/*
This file is part of jpcsp.

Jpcsp is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Jpcsp is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Jpcsp.  If not, see <http://www.gnu.org/licenses/>.
 */
package jpcsp.HLE.modules;

import jpcsp.HLE.HLEFunction;
import jpcsp.HLE.HLEModule;
import jpcsp.HLE.Modules;
import jpcsp.HLE.TPointer;
import jpcsp.memory.IMemoryReader;
import jpcsp.memory.MemoryReader;
import jpcsp.util.Utilities;
import org.apache.log4j.Logger;

import java.util.zip.Adler32;

public class sceAdler extends HLEModule {
    public static Logger log = Modules.getLogger("sceAdler");
    // Do not use the JDK Adler32 implementation as we need to specify the initial checksum value.
    // This value is always forced to 1 in the JDK Adler32 implementation.
    protected Adler32 adler32;

    @Override
    public void start() {
        adler32 = new Adler32();

        super.start();
    }

    @Override
    public void stop() {
        adler32 = null;

        super.stop();
    }

    @HLEFunction(nid = 0x9702EF11, version = 150)
    public int sceAdler32(int adler, TPointer data, int length) {
        if (log.isTraceEnabled()) {
            log.trace(String.format("sceAdler32 data:%s", Utilities.getMemoryDump(data.getAddress(), length)));
        }

        byte[] b = new byte[length];
        IMemoryReader memoryReader = MemoryReader.getMemoryReader(data.getAddress(), length, 1);
        for (int i = 0; i < length; i++) {
            b[i] = (byte) memoryReader.readNext();
        }

        adler32.reset();
        adler32.update(adler);
        adler32.update(b);
        int result = (int) adler32.getValue();

        if (log.isDebugEnabled()) {
            log.debug(String.format("sceAdler32 returning 0x%08X", result));
        }

        return result;
    }
}