package org.apidesign.delegatingwriter;

import java.io.IOException;

import java.io.StringWriter;

import java.io.StringWriter;

import org.junit.Before;

import org.junit.Test;

import static org.junit.Assert.*;

/** Emulates what goes wrong when delegating directly

 *

 * @author Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 */

public class BufferedWriterCryptoTest {

    private StringWriter writer;

    private String fromCode;

    private String toCode;

    public BufferedWriterCryptoTest() {

    }

    @Before

    public void setUp() {

        writer = new StringWriter();

        StringBuffer f = new StringBuffer();

        StringBuffer t = new StringBuffer();

        for (int i = 0; i < 500; i++) {

            f.append("VMS");

            t.append("WNT");

        }

        fromCode = f.toString();

        toCode = t.toString();

    }

    @Test

    public void testBehaviourOfRealBufferInJDKWorksFine() throws IOException {

        // BEGIN: writer.crypto.ok

        CryptoWriter bufferedWriter = new CryptoWriter(writer);

        bufferedWriter.append("VMS");

        bufferedWriter.flush();

        assertEquals("Converted", "WNT", writer.toString());

        // END: writer.crypto.ok

    }

    @Test

    public void testBehaviourOfRealBufferInJDKWorksFineOnLongSentences() throws IOException {

        CryptoWriter bufferedWriter = new CryptoWriter(writer);

        bufferedWriter.append(fromCode);

        bufferedWriter.flush();

        assertEquals("Converted", toCode, writer.toString());

    }

    @Test

    public void testBehaviourOfBufferThatDelegatesToAppendFails() throws IOException {

        CryptoWriter bufferedWriter = new CryptoWriter(writer, CryptoWriter.Behaviour.DELEGATE_TO_OUT);

        bufferedWriter.append(fromCode);

        bufferedWriter.flush();

        assertEquals("This will fail, as the direct delegation from append to " +

            "the underlaying writer will skip all the crypto methods", 

            toCode, writer.toString()

        );

    }

    @Test

    public void testBehaviourWhenDelegatingConditionallyIsOK() throws IOException {

        CryptoWriter bufferedWriter = new CryptoWriter(writer, AltBufferedWriter.Behaviour.DELEGATE_CONDITIONALLY);

        bufferedWriter.append("VMS");

        bufferedWriter.flush();

        assertEquals("Converted", "WNT", writer.toString());

    }

}