/*
 * This file is part of the Flowee project
 * Copyright (C) 2019 Tom Zander <tom@flowee.org>
 *
 * This program 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.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <QCoreApplication>
#include <QDir>
#include <QTextStream>
#include <QProcess>
#include <qdebug.h>

#include <unistd.h>
#include <signal.h>
/*
   Interprets env vars;
    FLOWEE_INDEXERS
        list of indexers to enable. For instance: =txid, address, spent

    FLOWEE_DB
        list of variables to connect to the DB
        driver=postgres,hostname=localhost,db=flowee,username=flowee_indexer,password=SECRET

    FLOWEE_HUB=host:port

    FLOWEE_LOGLEVEL
        info, quiet or silent
 */

static QProcess *indexer = new QProcess();

void HandleSignals(int) {
qWarning() << "Docker: TERM received";
    qint64 pid = indexer->processId();
    if (pid > 0) kill(pid, SIGTERM); // politely tell the indexer to terminate
}

int main(int x, char**y) {
    QCoreApplication app(x,y);

    QDir data("/data");
    if (!data.exists()) {
        qWarning() << "No volume found on /data, refusing to start";
        return 1;
    }

    const QDir confDir(QDir::homePath() + "/.config/flowee/indexer");
    confDir.mkpath(".");

    QFile configFile(confDir.absolutePath() + "/indexer.conf");
    if (!configFile.open(QIODevice::WriteOnly)) {
        qWarning() << "Can't write conf file";
    } else {
        QTextStream out(&configFile);
        out << "# autogenerated flowee indexer config\n";

        QString dbSpec = getenv("FLOWEE_DB");
        QStringList pairs = dbSpec.split(QRegExp("[ ,;&]"), QString::SkipEmptyParts);
        for (auto pair : pairs) {
            QStringList items = pair.split("=");
            if (items.size() != 2) {
                qWarning() << "DB item not understood:" << pair;
                continue;
            }
            auto token = items.at(0).toLower();
            if (token == "driver") {
                auto driver = items.at(1).toUpper();
                if (driver.startsWith("POSTGRES") || driver == "PSQL") {
                    driver = "QPSQL";
                }
                // TODO support other drivers
                out << "db_driver=" << driver << endl;
            }
            else if (token == "hostname") {
                out << "db_hostname=" << items.at(1) << endl;
            }
            else if (token == "db" || token == "database") {
                out << "db_database=" << items.at(1) << endl;
            }
            else if (token == "user" || token == "username" || token == "uname") {
                out << "db_username=" << items.at(1) << endl;
            }
            else if (token == "pwd" || token == "password" || token == "passwd") {
                out << "db_password=" << items.at(1) << endl;
            }
        }
        out << endl;

        QString indexers = getenv("FLOWEE_INDEXERS");
        if (indexers.isEmpty())
            indexers = "txid";
        QStringList components = indexers.split(QRegExp("[, :;]"), QString::SkipEmptyParts);
        for (auto c : components) {
            if (c.compare("txid", Qt::CaseInsensitive) == 0
                    || c.compare("txdb", Qt::CaseInsensitive) == 0
                    || c == "transaction-id") {
                out << "[txdb]\nenabled=true\n\n";
            }
            else if (c.compare("addressdb", Qt::CaseInsensitive) == 0
                    || c.compare("address", Qt::CaseInsensitive) == 0
                    || c.compare("addresses", Qt::CaseInsensitive) == 0) {
                out << "[addressdb]\nenabled=true\n\n";
            }
            else if (c.compare("spentdb", Qt::CaseInsensitive) == 0
                    || c.compare("spenddb", Qt::CaseInsensitive) == 0
                    || c.compare("spend", Qt::CaseInsensitive) == 0
                    || c.compare("spent", Qt::CaseInsensitive) == 0) {
                out << "[spentdb]\nenabled=true\n\n";
            }
        }

        configFile.close();
    }

    QFile logsFile(confDir.absolutePath() + "/logs.conf");
    QString logLevel = getenv("FLOWEE_LOGLEVEL");
    if (logLevel.isEmpty() && logsFile.exists()) {
        qWarning() << "Not changing existing logs.conf";
    }
    else if (!logsFile.open(QIODevice::WriteOnly)) {
        qWarning() << "Can't write logs.conf file" << confDir.absoluteFilePath("logs.conf");
    }
    else {
        QTextStream out(&logsFile);
        out << "# Flowee logging config.\n"
               "channel console\n"
               "  option timestamp\n"
               "channel file\n"
               "  option timestamp date time\n"
               "  option path /data/indexer.log\n";

        if (logLevel.toLower() == "info")
            out << "\nALL info\n";
        else if (logLevel.toLower() == "quiet")
            out << "\nALL quiet\n";
        else if (logLevel.toLower() == "silent")
            out << "\nALL silent\n";
        else if (!logLevel.isEmpty())
            qWarning() << "FLOWEE_LOGLEVEL not understood. Options are 'info', 'quiet' or 'silent'";
        logsFile.close();
    }

    struct sigaction sa;
    sa.sa_handler = HandleSignals;
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = 0;
    sigaction(SIGTERM, &sa, NULL);
    sigaction(SIGINT, &sa, NULL);

    // Ignore SIGPIPE
    signal(SIGPIPE, SIG_IGN);

    QStringList args;
    args << "--conf" << confDir.absolutePath() + "/indexer.conf"
        << "--datadir" << "/data"
        << "--bind" << "0.0.0.0:1234";
    if (getenv("FLOWEE_HUB")) {
        QString hub = getenv("FLOWEE_HUB");
        args << "--connect" << hub;
    } else {
        qWarning() << "WARNING: Without FLOWEE_HUB env-var we will not get updated!";
    }
    indexer->setReadChannel(QProcess::StandardOutput);
    indexer->start(QLatin1String("/usr/bin/indexer"), args, QIODevice::ReadOnly);
    indexer->waitForReadyRead(20000);
    if (indexer->state() == QProcess::NotRunning) { // time out
        qWarning() << "ERROR: indexer fails to start, timing out";
        indexer->kill();
        return 1;
    }
    QTextStream out(stdout);
    while (true) {
        auto logData = indexer->readAllStandardError();
        out << logData;
        logData = indexer->readAllStandardOutput();
        out << logData;
        if (indexer->state() != QProcess::Running)
            break;
        out.flush();
        indexer->waitForReadyRead(20000);
    }

    fflush(NULL);
    sync();

    return indexer->exitCode();
}