/*******************************************************************************
 * Copyright (c) 2000, 2004 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
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwt.dnd.URLTransfer;

//import java.net.URL;

import dwt.internal.ole.win32.COM;
import dwt.internal.ole.win32.OBJIDL;
import dwt.internal.win32.OS;

import dwt.dnd.ByteArrayTransfer;
import dwt.dnd.TransferData;
import dwt.dnd.DND;

import dwt.dwthelper.utils;
static import tango.text.Text;
alias tango.text.Text.Text!(char) StringBuffer;

/**
 * The class <code>URLTransfer</code> provides a platform specific mechanism
 * for converting text in URL format represented as a java <code>String[]</code>
 * to a platform specific representation of the data and vice versa.  See
 * <code>Transfer</code> for additional information. The first string in the
 * array is mandatory and must contain the fully specified url.  The second
 * string in the array is optional and if present contains the title for the
 * page.
 *
 * <p>An example of a java <code>String[]</code> containing a URL is shown
 * below:</p>
 *
 * <code><pre>
 *     String[] urlData = new String[] {"http://www.eclipse.org", "Eclipse.org Main Page"};
 * </code></pre>
 */
/*public*/ class URLTransfer : ByteArrayTransfer {

    static URLTransfer _instance;
    static const String CFSTR_INETURL = "UniformResourceLocator"; //$NON-NLS-1$
    static const int CFSTR_INETURLID;

static this(){
    CFSTR_INETURLID = registerType(CFSTR_INETURL);
}

private this() {}

/**
 * Returns the singleton instance of the URLTransfer class.
 *
 * @return the singleton instance of the URLTransfer class
 */
public static URLTransfer getInstance () {
    if( _instance is null ){
        synchronized {
            if( _instance is null ){
                _instance = new URLTransfer();
            }
        }
    }
    return _instance;
}

/**
 * This implementation of <code>javaToNative</code> converts a URL and optionally a title
 * represented by a java <code>String[]</code> to a platform specific representation.
 * For additional information see <code>Transfer#javaToNative</code>.
 *
 * @param object a java <code>String[]</code> containing a URL and optionally, a title
 * @param transferData an empty <code>TransferData</code> object; this
 *  object will be filled in on return with the platform specific format of the data
 */
public void javaToNative (Object object, TransferData transferData){
    if (!checkURL(object) || !isSupportedType(transferData)) {
        DND.error(DND.ERROR_INVALID_DATA);
    }
    transferData.result = COM.E_FAIL;
    // URL is stored as a null terminated byte array
    String url = (cast(ArrayWrapperString2)object).array[0];
    int codePage = OS.GetACP();
    wchar[] chars = StrToWCHARs(codePage, url, true );
    int cchMultiByte = OS.WideCharToMultiByte(codePage, 0, chars.ptr, -1, null, 0, null, null);
    if (cchMultiByte is 0) {
        transferData.stgmedium = new STGMEDIUM();
        transferData.result = COM.DV_E_STGMEDIUM;
        return;
    }
    auto lpMultiByteStr = cast(char*)OS.GlobalAlloc(OS.GMEM_FIXED | OS.GMEM_ZEROINIT, cchMultiByte);
    OS.WideCharToMultiByte(codePage, 0, chars.ptr, -1, lpMultiByteStr, cchMultiByte, null, null);
    transferData.stgmedium = new STGMEDIUM();
    transferData.stgmedium.tymed = COM.TYMED_HGLOBAL;
    transferData.stgmedium.unionField = lpMultiByteStr;
    transferData.stgmedium.pUnkForRelease = null;
    transferData.result = COM.S_OK;
    return;
}

/**
 * This implementation of <code>nativeToJava</code> converts a platform specific
 * representation of a URL and optionally, a title to a java <code>String[]</code>.
 * For additional information see <code>Transfer#nativeToJava</code>.
 *
 * @param transferData the platform specific representation of the data to be
 * been converted
 * @return a java <code>String[]</code> containing a URL and optionally a title if the
 * conversion was successful; otherwise null
 */
public Object nativeToJava(TransferData transferData){
    if (!isSupportedType(transferData) || transferData.pIDataObject is null) return null;
    IDataObject data = transferData.pIDataObject;
    data.AddRef();
    STGMEDIUM* stgmedium = new STGMEDIUM();
    FORMATETC* formatetc = transferData.formatetc;
    stgmedium.tymed = COM.TYMED_HGLOBAL;
    transferData.result = data.GetData(formatetc, stgmedium);
    data.Release();
    if (transferData.result !is COM.S_OK) return null;
    auto hMem = stgmedium.unionField;
    try {
        auto lpMultiByteStr = cast(char*)OS.GlobalLock(hMem);
        if (lpMultiByteStr is null) return null;
        try {
            int codePage = OS.GetACP();
            int cchWideChar  = OS.MultiByteToWideChar (codePage, OS.MB_PRECOMPOSED, lpMultiByteStr, -1, null, 0);
            if (cchWideChar is 0) return null;
            wchar[] lpWideCharStr = new wchar [cchWideChar - 1];
            OS.MultiByteToWideChar (codePage, OS.MB_PRECOMPOSED, lpMultiByteStr, -1, lpWideCharStr.ptr, lpWideCharStr.length);
            return new ArrayWrapperString2( [ WCHARzToStr( lpWideCharStr.ptr) ]);
        } finally {
            OS.GlobalUnlock(hMem);
        }
    } finally {
        OS.GlobalFree(hMem);
    }
}

protected int[] getTypeIds(){
    return [CFSTR_INETURLID];
}

protected String[] getTypeNames(){
    return [CFSTR_INETURL];
}

bool checkURL(Object object) {
    if( auto s = cast(ArrayWrapperString2)object ){
        if( s.array.length is 0 ) return false;
        String[] strings = s.array;
        if (strings[0] is null || strings[0].length is 0) return false;
        //PORTING_FIXME: how to validata URL?
        /+try {
            new URL(strings[0]);
        } catch (java.net.MalformedURLException e) {
            return false;
        }+/
        return true;
    }
    return false;
}

protected bool validate(Object object) {
    return checkURL(object);
}
}