/*
 * Adapted from The MIT License (MIT)
 *
 * Copyright (c) 2018-2025 DaPorkchop_
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software
 * is furnished to do so, subject to the following conditions:
 *
 * Any persons and/or organizations using this software must include the above copyright notice and this permission notice,
 * provide sufficient credit to the original authors of the project (IE: DaPorkchop_), as well as provide a link to the original project.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

package net.daporkchop.lib.common.reference.cache;

import lombok.AccessLevel;
import lombok.Getter;
import lombok.NonNull;
import lombok.RequiredArgsConstructor;
import lombok.experimental.Accessors;
import net.daporkchop.lib.common.misc.threadlocal.TL;
import net.daporkchop.lib.common.reference.ReferenceStrength;

import java.lang.ref.Reference;
import java.util.Objects;
import java.util.function.Supplier;

/**
 * @author DaPorkchop_
 */
@RequiredArgsConstructor(access = AccessLevel.PACKAGE)
@Accessors(fluent = true)
final class ThreadLocalCollectableCached<T> implements Cached<T> {
    private final TL<Reference<T>> tl = TL.create();

    @Getter
    private final @NonNull Supplier<T> factory;
    private final @NonNull ReferenceStrength strength;

    @Override
    public T get() {
        Reference<T> ref = this.tl.get();
        T value;
        if (ref != null && (value = ref.get()) != null) {
            return value;
        }

        return this.compute();
    }

    private T compute() {
        //we don't need to re-check the current value here, there's no races since everything is thread-local

        T value = Objects.requireNonNull(this.factory.get());
        this.tl.set(this.strength.createReference(value));
        return value;
    }
}
