package ex7;

import java.util.Map;
import java.util.Objects;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.LongAdder;

public final class Profiler {

    private static final class MonitorEntry {
        private final int hashCode;
        private final String name;

        public MonitorEntry(int hashCode, String name) {
            this.hashCode = hashCode;
            this.name = name;
        }

        public int getHashCode() {
            return hashCode;
        }

        public String getName() {
            return name;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            MonitorEntry that = (MonitorEntry) o;
            return hashCode == that.hashCode && Objects.equals(name, that.name);
        }

        @Override
        public int hashCode() {
            return Objects.hash(hashCode, name);
        }
    }

    private static final Map<MonitorEntry, LongAdder> monitorToAccessCount = new ConcurrentHashMap<>();

    static {
        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            for (final var entry : monitorToAccessCount.entrySet()) {
                System.out.printf("%d - %s - #Locks: %d%n",
                        entry.getKey().getHashCode(),
                        entry.getKey().getName(),
                        entry.getValue().intValue()
                );
            }
        }));
    }

    private Profiler() {
    }


    public static void countMonitorAccess(final Object obj) {
        final MonitorEntry monitorEntry = new MonitorEntry(obj.hashCode(), obj.getClass().getName());
        monitorToAccessCount.computeIfAbsent(monitorEntry, k -> new LongAdder());
        monitorToAccessCount.get(monitorEntry).increment();
    }


}