// Copyright 2012 Google Inc. All Rights Reserved.

#ifndef CDM_BASE_CDM_SESSION_H_
#define CDM_BASE_CDM_SESSION_H_

#include <set>

#include "crypto_session.h"
#include "license.h"
#include "policy_engine.h"
#include "wv_cdm_event_listener.h"
#include "wv_cdm_types.h"

namespace wvcdm {

// TODO(kqyang): Do we need it? CdmKey not defined yet
// typedef std::map<KeyId, CdmKey*> CdmSessionKeys;

class CdmSession {
 public:
  CdmSession() : state_(INITIAL), session_id_(GenerateSessionId()) {}
  ~CdmSession() {}

  bool Init();

  bool DestroySession();

  void set_key_system(const CdmKeySystem& ksystem) { key_system_ = ksystem; }
  const CdmKeySystem& key_system() { return key_system_; }

  const CdmSessionId& session_id() { return session_id_; }

  bool VerifySession(const CdmKeySystem& key_system,
                     const CdmInitData& init_data);

  CdmResponseType GenerateKeyRequest(const CdmInitData& init_data,
                                     CdmKeyMessage* key_request);

  // AddKey() - Accept license response and extract key info.
  CdmResponseType AddKey(const CdmKeyResponse& key_response);

  // CancelKeyRequest() - Cancel session.
  CdmResponseType CancelKeyRequest();

  // Query license information
  CdmResponseType QueryKeyStatus(CdmQueryMap* key_info);

  // Decrypt() - Accept encrypted buffer and return decrypted data.
  CdmResponseType Decrypt(const uint8_t* encrypted_buffer,
                          size_t encrypted_size,
                          size_t block_offset,
                          const std::vector<uint8_t>& iv,
                          const KeyId& key_id,
                          uint8_t* decrypted_buffer);

  // License renewal
  // GenerateRenewalRequest() - Construct valid renewal request for the current
  // session keys.
  CdmResponseType GenerateRenewalRequest(CdmKeyMessage* key_request);

  // RenewKey() - Accept renewal response and update key info.
  CdmResponseType RenewKey(const CdmKeyResponse& key_response);

  bool IsKeyValid(const KeyId& key_id);

  bool AttachEventListener(WvCdmEventListener* listener);
  bool DetachEventListener(WvCdmEventListener* listener);

  void OnTimerEvent();

 private:

  // Generate unique ID for each new session.
  CdmSessionId GenerateSessionId();

  typedef enum {
    INITIAL,
    LICENSE_REQUESTED,
    LICENSE_RESPONSE_DONE,
    RENEWAL_ENABLED,
    RENEWAL_REQUESTED,
    LICENSE_EXPIRED
  } CdmSessionState;

  // instance variables
  CdmSessionState state_;
  const CdmSessionId session_id_;
  CdmKeySystem key_system_;
  CdmLicense license_parser_;
  CryptoSession* crypto_session_;
  PolicyEngine policy_engine_;

  std::set<WvCdmEventListener*> listeners_;

  // TODO(kqyang): CdmKey not defined yet
  // CdmSessionKeys session_keys_;

  CORE_DISALLOW_COPY_AND_ASSIGN(CdmSession);
};

}  // namespace wvcdm

#endif  // CDM_BASE_CDM_SESSION_H_