/**
 * 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 {

class PolicyManager;
  
/**
 * 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(const ptr_lib::shared_ptr<Data>& data)> 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, const ptr_lib::shared_ptr<PolicyManager>& policyManager);

  /**
   * 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 
  sign(Data& data, const Name& certificateName, WireFormat& wireFormat = *WireFormat::getDefaultWireFormat());

  /**
   * 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 identityName The identity name for 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 
  signByIdentity(Data& data, const Name& identityName = 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 The Data object with the signature to check. It is an error if data does not have a wireEncoding. 
   * To set the wireEncoding, you can call data.wireDecode.
   * @param onVerified If the signature is verified, this calls onVerified(data).
   * @param onVerifyFailed If the signature check fails, this calls onVerifyFailed(data).
   */
  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_;
  ptr_lib::shared_ptr<PolicyManager> policyManager_;
  Face* face_;
  const int maxSteps_;
};

}

#endif