#ifndef MODEL_HPP
#define MODEL_HPP

#include <chrono>
#include <memory>
#include <optional>
#include <string>

#include "crow/json.h"

#include "tl/expected.hpp"
#include "big_int.hpp"

struct PublicKey {
  BigInt modulus; //: "daaa63ddda38c189b8c49020c8276adbe0a695685a...",
  BigInt public_exponent;//: 65537,

  crow::json::wvalue to_json() const;
};

struct WeightedUrl {
  uint32_t weight;
  std::string url;

  crow::json::wvalue to_json() const;
};

/** currency description document */
struct CDD {

  std::string additional_info;
  time_t cdd_expiry_date;//: 2023-07-22T15:45:53.164685
  std::string  cdd_location;//: https://opencent.org,
  size_t cdd_serial;//: 1,
  time_t  cdd_signing_date;//: 2022-07-22T15:45:53.164685,
  size_t  currency_divisor;//: 100,
  std::string  currency_name;//: OpenCent,
  std::vector<unsigned>  denominations;//: [1, 2, 5],
  BigInt id;//: 23ed956e629ba35f0002eaf833ea436aea7db5c2,

std::vector<WeightedUrl> info_service;
  /* eCipherSuite*/ std::string issuer_cipher_suite; //: RSA-SHA256-PSS-CHAUM82,
  PublicKey
      issuer_public_master_key; //: {
                                //  modulus:
                                //  daaa63ddda38c189b8c49020c8276adbe0a695685a...,
                                // public_exponent: 65537,
                                // type: rsa public key
  //},
  std::vector<WeightedUrl> mint_service;
  std::string protocol_version; //: https://opencoin.org/1.0,
  std::vector<WeightedUrl> redeem_service;
  std::vector<WeightedUrl> renew_service;

  crow::json::wvalue to_json() const;
};

struct CDDC {
  CDD cdd;
  std::string signature;

  crow::json::wvalue to_json() const;
};

struct MintKey {
  unsigned int cdd_serial;
  std::string coins_expiry_date; //": "2023-10-30T15:45:53.164685",
  unsigned int denomination; //": 1,
  BigInt id;   // "1ceb977bb531c65f133ab8b0d60862b17369d96",
  BigInt issuer_id; //": "23ed956e629ba35f0002eaf833ea436aea7db5c2",
  PublicKey public_mint_key;

  std::string sign_coins_not_after;
  std::string sign_coins_not_before;
  //    "type": "mint key"
  crow::json::wvalue to_json() const;
};

struct MintKeyCert {
  MintKey mint_key;
  std::string signature;

  crow::json::wvalue to_json() const;
};

enum class eError {
  JSON_PARSE_ERROR,
  JSON_MISSING_KEY,
  JSON_WRONG_REQUEST_TYPE,
  JSON_WRONG_VALUE_TYPE,
  JSON_ERROR,
  NOT_IMPLEMENTED
};

struct Response {
  unsigned int message_reference;
  unsigned int status_code;
  std::string status_description;

  virtual crow::json::wvalue to_json() const;
};

struct RequestCDDCSerial {
  unsigned int message_reference; /// Client internal message reference.
                                  /// (Integer)
  static tl::expected<RequestCDDCSerial, eError>
  from_string(const std::string &str);
};

struct ResponseCDDCSerial : Response {
  unsigned int cdd_serial;

  crow::json::wvalue to_json() const override;
};

struct RequestCDDC {
  unsigned int cdd_serial;        /// The version of the CDD. (Int)
  unsigned int message_reference; /// Client internal message reference.
                                  /// (Integer)
  static tl::expected<RequestCDDC, eError> from_string(const std::string &str);
};

struct ResponseCDDC : Response {
  CDDC cddc;

  crow::json::wvalue to_json() const override;
};

struct RequestMKCs {
  std::vector<unsigned int> denominations;
  unsigned int message_reference; /// Client internal message reference.
                                  /// (Integer)
  std::vector<BigInt> mint_key_ids;
  //  "type": "request mint key certificates"
  static tl::expected<RequestMKCs, eError> from_string(const std::string &str);
};

struct ResponseMKCs : Response {
  std::vector<MintKeyCert> keys;

  crow::json::wvalue to_json() const override;
};

struct Blind {
  BigInt blinded_payload_hash; //bigint
  BigInt mint_key_id; //bigint
  std::string reference;
  crow::json::wvalue to_json() const;
  static tl::expected<Blind, eError> from_json(const crow::json::rvalue &json);
};

struct BlindSignature {
  BigInt blind_signature;
  std::string reference;
  crow::json::wvalue to_json() const;
};

struct RequestMint {
  unsigned int message_reference; /// Client internal message reference.
                                  /// (Integer)
  BigInt transaction_reference; 
  std::vector<Blind> blinds;
  //  "type": "request mint"
  static tl::expected<RequestMint, eError> from_string(const std::string &str);
};

struct ResponseMint : Response {
  std::vector<BlindSignature> blind_signatures;

  crow::json::wvalue to_json() const override;
};

struct Coin {
  struct Payload {
    std::string cdd_location;
    unsigned int denomination;
    BigInt issuer_id;
    BigInt mint_key_id;
    std::string protocol_version;
    BigInt serial;
    
    crow::json::wvalue to_json() const;  
    static tl::expected<Payload,eError> from_json(const crow::json::rvalue& json);
  };

  Payload payload;
  std::string signature;

  crow::json::wvalue to_json() const;
  static tl::expected<Coin, eError> from_json(const crow::json::rvalue &json);
};

struct CoinStack {
  std::vector<Coin> coins;
  std::string subject;
  //  "type": "coinstack"
  crow::json::wvalue to_json() const;
};

struct RequestRenew {
  std::vector<Blind> blinds;
  std::vector<Coin> coins;
  unsigned int message_reference; /// Client internal message reference.
                                  /// (Integer)
  std::string transaction_reference;
  //  "type": "request renew"
  static tl::expected<RequestRenew, eError> from_string(const std::string &str);
};

struct ResponseDelay : Response {
  crow::json::wvalue to_json() const override;
};

struct RequestResume {
  unsigned int message_reference; /// Client internal message reference.
                                  /// (Integer)
  BigInt transaction_reference; 
  //  "type": "request resume"
  static tl::expected<RequestResume, eError>
  from_string(const std::string &str);
};

struct RequestRedeem {
  std::vector<Coin> coins;
  unsigned int message_reference; /// Client internal message reference.
                                  /// (Integer)
  //  "type": "request redeem"
  static tl::expected<RequestRedeem, eError>
  from_string(const std::string &str);
};

struct ResponseRedeem : Response {
  crow::json::wvalue to_json() const override;
};

class Model {
public:
  virtual ~Model(){};

  virtual tl::expected<CDDC *, bool> getCDDC(unsigned int cdd_serial) = 0;
  virtual tl::expected<CDDC *, bool> getCurrentCDDC() = 0;

  virtual const std::vector<MintKeyCert>
  getMKCs(const std::vector<unsigned int> &denominations,
          const std::vector<BigInt> &mint_key_ids) = 0;

  virtual std::vector<BlindSignature>
  mint(std::string const& transaction_reference,
       const std::vector<Blind> &blinds) = 0;
  virtual bool redeem(const std::vector<Coin> &coins) = 0;

  static std::unique_ptr<Model> getModel(const std::string &backend_name);

private:
};

#endif // #ifndef MODEL_HPP