/*
 * Copyright (C) 2015-2024 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. AND ITS 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 APPLE INC. OR ITS 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.
 */

#ifndef PlatformContentFilter_h
#define PlatformContentFilter_h

#include <WebCore/SharedBuffer.h>
#include <wtf/CheckedPtr.h>
#include <wtf/Ref.h>
#include <wtf/TZoneMallocInlines.h>
#include <wtf/ThreadSafeWeakPtr.h>
#include <wtf/WeakPtr.h>
#include <wtf/text/WTFString.h>

namespace WebCore {
class PlatformContentFilter;
}

namespace WTF {
template<typename T> struct IsDeprecatedWeakRefSmartPointerException;
template<> struct IsDeprecatedWeakRefSmartPointerException<WebCore::PlatformContentFilter> : std::true_type { };
}

namespace WebCore {

class ContentFilterUnblockHandler;
class FragmentedSharedBuffer;
class ResourceRequest;
class ResourceResponse;
class SharedBuffer;

class PlatformContentFilter : public ThreadSafeRefCountedAndCanMakeThreadSafeWeakPtr<PlatformContentFilter> {
    WTF_MAKE_TZONE_ALLOCATED_INLINE(PlatformContentFilter);
    WTF_MAKE_NONCOPYABLE(PlatformContentFilter);

public:
    enum class State {
        Stopped,
        Filtering,
        Allowed,
        Blocked,
    };

    bool needsMoreData() const { return m_state == State::Filtering; }
    bool didBlockData() const { return m_state == State::Blocked; }
    bool isAllowed() const { return m_state == State::Allowed; }

    virtual ~PlatformContentFilter() = default;
    virtual bool isEnabled() const { return true; }
    virtual void willSendRequest(ResourceRequest&, const ResourceResponse&) = 0;
    virtual void willSendRequest(ResourceRequest&&, const ResourceResponse&, CompletionHandler<void(String&&)>&&) = 0;
    virtual void responseReceived(const ResourceResponse&) = 0;
    virtual void addData(const SharedBuffer&) = 0;
    virtual void finishedAddingData() = 0;
    virtual Ref<FragmentedSharedBuffer> replacementData() const = 0;
#if ENABLE(CONTENT_FILTERING)
    virtual ContentFilterUnblockHandler unblockHandler() const = 0;
#endif
    virtual String unblockRequestDeniedScript() const { return emptyString(); }

#if HAVE(AUDIT_TOKEN)
    const std::optional<audit_token_t> hostProcessAuditToken() const { return m_hostProcessAuditToken; }
    void setHostProcessAuditToken(const std::optional<audit_token_t>& token) { m_hostProcessAuditToken = token; }
#endif

    struct FilterParameters {
#if HAVE(WEBCONTENTRESTRICTIONS)
        bool usesWebContentRestrictions { false };
#endif
#if HAVE(WEBCONTENTRESTRICTIONS_PATH_SPI)
        String webContentRestrictionsConfigurationPath { };
#endif
    };

protected:
    PlatformContentFilter() = default;
#if HAVE(AUDIT_TOKEN)
    std::optional<audit_token_t> m_hostProcessAuditToken;
#endif
    State m_state { State::Filtering };
};

} // namespace WebCore

#endif // PlatformContentFilter_h
