/*

 * Copyright (C) 2008 Apple 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:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. 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.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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 "IconFetcher.h"

#include "Frame.h"

#include "HTMLHeadElement.h"

#include "HTMLLinkElement.h"

#include "HTMLNames.h"

#include "ResourceHandle.h"

#include "ResourceRequest.h"

#include "SharedBuffer.h"

namespace WebCore {

using namespace HTMLNames;

struct IconLinkEntry {

public:

    enum IconType {

        Unknown,

        ICNS,

        ICO,

    };

    IconLinkEntry(IconType type, const KURL& url) 

        : m_type(type)

        , m_url(url)

    {

    }

    IconType type() const { return m_type; }

    const KURL& url() const { return m_url; }

    SharedBuffer* buffer() 

    {

        if (!m_buffer)

            m_buffer = SharedBuffer::create();

        return m_buffer.get();

    }

private:

    RefPtr<SharedBuffer> m_buffer;

    IconType m_type;

    KURL m_url;

};

#if PLATFORM(MAC)

static const IconLinkEntry::IconType NativeIconType = IconLinkEntry::ICNS;

#elif PLATFORM(WIN)

static const IconLinkEntry::IconType NativeIconType = IconLinkEntry::ICO;

#else

static const IconLinkEntry::IconType NativeIconType = IconLinkEntry::Unknown;

#endif

static void parseIconLink(HTMLLinkElement* link, Vector<IconLinkEntry>& entries)

{

    // FIXME: Parse the size attribute too.

    IconLinkEntry::IconType type = IconLinkEntry::Unknown;

    const KURL& url = link->href();

    // Try to determine the file type.

    String path = url.path();

    int pos = path.reverseFind('.');

    if (pos >= 0) {

        String extension = path.substring(pos + 1);

        if (equalIgnoringCase(extension, "icns"))

            type = IconLinkEntry::ICNS;

        else if (equalIgnoringCase(extension, "ico"))

            type = IconLinkEntry::ICO;

    }

    entries.append(IconLinkEntry(type, url));

}

PassRefPtr<IconFetcher> IconFetcher::create(Frame* frame, IconFetcherClient* client)

{

    Document* document = frame->document();

    HTMLHeadElement* head = document->head();

    if (!head)

        return 0;

    Vector<IconLinkEntry> entries;

    for (Node* n = head; n; n = n->traverseNextNode()) {

        if (!n->hasTagName(linkTag))    

            continue;

        HTMLLinkElement* link = static_cast<HTMLLinkElement*>(n);

        if (!link->isIcon())

            continue;

        parseIconLink(link, entries);

    }

    if (entries.isEmpty())

        return 0;

    // Check if any of the entries have the same type as the native icon type.

    // FIXME: This should be way more sophisticated, and handle conversion

    // of multisize formats for example.

    for (unsigned i = 0; i < entries.size(); i++) {

        const IconLinkEntry& entry = entries[i];

        if (entry.type() == NativeIconType) {

            RefPtr<IconFetcher> iconFetcher = adoptRef(new IconFetcher(frame, client));

            iconFetcher->m_entries.append(entry);

            iconFetcher->loadEntry();

            return iconFetcher.release();

        }

    }

    return 0;

}    

IconFetcher::IconFetcher(Frame* frame, IconFetcherClient* client)

    : m_frame(frame)

    , m_client(client)

    , m_currentEntry(0)

{

}

IconFetcher::~IconFetcher()

{

    cancel();

}

void IconFetcher::cancel()

{

    if (m_handle)

        m_handle->cancel();

}

PassRefPtr<SharedBuffer> IconFetcher::createIcon()

{

    ASSERT(!m_entries.isEmpty());

    // For now, just return the data of the first entry.

    return m_entries.first().buffer();

}

void IconFetcher::loadEntry()

{

    ASSERT(m_currentEntry < m_entries.size());

    ASSERT(!m_handle);

    m_handle = ResourceHandle::create(m_entries[m_currentEntry].url(), this, m_frame, false, false);

}

void IconFetcher::loadFailed()

{

    m_handle = 0;

    m_client->finishedFetchingIcon(0);

}    

void IconFetcher::didReceiveResponse(ResourceHandle* handle, const ResourceResponse& response)

{

    ASSERT_UNUSED(handle, m_handle == handle);

    int statusCode = response.httpStatusCode() / 100;

    if (statusCode == 4 || statusCode == 5) {

        loadFailed();

        return;

    }    

}

void IconFetcher::didReceiveData(ResourceHandle* handle, const char* data, int length, int)

{

    ASSERT_UNUSED(handle, m_handle == handle);

    m_entries[m_currentEntry].buffer()->append(data, length);

}

void IconFetcher::didFinishLoading(ResourceHandle* handle)

{

    ASSERT_UNUSED(handle, m_handle == handle);

    if (m_currentEntry == m_entries.size() - 1) {

        // We finished loading, create the icon

        RefPtr<SharedBuffer> iconData = createIcon();

        m_client->finishedFetchingIcon(iconData.release());

        return;

    }

    // Load the next entry

    m_currentEntry++;

    loadEntry();

}

void IconFetcher::didFail(ResourceHandle* handle, const ResourceError&)

{

    ASSERT_UNUSED(handle, m_handle == handle);

    loadFailed();

}

} // namespace WebCore