/*
 * 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 org.apache.nifi.processors.standard;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.HashMap;

import org.apache.nifi.util.MockFlowFile;
import org.apache.nifi.util.TestRunner;
import org.apache.nifi.util.TestRunners;

import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class TestModifyBytes {

    /*
     * ModifyBytes treats FlowFiles as binary content, not line oriented text, so the tests use byte offsets
     * and are not line oriented.  Any changes to the test data files needs to be considered based on the
     * byte offset impacts of any end-of-line changing edits.
     *
     * The test data files are assumed to be in Unix end-of-line format (i.e. LF).
     */

    private final Path testFilePath = Paths.get("src/test/resources/TestModifyBytes/testFile.txt");
    private final Path noFooterPath = Paths.get("src/test/resources/TestModifyBytes/noFooter.txt");
    private final Path noHeaderPath = Paths.get("src/test/resources/TestModifyBytes/noHeader.txt");
    private final Path noFooterNoHeaderPath = Paths.get("src/test/resources/TestModifyBytes/noFooter_noHeader.txt");

    private final File testFile = testFilePath.toFile();
    private final File noFooterFile = noFooterPath.toFile();
    private final File noHeaderFile = noHeaderPath.toFile();
    private final File noFooterNoHeaderFile = noFooterNoHeaderPath.toFile();

    @Test
    public void testReturnEmptyFile() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "1 MB");
        runner.setProperty(ModifyBytes.END_OFFSET, "1 MB");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        out.assertContentEquals("".getBytes("UTF-8"));
    }

    @Test
    public void testReturnSameFile() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "0 MB");
        runner.setProperty(ModifyBytes.END_OFFSET, "0 MB");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        out.assertContentEquals(testFile);
    }

    @Test
    public void testRemoveHeader() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "12 B"); //REMOVE - '<<<HEADER>>>'
        runner.setProperty(ModifyBytes.END_OFFSET, "0 MB");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        final String outContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
        System.out.println(outContent);
        out.assertContentEquals(noHeaderFile);
    }

    @Test
    public void testRemoveHeaderEL() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "${numBytes}"); //REMOVE - '<<<HEADER>>>'
        runner.setProperty(ModifyBytes.END_OFFSET, "0 MB");

        runner.enqueue(testFilePath, new HashMap<String, String>() {{
            put("numBytes", "12 B");
        }});
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        final String outContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
        System.out.println(outContent);
        out.assertContentEquals(noHeaderFile);
    }

    @Test
    public void testKeepFooter() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "181 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "0 B");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        final String outContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
        System.out.println(outContent);
        out.assertContentEquals("<<<FOOTER>>>".getBytes("UTF-8"));
    }

    @Test
    public void testKeepHeader() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "0 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "181 B");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        out.assertContentEquals("<<<HEADER>>>".getBytes("UTF-8"));
    }

    @Test
    public void testKeepHeaderEL() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "0 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "${numBytes}");

        runner.enqueue(testFilePath, new HashMap<String, String>() {{
            put("numBytes", "181 B");
        }});
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        out.assertContentEquals("<<<HEADER>>>".getBytes("UTF-8"));
    }

    @Test
    public void testRemoveFooter() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "0 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "12 B");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        final String outContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
        System.out.println(outContent);
        out.assertContentEquals(noFooterFile);
    }

    @Test
    public void testRemoveHeaderAndFooter() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "12 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "12 B");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        final String outContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
        System.out.println(outContent);
        out.assertContentEquals(noFooterNoHeaderFile);
    }

    @Test
    public void testReturnZeroByteFile() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "97 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "97 B");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        out.assertContentEquals("".getBytes("UTF-8"));
    }

    @Test
    public void testDew() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "94 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "96 B");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        final String outContent = new String(out.toByteArray(), StandardCharsets.UTF_8);
        System.out.println(outContent);
        out.assertContentEquals("Dew".getBytes("UTF-8"));
    }

    @Test
    public void testRemoveAllContent() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "0 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "0 B");
        runner.setProperty(ModifyBytes.REMOVE_ALL, "true");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        assertEquals(0L, out.getSize());
    }

    @Test
    public void testRemoveAllOverridesWhenSet() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "10 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "10 B");
        runner.setProperty(ModifyBytes.REMOVE_ALL, "true");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        assertEquals(0L, out.getSize());
    }

    @Test
    public void testRemoveAllNoOverridesWhenFalse() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.START_OFFSET, "10 B");
        runner.setProperty(ModifyBytes.END_OFFSET, "10 B");
        runner.setProperty(ModifyBytes.REMOVE_ALL, "false");

        runner.enqueue(testFilePath);
        runner.run();

        runner.assertAllFlowFilesTransferred(ModifyBytes.REL_SUCCESS, 1);
        final MockFlowFile out = runner.getFlowFilesForRelationship(ModifyBytes.REL_SUCCESS).get(0);
        assertEquals(testFile.length() - 20, out.getSize());
    }

    @Test
    public void testCheckAllowableValues() throws IOException {
        final TestRunner runner = TestRunners.newTestRunner(new ModifyBytes());
        runner.setProperty(ModifyBytes.REMOVE_ALL, "maybe");
        runner.assertNotValid();
        runner.setProperty(ModifyBytes.REMOVE_ALL, "true");
        runner.assertValid();
        runner.setProperty(ModifyBytes.REMOVE_ALL, "false");
        runner.assertValid();
        runner.setProperty(ModifyBytes.REMOVE_ALL, "certainly");
        runner.assertNotValid();
    }
}