
 * @author: Jeff Thompson <jefft0@remap.ucla.edu>
 * See COPYING for copyright and distribution information.
 */

#ifndef NDN_KEY_CHAIN_HPP
#define NDN_KEY_CHAIN_HPP

#include "../data.hpp"
#include "../face.hpp"
#include "identity/identity-manager.hpp"

namespace ndn {

/**
 * An OnVerified function object is used to pass a callback to verifyData to report a successful verification.
 */
typedef func_lib::function<void(const ptr_lib::shared_ptr<Data>& data)> OnVerified;

/**
 * An OnVerifyFailed function object is used to pass a callback to verifyData to report a failed verification.
 */
typedef func_lib::function<void()> OnVerifyFailed;

/**
 * Keychain is main class of security library.
 *
 * The Keychain class provides a set of interfaces to the security library such as identity management, policy configuration 
 * and packet signing and verification.
 */
class KeyChain {
public:
  KeyChain(const ptr_lib::shared_ptr<IdentityManager>& identityManager);

  /**
   * Get the default certificate name for the specified identity, which will be used when signing is performed based on identity.
   * @param identityName The name of the specified identity.
   * @return The requested certificate name.
   */
  Name
  getDefaultCertificateNameForIdentity(const Name& identityName)
  {
    return identityManager_->getDefaultCertificateNameForIdentity(identityName);
  }
  
  /**
   * Examine the data packet Name and infer the identity name for signing the content.
   * @param name The data packet name to examine.
   * @return A new identity name for signing a data packet.
   */
  Name
  inferSigningIdentity(const Name& name)
  {
#if 0
    policyManager_->inferSigningIdentity(name)
#else
    return Name();
#endif
  }

  /**
   * Wire encode the Data object, sign it and set its signature.
   * Note: the caller must make sure the timestamp is correct, for example with 
   * data.getMetaInfo().setTimestampMilliseconds(time(NULL) * 1000.0).
   * @param data The Data object to be signed.  This updates its signature and key locator field and wireEncoding.
   * @param certificateName The certificate name of the key to use for signing.  If omitted, infer the signing identity from the data packet name.
   * @param wireFormat A WireFormat object used to encode the input. If omitted, use WireFormat getDefaultWireFormat().
   */
  void 
  signData(Data& data, const Name& certificateName = Name(), WireFormat& wireFormat = *WireFormat::getDefaultWireFormat());

  /**
   * Check the signature on the Data object and call either onVerify or onVerifyFailed. 
   * We use callback functions because verify may fetch information to check the signature.
   * @param data
   * @param onVerified
   * @param onVerifyFailed
   */
  void
  verifyData
    (const ptr_lib::shared_ptr<Data>& data, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed, int stepCount = 0);

  /**
   * Set the Face which will be used to fetch required certificates.
   * @param face A pointer to the Face object.
   */
  void
  setFace(Face* face) { face_ = face; }

private:
  ptr_lib::shared_ptr<IdentityManager> identityManager_;
  Face* face_;
  const int maxSteps_;
};

}

#endif