/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
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 * decision by deleting the provisions above and replace them with the notice
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 * ***** END LICENSE BLOCK ***** */

#include "nsScriptableInputStream.h"
#include "nsMemory.h"
#include "nsString.h"

NS_IMPL_ISUPPORTS1(nsScriptableInputStream, nsIScriptableInputStream)

// nsIBaseStream methods
NS_IMETHODIMP
nsScriptableInputStream::Close(void) {
    if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
    return mInputStream->Close();
}

// nsIScriptableInputStream methods
NS_IMETHODIMP
nsScriptableInputStream::Init(nsIInputStream *aInputStream) {
    if (!aInputStream) return NS_ERROR_NULL_POINTER;
    mInputStream = aInputStream;
    return NS_OK;
}

NS_IMETHODIMP
nsScriptableInputStream::Available(PRUint32 *_retval) {
    if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
    return mInputStream->Available(_retval);
}

NS_IMETHODIMP
nsScriptableInputStream::Read(PRUint32 aCount, char **_retval) {
    nsresult rv = NS_OK;
    PRUint32 count = 0;
    char *buffer = nsnull;

    if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;

    rv = mInputStream->Available(&count);
    if (NS_FAILED(rv)) return rv;

    count = PR_MIN(count, aCount);
    buffer = (char*)nsMemory::Alloc(count+1); // make room for '\0'
    if (!buffer) return NS_ERROR_OUT_OF_MEMORY;

    PRUint32 amtRead = 0;
    rv = mInputStream->Read(buffer, count, &amtRead);
    if (NS_FAILED(rv)) {
        nsMemory::Free(buffer);
        return rv;
    }

    buffer[amtRead] = '\0';
    *_retval = buffer;
    return NS_OK;
}

NS_IMETHODIMP
nsScriptableInputStream::ReadBytes(PRUint32 aCount, nsACString &_retval) {
    if (!mInputStream) {
      return NS_ERROR_NOT_INITIALIZED;
    }

    _retval.SetLength(aCount);
    if (_retval.Length() != aCount) {
      return NS_ERROR_OUT_OF_MEMORY;
    }

    char *ptr = _retval.BeginWriting();
    PRUint32 totalBytesRead = 0;
    while (1) {
      PRUint32 bytesRead;
      nsresult rv = mInputStream->Read(ptr + totalBytesRead,
                                       aCount - totalBytesRead,
                                       &bytesRead);
      if (NS_FAILED(rv)) {
        return rv;
      }

      totalBytesRead += bytesRead;
      if (totalBytesRead == aCount) {
        break;
      }

      // If we have read zero bytes, we have hit EOF.
      if (bytesRead == 0) {
        _retval.Truncate();
        return NS_ERROR_FAILURE;
      }

    }
    return NS_OK;
}

nsresult
nsScriptableInputStream::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult) {
    if (aOuter) return NS_ERROR_NO_AGGREGATION;

    nsScriptableInputStream *sis = new nsScriptableInputStream();
    if (!sis) return NS_ERROR_OUT_OF_MEMORY;

    NS_ADDREF(sis);
    nsresult rv = sis->QueryInterface(aIID, aResult);
    NS_RELEASE(sis);
    return rv;
}
