// SPDX-License-Identifier: GPL-3.0-or-later
// SPDX-FileCopyrightText: 2026 A-La-Karte Contributors

#pragma once

#include <QFutureWatcher>
#include <QList>
#include <QObject>
#include <QString>
#include <QTimer>
#include <QtGlobal>
#include <functional>

class ProcessScanner : public QObject
{
    Q_OBJECT

public:
    explicit ProcessScanner(QObject *parent = nullptr);

    struct Match {
        uint pid = 0;
        QString exe;
        QString cmdline;
    };

    // Find PIDs whose /proc/<pid>/environ contains key=value
    static QList<Match> findByEnvironment(const QString &key, const QString &value);

    // Find PIDs whose /proc/<pid>/environ contains any of key=value for the provided keys
    static QList<Match> findByAnyEnvironment(const QStringList &keys, const QString &value);

    // Find PIDs whose /proc/<pid>/cmdline contains the substring
    static QList<Match> findByCmdline(const QString &substring);

    // Find PIDs whose /proc/<pid>/exe resolves to a path under the given directory
    static QList<Match> findByExePath(const QString &dirPrefix);

    // Async poll: calls matcher repeatedly until it returns non-empty or timeout.
    // Emits found() with matching PIDs, or timedOut() on failure.
    void pollUntilFound(std::function<QList<Match>()> matcher, int intervalMs = 500, int timeoutMs = 15000);

    void cancel();

Q_SIGNALS:
    void found(const QList<ProcessScanner::Match> &matches);
    void timedOut();

private:
    void startScan();

    QTimer m_timer;
    QTimer m_deadline;
    std::function<QList<Match>()> m_matcher;
    quint64 m_generation = 0;
    bool m_scanInFlight = false;
    quint64 m_scanGeneration = 0;
};