/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package jakarta.servlet;

import java.util.Objects;

import jakarta.servlet.annotation.MultipartConfig;

/**
 * The programmatic equivalent of {@link jakarta.servlet.annotation.MultipartConfig} used to configure multipart
 * handling for a Servlet when registering a Servlet via code.
 *
 * @since Servlet 3.0
 */
public class MultipartConfigElement {

    private final String location;// = "";
    private final long maxFileSize;// = -1;
    private final long maxRequestSize;// = -1;
    private final int fileSizeThreshold;// = 0;

    /**
     * Create a programmatic multipart configuration with a specific location and defaults for the remaining
     * configuration elements.
     *
     * @param location The temporary location to store files
     */
    public MultipartConfigElement(String location) {
        // Keep empty string default if location is null
        this.location = Objects.requireNonNullElse(location, "");
        this.maxFileSize = -1;
        this.maxRequestSize = -1;
        this.fileSizeThreshold = 0;
    }

    /**
     * Create a programmatic multipart configuration from the individual configuration elements.
     *
     * @param location          The temporary location to store files
     * @param maxFileSize       The maximum permitted size for a single file
     * @param maxRequestSize    The maximum permitted size for a request
     * @param fileSizeThreshold The size above which the file is saved in the temporary location rather than retained in
     *                              memory.
     */
    public MultipartConfigElement(String location, long maxFileSize, long maxRequestSize, int fileSizeThreshold) {
        // Keep empty string default if location is null
        this.location = Objects.requireNonNullElse(location, "");
        this.maxFileSize = maxFileSize;
        this.maxRequestSize = maxRequestSize;
        // Avoid threshold values of less than zero as they cause trigger NPEs
        // in the Commons FileUpload port for fields that have no data.
        this.fileSizeThreshold = Math.max(fileSizeThreshold, 0);
    }

    /**
     * Create a programmatic configuration from an annotation.
     *
     * @param annotation The source annotation to copy to create the programmatic equivalent.
     */
    public MultipartConfigElement(MultipartConfig annotation) {
        location = annotation.location();
        maxFileSize = annotation.maxFileSize();
        maxRequestSize = annotation.maxRequestSize();
        fileSizeThreshold = annotation.fileSizeThreshold();
    }

    /**
     * Obtain the location where temporary files should be stored.
     *
     * @return the location where temporary files should be stored.
     */
    public String getLocation() {
        return location;
    }

    /**
     * Obtain the maximum permitted size for a single file.
     *
     * @return the maximum permitted size for a single file.
     */
    public long getMaxFileSize() {
        return maxFileSize;
    }

    /**
     * Obtain the maximum permitted size for a single request.
     *
     * @return the maximum permitted size for a single request.
     */
    public long getMaxRequestSize() {
        return maxRequestSize;
    }

    /**
     * Obtain the size above which the file is saved in the temporary location rather than retained in memory.
     *
     * @return the size above which the file is saved in the temporary location rather than retained in memory.
     */
    public int getFileSizeThreshold() {
        return fileSizeThreshold;
    }
}