package jdk.jfr.internal;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import jdk.jfr.Enabled;

import jdk.jfr.RecordingState;

import jdk.jfr.internal.settings.CutoffSetting;

import jdk.jfr.internal.test.WhiteBox;

// The Old Object event could have been implemented as a periodic event, but

// due to chunk rotations and how settings are calculated when multiple recordings

// are running at the same time, it would lead to unacceptable overhead.

//

// Instead, the event is only emitted before a recording stops and

// if that recording has the event enabled.

//

// This requires special handling and the purpose of this class is to provide that

//

public final class OldObjectSample {

    private static final String EVENT_NAME = Type.EVENT_NAME_PREFIX + "OldObjectSample";

    private static final String OLD_OBJECT_CUTOFF = EVENT_NAME + "#" + Cutoff.NAME;

    private static final String OLD_OBJECT_ENABLED = EVENT_NAME + "#" + Enabled.NAME;

    // Emit if old object is enabled in recoding with cutoff for that recording

    public static void emit(PlatformRecording recording) {

        if (isEnabled(recording)) {

            long nanos = CutoffSetting.parseValueSafe(recording.getSettings().get(OLD_OBJECT_CUTOFF));

            long ticks = Utils.nanosToTicks(nanos);

            JVM.getJVM().emitOldObjectSamples(ticks, WhiteBox.getWriteAllObjectSamples());

        }

    }

    // Emit if old object is enabled for at least one recording, and use the largest

    // cutoff for an enabled recoding

    public static void emit(List<PlatformRecording> recordings, Boolean pathToGcRoots) {

        boolean enabled = false;

        long cutoffNanos = Boolean.TRUE.equals(pathToGcRoots) ? Long.MAX_VALUE : 0L;

        for (PlatformRecording r : recordings) {

            if (r.getState() == RecordingState.RUNNING) {

                if (isEnabled(r)) {

                    enabled = true;

                    long c = CutoffSetting.parseValueSafe(r.getSettings().get(OLD_OBJECT_CUTOFF));

                    cutoffNanos = Math.max(c, cutoffNanos);

                }

            }

        }

        if (enabled) {

            long ticks = Utils.nanosToTicks(cutoffNanos);

            JVM.getJVM().emitOldObjectSamples(ticks, WhiteBox.getWriteAllObjectSamples());

        }

    }

    public static void updateSettingPathToGcRoots(Map<String, String> s, Boolean pathToGcRoots) {

        if (pathToGcRoots != null) {

            s.put(OLD_OBJECT_CUTOFF, pathToGcRoots ? "infinity" : "0 ns");

        }

    }

    public static Map<String, String> createSettingsForSnapshot(PlatformRecording recording, Boolean pathToGcRoots) {

        Map<String, String> settings = new HashMap<>(recording.getSettings());

        updateSettingPathToGcRoots(settings, pathToGcRoots);

        return settings;

    }

    private static boolean isEnabled(PlatformRecording r) {

        Map<String, String> settings = r.getSettings();

        String s = settings.get(OLD_OBJECT_ENABLED);

        return "true".equals(s);

    }

}