/*
 * 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.codec.binary;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.junit.jupiter.api.Assertions.fail;

import org.junit.jupiter.api.Test;

/**
 * Tests {@link CharSequenceUtils}.
 *
 * <p>Tests copied from Apache Commons Lang 3.11. The implementation in codec is based on
 * an earlier version of Lang and some tests fail. The CharSequenceUtils class is public but
 * the method is package private. The failing tests have been commented out and the
 * implementation left unchanged.
 */
class CharSequenceUtilsTest {

    private abstract static class RunTest {

        abstract boolean invoke();

        void run(final TestData data, final String id) {
            if (data.throwable != null) {
                final String msg = id + " Expected " + data.throwable;
                try {
                    invoke();
                    fail(msg + " but nothing was thrown.");
                } catch (final Exception ex) {
                    assertTrue(data.throwable.isAssignableFrom(ex.getClass()),
                            msg + " but was " + ex.getClass().getSimpleName());
                }
            } else {
                final boolean stringCheck = invoke();
                assertEquals(data.expected, stringCheck, id + " Failed test " + data);
            }
        }

    }

    // Note: The commented out tests fail due to the CharSequenceUtils method
    // being based on Lang 3.3.2 and the tests are from 3.11.

    static class TestData {

        final String source;
        final boolean ignoreCase;
        final int toffset;
        final String other;
        final int ooffset;
        final int len;
        final boolean expected;
        final Class<? extends Throwable> throwable;

        TestData(final String source, final boolean ignoreCase, final int toffset, final String other, final int ooffset, final int len,
                final boolean expected) {
            this.source = source;
            this.ignoreCase = ignoreCase;
            this.toffset = toffset;
            this.other = other;
            this.ooffset = ooffset;
            this.len = len;
            this.expected = expected;
            this.throwable = null;
        }

        TestData(final String source, final boolean ignoreCase, final int toffset, final String other, final int ooffset, final int len,
                final Class<? extends Throwable> throwable) {
            this.source = source;
            this.ignoreCase = ignoreCase;
            this.toffset = toffset;
            this.other = other;
            this.ooffset = ooffset;
            this.len = len;
            this.expected = false;
            this.throwable = throwable;
        }

        @Override
        public String toString() {
            final StringBuilder sb = new StringBuilder();
            sb.append(source).append("[").append(toffset).append("]");
            sb.append(ignoreCase ? " caseblind " : " samecase ");
            sb.append(other).append("[").append(ooffset).append("]");
            sb.append(" ").append(len).append(" => ");
            if (throwable != null) {
                sb.append(throwable);
            } else {
                sb.append(expected);
            }
            return sb.toString();
        }
    }

    private static final TestData[] TEST_DATA = {
            //          Source  IgnoreCase Offset Other  Offset Length Result
            //new TestData("",    true,      -1,    "",    -1,    -1,    false),
            //new TestData("",    true,      0,     "",    0,     1,     false),
            new TestData("a",   true,      0,     "abc", 0,     0,     true),
            new TestData("a",   true,      0,     "abc", 0,     1,     true),
            //new TestData("a",   true,      0,     null,  0,     0,     NullPointerException.class),
            //new TestData(null,  true,      0,     null,  0,     0,     NullPointerException.class),
            //new TestData(null,  true,      0,     "",    0,     0,     NullPointerException.class),
            new TestData("Abc", true,      0,     "abc", 0,     3,     true),
            new TestData("Abc", false,     0,     "abc", 0,     3,     false),
            new TestData("Abc", true,      1,     "abc", 1,     2,     true),
            new TestData("Abc", false,     1,     "abc", 1,     2,     true),
            new TestData("Abcd", true,      1,     "abcD", 1,     2,     true),
            new TestData("Abcd", false,     1,     "abcD", 1,     2,     true),
    };

    /**
     * Test the constructor exists. This is here for code coverage. The class ideally should
     * be package private, marked as final and have a private constructor to prevent instances.
     */
    @SuppressWarnings("unused")
    @Test
    void testConstructor() {
        new CharSequenceUtils();
    }

    @Test
    void testRegionMatches() {
        for (final TestData data : TEST_DATA) {
            new RunTest() {
                @Override
                boolean invoke() {
                    return data.source.regionMatches(data.ignoreCase, data.toffset, data.other, data.ooffset, data.len);
                }
            }.run(data, "String");
            new RunTest() {
                @Override
                boolean invoke() {
                    return CharSequenceUtils.regionMatches(data.source, data.ignoreCase, data.toffset, data.other, data.ooffset, data.len);
                }
            }.run(data, "CSString");
            new RunTest() {
                @Override
                boolean invoke() {
                    return CharSequenceUtils.regionMatches(new StringBuilder(data.source), data.ignoreCase, data.toffset, data.other, data.ooffset, data.len);
                }
            }.run(data, "CSNonString");
        }
    }
}
