// Copyright 2012 Google Inc. All Rights Reserved.
//
// Crypto - wrapper classes for OEMCrypto interface
//

#include "crypto_engine.h"

#include <arpa/inet.h>  // TODO(fredgc): Add ntoh to wv_cdm_utilities.h
#include <iostream>
#include <vector>

#include "log.h"
#include "OEMCryptoCENC.h"
#include "properties.h"
#include "wv_cdm_constants.h"

namespace wvcdm {

CryptoEngine* CryptoEngine::crypto_engine_ = NULL;
Lock CryptoEngine::crypto_engine_lock_;

// wrapper classes for OEMCrypto interface
// CryptoEngine -- top-level interface
// CryptoSession -- session-specific interface
// CryptoKey -- key interface

// CryptoEngine methods

CryptoEngine::CryptoEngine() : initialized_(false) {}

CryptoEngine::~CryptoEngine() {
  if (initialized_) {
    Terminate();
  }

  CryptoSessionMap::iterator i(sessions_.begin());
  for (; i != sessions_.end(); ++i)
    delete i->second;
  sessions_.clear();
}

// get the instance of OEMCrypto Client
CryptoEngine* CryptoEngine::GetInstance() {
  if (NULL == crypto_engine_) {
    crypto_engine_ = CreateSingleton();
  }
  return crypto_engine_;
}

CryptoEngine* CryptoEngine::CreateSingleton() {
  AutoLock auto_lock(crypto_engine_lock_);
  if (NULL == crypto_engine_) {
    crypto_engine_ = new CryptoEngine;
  }
  return crypto_engine_;
}

void CryptoEngine::DeleteInstance() {
  if (NULL != crypto_engine_) {
    delete crypto_engine_;
    LOGV("CryptoEngine::DeleteInstance");
    crypto_engine_ = NULL;
  }
}

bool CryptoEngine::Init() {
  LOGV("CryptoEngine::Init: Lock");
  AutoLock auto_lock(crypto_lock_);
  if (!initialized_) {
    OEMCryptoResult result = OEMCrypto_Initialize();
    initialized_ = (OEMCrypto_SUCCESS == result);
  }
  return initialized_;
}

bool CryptoEngine::Terminate() {
  DestroySessions();
  LOGV("CryptoEngine::Terminate: Lock");
  AutoLock auto_lock(crypto_lock_);
  OEMCryptoResult result = OEMCrypto_Terminate();
  if (OEMCrypto_SUCCESS == result) {
    initialized_ = false;
  }
  return !initialized_;
}

bool CryptoEngine::ValidateKeybox() {
  LOGV("CryptoEngine::ValidateKeybox: Lock");
  AutoLock auto_lock(crypto_lock_);
  OEMCryptoResult result = OEMCrypto_IsKeyboxValid();
  return (OEMCrypto_SUCCESS == result);
}

CryptoSession* CryptoEngine::CreateSession(const CdmSessionId& session_id) {
  LOGV("CryptoEngine::CreateSession: SLock");
  AutoLock auto_lock(sessions_lock_);
  if (0 == sessions_.size()) {
    if (!Init()) {
      return NULL;
    }
  }

  CryptoSessionMap::iterator it = sessions_.find(session_id);
  if (it != sessions_.end()) {
    LOGE("CryptoEngine::CreateSession : Duplicate session ID.");
    return NULL;
  }

  CryptoSession* new_session = new CryptoSession(session_id);
  if (!new_session) {
    return NULL;
  }

  if (!new_session->Open()) {
    delete new_session;
    return NULL;
  }

  sessions_[session_id] = new_session;
  return new_session;
}

CryptoSession* CryptoEngine::FindSessionInternal(
    const CdmSessionId& session_id) {
  // must hold sessions_lock_
  CryptoSessionMap::iterator it = sessions_.find(session_id);
  if (it != sessions_.end()) {
    return it->second;
  }
  return NULL;
}

CryptoSession* CryptoEngine::FindSession(const CdmSessionId& session_id) {
  LOGV("CryptoEngine::FindSession: SLock");
  AutoLock auto_lock(sessions_lock_);
  return FindSessionInternal(session_id);
}

bool CryptoEngine::DestroySession(const CdmSessionId& session_id) {
  LOGV("CryptoEngine::DestroySession: SLock");
  AutoLock auto_lock(sessions_lock_);
  if (0 == sessions_.size()) {
    return false;
  }
  CryptoSession* session = FindSessionInternal(session_id);
  if (session) {
    delete session;
    sessions_.erase(session_id);
    return true;
  } else {
    return false;
  }
}

bool CryptoEngine::DestroySessions() {
  for (CryptoSessionMap::iterator it = sessions_.begin();
      it != sessions_.end(); ++it) {
    delete it->second;
  }
  sessions_.clear();
  return true;
}

bool CryptoEngine::GetToken(std::string* token) {
  LOGV("CryptoEngine::GetToken: Lock");
  AutoLock auto_lock(crypto_lock_);
  if (!token) {
    LOGE("CryptoEngine::GetToken : No token passed to method.");
    return false;
  }
  uint8_t buf[72];
  size_t buflen = 72;
  OEMCryptoResult sts = OEMCrypto_GetKeyData(buf, &buflen);
  if (OEMCrypto_SUCCESS != sts) {
    return false;
  }
  token->assign((const char*)buf, (size_t)buflen);
  return true;
}

CryptoEngine::SecurityLevel CryptoEngine::GetSecurityLevel() {
  if (!Init())
    return kSecurityLevelUnknown;

  std::string security_level = OEMCrypto_SecurityLevel();

  if ((security_level.size() != 2) ||
      (security_level.at(0) != 'L')) {
    return kSecurityLevelUnknown;
  }

  switch (security_level.at(1)) {
    case '1': return kSecurityLevelL1;
    case '2': return kSecurityLevelL2;
    case '3': return kSecurityLevelL3;
    default : return kSecurityLevelUnknown;
  }

  return kSecurityLevelUnknown;
}

bool CryptoEngine::GetDeviceUniqueId(std::string* deviceId) {
  if (!Init())
    return false;

  std::vector<uint8_t> id;
  size_t idLength = 32;

  id.resize(idLength);

  OEMCryptoResult sts = OEMCrypto_GetDeviceID(&id[0], &idLength);

  if (OEMCrypto_SUCCESS != sts) {
    return false;
  }

  *deviceId = reinterpret_cast<const char*>(&id[0]);
  return true;
}

bool CryptoEngine::GetSystemId(uint32_t* systemId) {
  if (!Init())
    return false;

  uint8_t buf[72];
  size_t buflen = 72;

  OEMCryptoResult sts = OEMCrypto_GetKeyData(buf, &buflen);

  if (OEMCrypto_SUCCESS != sts) {
    return false;
  }

  // Decode 32-bit int encoded as network-byte-order byte array starting at
  // index 4.
  uint32_t* id = reinterpret_cast<uint32_t*>(&buf[4]);

  *systemId = ntohl(*id);
  return true;
}

};  // namespace wvcdm