text: // Copyright (c) 2017-2019 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #ifndef BITCOIN_RPC_UTIL_H
  #define BITCOIN_RPC_UTIL_H
  
  #include <node/transaction.h>
  #include <pubkey.h>
  #include <rpc/protocol.h>
  #include <script/standard.h>
  #include <univalue.h>
  
  #include <string>
  #include <vector>
  
  #include <boost/variant.hpp>
  
  class CKeyStore;
  class CPubKey;
  class CScript;
  struct InitInterfaces;
  
  //! Pointers to interfaces that need to be accessible from RPC methods. Due to
  //! limitations of the RPC framework, there's currently no direct way to pass in
  //! state to RPC method implementations.
  extern InitInterfaces* g_rpc_interfaces;
  
  CPubKey HexToPubKey(const std::string& hex_in);
  CPubKey AddrToPubKey(CKeyStore* const keystore, const std::string& addr_in);
  CScript CreateVaultAddressRedeemscript(const std::vector<CPubKey>& pubkeys, bool instant);
  CScript CreateMultisigRedeemscript(const int required, const std::vector<CPubKey>& pubkeys);
  
  UniValue DescribeAddress(const CTxDestination& dest);
  
  //! Parse a confirm target option and raise an RPC error if it is invalid.
  unsigned int ParseConfirmTarget(const UniValue& value);
  
  RPCErrorCode RPCErrorFromTransactionError(TransactionError terr);
  UniValue JSONRPCTransactionError(TransactionError terr, const std::string& err_string = "");
  
  //! Parse a JSON range specified as int64, or [int64, int64]
  std::pair<int64_t, int64_t> ParseRange(const UniValue& value);
  
  struct RPCArg {
      enum class Type {
          OBJ,
          ARR,
          STR,
          NUM,
          BOOL,
          OBJ_USER_KEYS, //!< Special type where the user must set the keys e.g. to define multiple addresses; as opposed to e.g. an options object where the keys are predefined
          AMOUNT,        //!< Special type representing a floating point amount (can be either NUM or STR)
          STR_HEX,       //!< Special type that is a STR with only hex chars
          RANGE,         //!< Special type that is a NUM or [NUM,NUM]
      };
  
      enum class Optional {
          /** Required arg */
          NO,
          /**
           * Optional arg that is a named argument and has a default value of
           * `null`. When possible, the default value should be specified.
           */
          OMITTED_NAMED_ARG,
          /**
           * Optional argument with default value omitted because they are
           * implicitly clear. That is, elements in an array or object may not
           * exist by default.
           * When possible, the default value should be specified.
           */
          OMITTED,
      };
      using Fallback = boost::variant<Optional, /* default value for optional args */ std::string>;
      const std::string m_name; //!< The name of the arg (can be empty for inner args)
      const Type m_type;
      const std::vector<RPCArg> m_inner; //!< Only used for arrays or dicts
      const Fallback m_fallback;
      const std::string m_description;
      const std::string m_oneline_description; //!< Should be empty unless it is supposed to override the auto-generated summary line
      const std::vector<std::string> m_type_str; //!< Should be empty unless it is supposed to override the auto-generated type strings. Vector length is either 0 or 2, m_type_str.at(0) will override the type of the value in a key-value pair, m_type_str.at(1) will override the type in the argument description.
  
      RPCArg(
          const std::string& name,
          const Type& type,
          const Fallback& fallback,
          const std::string& description,
          const std::string& oneline_description = "",
          const std::vector<std::string>& type_str = {})
          : m_name{name},
            m_type{type},
            m_fallback{fallback},
            m_description{description},
            m_oneline_description{oneline_description},
            m_type_str{type_str}
      {
          assert(type != Type::ARR && type != Type::OBJ);
      }
  
      RPCArg(
          const std::string& name,
          const Type& type,
          const Fallback& fallback,
          const std::string& description,
          const std::vector<RPCArg>& inner,
          const std::string& oneline_description = "",
          const std::vector<std::string>& type_str = {})
          : m_name{name},
            m_type{type},
            m_inner{inner},
            m_fallback{fallback},
            m_description{description},
            m_oneline_description{oneline_description},
            m_type_str{type_str}
      {
          assert(type == Type::ARR || type == Type::OBJ);
      }
  
      bool IsOptional() const;
  
      /**
       * Return the type string of the argument.
       * Set oneline to allow it to be overridden by a custom oneline type string (m_oneline_description).
       */
      std::string ToString(bool oneline) const;
      /**
       * Return the type string of the argument when it is in an object (dict).
       * Set oneline to get the oneline representation (less whitespace)
       */
      std::string ToStringObj(bool oneline) const;
      /**
       * Return the description string, including the argument type and whether
       * the argument is required.
       */
      std::string ToDescriptionString() const;
  };
  
  struct RPCResult {
      const std::string m_cond;
      const std::string m_result;
  
      explicit RPCResult(std::string result)
          : m_cond{}, m_result{std::move(result)}
      {
          assert(!m_result.empty());
      }
  
      RPCResult(std::string cond, std::string result)
          : m_cond{std::move(cond)}, m_result{std::move(result)}
      {
          assert(!m_cond.empty());
          assert(!m_result.empty());
      }
  };
  
  struct RPCResults {
      const std::vector<RPCResult> m_results;
  
      RPCResults()
          : m_results{}
      {
      }
  
      RPCResults(RPCResult result)
          : m_results{{result}}
      {
      }
  
      RPCResults(std::initializer_list<RPCResult> results)
          : m_results{results}
      {
      }
  
      /**
       * Return the description string.
       */
      std::string ToDescriptionString() const;
  };
  
  struct RPCExamples {
      const std::string m_examples;
      RPCExamples(
          std::string examples)
          : m_examples(std::move(examples))
      {
      }
      std::string ToDescriptionString() const;
  };
  
  class RPCHelpMan
  {
  public:
      RPCHelpMan(std::string name, std::string description, std::vector<RPCArg> args, RPCResults results, RPCExamples examples);
  
      std::string ToString() const;
      /** If the supplied number of args is neither too small nor too high */
      bool IsValidNumArgs(size_t num_args) const;
  
  private:
      const std::string m_name;
      const std::string m_description;
      const std::vector<RPCArg> m_args;
      const RPCResults m_results;
      const RPCExamples m_examples;
  };
  
  #endif // BITCOIN_RPC_UTIL_H
  