// Copyright 2013 Google Inc. All Rights Reserved.

#ifndef CDM_BASE_CDM_ENGINE_H_
#define CDM_BASE_CDM_ENGINE_H_

#include "timer.h"
#include "wv_cdm_types.h"

namespace wvcdm {

class CdmSession;
class CryptoEngine;
class WvCdmEventListener;

typedef std::map<CdmSessionId, CdmSession*> CdmSessionMap;

class CdmEngine : public TimerHandler {
 public:
  CdmEngine();
  ~CdmEngine();

  // Session related methods
  CdmResponseType OpenSession(const CdmKeySystem& key_system,
                              CdmSessionId* session_id);
  CdmResponseType CloseSession(const CdmSessionId& session_id);

  // License related methods
  // Construct a valid license request
  CdmResponseType GenerateKeyRequest(const CdmSessionId& session_id,
                                     bool is_key_system_present,
                                     const CdmKeySystem& key_system,
                                     const CdmInitData& init_data,
                                     const CdmLicenseType license_type,
                                     CdmAppParameterMap& app_parameters,
                                     CdmKeyMessage* key_request,
                                     std::string* server_url);

  // Accept license response and extract key info.
  CdmResponseType AddKey(const CdmSessionId& session_id,
                         const CdmKeyResponse& key_data);

  // Cancel session and unload keys.
  CdmResponseType CancelKeyRequest(const CdmSessionId& session_id,
                                   bool is_key_system_present,
                                   const CdmKeySystem& key_system);

  // Construct valid renewal request for the current session keys.
  CdmResponseType GenerateRenewalRequest(const CdmSessionId& session_id,
                                         CdmKeyMessage* key_request,
                                         std::string* server_url);

  // Accept renewal response and update key info.
  CdmResponseType RenewKey(const CdmSessionId& session_id,
                           const CdmKeyResponse& key_data);

  // Query system information
  CdmResponseType QueryStatus(CdmQueryMap* info);

  // Query license information
  CdmResponseType QueryKeyStatus(const CdmSessionId& session_id,
                                 CdmQueryMap* key_info);

  // Query seesion control information
  CdmResponseType QueryKeyControlInfo(const CdmSessionId& session_id,
                                      CdmQueryMap* key_info);

  // Provisioning related methods
  CdmResponseType GetProvisioningRequest(CdmProvisioningRequest* request,
                                         std::string* default_url);

  CdmResponseType HandleProvisioningResponse(CdmProvisioningResponse& response);

  // Secure stop related methods
  CdmResponseType GetSecureStops(CdmSecureStops* secure_stops);
  CdmResponseType ReleaseSecureStops(const CdmSecureStopReleaseMessage& message);

  // Decryption and key related methods
  // Accept encrypted buffer and return decrypted data.
  CdmResponseType Decrypt(const CdmSessionId& session_id,
                          bool is_encrypted,
                          bool is_secure,
                          const KeyId& key_id,
                          const uint8_t* encrypt_buffer,
                          size_t encrypt_length,
                          const std::vector<uint8_t>& iv,
                          size_t block_offset,
                          void* decrypt_buffer,
                          size_t decrypt_buffer_offset,
                          bool is_video);

  // Is the key known to any session?
  bool IsKeyValid(const KeyId& key_id);

  // Event listener related methods
  bool AttachEventListener(const CdmSessionId& session_id,
                           WvCdmEventListener* listener);
  bool DetachEventListener(const CdmSessionId& session_id,
                           WvCdmEventListener* listener);
 private:
  // private methods
  // Cancel all sessions
  bool CancelSessions();
  void CleanupProvisioningSession(const CdmSessionId& cdm_session_id);
  void ComposeJsonRequest(const std::string& message,
                          CdmProvisioningRequest* request);

  // Parse a blob of multiple concatenated PSSH atoms to extract the first
  // widevine pssh
  // TODO(gmorgan): This should be done by the user of this class.
  bool ExtractWidevinePssh(const CdmInitData& init_data,
                           CdmInitData* output);
  bool ParseJsonResponse(const CdmProvisioningResponse& json_str,
                         const std::string& start_substr,
                         const std::string& end_substr,
                         std::string* result);
  bool ValidateKeySystem(const CdmKeySystem& key_system);

  // timer related methods to drive policy decisions
  void EnablePolicyTimer();
  void DisablePolicyTimer();
  virtual void OnTimerEvent();

  // instance variables
  CdmSession* provisioning_session_;
  CdmSessionMap sessions_;

  // policy timer
  Timer policy_timer_;

  CORE_DISALLOW_COPY_AND_ASSIGN(CdmEngine);
};

}  // namespace wvcdm

#endif  // CDM_BASE_CDM_ENGINE_H_