/*
 * 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
 */

#ifndef SMOLBOTE_ADBLOCKRULE_H
#define SMOLBOTE_ADBLOCKRULE_H

#include "../filterleaf.h"
#include <optional>
#include <QRegularExpression>
#include <QStringMatcher>

class Matcher
{
public:
    virtual bool hasMatch(const QString &where) const = 0;
};

template <typename T>
class ContentsMatcher : public Matcher
{
public:
    ContentsMatcher(const QString &pattern, FilterLeaf::UrlMatchType matchType)
    {
        this->matchType = matchType;
        patternLength = pattern.length();


        if constexpr(std::is_same_v<T, QRegularExpression>) {
            matcher.setPatternOptions(matcher.patternOptions() | QRegularExpression::CaseInsensitiveOption);
            matcher.setPattern(pattern);
        } else if constexpr(std::is_same_v<T, QStringMatcher>) {
            matcher.setCaseSensitivity(Qt::CaseInsensitive);
            matcher.setPattern(pattern);
        } else if constexpr(std::is_same_v<T, QString>) {
            matcher = QUrl::fromUserInput(pattern).host();
//            qDebug("matcher: %s", qUtf8Printable(matcher));
        }
    }

    bool hasMatch(const QString &where) const override
    {
        if constexpr(std::is_same_v<T, QStringMatcher>) {
            switch (matchType) {
            case FilterLeaf::InvalidMatch:
            case FilterLeaf::RegularExpressionMatch:
            case FilterLeaf::DomainMatch:
                qWarning("ContentsMatcher is a String Matcher, but not doing string matching!");
                return false;

            case FilterLeaf::StringContains:
                return (matcher.indexIn(where) != -1);

            case FilterLeaf::StringStartsWith:
                return (matcher.indexIn(where) == 0);

            case FilterLeaf::StringEndsWith:
                return (matcher.indexIn(where) == where.length() - patternLength);

            case FilterLeaf::StringEquals:
                return (matcher.indexIn(where) == 0) && (patternLength == where.length());
            }

        } else if constexpr(std::is_same_v<T, QRegularExpression>) {
            if(matchType != FilterLeaf::RegularExpressionMatch)
                qWarning("ContentsMatcher is a regular expression, but not doing a regular expression match!");
            return matcher.match(where).hasMatch();
        } else if constexpr(std::is_same_v<T, QString>) {
            // TODO: fix
            if(matchType == FilterLeaf::DomainMatch) {
//                qDebug("matching %s", qUtf8Printable(QUrl(where).host()));
                return QUrl(where).host().endsWith(matcher);
            } else
                return matcher == where;
        } else {
            qWarning("Matcher has no backend, returning false");
            return false;
        }
    }

private:
    int patternLength;
    T matcher;
    FilterLeaf::UrlMatchType matchType;
};

class AdBlockRule : public FilterLeaf
{
public:
    explicit AdBlockRule(FilterLeaf::UrlMatchType matchType, const QString &filter, FilterLeaf::Action action);
    ~AdBlockRule()
    {
        delete stringMatcher;
        delete regExp;
    };

    void mergeOptions(const QHash<QWebEngineUrlRequestInfo::ResourceType, bool> &options);

    bool match(const QUrl &requestUrl) const override;
    bool match(const QUrl &requestUrl, QWebEngineUrlRequestInfo::ResourceType type) const;
    std::pair<FilterLeaf::Action, QVariant> action() const override;

private:
    /* Once C++20 comes out, perhaps this can be replaced with a concept template */
    QStringMatcher *stringMatcher = nullptr;
    QRegExp *regExp = nullptr;
};

#endif // SMOLBOTE_ADBLOCKRULE_H