BrAPIPage.java

/*
 * Copyright 2020 Global Crop Diversity Trust
 *
 * Licensed 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 org.gringlobal.brapi;

import java.util.Arrays;

import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;

/**
 * Data pagination request.
 *
 * @author Matija Obreza
 */
public class BrAPIPage {

	private static final int MAX_PAGE_SIZE = 1000;

	/** The default sort properties. */
	private final String[] DEFAULT_SORT_PROPERTIES = { "id" };

	/** Page (0-based). */
	private Integer page;

	/** Page size (length). */
	private Integer pageSize;

	/** Sort direction. */
	private Sort.Direction dir;

	/** Sort properties. */
	private String[] sort;

	/**
	 * Gets the page.
	 *
	 * @return the page
	 */
	public int getPage() {
		return page;
	}

	/**
	 * Sets the page.
	 *
	 * @param p the new page
	 */
	public void setPage(int p) {
		this.page = p;
	}

	/**
	 * Gets the pageSize.
	 *
	 * @return the pageSize
	 */
	public int getPageSize() {
		return pageSize;
	}

	/**
	 * Sets the pageSize.
	 *
	 * @param l the new pageSize
	 */
	public void setPageSize(int l) {
		this.pageSize = l;
	}

	/**
	 * Gets the d.
	 *
	 * @return the d
	 */
	public Sort.Direction getDir() {
		return dir;
	}

	/**
	 * Sets the d.
	 *
	 * @param d the new d
	 */
	public void setDir(Sort.Direction d) {
		this.dir = d;
	}

	/**
	 * Gets the s.
	 *
	 * @return the s
	 */
	public String[] getSort() {
		return sort;
	}

	/**
	 * Sets the s.
	 *
	 * @param s the new s
	 */
	public void setSort(String[] s) {
		this.sort = s;
	}

	/* (non-Javadoc)
	 * @see java.lang.Object#toString()
	 */
	@Override
	public String toString() {
		return "BrAPIPage page=" + page + ", pageSize=" + pageSize + ", dir=" + dir + ", sort=" + Arrays.toString(sort);
	}

	/**
	 * Get sort direction or {@link Sort.Direction#ASC} if null.
	 *
	 * @param defaultDir the default dir
	 * @return sort direction or {@link Sort.Direction#ASC}
	 */
	private Sort.Direction getDirection(Sort.Direction defaultDir) {
		return dir == null ? defaultDir : dir;
	}

	/**
	 * Gets list of sort properties or provided defaults.
	 *
	 * @param defaultSortProps the default sort props
	 * @return provided properties or defaultSortProps
	 */
	private String[] getSortProperties(String[] defaultSortProps) {
		return sort == null || sort.length == 0 ? defaultSortProps : sort;
	}

	/**
	 * To page request using the {@link #DEFAULT_SORT_PROPERTIES} and ASC sort
	 *
	 * @return the pageable
	 */
	public Pageable toPageRequest() {
		return PageRequest.of(page == null ? 0 : page, Integer.min(pageSize == null ? MAX_PAGE_SIZE : pageSize, MAX_PAGE_SIZE), getDirection(Sort.Direction.ASC), getSortProperties(DEFAULT_SORT_PROPERTIES));
	}

	/**
	 * To page request.
	 *
	 * @param maxPageSize the max page size
	 * @param defaultDir the default dir
	 * @param defaultSort the default sort
	 * @return the pageable
	 */
	public Pageable toPageRequest(int maxPageSize, Sort.Direction defaultDir, String... defaultSort) {
		return PageRequest.of(page == null ? 0 : page, Integer.min(pageSize == null ? maxPageSize : pageSize, maxPageSize), getDirection(defaultDir), getSortProperties(defaultSort));
	}

	/**
	 * To page request.
	 *
	 * @param maxPageSize the max page size
	 * @param sort the sort
	 * @return the pageable
	 */
	public static Pageable toPageRequest(int maxPageSize, Sort sort) {
		return PageRequest.of(0, maxPageSize, sort);
	}

	public static Pageable make(BrAPIPage page) {
		return page == null ? PageRequest.of(0, MAX_PAGE_SIZE) : page.toPageRequest();
	}
}