// Copyright (c) 2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 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_RPCPROTOCOL_H
#define BITCOIN_RPCPROTOCOL_H

#include <list>
#include <map>
#include <stdint.h>
#include <string>
#include <boost/iostreams/concepts.hpp>
#include <boost/iostreams/stream.hpp>
#include <boost/asio.hpp>
#include <boost/asio/ssl.hpp>

#include "univalue/univalue.h"

// Boost Support for 1.70+
#if BOOST_VERSION >= 107000
    #define GetIOService(s) ((boost::asio::io_context&)(s).get_executor().context())
    #define GetIOServiceFromPtr(s) ((boost::asio::io_context&)(s->get_executor().context())) // this one
    typedef boost::asio::io_context ioContext;

#else
    #define GetIOService(s) ((s).get_io_service())
    #define GetIOServiceFromPtr(s) ((s)->get_io_service())
    typedef boost::asio::io_service ioContext;
#endif



//! HTTP status codes
enum HTTPStatusCode
{
    HTTP_OK                    = 200,
    HTTP_BAD_REQUEST           = 400,
    HTTP_UNAUTHORIZED          = 401,
    HTTP_FORBIDDEN             = 403,
    HTTP_NOT_FOUND             = 404,
    HTTP_INTERNAL_SERVER_ERROR = 500,
    HTTP_SERVICE_UNAVAILABLE   = 503,
};

//! Bitcoin RPC error codes
enum RPCErrorCode
{
    //! Standard JSON-RPC 2.0 errors
    RPC_INVALID_REQUEST  = -32600,
    RPC_METHOD_NOT_FOUND = -32601,
    RPC_INVALID_PARAMS   = -32602,
    RPC_INTERNAL_ERROR   = -32603,
    RPC_PARSE_ERROR      = -32700,

    //! General application defined errors
    RPC_MISC_ERROR                  = -1,  //! std::exception thrown in command handling
    RPC_FORBIDDEN_BY_SAFE_MODE      = -2,  //! Server is in safe mode, and command is not allowed in safe mode
    RPC_TYPE_ERROR                  = -3,  //! Unexpected type was passed as parameter
    RPC_INVALID_ADDRESS_OR_KEY      = -5,  //! Invalid address or key
    RPC_OUT_OF_MEMORY               = -7,  //! Ran out of memory during operation
    RPC_INVALID_PARAMETER           = -8,  //! Invalid, missing or duplicate parameter
    RPC_DATABASE_ERROR              = -20, //! Database error
    RPC_DESERIALIZATION_ERROR       = -22, //! Error parsing or validating structure in raw format
    RPC_VERIFY_ERROR                = -25, //! General error during transaction or block submission
    RPC_VERIFY_REJECTED             = -26, //! Transaction or block was rejected by network rules
    RPC_VERIFY_ALREADY_IN_CHAIN     = -27, //! Transaction already in chain
    RPC_IN_WARMUP                   = -28, //! Client still warming up

    //! Aliases for backward compatibility
    RPC_TRANSACTION_ERROR           = RPC_VERIFY_ERROR,
    RPC_TRANSACTION_REJECTED        = RPC_VERIFY_REJECTED,
    RPC_TRANSACTION_ALREADY_IN_CHAIN= RPC_VERIFY_ALREADY_IN_CHAIN,

    //! P2P client errors
    RPC_CLIENT_NOT_CONNECTED        = -9,  //! Bitcoin is not connected
    RPC_CLIENT_IN_INITIAL_DOWNLOAD  = -10, //! Still downloading initial blocks
    RPC_CLIENT_NODE_ALREADY_ADDED   = -23, //! Node is already added
    RPC_CLIENT_NODE_NOT_ADDED       = -24, //! Node has not been added before

    //! Wallet errors
    RPC_WALLET_ERROR                = -4,  //! Unspecified problem with wallet (key not found etc.)
    RPC_WALLET_INSUFFICIENT_FUNDS   = -6,  //! Not enough funds in wallet or account
    RPC_WALLET_INVALID_ACCOUNT_NAME = -11, //! Invalid account name
    RPC_WALLET_KEYPOOL_RAN_OUT      = -12, //! Keypool ran out, call keypoolrefill first
    RPC_WALLET_UNLOCK_NEEDED        = -13, //! Enter the wallet passphrase with walletpassphrase first
    RPC_WALLET_PASSPHRASE_INCORRECT = -14, //! The wallet passphrase entered was incorrect
    RPC_WALLET_WRONG_ENC_STATE      = -15, //! Command given in wrong wallet encryption state (encrypting an encrypted wallet etc.)
    RPC_WALLET_ENCRYPTION_FAILED    = -16, //! Failed to encrypt the wallet
    RPC_WALLET_ALREADY_UNLOCKED     = -17, //! Wallet is already unlocked
};

/**
 * IOStream device that speaks SSL but can also speak non-SSL
 */
template <typename Protocol>
class SSLIOStreamDevice : public boost::iostreams::device<boost::iostreams::bidirectional> {
public:
    SSLIOStreamDevice(boost::asio::ssl::stream<typename Protocol::socket> &streamIn, bool fUseSSLIn) : stream(streamIn)
    {
        fUseSSL = fUseSSLIn;
        fNeedHandshake = fUseSSLIn;
    }

    void handshake(boost::asio::ssl::stream_base::handshake_type role)
    {
        if (!fNeedHandshake) return;
        fNeedHandshake = false;
        stream.handshake(role);
    }
    std::streamsize read(char* s, std::streamsize n)
    {
        handshake(boost::asio::ssl::stream_base::server); // HTTPS servers read first
        if (fUseSSL) return stream.read_some(boost::asio::buffer(s, n));
        return stream.next_layer().read_some(boost::asio::buffer(s, n));
    }
    std::streamsize write(const char* s, std::streamsize n)
    {
        handshake(boost::asio::ssl::stream_base::client); // HTTPS clients write first
        if (fUseSSL) return boost::asio::write(stream, boost::asio::buffer(s, n));
        return boost::asio::write(stream.next_layer(), boost::asio::buffer(s, n));
    }
    bool connect(const std::string& server, const std::string& port)
    {
        using namespace boost::asio::ip;
        boost::asio::ip::tcp::resolver resolver(GetIOService(stream));
        tcp::resolver::iterator endpoint_iterator;
#if BOOST_VERSION >= 104300
        try {
#endif
            // The default query (flags address_configured) tries IPv6 if
            // non-localhost IPv6 configured, and IPv4 if non-localhost IPv4
            // configured.
            tcp::resolver::query query(server.c_str(), port.c_str());
            endpoint_iterator = resolver.resolve(query);
#if BOOST_VERSION >= 104300
        } catch (const boost::system::system_error&) {
            // If we at first don't succeed, try blanket lookup (IPv4+IPv6 independent of configured interfaces)
            tcp::resolver::query query(server.c_str(), port.c_str(), resolver_query_base::flags());
            endpoint_iterator = resolver.resolve(query);
        }
#endif
        boost::system::error_code error = boost::asio::error::host_not_found;
        tcp::resolver::iterator end;
        while (error && endpoint_iterator != end)
        {
            stream.lowest_layer().close();
            stream.lowest_layer().connect(*endpoint_iterator++, error);
        }
        if (error)
            return false;
        return true;
    }

private:
    bool fNeedHandshake;
    bool fUseSSL;
    boost::asio::ssl::stream<typename Protocol::socket>& stream;
};

std::string HTTPPost(const std::string& strMsg, const std::map<std::string,std::string>& mapRequestHeaders);
std::string HTTPError(int nStatus, bool keepalive,
                      bool headerOnly = false);
std::string HTTPReplyHeader(int nStatus, bool keepalive, size_t contentLength,
                      const char *contentType = "application/json");
std::string HTTPReply(int nStatus, const std::string& strMsg, bool keepalive,
                      bool headerOnly = false,
                      const char *contentType = "application/json");
bool ReadHTTPRequestLine(std::basic_istream<char>& stream, int &proto,
                         std::string& http_method, std::string& http_uri);
int ReadHTTPStatus(std::basic_istream<char>& stream, int &proto);
int ReadHTTPHeaders(std::basic_istream<char>& stream, std::map<std::string, std::string>& mapHeadersRet);
int ReadHTTPMessage(std::basic_istream<char>& stream, std::map<std::string, std::string>& mapHeadersRet,
                    std::string& strMessageRet, int nProto, size_t max_size);
std::string JSONRPCRequest(const std::string& strMethod, const UniValue& params, const UniValue& id);
UniValue JSONRPCReplyObj(const UniValue& result, const UniValue& error, const UniValue& id);
std::string JSONRPCReply(const UniValue& result, const UniValue& error, const UniValue& id);
UniValue JSONRPCError(int code, const std::string& message);

#endif // BITCOIN_RPCPROTOCOL_H
