/*
 * Copyright (c) 2004-2022, University of Oslo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * Neither the name of the HISP project nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.hisp.dhis.cache;

import java.util.concurrent.TimeUnit;
import lombok.extern.slf4j.Slf4j;

/**
 * A Builder class that helps in building Cache instances. Sensible defaults are in place which can
 * be modified with a fluent builder api.
 *
 * @author Ameen Mohamed
 * @param <V> The Value type to be stored in cache
 */
@Slf4j
public class SimpleCacheBuilder<V> implements CacheBuilder<V> {
  private long maximumSize;

  private int initialCapacity;

  private String region;

  private boolean refreshExpiryOnAccess;

  private long expiryInSeconds;

  private V defaultValue;

  private boolean expiryEnabled;

  private boolean disabled;

  public SimpleCacheBuilder() {
    // Applying sensible defaults explicitly
    this.maximumSize = -1;
    this.region = "default";
    this.refreshExpiryOnAccess = false;
    this.expiryInSeconds = 0;
    this.defaultValue = null;
    this.expiryEnabled = false;
    this.disabled = false;
    this.initialCapacity = 16;
  }

  public CacheBuilder<V> withMaximumSize(long maximumSize) {
    if (maximumSize < 0) {
      throw new IllegalArgumentException("MaximumSize cannot be negative");
    }
    this.maximumSize = maximumSize;
    return this;
  }

  public CacheBuilder<V> withInitialCapacity(int initialCapacity) {
    if (initialCapacity < 0) {
      throw new IllegalArgumentException("InitialCapacity cannot be negative");
    }
    this.initialCapacity = initialCapacity;
    return this;
  }

  public CacheBuilder<V> forRegion(String region) {
    if (region == null) {
      throw new IllegalArgumentException("Region cannot be null");
    }
    this.region = region;
    return this;
  }

  public CacheBuilder<V> expireAfterAccess(long duration, TimeUnit timeUnit) {
    if (timeUnit == null) {
      throw new IllegalArgumentException("TimeUnit cannot be null");
    }
    this.expiryInSeconds = timeUnit.toSeconds(duration);
    this.refreshExpiryOnAccess = true;
    this.expiryEnabled = true;
    return this;
  }

  public CacheBuilder<V> expireAfterWrite(long duration, TimeUnit timeUnit) {
    if (timeUnit == null) {
      throw new IllegalArgumentException("TimeUnit cannot be null");
    }
    this.expiryInSeconds = timeUnit.toSeconds(duration);
    this.refreshExpiryOnAccess = false;
    this.expiryEnabled = true;
    return this;
  }

  public CacheBuilder<V> withDefaultValue(V defaultValue) {
    this.defaultValue = defaultValue;
    return this;
  }

  public CacheBuilder<V> disabled() {
    this.disabled = true;
    return this;
  }

  /**
   * Creates and returns a {@link LocalCache}. If {@code maximumSize} is 0 or {@code disabled} is
   * true then a NoOpCache instance will be returned which does not cache anything.
   *
   * @return A cache instance based on the input parameters. Returns one of {@link LocalCache} or
   *     {@link NoOpCache}
   */
  public Cache<V> build() {
    if (maximumSize == 0 || disabled) {
      log.info(String.format("NoOp Cache instance created for region:'%s'", region));
      return new NoOpCache<V>(this);
    } else {
      log.info(String.format("Simple Local Cache instance created for region:'%s'", region));
      return new LocalCache<V>(this);
    }
  }

  public long getMaximumSize() {
    return maximumSize;
  }

  public int getInitialCapacity() {
    return initialCapacity;
  }

  public String getRegion() {
    return region;
  }

  public boolean isRefreshExpiryOnAccess() {
    return refreshExpiryOnAccess;
  }

  public boolean isExpiryEnabled() {
    return expiryEnabled;
  }

  public boolean isDisabled() {
    return disabled;
  }

  public long getExpiryInSeconds() {
    return expiryInSeconds;
  }

  public V getDefaultValue() {
    return defaultValue;
  }

  public CacheBuilder<V> forceInMemory() {
    return this;
  }
}
