cpfm/src/datasources/blockchain_info.cpp

/*
 * Copyright (c) 2021, evilny0
 * 
 * This file is part of cpfm.
 *
 * cpfm is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * cpm is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with cpfm. If not, see <http://www.gnu.org/licenses/>.
 * 
 */

#include "datasources/blockchain_info.h"

list<BlockchainTxDetailsTypeBTC> BlockchainDataSourceBTC_BlockchainInfo::getTxDetailsListForAddress(string address)
{
    linfo << "Blockchain.info : Analyzing address: " << address;

    list<BlockchainTxDetailsTypeBTC> l;

    if (!bfs::exists(getCacheFilenameForAddress(address)))
    {
        saveBlockchainAddressDataToCacheFile(address);
    }

    if (!bfs::exists(getCacheFilenameForAddress(address)))
    {
        lerr << "Blockchain.info : cache file could not be found. Address data was not retrieved.";
        return l;
    }

    ifstream f;
    f.open(getCacheFilenameForAddress(address));
    json::value jvalue = json::value::parse(f);
    f.close();

    linfo << "Blockchain.info : analyzing address: " << jvalue["address"].as_string();

    for (int i=0;i<jvalue["txs"].size();i++)
    {
        BlockchainTxDetailsTypeBTC tx;

        tx.hash = jvalue["txs"][i]["hash"].as_string();
        tx.time.setFromUnixTime(jvalue["txs"][i]["time"].as_integer());

        for (int j=0;j<jvalue["txs"][i]["inputs"].size();j++)
        {
            string addr = jvalue["txs"][i]["inputs"][j]["prev_out"]["addr"].as_string();
            __int64 amount = jvalue["txs"][i]["inputs"][j]["prev_out"]["value"].as_integer();

            Money m = amount;
            Money mdecimals = m/100000000;

            // The same address can be multiple time in the inputs, so we need to sum the amounts.
            tx.inputs[addr] += mdecimals;
        }

        for (int j=0;j<jvalue["txs"][i]["out"].size();j++)
        {
            string addr = jvalue["txs"][i]["out"][j]["addr"].as_string();
            __int64 amount = jvalue["txs"][i]["out"][j]["value"].as_integer();

            Money m = amount;
            Money mdecimals = m/100000000;

            // The same address can only be once in the outputs.
            tx.outputs[addr] = mdecimals;
        }

        l.push_back(tx);
    }

    return l;
}

string BlockchainDataSourceBTC_BlockchainInfo::getCacheFilenameForAddress(string address)
{
    string cacheFilename("data/cache/blockchain.info/btc/" + address);
    return cacheFilename;
}

void BlockchainDataSourceBTC_BlockchainInfo::saveBlockchainAddressDataToCacheFile(string address)
{
    try
    {
        linfo << "Blockchain.info : querying API about " << address;

        string sRequestURL = "/rawaddr/";
        sRequestURL += address;
        http_client apiclient("https://blockchain.info/");

        m_currentRequestCacheFilename = getCacheFilenameForAddress(address);

        apiclient.request(methods::GET,sRequestURL).then([](http_response response)
        {
            if (response.status_code() == status_codes::OK)
            {
                ldebug << "Blockchain.info : response OK.";
                return response.extract_json();
            }
            else if (response.status_code() == status_codes::TooManyRequests)
            {
                lwarn << "Blockchain.info : too many queries! We are being rate limited.";
                pplx::task_from_result(json::value());
            }
            return pplx::task_from_result(json::value());
        })
        .then([this](pplx::task<json::value> previousTask)
        {
            if (previousTask.get() != json::value::null())
            {
                linfo << "Blockchain.info : saving query result to " << m_currentRequestCacheFilename;
                ofstream f;
                f.open(m_currentRequestCacheFilename);
                f << previousTask.get();
                f.close();
            }
            else
            {
                lerr << "Blockchain.info : query result is empty. Nothing will be saved to the cache file.";
            }
        })
        .wait();
    }
    catch(const http::http_exception& e)
    {
        lerr << "Blockchain.info : failed to query API about " << address;
    }
}