/*
 * This file is part of smolbote. It's copyrighted by the contributors recorded
 * in the version control history of the file, available from its original
 * location: https://neueland.iserlohn-fortress.net/smolbote.hg
 *
 * SPDX-License-Identifier: GPL-3.0
 */

#include "urlinterceptor.h"
#include <QDir>
#include <QTextStream>
#include <QtConcurrent>

UrlRequestInterceptor::UrlRequestInterceptor(const QString &path, QObject *parent)
    : QWebEngineUrlRequestInterceptor(parent)
{
    QDir hostsD(path);
    const QStringList hostFiles = hostsD.entryList(QDir::Files);
    for(const QString &file : hostFiles) {
        const QString absPath = hostsD.absoluteFilePath(file);
        QtConcurrent::run([this, absPath]() {
            auto r = parse(absPath);
#ifdef QT_DEBUG
            qDebug("Parsed %i rules from %s", r.count(), qUtf8Printable(absPath));
#endif

            rulesLock.lock();
            rules.unite(r);
            rulesLock.unlock();
        });
    }
}

UrlRequestInterceptor::~UrlRequestInterceptor() = default;

void UrlRequestInterceptor::interceptRequest(QWebEngineUrlRequestInfo &info)
{
    rulesLock.lock();
    if(rules.contains(info.requestUrl().host())) {
        info.block(rules.value(info.requestUrl().host()).isBlocking);
    }
    rulesLock.unlock();
}

QHash<QString, UrlRequestInterceptor::HostRule> parse(const QString &filename)
{
    QHash<QString, UrlRequestInterceptor::HostRule> rules;

    QFile hostfile(filename);
    if(hostfile.open(QIODevice::ReadOnly | QIODevice::Text)) {

        // with a QTextStream we can read lines without getting linebreaks at the end
        QTextStream hostfile_stream(&hostfile);

        while(!hostfile_stream.atEnd()) {

            // read line and remove any whitespace at the end
            const QString &line = hostfile_stream.readLine().trimmed();

            // skip comments and empty lines
            if(line.isEmpty() || line.startsWith('#'))
                continue;

            // everything else should be a rule
            // format is <redirect> <host>
            // 0.0.0.0 hostname
            const QStringList &parts = line.split(' ');
            const QString &redirect = parts.at(0);

            for(auto i = parts.constBegin() + 1; i != parts.constEnd(); ++i) {
                if(!rules.contains(*i)) {
                    UrlRequestInterceptor::HostRule rule{};
                    rule.isBlocking = (redirect == "0.0.0.0");
                    rules.insert(*i, rule);
                }
            }

//            for(const QString &host : parts.mid(1)) {
//                if(!rules.contains(host)) {
//                    UrlRequestInterceptor::HostRule rule{};
//                    rule.isBlocking = redirect == "0.0.0.0";
//                    rules.insert(host, rule);
//                }
//            }
        }

        hostfile.close();
    }

    return rules;
};