/*
  ==============================================================================

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

   THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
   WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.

  ==============================================================================
*/

struct CameraDevice::Pimpl
{
    Pimpl (CameraDevice& ownerToUse, const String& deviceNameToUse, int /*index*/,
           int /*minWidth*/, int /*minHeight*/,
           int /*maxWidth*/, int /*maxHeight*/,
           bool useHighQuality)
        : owner (ownerToUse),
          deviceName (deviceNameToUse)
    {
        imageOutput = []() -> std::unique_ptr<ImageOutputBase>
        {
            if (@available (macOS 10.15, *))
                return std::make_unique<PostCatalinaPhotoOutput>();

           return std::make_unique<PreCatalinaStillImageOutput>();
        }();

        session = [[AVCaptureSession alloc] init];

        session.sessionPreset = useHighQuality ? AVCaptureSessionPresetHigh
                                               : AVCaptureSessionPresetMedium;

        refreshConnections();

        static DelegateClass cls;
        callbackDelegate = (id<AVCaptureFileOutputRecordingDelegate>) [cls.createInstance() init];
        DelegateClass::setOwner (callbackDelegate, this);

        JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wundeclared-selector")
        [[NSNotificationCenter defaultCenter] addObserver: callbackDelegate
                                                 selector: @selector (captureSessionRuntimeError:)
                                                     name: AVCaptureSessionRuntimeErrorNotification
                                                   object: session];
        JUCE_END_IGNORE_WARNINGS_GCC_LIKE
    }

    ~Pimpl()
    {
        [[NSNotificationCenter defaultCenter] removeObserver: callbackDelegate];

        [session stopRunning];
        removeInput();
        removeImageCapture();
        removeMovieCapture();
        [session release];
        [callbackDelegate release];
    }

    //==============================================================================
    bool openedOk() const noexcept       { return openingError.isEmpty(); }

    void startSession()
    {
        if (! [session isRunning])
            [session startRunning];
    }

    void takeStillPicture (std::function<void (const Image&)> pictureTakenCallbackToUse)
    {
        if (pictureTakenCallbackToUse == nullptr)
        {
            jassertfalse;
            return;
        }

        pictureTakenCallback = std::move (pictureTakenCallbackToUse);

        triggerImageCapture();
    }

    void startRecordingToFile (const File& file, int /*quality*/)
    {
        stopRecording();
        refreshIfNeeded();
        firstPresentationTime = Time::getCurrentTime();
        file.deleteFile();

        startSession();
        isRecording = true;
        [fileOutput startRecordingToOutputFileURL: createNSURLFromFile (file)
                                recordingDelegate: callbackDelegate];
    }

    void stopRecording()
    {
        if (isRecording)
        {
            [fileOutput stopRecording];
            isRecording = false;
        }
    }

    Time getTimeOfFirstRecordedFrame() const
    {
        return firstPresentationTime;
    }

    void addListener (CameraDevice::Listener* listenerToAdd)
    {
        const ScopedLock sl (listenerLock);
        listeners.add (listenerToAdd);

        if (listeners.size() == 1)
            triggerImageCapture();
    }

    void removeListener (CameraDevice::Listener* listenerToRemove)
    {
        const ScopedLock sl (listenerLock);
        listeners.remove (listenerToRemove);
    }

    static NSArray* getCaptureDevices()
    {
        if (@available (macOS 10.15, *))
        {
            JUCE_BEGIN_IGNORE_DEPRECATION_WARNINGS
            const auto deviceType = AVCaptureDeviceTypeExternalUnknown;
            JUCE_END_IGNORE_DEPRECATION_WARNINGS

            auto* discovery = [AVCaptureDeviceDiscoverySession discoverySessionWithDeviceTypes: @[AVCaptureDeviceTypeBuiltInWideAngleCamera, deviceType]
                                                                                     mediaType: AVMediaTypeVideo
                                                                                      position: AVCaptureDevicePositionUnspecified];

            return [discovery devices];
        }

        JUCE_BEGIN_IGNORE_DEPRECATION_WARNINGS
        return [AVCaptureDevice devicesWithMediaType: AVMediaTypeVideo];
        JUCE_END_IGNORE_DEPRECATION_WARNINGS
    }

    static StringArray getAvailableDevices()
    {
        StringArray results;

        for (AVCaptureDevice* device : getCaptureDevices())
            results.add (nsStringToJuce ([device localizedName]));

        return results;
    }

    AVCaptureSession* getCaptureSession()
    {
        return session;
    }

    NSView* createVideoCapturePreview()
    {
        // The video preview must be created before the capture session is
        // started. Make sure you haven't called `addListener`,
        // `startRecordingToFile`, or `takeStillPicture` before calling this
        // function.
        jassert (! [session isRunning]);
        startSession();

        JUCE_AUTORELEASEPOOL
        {
            NSView* view = [[NSView alloc] init];
            [view setLayer: [AVCaptureVideoPreviewLayer layerWithSession: getCaptureSession()]];
            return view;
        }
    }

private:
    //==============================================================================
    struct DelegateClass  : public ObjCClass<NSObject>
    {
        DelegateClass()  : ObjCClass<NSObject> ("JUCECameraDelegate_")
        {
            addIvar<Pimpl*> ("owner");
            addProtocol (@protocol (AVCaptureFileOutputRecordingDelegate));

            addMethod (@selector (captureOutput:didStartRecordingToOutputFileAtURL:  fromConnections:),       didStartRecordingToOutputFileAtURL);
            addMethod (@selector (captureOutput:didPauseRecordingToOutputFileAtURL:  fromConnections:),       didPauseRecordingToOutputFileAtURL);
            addMethod (@selector (captureOutput:didResumeRecordingToOutputFileAtURL: fromConnections:),       didResumeRecordingToOutputFileAtURL);
            addMethod (@selector (captureOutput:willFinishRecordingToOutputFileAtURL:fromConnections:error:), willFinishRecordingToOutputFileAtURL);

            JUCE_BEGIN_IGNORE_WARNINGS_GCC_LIKE ("-Wundeclared-selector")
            addMethod (@selector (captureSessionRuntimeError:), sessionRuntimeError);
            JUCE_END_IGNORE_WARNINGS_GCC_LIKE

            registerClass();
        }

        static void setOwner (id self, Pimpl* owner)   { object_setInstanceVariable (self, "owner", owner); }
        static Pimpl& getOwner (id self)               { return *getIvar<Pimpl*> (self, "owner"); }

    private:
        static void didStartRecordingToOutputFileAtURL (id, SEL, AVCaptureFileOutput*, NSURL*, NSArray*) {}
        static void didPauseRecordingToOutputFileAtURL (id, SEL, AVCaptureFileOutput*, NSURL*, NSArray*) {}
        static void didResumeRecordingToOutputFileAtURL (id, SEL, AVCaptureFileOutput*, NSURL*, NSArray*) {}
        static void willFinishRecordingToOutputFileAtURL (id, SEL, AVCaptureFileOutput*, NSURL*, NSArray*, NSError*) {}

        static void sessionRuntimeError (id self, SEL, NSNotification* notification)
        {
            JUCE_CAMERA_LOG (nsStringToJuce ([notification description]));

            NSError* error = [notification.userInfo objectForKey: AVCaptureSessionErrorKey];
            auto errorString = error != nil ? nsStringToJuce (error.localizedDescription) : String();
            getOwner (self).cameraSessionRuntimeError (errorString);
        }
    };

    //==============================================================================
    struct ImageOutputBase
    {
        virtual ~ImageOutputBase() = default;

        virtual void addImageCapture (AVCaptureSession*) = 0;
        virtual void removeImageCapture (AVCaptureSession*) = 0;
        virtual NSArray<AVCaptureConnection*>* getConnections() const = 0;
        virtual void triggerImageCapture (Pimpl& p) = 0;
    };

    class API_AVAILABLE (macos (10.15)) PostCatalinaPhotoOutput  : public ImageOutputBase
    {
    public:
        PostCatalinaPhotoOutput()
        {
            static PhotoOutputDelegateClass cls;
            delegate.reset ([cls.createInstance() init]);
        }

        void addImageCapture (AVCaptureSession* s) override
        {
            if (imageOutput != nil)
                return;

            imageOutput = [[AVCapturePhotoOutput alloc] init];
            [s addOutput: imageOutput];
        }

        void removeImageCapture (AVCaptureSession* s) override
        {
            if (imageOutput == nil)
                return;

            [s removeOutput: imageOutput];
            [imageOutput release];
            imageOutput = nil;
        }

        NSArray<AVCaptureConnection*>* getConnections() const override
        {
            if (imageOutput != nil)
                return imageOutput.connections;

            return nil;
        }

        void triggerImageCapture (Pimpl& p) override
        {
            if (imageOutput == nil)
                return;

            PhotoOutputDelegateClass::setOwner (delegate.get(), &p);

            [imageOutput capturePhotoWithSettings: [AVCapturePhotoSettings photoSettings]
                                         delegate: delegate.get()];
        }

    private:
        class PhotoOutputDelegateClass : public ObjCClass<NSObject<AVCapturePhotoCaptureDelegate>>
        {
        public:
            PhotoOutputDelegateClass()
                : ObjCClass ("PhotoOutputDelegateClass_")
            {
                addMethod (@selector (captureOutput:didFinishProcessingPhoto:error:), [] (id self, SEL, AVCapturePhotoOutput*, AVCapturePhoto* photo, NSError* error)
                {
                    if (error != nil)
                    {
                        [[maybe_unused]] String errorString = error != nil ? nsStringToJuce (error.localizedDescription) : String();

                        JUCE_CAMERA_LOG ("Still picture capture failed, error: " + errorString);
                        jassertfalse;

                        return;
                    }

                    auto* imageData = [photo fileDataRepresentation];
                    auto image = ImageFileFormat::loadFrom (imageData.bytes, (size_t) imageData.length);

                    getOwner (self).imageCaptureFinished (image);
                });

                addIvar<Pimpl*> ("owner");
                registerClass();
            }

            static Pimpl& getOwner (id self) { return *getIvar<Pimpl*> (self, "owner"); }
            static void setOwner (id self, Pimpl* t) { object_setInstanceVariable (self, "owner", t); }
        };

        AVCapturePhotoOutput* imageOutput = nil;
        NSUniquePtr<NSObject<AVCapturePhotoCaptureDelegate>> delegate;
    };

    JUCE_BEGIN_IGNORE_DEPRECATION_WARNINGS
    class PreCatalinaStillImageOutput  : public ImageOutputBase
    {
    public:
        void addImageCapture (AVCaptureSession* s) override
        {
            if (imageOutput != nil)
                return;

            const auto codecType = []
            {
                if (@available (macOS 10.13, *))
                   return AVVideoCodecTypeJPEG;

                return AVVideoCodecJPEG;
            }();

            imageOutput = [[AVCaptureStillImageOutput alloc] init];
            auto imageSettings = [[NSDictionary alloc] initWithObjectsAndKeys: codecType, AVVideoCodecKey, nil];
            [imageOutput setOutputSettings: imageSettings];
            [imageSettings release];
            [s addOutput: imageOutput];
        }

        void removeImageCapture (AVCaptureSession* s) override
        {
            if (imageOutput == nil)
                return;

            [s removeOutput: imageOutput];
            [imageOutput release];
            imageOutput = nil;
        }

        NSArray<AVCaptureConnection*>* getConnections() const override
        {
            if (imageOutput != nil)
                return imageOutput.connections;

            return nil;
        }

        void triggerImageCapture (Pimpl& p) override
        {
            if (auto* videoConnection = p.getVideoConnection())
            {
                [imageOutput captureStillImageAsynchronouslyFromConnection: videoConnection
                                                         completionHandler: ^(CMSampleBufferRef sampleBuffer, NSError* error)
                {
                    if (error != nil)
                    {
                        JUCE_CAMERA_LOG ("Still picture capture failed, error: " + nsStringToJuce (error.localizedDescription));
                        jassertfalse;
                        return;
                    }

                    auto* imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation: sampleBuffer];
                    auto image = ImageFileFormat::loadFrom (imageData.bytes, (size_t) imageData.length);
                    p.imageCaptureFinished (image);
                }];
            }
        }

    private:
        AVCaptureStillImageOutput* imageOutput = nil;
    };
    JUCE_END_IGNORE_DEPRECATION_WARNINGS

    //==============================================================================
    void addImageCapture()
    {
        imageOutput->addImageCapture (session);
    }

    void addMovieCapture()
    {
        if (fileOutput == nil)
        {
            fileOutput = [[AVCaptureMovieFileOutput alloc] init];
            [session addOutput: fileOutput];
        }
    }

    void removeImageCapture()
    {
        imageOutput->removeImageCapture (session);
    }

    void removeMovieCapture()
    {
        if (fileOutput != nil)
        {
            [session removeOutput: fileOutput];
            [fileOutput release];
            fileOutput = nil;
        }
    }

    void removeCurrentSessionVideoInputs()
    {
        if (session != nil)
        {
            NSArray<AVCaptureDeviceInput*>* inputs = session.inputs;

            for (AVCaptureDeviceInput* input : inputs)
                if ([input.device hasMediaType: AVMediaTypeVideo])
                    [session removeInput:input];
        }
    }

    void addInput()
    {
        if (currentInput == nil)
        {
            for (AVCaptureDevice* device : getCaptureDevices())
            {
                if (deviceName == nsStringToJuce ([device localizedName]))
                {
                    removeCurrentSessionVideoInputs();

                    NSError* err = nil;
                    AVCaptureDeviceInput* inputDevice = [[AVCaptureDeviceInput alloc] initWithDevice: device
                                                                                               error: &err];

                    jassert (err == nil);

                    if ([session canAddInput: inputDevice])
                    {
                        [session addInput: inputDevice];
                        currentInput = inputDevice;
                    }
                    else
                    {
                        jassertfalse;
                        [inputDevice release];
                    }

                    return;
                }
            }
        }
    }

    void removeInput()
    {
        if (currentInput != nil)
        {
            [session removeInput: currentInput];
            [currentInput release];
            currentInput = nil;
        }
    }

    void refreshConnections()
    {
        [session beginConfiguration];
        removeInput();
        removeImageCapture();
        removeMovieCapture();
        addInput();
        addImageCapture();
        addMovieCapture();
        [session commitConfiguration];
    }

    void refreshIfNeeded()
    {
        if (getVideoConnection() == nullptr)
            refreshConnections();
    }

    AVCaptureConnection* getVideoConnection() const
    {
        auto* connections = imageOutput->getConnections();

        if (connections != nil)
            for (AVCaptureConnection* connection in connections)
                if ([connection isActive] && [connection isEnabled])
                    for (AVCaptureInputPort* port in [connection inputPorts])
                        if ([[port mediaType] isEqual: AVMediaTypeVideo])
                            return connection;

        return nil;
    }

    void imageCaptureFinished (const Image& image)
    {
        handleImageCapture (image);

        MessageManager::callAsync ([weakRef = WeakReference<Pimpl> { this }, image]() mutable
        {
            if (weakRef != nullptr)
                NullCheckedInvocation::invoke (weakRef->pictureTakenCallback, image);
        });
    }

    void handleImageCapture (const Image& image)
    {
        const ScopedLock sl (listenerLock);
        listeners.call ([=] (Listener& l) { l.imageReceived (image); });

        if (! listeners.isEmpty())
            triggerImageCapture();
    }

    void triggerImageCapture()
    {
        refreshIfNeeded();

        startSession();

        if (getVideoConnection() != nullptr)
            imageOutput->triggerImageCapture (*this);
    }

    void cameraSessionRuntimeError (const String& error)
    {
        JUCE_CAMERA_LOG ("cameraSessionRuntimeError(), error = " + error);

        NullCheckedInvocation::invoke (owner.onErrorOccurred, error);
    }

    //==============================================================================
    CameraDevice& owner;
    String deviceName;

    AVCaptureSession* session = nil;
    AVCaptureMovieFileOutput* fileOutput = nil;
    std::unique_ptr<ImageOutputBase> imageOutput;
    AVCaptureDeviceInput* currentInput = nil;

    id<AVCaptureFileOutputRecordingDelegate> callbackDelegate = nil;
    String openingError;
    Time firstPresentationTime;
    bool isRecording = false;

    CriticalSection listenerLock;
    ListenerList<Listener> listeners;

    std::function<void (const Image&)> pictureTakenCallback = nullptr;

    //==============================================================================
    JUCE_DECLARE_WEAK_REFERENCEABLE (Pimpl)
    JUCE_DECLARE_NON_COPYABLE       (Pimpl)
};

//==============================================================================
struct CameraDevice::ViewerComponent  : public NSViewComponent
{
    ViewerComponent (CameraDevice& device)
    {
        setView (device.pimpl->createVideoCapturePreview());
    }

    ~ViewerComponent()
    {
        setView (nil);
    }

    JUCE_DECLARE_NON_COPYABLE (ViewerComponent)
};

String CameraDevice::getFileExtension()
{
    return ".mov";
}