/*
 * Copyright 2002-2019 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.beans.propertyeditors;

import java.beans.PropertyEditorSupport;

import org.springframework.lang.Nullable;
import org.springframework.util.ObjectUtils;
import org.springframework.util.StringUtils;

/**
 * Custom {@link java.beans.PropertyEditor} for String arrays.
 *
 * <p>Strings must be in CSV format, with a customizable separator.
 * By default values in the result are trimmed of whitespace.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @author Dave Syer
 * @see org.springframework.util.StringUtils#delimitedListToStringArray
 * @see org.springframework.util.StringUtils#arrayToDelimitedString
 */
public class StringArrayPropertyEditor extends PropertyEditorSupport {

        /**
         * Default separator for splitting a String: a comma (",").
         */
        public static final String DEFAULT_SEPARATOR = ",";


        private final String separator;

        @Nullable
        private final String charsToDelete;

        private final boolean emptyArrayAsNull;

        private final boolean trimValues;


        /**
         * Create a new {@code StringArrayPropertyEditor} with the default separator
         * (a comma).
         * <p>An empty text (without elements) will be turned into an empty array.
         */
        public StringArrayPropertyEditor() {
                this(DEFAULT_SEPARATOR, null, false);
        }

        /**
         * Create a new {@code StringArrayPropertyEditor} with the given separator.
         * <p>An empty text (without elements) will be turned into an empty array.
         * @param separator the separator to use for splitting a {@link String}
         */
        public StringArrayPropertyEditor(String separator) {
                this(separator, null, false);
        }

        /**
         * Create a new {@code StringArrayPropertyEditor} with the given separator.
         * @param separator the separator to use for splitting a {@link String}
         * @param emptyArrayAsNull {@code true} if an empty String array
         * is to be transformed into {@code null}
         */
        public StringArrayPropertyEditor(String separator, boolean emptyArrayAsNull) {
                this(separator, null, emptyArrayAsNull);
        }

        /**
         * Create a new {@code StringArrayPropertyEditor} with the given separator.
         * @param separator the separator to use for splitting a {@link String}
         * @param emptyArrayAsNull {@code true} if an empty String array
         * is to be transformed into {@code null}
         * @param trimValues {@code true} if the values in the parsed arrays
         * are to be trimmed of whitespace (default is true)
         */
        public StringArrayPropertyEditor(String separator, boolean emptyArrayAsNull, boolean trimValues) {
                this(separator, null, emptyArrayAsNull, trimValues);
        }

        /**
         * Create a new {@code StringArrayPropertyEditor} with the given separator.
         * @param separator the separator to use for splitting a {@link String}
         * @param charsToDelete a set of characters to delete, in addition to
         * trimming an input String. Useful for deleting unwanted line breaks:
         * e.g. "\r\n\f" will delete all new lines and line feeds in a String.
         * @param emptyArrayAsNull {@code true} if an empty String array
         * is to be transformed into {@code null}
         */
        public StringArrayPropertyEditor(String separator, @Nullable String charsToDelete, boolean emptyArrayAsNull) {
                this(separator, charsToDelete, emptyArrayAsNull, true);
        }

        /**
         * Create a new {@code StringArrayPropertyEditor} with the given separator.
         * @param separator the separator to use for splitting a {@link String}
         * @param charsToDelete a set of characters to delete, in addition to
         * trimming an input String. Useful for deleting unwanted line breaks:
         * e.g. "\r\n\f" will delete all new lines and line feeds in a String.
         * @param emptyArrayAsNull {@code true} if an empty String array
         * is to be transformed into {@code null}
         * @param trimValues {@code true} if the values in the parsed arrays
         * are to be trimmed of whitespace (default is true)
         */
        public StringArrayPropertyEditor(
                        String separator, @Nullable String charsToDelete, boolean emptyArrayAsNull, boolean trimValues) {

                this.separator = separator;
                this.charsToDelete = charsToDelete;
                this.emptyArrayAsNull = emptyArrayAsNull;
                this.trimValues = trimValues;
        }

        @Override
        public void setAsText(String text) throws IllegalArgumentException {
                String[] array = StringUtils.delimitedListToStringArray(text, this.separator, this.charsToDelete);
                if (this.emptyArrayAsNull && array.length == 0) {
                        setValue(null);
                }
                else {
                        if (this.trimValues) {
                                array = StringUtils.trimArrayElements(array);
                        }
                        setValue(array);
                }
        }

        @Override
        public String getAsText() {
                return StringUtils.arrayToDelimitedString(ObjectUtils.toObjectArray(getValue()), this.separator);
        }

}