/*
 * 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/blockchair.h"


Time BlockchainDataSourceTypeBTC_Blockchair::getTimeFromString(string s)
{
    std::istringstream in{s};
    date::sys_time<std::chrono::seconds> tp;
    in >> date::parse("%F %T", tp);

    Time t;
    t.setFromUnixTime(std::chrono::system_clock::to_time_t(tp));

    return t;
}

list<BlockchainTxDetailsTypeBTC> BlockchainDataSourceTypeBTC_Blockchair::getTxDetailsListForAddresses(list<string> addresses)
{
    linfo << "Blockchair : analyzing address list";

    list<BlockchainTxDetailsTypeBTC> l;

    if (!bfs::exists(getCacheFilenameForAddresses(addresses)))
    {
        saveBlockchainAddressesDataToCacheFile(addresses);
    }

    if (!bfs::exists(getCacheFilenameForAddresses(addresses)))
    {
        lerr << "Blockchair : cache file could not be found. Addresses data was not retrieved.";
        return l;
    }

    ifstream f;
    f.open(getCacheFilenameForAddresses(addresses));
    json::value jvalue = json::value::parse(f);
    f.close();

    for (int i=0;i<jvalue["data"]["transactions"].size();i++)
    {
        string txHash = jvalue["data"]["transactions"][i].as_string();

        linfo << "Blockchair : found tx " << txHash << ". Starting analysis.";

        if (!bfs::exists(getCacheFilenameForTx(txHash)))
        {
            saveBlockchainTxDataToCacheFile(txHash);
        }

        if (!bfs::exists(getCacheFilenameForTx(txHash)))
        {
            lerr << "Blockchair : cache file for tx " << txHash << " could not be found. Tx data was not retrieved.";
        }
       
        ifstream fTx;
        fTx.open(getCacheFilenameForTx(txHash));
        json::value jvalueTx = json::value::parse(fTx);
        fTx.close();

        BlockchainTxDetailsTypeBTC tx;

        tx.hash = txHash;
        tx.time = getTimeFromString (jvalueTx["data"][txHash]["transaction"]["time"].as_string());

        for (int j=0;j<jvalueTx["data"][txHash]["inputs"].size();j++)
        {
            string addr = jvalueTx["data"][txHash]["inputs"][j]["recipient"].as_string();
            __int64 amount = jvalueTx["data"][txHash]["inputs"][j]["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<jvalueTx["data"][txHash]["outputs"].size();j++)
        {
            string addr = jvalueTx["data"][txHash]["outputs"][j]["recipient"].as_string();
            __int64 amount = jvalueTx["data"][txHash]["outputs"][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);

        linfo << "Blockchair : finished analysis for tx " << txHash << ".";
    }

    linfo << "Blockchair : finished analysis for address list.";

    return l;
}

string BlockchainDataSourceTypeBTC_Blockchair::getCacheFilenameForAddresses(list<string> addresses)
{
    string s;

    for (const auto a: addresses)
        s = s+a;

    string cacheFilename("data/cache/blockchair/"+m_blockchainName+"/addresses/" + s);
    return cacheFilename;
}

string BlockchainDataSourceTypeBTC_Blockchair::getCacheFilenameForTx(string txHash)
{
    string cacheFilename("data/cache/blockchair/"+m_blockchainName+"/tx/" + txHash);
    return cacheFilename;
}

void BlockchainDataSourceTypeBTC_Blockchair::saveBlockchainAddressesDataToCacheFile(list<string> addresses)
{    
    try
    {
        string s;

        for (const auto a: addresses)
        {
            if (s.length())
                s = s+","+a;
            else
                s = a;
        }
        
        linfo << "Blockchair : querying API about addresses : " << s;

        string sRequestURL = "/"+m_blockchainName+"/dashboards/addresses/";
        sRequestURL += s;
        http_client apiclient("https://api.blockchair.com/");

        m_currentRequestCacheFilename = getCacheFilenameForAddresses(addresses);

        ltrace << "Blockchair : query : " << sRequestURL;
        
        apiclient.request(methods::GET,sRequestURL).then([](http_response response)
        {
            if (response.status_code() == status_codes::OK)
            {
                ldebug << "Blockchair : response OK.";
                return response.extract_json();
            }
            else if (response.status_code() == status_codes::TooManyRequests)
            {
                lwarn << "Blockchair : 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 << "Blockchair : saving query result to " << m_currentRequestCacheFilename;
                ofstream f;
                f.open(m_currentRequestCacheFilename);
                f << previousTask.get();
                f.close();
            }
            else
            {
                lerr << "Blockchair : query result is empty. Nothing will be saved to the cache file.";
            }
        })
        .wait();
    }
    catch(const http::http_exception& e)
    {
        lerr << "Blockchair : failed to query API";
    }
}

void BlockchainDataSourceTypeBTC_Blockchair::saveBlockchainTxDataToCacheFile(string txHash)
{
    try
    {
        linfo << "Blockchair : querying API about tx : " << txHash;

        string sRequestURL = "/"+m_blockchainName+"/dashboards/transaction/";
        sRequestURL += txHash;
        http_client apiclient("https://api.blockchair.com/");

        m_currentRequestCacheFilename = getCacheFilenameForTx(txHash);

        ltrace << "Blockchair : query : " << sRequestURL;

        apiclient.request(methods::GET,sRequestURL).then([](http_response response)
        {
            if (response.status_code() == status_codes::OK)
            {
                ldebug << "Blockchair : response OK.";
                return response.extract_json();
            }
            else if (response.status_code() == status_codes::TooManyRequests)
            {
                lwarn << "Blockchair : 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 << "Blockchair : saving query result to " << m_currentRequestCacheFilename;
                ofstream f;
                f.open(m_currentRequestCacheFilename);
                f << previousTask.get();
                f.close();
            }
            else
            {
                lerr << "Blockchair : query result is empty. Nothing will be saved to the cache file.";
            }
        })
        .wait();
    }
    catch(const http::http_exception& e)
    {
        lerr << "Blockchair : failed to query API about " << txHash;
    }
}