/*
 * 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.jena.dboe.base.file;

import java.nio.ByteBuffer;

import org.junit.Assert;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public abstract class AbstractTestChannel extends Assert
{
    protected abstract BufferChannel open();

    private BufferChannel store;
    @Before public void before() { store = open(); }
    @After  public void after()  { store.close(); }

    static final int blkSize = 100;

    protected static ByteBuffer data(int len) {
        ByteBuffer b = ByteBuffer.allocate(len);
        for (int i = 0; i < len ; i++ )
            b.put((byte)(i&0xFF));
        b.clear();
        return b;
    }

    protected static boolean same(ByteBuffer bb1, ByteBuffer bb2) {
        if ( bb1.capacity() != bb2.capacity() ) return false;
        bb1.clear();
        bb2.clear();
        for ( int i = 0; i < bb1.capacity() ; i++ )
            if ( bb1.get(i) != bb2.get(i) ) return false;
        return true;
    }

    @Test public void storage_01() {
        assertEquals(0, store.size());
    }

    @Test public void storage_02() {
        ByteBuffer b = data(blkSize);
        store.write(b);
        long x = store.size();
        assertEquals(blkSize, x);
    }

    @Test public void storage_03() {
        ByteBuffer b1 = data(blkSize);
        long posn = store.position();
        store.write(b1);
        ByteBuffer b9 = ByteBuffer.allocate(blkSize);
        int r = store.read(b9, posn);
        assertEquals(blkSize, r);
        assertTrue(same(b1, b9));
    }

    @Test public void storage_04() {
        ByteBuffer b1 = data(blkSize);
        ByteBuffer b2 = data(blkSize/2);

        store.write(b2, 0);
        store.write(b1, 0);

        assertEquals(blkSize, store.size());
        ByteBuffer b9 = ByteBuffer.allocate(5);
        int z = store.read(b9);
        assertEquals(5, z);
    }

    @Test public void storage_05() {
        ByteBuffer b1 = data(blkSize);
        ByteBuffer b1a = ByteBuffer.allocate(blkSize);
        ByteBuffer b2 = data(blkSize/2);
        ByteBuffer b2a = ByteBuffer.allocate(blkSize/2);
        store.write(b1);
        store.write(b2);
        store.position(0);
        store.read(b1a);
        assertTrue(same(b1, b1a));
        store.read(b2a);
        assertTrue(same(b2, b2a));
    }

    @Test public void storage_06() {
        ByteBuffer b1 = data(blkSize);
        store.write(b1);
        store.truncate(0);
        assertEquals(0, store.size());
        // Check for:
        // http://bugs.sun.com/view_bug.do?bug_id=6191269
        assertEquals(0, store.position());
    }

    @Test public void storage_07() {
        ByteBuffer b1 = data(blkSize);
        store.write(b1);
        store.position(10);
        b1.rewind();
        store.write(b1);
        assertEquals(blkSize+10, store.size());
    }

    @Test public void storage_08() {
        ByteBuffer b1 = data(blkSize);
        ByteBuffer b2 = data(blkSize);
        store.write(b1);
        store.write(b2);
        store.position(10);
        b1.rewind();
        store.write(b1);
        assertEquals(2*blkSize, store.size());
    }

}
