// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
// source code may only be used and distributed under the Widevine Master
// License Agreement.

#ifndef ECM_PARSER_V2_H
#define ECM_PARSER_V2_H

#include <memory>
#include <vector>

#include "cas_types.h"
#include "ecm_parser.h"

namespace wvcas {

struct EcmKeyData;

// EcmParserV2 allows random access to the fields of an ECM version 2 and under.
// It should be initialized via EcmParser factory create only.
class EcmParserV2 : public EcmParser {
 public:
  ~EcmParserV2() override = default;
  EcmParserV2(const EcmParserV2&) = delete;
  EcmParserV2& operator=(const EcmParserV2&) = delete;

  // The EcmParserV2 factory method.
  // |ecm| must be Widevine ECM v2 or under without section header.
  // Validates the ecm. The only validation performed is to ensure that the ecm
  // passed in is large enough to hold a single key entry. If validations is
  // successful returns true and constructs an EcmParserV2 in |parser| using
  // |ecm|.
  static bool create(const CasEcm& cas_ecm,
                     std::unique_ptr<EcmParserV2>* parser);

  // Accessor methods.
  uint8_t version() const override;
  CryptoMode crypto_mode() const override;
  bool rotation_enabled() const override;
  size_t content_iv_size() const override;
  uint8_t age_restriction() const override;
  std::vector<uint8_t> entitlement_key_id(KeySlotId id) const override;
  std::vector<uint8_t> content_key_id(KeySlotId id) const override;
  std::vector<uint8_t> wrapped_key_data(KeySlotId id) const override;
  std::vector<uint8_t> wrapped_key_iv(KeySlotId id) const override;
  std::vector<uint8_t> content_iv(KeySlotId id) const override;

  // Group keys not supported in v2.
  bool set_group_id(const std::string& group_id) override {
    return group_id.empty();
  };

  // ECM v2 or under does not have these fields.
  bool has_fingerprinting() const override { return false; }
  video_widevine::Fingerprinting fingerprinting() const override {
    video_widevine::Fingerprinting fingerprinting;
    return fingerprinting;
  }
  bool has_service_blocking() const override { return false; };
  video_widevine::ServiceBlocking service_blocking() const override {
    video_widevine::ServiceBlocking service_blocking;
    return service_blocking;
  }
  std::string ecm_serialized_payload() const override { return ""; }
  std::string signature() const override { return ""; }

  bool is_entitlement_rotation_enabled() const override { return false; }
  uint32_t entitlement_period_index() const override { return 0; }
  uint32_t entitlement_rotation_window_left() const override { return 0; }

 private:
  // Constructs an EcmParserV2 using |ecm|.
  explicit EcmParserV2(const CasEcm& ecm);

  size_t key_data_size() const;
  // Returns false if the ecm used to construct the object is not a valid size.
  // TODO(jfore): Add validation using the version field.
  bool is_valid_size() const;
  const EcmKeyData* key_slot_data(KeySlotId id) const;

  CasEcm ecm_;
};

}  // namespace wvcas

#endif  // ECM_PARSER_V2_H