// Copyright (c) 2010 Satoshi Nakamoto
// Copyright (c) 2009-2018 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <consensus/validation.h>
#include <net.h>
#include <net_processing.h>
#include <txmempool.h>
#include <util/validation.h>
#include <validation.h>
#include <validationinterface.h>
#include <node/transaction.h>

#include <future>

TransactionError BroadcastTransaction(const CTransactionRef tx, std::string& err_string, const CAmount& max_tx_fee, bool relay, bool wait_callback)
{
    assert(g_connman);
    std::promise<void> promise;
    uint256 hashTx = tx->GetHash();
    bool callback_set = false;

    { // cs_main scope
    LOCK(cs_main);
    CCoinsViewCache &view = *pcoinsTip;
    bool fHaveChain = false;
    for (size_t o = 0; !fHaveChain && o < tx->vout.size(); o++) {
        const Coin& existingCoin = view.AccessCoin(COutPoint(hashTx, o));
        fHaveChain = !existingCoin.IsSpent();
    }
    bool fHaveMempool = mempool.exists(hashTx);
    if (!fHaveMempool && !fHaveChain) {
        // push to local node and sync with wallets
        CValidationState state;
        bool fMissingInputs;
        if (!AcceptToMemoryPool(mempool, state, std::move(tx), &fMissingInputs,
                nullptr /* plTxnReplaced */, false /* bypass_limits */, max_tx_fee)) {
            if (state.IsInvalid()) {
                err_string = FormatStateMessage(state);
                return TransactionError::MEMPOOL_REJECTED;
            } else {
                if (fMissingInputs) {
                    return TransactionError::MISSING_INPUTS;
                }
                err_string = FormatStateMessage(state);
                return TransactionError::MEMPOOL_ERROR;
            }
        } else if (wait_callback) {
            // If wallet is enabled, ensure that the wallet has been made aware
            // of the new transaction prior to returning. This prevents a race
            // where a user might call sendrawtransaction with a transaction
            // to/from their wallet, immediately call some wallet RPC, and get
            // a stale result because callbacks have not yet been processed.
            CallFunctionInValidationInterfaceQueue([&promise] {
                promise.set_value();
            });
            callback_set = true;
        }
    } else if (fHaveChain) {
        return TransactionError::ALREADY_IN_CHAIN;
    }

    } // cs_main

    if (callback_set) {
        promise.get_future().wait();
    }

    if (relay) {
        RelayTransaction(hashTx, *g_connman);
    }

    return TransactionError::OK;
}