/*
 * 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/gitea/aqua/smolbote
 *
 * SPDX-License-Identifier: GPL-3.0
 */

#include "filter.h"
#include "urlinterceptor.h"
#include <QDir>
#include <QJsonArray>
#include <QJsonDocument>
#include <QTextStream>
#include <configuration/configuration.h>
#include "util.h"


QHash<QString, Filter::HostRule> parseHostlist(const QString &filename)
{
    QHash<QString, Filter::HostRule> rules;

    if(QFile hostfile(filename); 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)) {
                    Filter::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;
}
/*
inline std::vector<FilterRule> parseAdBlockList(const QString &filename)
{
    std::vector<FilterRule> rules;
    QFile list(filename);

    if(list.open(QIODevice::ReadOnly | QIODevice::Text), true) {
        QTextStream l(&list);
        QString line;
        while(l.readLineInto(&line)) {
            AdBlockRule rule(line);
            if(rule.isEnabled()) {
                rules.emplace_back(std::move(rule));
            }
        }
        list.close();
    }

    return rules;
}*/

Filter::Filter::Filter(const std::unique_ptr<Configuration> &config, QObject* parent)
    : QObject(parent)
{
    // parse headers
    if(const auto headers = config->value<QStringList>("filter.header"); headers) {
        for(const QString &header : headers.value()) {
            const auto list = header.split(QLatin1Literal(":"));
            if(list.length() == 2)
                m_headers.insert(list.at(0).toLatin1(), list.at(1).toLatin1());
        }
    }

    const QStringList hostfiles = Util::files(config->value<QString>("filter.path").value());
    for(const QString &hostfile : hostfiles) {
        m_hostlist.unite(parseHostlist(hostfile));
    }

    /*
    auto filtersPath = config->value<QString>("filter.adblock");
    if(filtersPath)
        filters = parseAdBlockList(filtersPath.value());
    */
}

std::optional<Filter::HostRule> Filter::hostlistRule(const QString& url) const
{
    if(!m_hostlist.contains(url))
        return std::nullopt;

    return std::optional<Filter::HostRule>(m_hostlist.value(url));
}