// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_CDM_PPAPI_CDM_WRAPPER_H_
#define MEDIA_CDM_PPAPI_CDM_WRAPPER_H_

#include "base/basictypes.h"
#include "media/cdm/ppapi/api/content_decryption_module.h"
#include "media/cdm/ppapi/cdm_helpers.h"
#include "ppapi/cpp/logging.h"

namespace media {

// CdmWrapper wraps different versions of ContentDecryptionModule interfaces and
// exposes a common interface to the caller.
//
// The caller should call CdmWrapper::Create() to create a CDM instance.
// CdmWrapper will first try to create a CDM instance that supports the latest
// CDM interface (ContentDecryptionModule). If such an instance cannot be
// created (e.g. an older CDM was loaded), CdmWrapper will try to create a CDM
// that supports an older version of CDM interface (e.g.
// ContentDecryptionModule_*). Internally CdmWrapper converts the CdmWrapper
// calls to corresponding ContentDecryptionModule calls.
//
// Note that CdmWrapper interface always reflects the latest state of content
// decryption related PPAPI APIs (e.g. pp::ContentDecryptor_Private).
//
// Since this file is highly templated and default implementations are short
// (just a shim layer in most cases), everything is done in this header file.
class CdmWrapper {
 public:
  static CdmWrapper* Create(const char* key_system,
                            uint32_t key_system_size,
                            GetCdmHostFunc get_cdm_host_func,
                            void* user_data);

  virtual ~CdmWrapper() {};

  virtual cdm::Status GenerateKeyRequest(const char* type,
                                         uint32_t type_size,
                                         const uint8_t* init_data,
                                         uint32_t init_data_size) = 0;
  virtual cdm::Status AddKey(const char* session_id,
                             uint32_t session_id_size,
                             const uint8_t* key,
                             uint32_t key_size,
                             const uint8_t* key_id,
                             uint32_t key_id_size) = 0;
  virtual cdm::Status CancelKeyRequest(const char* session_id,
                                       uint32_t session_id_size) = 0;
  virtual void TimerExpired(void* context) = 0;
  virtual cdm::Status Decrypt(const cdm::InputBuffer& encrypted_buffer,
                              cdm::DecryptedBlock* decrypted_buffer) = 0;
  virtual cdm::Status InitializeAudioDecoder(
      const cdm::AudioDecoderConfig& audio_decoder_config) = 0;
  virtual cdm::Status InitializeVideoDecoder(
      const cdm::VideoDecoderConfig& video_decoder_config) = 0;
  virtual void DeinitializeDecoder(cdm::StreamType decoder_type) = 0;
  virtual void ResetDecoder(cdm::StreamType decoder_type) = 0;
  virtual cdm::Status DecryptAndDecodeFrame(
      const cdm::InputBuffer& encrypted_buffer,
      cdm::VideoFrame* video_frame) = 0;
  virtual cdm::Status DecryptAndDecodeSamples(
      const cdm::InputBuffer& encrypted_buffer,
      cdm::AudioFrames* audio_frames) = 0;
  virtual void OnPlatformChallengeResponse(
      const cdm::PlatformChallengeResponse& response) = 0;
  virtual void OnQueryOutputProtectionStatus(
      uint32_t link_mask,
      uint32_t output_protection_mask) = 0;

 protected:
  CdmWrapper() {};

 private:
  DISALLOW_COPY_AND_ASSIGN(CdmWrapper);
};

// Template class that does the CdmWrapper -> CdmInterface conversion. Default
// implementations are provided. Any methods that need special treatment should
// be specialized.
template <class CdmInterface>
class CdmWrapperImpl : public CdmWrapper {
 public:
  static CdmWrapper* Create(const char* key_system,
                            uint32_t key_system_size,
                            GetCdmHostFunc get_cdm_host_func,
                            void* user_data) {
    void* cdm_instance = ::CreateCdmInstance(
        CdmInterface::kVersion, key_system, key_system_size, get_cdm_host_func,
        user_data);
    if (!cdm_instance)
      return NULL;

    return new CdmWrapperImpl<CdmInterface>(
        static_cast<CdmInterface*>(cdm_instance));
  }

  virtual ~CdmWrapperImpl() {
    cdm_->Destroy();
  }

  virtual cdm::Status GenerateKeyRequest(const char* type,
                                         uint32_t type_size,
                                         const uint8_t* init_data,
                                         uint32_t init_data_size) OVERRIDE {
    return cdm_->GenerateKeyRequest(type, type_size, init_data, init_data_size);
  }

  virtual cdm::Status AddKey(const char* session_id,
                             uint32_t session_id_size,
                             const uint8_t* key,
                             uint32_t key_size,
                             const uint8_t* key_id,
                             uint32_t key_id_size) OVERRIDE {
    return cdm_->AddKey(
        session_id, session_id_size, key, key_size, key_id, key_id_size);
  }

  virtual cdm::Status CancelKeyRequest(const char* session_id,
                                       uint32_t session_id_size) OVERRIDE {
    return cdm_->CancelKeyRequest(session_id, session_id_size);
  }

  virtual void TimerExpired(void* context) OVERRIDE {
    cdm_->TimerExpired(context);
  }

  virtual cdm::Status Decrypt(const cdm::InputBuffer& encrypted_buffer,
                              cdm::DecryptedBlock* decrypted_buffer) OVERRIDE {
    return cdm_->Decrypt(encrypted_buffer, decrypted_buffer);
  }

  virtual cdm::Status InitializeAudioDecoder(
      const cdm::AudioDecoderConfig& audio_decoder_config) OVERRIDE {
    return cdm_->InitializeAudioDecoder(audio_decoder_config);
  }

  virtual cdm::Status InitializeVideoDecoder(
      const cdm::VideoDecoderConfig& video_decoder_config) OVERRIDE {
    return cdm_->InitializeVideoDecoder(video_decoder_config);
  }

  virtual void DeinitializeDecoder(cdm::StreamType decoder_type) OVERRIDE {
    cdm_->DeinitializeDecoder(decoder_type);
  }

  virtual void ResetDecoder(cdm::StreamType decoder_type) OVERRIDE {
    cdm_->ResetDecoder(decoder_type);
  }

  virtual cdm::Status DecryptAndDecodeFrame(
      const cdm::InputBuffer& encrypted_buffer,
      cdm::VideoFrame* video_frame) OVERRIDE {
    return cdm_->DecryptAndDecodeFrame(encrypted_buffer, video_frame);
  }

  virtual cdm::Status DecryptAndDecodeSamples(
      const cdm::InputBuffer& encrypted_buffer,
      cdm::AudioFrames* audio_frames) OVERRIDE {
    return cdm_->DecryptAndDecodeSamples(encrypted_buffer, audio_frames);
  }

  virtual void OnPlatformChallengeResponse(
      const cdm::PlatformChallengeResponse& response) OVERRIDE {
    cdm_->OnPlatformChallengeResponse(response);
  }

  virtual void OnQueryOutputProtectionStatus(
      uint32_t link_mask,
      uint32_t output_protection_mask) OVERRIDE {
    cdm_->OnQueryOutputProtectionStatus(link_mask, output_protection_mask);
  }

 private:
  CdmWrapperImpl(CdmInterface* cdm) : cdm_(cdm) {
    PP_DCHECK(cdm_);
  }

  CdmInterface* cdm_;

  DISALLOW_COPY_AND_ASSIGN(CdmWrapperImpl);
};

// Specializations for ContentDecryptionModule_1.

template <> void CdmWrapperImpl<cdm::ContentDecryptionModule_1>::
    OnPlatformChallengeResponse(
        const cdm::PlatformChallengeResponse& response) {
  PP_NOTREACHED();
}

template <> void CdmWrapperImpl<cdm::ContentDecryptionModule_1>::
    OnQueryOutputProtectionStatus(uint32_t link_mask,
                                  uint32_t output_protection_mask) {
  PP_NOTREACHED();
}

template <> cdm::Status CdmWrapperImpl<cdm::ContentDecryptionModule_1>::
    DecryptAndDecodeSamples(const cdm::InputBuffer& encrypted_buffer,
                            cdm::AudioFrames* audio_frames) {
  AudioFramesImpl audio_frames_1;
  cdm::Status status =
      cdm_->DecryptAndDecodeSamples(encrypted_buffer, &audio_frames_1);
  if (status != cdm::kSuccess)
    return status;

  audio_frames->SetFrameBuffer(audio_frames_1.PassFrameBuffer());
  audio_frames->SetFormat(cdm::kAudioFormatS16);
  return cdm::kSuccess;
}

CdmWrapper* CdmWrapper::Create(const char* key_system,
                               uint32_t key_system_size,
                               GetCdmHostFunc get_cdm_host_func,
                               void* user_data) {
  // Try to create the CDM using the latest CDM interface version.
  CdmWrapper* cdm_adapter =
      CdmWrapperImpl<cdm::ContentDecryptionModule>::Create(
          key_system, key_system_size, get_cdm_host_func, user_data);
  if (cdm_adapter)
    return cdm_adapter;

  // Try to see if the CDM supports older version(s) of CDM interface(s).
  cdm_adapter = CdmWrapperImpl<cdm::ContentDecryptionModule_1>::Create(
      key_system, key_system_size, get_cdm_host_func, user_data);
  return cdm_adapter;
}

// When updating the CdmAdapter, ensure you've updated the CdmWrapper to contain
// stub implementations for new or modified methods that the older CDM interface
// does not have.
COMPILE_ASSERT(cdm::ContentDecryptionModule::kVersion ==
                   cdm::ContentDecryptionModule_2::kVersion,
               ensure_cdm_wrapper_templates_have_old_version_support);

}  // namespace media

#endif  // MEDIA_CDM_PPAPI_CDM_WRAPPER_H_