/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"

#include "BlobBuilder.h"

#include "Blob.h"
#include "ExceptionCode.h"
#include "File.h"
#include "LineEnding.h"
#include "TextEncoding.h"
#include <wtf/text/AtomicString.h>

namespace WebCore {

static CString convertToCString(const String& text, const String& endingType, ExceptionCode& ec)
{
    DEFINE_STATIC_LOCAL(AtomicString, transparent, ("transparent"));
    DEFINE_STATIC_LOCAL(AtomicString, native, ("native"));

    ec = 0;

    if (endingType.isEmpty() || endingType == transparent)
        return UTF8Encoding().encode(text.characters(), text.length(), EntitiesForUnencodables);
    if (endingType == native)
        return normalizeLineEndingsToNative(UTF8Encoding().encode(text.characters(), text.length(), EntitiesForUnencodables));

    ec = SYNTAX_ERR;
    return CString();
}

static CString concatenateTwoCStrings(const CString& a, const CString& b)
{
    if (a.isNull() && b.isNull())
        return CString();

    char* q;
    CString result = CString::newUninitialized(a.length() + b.length(), q);
    if (a.length())
        memcpy(q, a.data(), a.length());
    if (b.length())
        memcpy(q + a.length(), b.data(), b.length());
    return result;
}

BlobBuilder::BlobBuilder()
    : m_size(0)
{
}

bool BlobBuilder::append(const String& text, const String& endingType, ExceptionCode& ec)
{
    CString cstr = convertToCString(text, endingType, ec);
    if (ec)
        return false;

    m_size += cstr.length();

    // If the last item is a string, concatenate it with current string.
    if (!m_items.isEmpty() && m_items[m_items.size() - 1].type == BlobDataItem::Data)
        m_items[m_items.size() - 1].data = concatenateTwoCStrings(m_items[m_items.size() - 1].data, cstr);
    else
        m_items.append(BlobDataItem(cstr));
    return true;
}

bool BlobBuilder::append(const String& text, ExceptionCode& ec)
{
    return append(text, String(), ec);
}

bool BlobBuilder::append(PassRefPtr<Blob> blob)
{
    if (blob->isFile()) {
        // If the blob is file that is not snapshoted, capture the snapshot now.
        // FIXME: This involves synchronous file operation. We need to figure out how to make it asynchronous.
        File* file = static_cast<File*>(blob.get());
        long long snapshotSize;
        double snapshotModificationTime;
        file->captureSnapshot(snapshotSize, snapshotModificationTime);

        m_size += snapshotSize;
        m_items.append(BlobDataItem(file->path(), 0, snapshotSize, snapshotModificationTime));
    } else {
        long long blobSize = static_cast<long long>(blob->size());
        m_size += blobSize;
        m_items.append(BlobDataItem(blob->url(), 0, blobSize));
    }
    return true;
}

PassRefPtr<Blob> BlobBuilder::getBlob(const String& contentType)
{
    OwnPtr<BlobData> blobData = BlobData::create();
    blobData->setContentType(contentType);
    blobData->swapItems(m_items);

    RefPtr<Blob> blob = Blob::create(blobData.release(), m_size);

    // After creating a blob from the current blob data, we do not need to keep the data around any more. Instead, we only
    // need to keep a reference to the URL of the blob just created.
    m_items.append(BlobDataItem(blob->url(), 0, m_size));

    return blob;
}

} // namespace WebCore