/*
 * 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
 *
 *   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.apache.commons.csv.issues;

import static org.junit.jupiter.api.Assertions.assertThrows;

import java.io.IOException;
import java.io.StringReader;

import org.apache.commons.csv.CSVFormat;
import org.apache.commons.csv.CSVParser;
import org.apache.commons.csv.DuplicateHeaderMode;
import org.junit.jupiter.api.Test;

/**
 * When {@link CSVFormat#withHeader(String...)} is not null; duplicate headers
 * with empty strings should not be allowed.
 *
 * @see <a href="https://issues.apache.org/jira/browse/CSV-264">Jira Ticker</a>
 */
class JiraCsv264Test {

    private static final String CSV_STRING = "\"\",\"B\",\"\"\n" +
                                             "\"1\",\"2\",\"3\"\n" +
                                             "\"4\",\"5\",\"6\"";

    /**
     * A CSV file with a random gap in the middle.
     */
    private static final String CSV_STRING_GAP = "\"A\",\"B\",\"\",\"\",\"E\"\n" +
                                                 "\"1\",\"2\",\"\",\"\",\"5\"\n" +
                                                 "\"6\",\"7\",\"\",\"\",\"10\"";

    @Test
    void testJiraCsv264() {
        final CSVFormat csvFormat = CSVFormat.DEFAULT
            .builder()
            .setHeader()
            .setDuplicateHeaderMode(DuplicateHeaderMode.DISALLOW)
            .setAllowMissingColumnNames(true)
            .get();
        try (StringReader reader = new StringReader(CSV_STRING)) {
            assertThrows(IllegalArgumentException.class, () -> csvFormat.parse(reader));
        }
    }

    @Test
    void testJiraCsv264WithGapAllowEmpty() throws IOException {
        final CSVFormat csvFormat = CSVFormat.DEFAULT
            .builder()
            .setHeader()
            .setDuplicateHeaderMode(DuplicateHeaderMode.ALLOW_EMPTY)
            .setAllowMissingColumnNames(true)
            .get();
        try (StringReader reader = new StringReader(CSV_STRING_GAP); CSVParser parser = csvFormat.parse(reader)) {
            // empty
        }
    }

    @Test
    void testJiraCsv264WithGapDisallow() {
        final CSVFormat csvFormat = CSVFormat.DEFAULT
            .builder()
            .setHeader()
            .setDuplicateHeaderMode(DuplicateHeaderMode.DISALLOW)
            .setAllowMissingColumnNames(true)
            .get();
        try (StringReader reader = new StringReader(CSV_STRING_GAP)) {
            assertThrows(IllegalArgumentException.class, () -> csvFormat.parse(reader));
        }
    }
}
