// Copyright 2013 Google Inc. All Rights Reserved.

#ifndef WVCDM_CORE_CDM_ENGINE_H_
#define WVCDM_CORE_CDM_ENGINE_H_

#include <string>
#include <vector>

#include "certificate_provisioning.h"
#include "clock.h"
#include "crypto_session.h"
#include "file_store.h"
#include "initialization_data.h"
#include "lock.h"
#include "oemcrypto_adapter.h"
#include "scoped_ptr.h"
#include "service_certificate.h"
#include "wv_cdm_constants.h"
#include "wv_cdm_types.h"

namespace wvcdm {

class CdmClientPropertySet;
class CdmSession;
class CryptoEngine;
class UsagePropertySet;
class WvCdmEventListener;

typedef std::map<CdmSessionId, CdmSession*> CdmSessionMap;
typedef std::map<
    CdmKeySetId,
    std::pair<CdmSessionId, int64_t /* expiration time in seconds */> >
    CdmReleaseKeySetMap;

class CdmEngine {
 public:
  CdmEngine(FileSystem* file_system, const std::string& spoid = EMPTY_SPOID);
  virtual ~CdmEngine();

  // Set service certificate for all sessions under this CDM/CdmEngine.
  // Setting to the empty string is OK. If the License Service certificate is
  // empty and privacy mode is true, the certificate will be fetched from
  // the server before the first license request.
  virtual CdmResponseType SetServiceCertificate(
      const std::string& certificate);

  // Session related methods
  virtual CdmResponseType OpenSession(
      const CdmKeySystem& key_system, CdmClientPropertySet* property_set,
      const CdmSessionId& forced_session_id,
      WvCdmEventListener* event_listener);

  virtual CdmResponseType OpenSession(
      const CdmKeySystem& key_system, CdmClientPropertySet* property_set,
      WvCdmEventListener* event_listener, CdmSessionId* session_id);

  virtual CdmResponseType CloseSession(const CdmSessionId& session_id);

  virtual bool IsOpenSession(const CdmSessionId& session_id);

  virtual CdmResponseType OpenKeySetSession(
      const CdmKeySetId& key_set_id, CdmClientPropertySet* property_set,
      WvCdmEventListener* event_listener);

  virtual CdmResponseType CloseKeySetSession(const CdmKeySetId& key_set_id);

  // License related methods

  // Construct a valid license request. The arguments are used as follows:
  // session_id: The Session ID of the session the request is being generated
  //             for. This is ignored for license release requests.
  // key_set_id: The Key Set ID of the key set the request is being generated
  //             for. This is ignored except for license release requests.
  // init_data: The initialization data from the media file, which is used to
  //            build the key request. This is ignored for release and renewal
  //            requests.
  // license_type: The type of license being requested. Never ignored.
  // app_parameters: Additional, application-specific parameters that factor
  //                 into the request generation. This is ignored for release
  //                 and renewal requests.
  // key_request: This must be non-null and point to a CdmKeyRequest. The
  //              message field will be filled with the key request, the
  //              type field will be filled with the key request type,
  //              whether it is an initial request, renewal request,
  //              release request, etc. The url field will be filled with
  //              the default URL (if one is known) to send this key
  //              request to.
  virtual CdmResponseType GenerateKeyRequest(
      const CdmSessionId& session_id, const CdmKeySetId& key_set_id,
      const InitializationData& init_data, const CdmLicenseType license_type,
      CdmAppParameterMap& app_parameters, CdmKeyRequest* key_request);
  // Accept license response and extract key info.
  virtual CdmResponseType AddKey(const CdmSessionId& session_id,
                                 const CdmKeyResponse& key_data,
                                 CdmKeySetId* key_set_id);

  virtual CdmResponseType RestoreKey(const CdmSessionId& session_id,
                                     const CdmKeySetId& key_set_id);

  virtual CdmResponseType RemoveKeys(const CdmSessionId& session_id);

  // Construct valid renewal request for the current session keys.
  virtual CdmResponseType GenerateRenewalRequest(
      const CdmSessionId& session_id, CdmKeyRequest* key_request);

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

  // Query system information
  virtual CdmResponseType QueryStatus(SecurityLevel security_level,
                                      const std::string& query_token,
                                      std::string* query_response);

  // Query session information
  virtual CdmResponseType QuerySessionStatus(const CdmSessionId& session_id,
                                             CdmQueryMap* query_response);
  virtual bool IsReleaseSession(const CdmSessionId& session_id);
  virtual bool IsOfflineSession(const CdmSessionId& session_id);

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

  // Query the types of usage permitted for the specified key.
  virtual CdmResponseType QueryKeyAllowedUsage(const CdmSessionId& session_id,
                                               const std::string& key_id,
                                               CdmKeyAllowedUsage* key_usage);

  // Query the types of usage permitted for the specified key.
  // Apply the query across all sessions.  If the key is found in more than
  // one session, return the allowed usage settings only if the usage settings
  // are identical for each instance of the key.  Otherwise, clear the settings
  // and return KEY_CONFLICT_1.
  virtual CdmResponseType QueryKeyAllowedUsage(const std::string& key_id,
                                               CdmKeyAllowedUsage* key_usage);

  // Query OEMCrypto session ID
  virtual CdmResponseType QueryOemCryptoSessionId(
      const CdmSessionId& session_id, CdmQueryMap* query_response);

  // Generate and return a valid provisioning request.
  virtual CdmResponseType GetProvisioningRequest(
      CdmCertificateType cert_type, const std::string& cert_authority,
      CdmProvisioningRequest* request, std::string* default_url);

  // Verify and process a provisioning response.
  virtual CdmResponseType HandleProvisioningResponse(
      const CdmProvisioningResponse& response, std::string* cert,
      std::string* wrapped_key);

  // Return true if there is a device certificate on the current
  // (origin-specific) file system.
  virtual bool IsProvisioned(CdmSecurityLevel security_level);

  // Remove provisioning-related from the current (origin-specific) file system.
  // This will force the device to reprovision itself.
  virtual CdmResponseType Unprovision(CdmSecurityLevel security_level);

  // Delete OEMCrypto usage tables. Used by Unprovision().
  CdmResponseType DeleteUsageTable(CdmSecurityLevel security_level);

  // Return the list of key_set_ids stored on the current (origin-specific)
  // file system.
  virtual CdmResponseType ListStoredLicenses(
      CdmSecurityLevel security_level, std::vector<std::string>* key_set_ids);

  // Usage related methods for streaming licenses
  // Retrieve a random usage info from the list of all usage infos for this app
  // id.
  virtual CdmResponseType GetUsageInfo(const std::string& app_id,
                                       CdmUsageInfo* usage_info);
  // Retrieve the usage info for the specified pst.
  // Returns UNKNOWN_ERROR if no usage info was found.
  virtual CdmResponseType GetUsageInfo(const std::string& app_id,
                                       const CdmSecureStopId& ssid,
                                       CdmUsageInfo* usage_info);
  virtual CdmResponseType ReleaseAllUsageInfo(const std::string& app_id);
  virtual CdmResponseType ReleaseUsageInfo(
      const CdmUsageInfoReleaseMessage& message);
  virtual CdmResponseType LoadUsageSession(const CdmKeySetId& key_set_id,
                                           CdmKeyMessage* release_message);

  // Decryption and key related methods
  // Accept encrypted buffer and return decrypted data.
  virtual CdmResponseType Decrypt(const CdmSessionId& session_id,
                                  const CdmDecryptionParameters& parameters);

  // Generic crypto operations - provides basic crypto operations that an
  // application can use outside of content stream processing

  // Encrypts a buffer of app-level data.
  virtual CdmResponseType GenericEncrypt(
      const std::string& session_id, const std::string& in_buffer,
      const std::string& key_id, const std::string& iv,
      CdmEncryptionAlgorithm algorithm, std::string* out_buffer);

  // Decrypts a buffer of app-level data.
  virtual CdmResponseType GenericDecrypt(
      const std::string& session_id, const std::string& in_buffer,
      const std::string& key_id, const std::string& iv,
      CdmEncryptionAlgorithm algorithm, std::string* out_buffer);

  // Computes the signature for a message.
  virtual CdmResponseType GenericSign(const std::string& session_id,
                                      const std::string& message,
                                      const std::string& key_id,
                                      CdmSigningAlgorithm algorithm,
                                      std::string* signature);

  // Verifies the signature on a buffer of app-level data.
  virtual CdmResponseType GenericVerify(const std::string& session_id,
                                        const std::string& message,
                                        const std::string& key_id,
                                        CdmSigningAlgorithm algorithm,
                                        const std::string& signature);

  virtual size_t SessionSize() const { return sessions_.size(); }

  // Is the key known to any session?
  virtual bool IsKeyLoaded(const KeyId& key_id);
  virtual bool FindSessionForKey(const KeyId& key_id, CdmSessionId* sessionId);

  // Used for notifying the Max-Res Engine of resolution changes.
  // Return false if no match is found for session_id.
  virtual bool NotifyResolution(const CdmSessionId& session_id, uint32_t width,
                                uint32_t height);

  // Timer expiration method. This method is not re-entrant -- there can be
  // only one timer.
  // This method triggers appropriate event callbacks from |event_listener_|,
  // which is assumed to be asynchronous -- i.e. an event should be dispatched
  // to another thread which does the actual work. In particular, if a
  // synchronous listener calls OpenSession or CloseSession, the thread will
  // dead lock.
  virtual void OnTimerEvent();

 private:
  // private methods
  CdmResponseType OpenSession(
      const CdmKeySystem& key_system, CdmClientPropertySet* property_set,
      WvCdmEventListener* event_listener, const CdmSessionId* forced_session_id,
      CdmSessionId* session_id);

  void DeleteAllUsageReportsUponFactoryReset();
  bool ValidateKeySystem(const CdmKeySystem& key_system);
  CdmResponseType GetUsageInfo(const std::string& app_id,
                               SecurityLevel requested_security_level,
                               CdmUsageInfo* usage_info);

  void OnKeyReleaseEvent(const CdmKeySetId& key_set_id);

  std::string MapHdcpVersion(CryptoSession::HdcpCapability version);

  void CloseExpiredReleaseSessions();

  // instance variables
  CdmSessionMap sessions_;
  CdmReleaseKeySetMap release_key_sets_;
  scoped_ptr<CertificateProvisioning> cert_provisioning_;
  SecurityLevel cert_provisioning_requested_security_level_;
  FileSystem* file_system_;
  Clock clock_;
  std::string spoid_;

  static bool seeded_;

  // Service certificate for license server and provisioning server.
  // It is initially empty.  If left empty, the operations that
  // require them (getting provider_id, encrypting ClientIdentification)
  // are not performed.
  ServiceCertificate service_certificate_;

  // usage related variables
  scoped_ptr<CdmSession> usage_session_;
  scoped_ptr<UsagePropertySet> usage_property_set_;
  int64_t last_usage_information_update_time_;

  // Locks the list of sessions, |sessions_|, for the event timer.  It will be
  // locked in OpenSession, CloseSession. It is also locked in OnTimerEvent and
  // OnKeyReleaseEvent while the list of event listeners is being generated.
  // The layer above the CDM implementation is expected to handle thread
  // synchronization to make sure other functions that access sessions do not
  // occur simultaneously with OpenSession or CloseSession.
  Lock session_list_lock_;

  Lock release_key_sets_lock_;

  CORE_DISALLOW_COPY_AND_ASSIGN(CdmEngine);
};

}  // namespace wvcdm

#endif  // WVCDM_CORE_CDM_ENGINE_H_