GetAggregatePrice.hpp

//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2024, the clio developers.
 
    Permission to use, copy, modify, and distribute this software for any
    purpose with or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#pragma once
 
#include "data/BackendInterface.hpp"
#include "rpc/Errors.hpp"
#include "rpc/JS.hpp"
#include "rpc/common/MetaProcessors.hpp"
#include "rpc/common/Modifiers.hpp"
#include "rpc/common/Specs.hpp"
#include "rpc/common/Types.hpp"
#include "rpc/common/Validators.hpp"
 
#include <boost/asio/spawn.hpp>
#include <boost/json/array.hpp>
#include <boost/json/conversion.hpp>
#include <xrpl/basics/Number.h>
#include <xrpl/protocol/AccountID.h>
#include <xrpl/protocol/STAmount.h>
#include <xrpl/protocol/STObject.h>
#include <xrpl/protocol/jss.h>
 
#include <cstdint>
#include <functional>
#include <memory>
#include <optional>
#include <string>
#include <string_view>
#include <utility>
#include <vector>
 
namespace rpc {
 
class GetAggregatePriceHandler {
    std::shared_ptr<BackendInterface> sharedPtrBackend_;
 
public:
    struct Stats {
        ripple::STAmount avg;
        ripple::Number sd;  // standard deviation
        uint32_t size{0};
    };
 
    struct Output {
        uint32_t time;
        Stats extireStats;
        std::optional<Stats> trimStats;
        std::string ledgerHash;
        uint32_t ledgerIndex;
        std::string median;
        bool validated = true;
 
        Output(uint32_t time, std::string ledgerHash, uint32_t ledgerIndex)
            : time(time), ledgerHash(std::move(ledgerHash)), ledgerIndex(ledgerIndex)
        {
        }
    };
 
    struct Oracle {
        std::uint32_t documentId{0};
        ripple::AccountID account;
    };
 
    struct Input {
        std::optional<std::string> ledgerHash;
        std::optional<std::uint32_t> ledgerIndex;
        std::vector<Oracle> oracles;  // valid range is 1-200
        std::string baseAsset;
        std::string quoteAsset;
        std::optional<std::uint32_t> timeThreshold;
        std::optional<std::uint8_t> trim;  // valid range is 1-25
    };
 
    using Result = HandlerReturnType<Output>;
 
    GetAggregatePriceHandler(std::shared_ptr<BackendInterface> const& sharedPtrBackend)
        : sharedPtrBackend_(sharedPtrBackend)
    {
    }
 
    static RpcSpecConstRef
    spec([[maybe_unused]] uint32_t apiVersion)
    {
        static constexpr auto kORACLES_MAX = 200;
 
        static auto const kORACLES_VALIDATOR =
            modifiers::CustomModifier{[](boost::json::value& value, std::string_view) -> MaybeError {
                if (!value.is_array() or value.as_array().empty() or value.as_array().size() > kORACLES_MAX)
                    return Error{Status{RippledError::rpcORACLE_MALFORMED}};
 
                for (auto& oracle : value.as_array()) {
                    if (!oracle.is_object() or !oracle.as_object().contains(JS(oracle_document_id)) or
                        !oracle.as_object().contains(JS(account)))
                        return Error{Status{RippledError::rpcORACLE_MALFORMED}};
 
                    auto maybeError = validation::Type<std::uint32_t, std::string>{}.verify(
                        oracle.as_object(), JS(oracle_document_id)
                    );
                    if (!maybeError)
                        return maybeError;
 
                    maybeError = modifiers::ToNumber::modify(oracle, JS(oracle_document_id));
                    if (!maybeError)
                        return maybeError;
 
                    maybeError =
                        validation::CustomValidators::accountBase58Validator.verify(oracle.as_object(), JS(account));
                    if (!maybeError)
                        return Error{Status{RippledError::rpcINVALID_PARAMS}};
                };
 
                return MaybeError{};
            }};
 
        static auto const kRPC_SPEC = RpcSpec{
            {JS(ledger_hash), validation::CustomValidators::uint256HexStringValidator},
            {JS(ledger_index), validation::CustomValidators::ledgerIndexValidator},
            // validate quoteAsset and base_asset in accordance to the currency code found in XRPL doc:
            // https://xrpl.org/docs/references/protocol/data-types/currency-formats#currency-codes
            // usually Clio returns rpcMALFORMED_CURRENCY , return InvalidParam here just to mimic rippled
            {JS(base_asset),
             validation::Required{},
             meta::WithCustomError{
                 validation::CustomValidators::currencyValidator, Status(RippledError::rpcINVALID_PARAMS)
             }},
            {JS(quote_asset),
             validation::Required{},
             meta::WithCustomError{
                 validation::CustomValidators::currencyValidator, Status(RippledError::rpcINVALID_PARAMS)
             }},
            {JS(oracles), validation::Required{}, kORACLES_VALIDATOR},
            // note: Unlike `rippled`, Clio only supports UInt as input, no string, no `null`, etc.
            {JS(time_threshold), validation::Type<std::uint32_t>{}},
            {
                JS(trim),
                validation::Type<std::uint8_t>{},
                validation::Between<std::uint8_t>{1, 25},
            }
        };
 
        return kRPC_SPEC;
    }
 
    Result
    process(Input input, Context const& ctx) const;
 
private:
    void
    tracebackOracleObject(
        boost::asio::yield_context yield,
        ripple::STObject const& oracleObject,
        std::function<bool(ripple::STObject const&)> const& callback
    ) const;
 
    friend void
    tag_invoke(boost::json::value_from_tag, boost::json::value& jv, Output const& output);
 
    friend Input
    tag_invoke(boost::json::value_to_tag<Input>, boost::json::value const& jv);
};
 
}  // namespace rpc