/*******************************************************************************
 * Copyright (c) 2003, 2007 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
module dwt.browser.InputStream;

import dwt.dwthelper.utils;

import dwt.internal.C;
import dwt.internal.mozilla.XPCOM;
import dwt.internal.mozilla.XPCOMObject;
import dwt.internal.mozilla.nsID;
import dwt.internal.mozilla.nsIInputStream;
import dwt.internal.mozilla.nsISupports;

class InputStream {
    XPCOMObject inputStream;
    int refCount = 0;

    byte[] buffer;
    int index = 0;
    
this (byte[] buffer) {
    this.buffer = buffer;
    index = 0;
    createCOMInterfaces ();
}

int AddRef () {
    refCount++;
    return refCount;
}

void createCOMInterfaces () {
    /* Create each of the interfaces that this object implements */
    inputStream = new XPCOMObject (new int[] {2, 0, 0, 0, 1, 3, 4, 1}) {
        public int /*long*/ method0 (int /*long*/[] args) {return QueryInterface (args[0], args[1]);}
        public int /*long*/ method1 (int /*long*/[] args) {return AddRef ();}
        public int /*long*/ method2 (int /*long*/[] args) {return Release ();}
        public int /*long*/ method3 (int /*long*/[] args) {return Close ();}
        public int /*long*/ method4 (int /*long*/[] args) {return Available (args[0]);}
        public int /*long*/ method5 (int /*long*/[] args) {return Read (args[0], cast(int)/*64*/args[1], args[2]);}
        public int /*long*/ method6 (int /*long*/[] args) {return ReadSegments (args[0], args[1], cast(int)/*64*/args[2], args[3]);}
        public int /*long*/ method7 (int /*long*/[] args) {return IsNonBlocking (args[0]);}
    };
}

void disposeCOMInterfaces () {
    if (inputStream !is null) {
        inputStream.dispose ();
        inputStream = null; 
    }
}

int /*long*/ getAddress () {
    return inputStream.getAddress ();
}

int QueryInterface (int /*long*/ riid, int /*long*/ ppvObject) {
    if (riid is 0 || ppvObject is 0) return XPCOM.NS_ERROR_NO_INTERFACE;
    nsID guid = new nsID ();
    XPCOM.memmove (guid, riid, nsID.sizeof);
    
    if (guid.Equals (nsISupports.NS_ISUPPORTS_IID)) {
        XPCOM.memmove (ppvObject, new int /*long*/[] {inputStream.getAddress ()}, C.PTR_SIZEOF);
        AddRef ();
        return XPCOM.NS_OK;
    }
    if (guid.Equals (nsIInputStream.NS_IINPUTSTREAM_IID)) {
        XPCOM.memmove (ppvObject, new int /*long*/[] {inputStream.getAddress ()}, C.PTR_SIZEOF);
        AddRef ();
        return XPCOM.NS_OK;
    }   
    XPCOM.memmove (ppvObject, new int /*long*/[] {0}, C.PTR_SIZEOF);
    return XPCOM.NS_ERROR_NO_INTERFACE;
}
            
int Release () {
    refCount--;
    if (refCount is 0) disposeCOMInterfaces ();
    return refCount;
}
    
/* nsIInputStream implementation */

int Close () {
    buffer = null;
    index = 0;
    return XPCOM.NS_OK;
}

int Available (int /*long*/ _retval) {
    int available = buffer is null ? 0 : buffer.length - index;
    XPCOM.memmove (_retval, new int[] {available}, 4);
    return XPCOM.NS_OK;
}

int Read(int /*long*/ aBuf, int aCount, int /*long*/ _retval) {
    int max = Math.min (aCount, buffer is null ? 0 : buffer.length - index);
    if (max > 0) {
        byte[] src = new byte[max];
        System.arraycopy (buffer, index, src, 0, max);
        XPCOM.memmove (aBuf, src, max);
        index += max;
    }
    XPCOM.memmove(_retval, new int[] {max}, 4);
    return XPCOM.NS_OK;
}

int ReadSegments (int /*long*/ aWriter, int /*long*/ aClosure, int aCount, int /*long*/ _retval) {
    int max = Math.min (aCount, buffer is null ? 0 : buffer.length - index);
    int cnt = max;
    while (cnt > 0) {
        int[] aWriteCount = new int[1];
        int /*long*/ rc = XPCOM.Call (aWriter, getAddress (), aClosure, buffer, index, cnt, aWriteCount);
        if (rc !is XPCOM.NS_OK) break;
        index += aWriteCount[0];
        cnt -= aWriteCount[0];
    }
    XPCOM.memmove (_retval, new int[] {max - cnt}, 4);
    return XPCOM.NS_OK;
}

int IsNonBlocking (int /*long*/ _retval) {
    /* blocking */
    XPCOM.memmove (_retval, new int[] {0}, 4);
    return XPCOM.NS_OK;
}       
}