/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2025      - Joseph Mattiello
 *
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include <TargetConditionals.h>
#include <Foundation/Foundation.h>
#include <AVFoundation/AVFoundation.h>
#include <libretro.h>
#include "../camera/camera_driver.h"
#include "../verbosity.h"
/// For image scaling and color space DSP
#import <Accelerate/Accelerate.h>
#if TARGET_OS_IOS
/// For camera rotation detection
#import <UIKit/UIKit.h>
#endif

// TODO: Add an API to retroarch to allow selection of camera
#ifndef CAMERA_PREFER_FRONTFACING
#define CAMERA_PREFER_FRONTFACING 1  /// Default to front camera
#endif

#ifndef CAMERA_MIRROR_FRONT_CAMERA
#define CAMERA_MIRROR_FRONT_CAMERA 1
#endif

@interface AVCameraManager : NSObject <AVCaptureVideoDataOutputSampleBufferDelegate>
@property (strong, nonatomic) AVCaptureSession *session;
@property (strong, nonatomic) AVCaptureDeviceInput *input;
@property (strong, nonatomic) AVCaptureVideoDataOutput *output;
@property (assign) uint32_t *frameBuffer;
@property (assign) size_t width;
@property (assign) size_t height;

- (bool)setupCameraSession;
@end

@implementation AVCameraManager

+ (AVCameraManager *)sharedInstance {
    static AVCameraManager *instance = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        instance = [[AVCameraManager alloc] init];
    });
    return instance;
}

- (void)requestCameraAuthorizationWithCompletion:(void (^)(BOOL granted))completion {
    RARCH_LOG("[Camera]: Checking camera authorization status\n");

    AVAuthorizationStatus status = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];

    switch (status) {
        case AVAuthorizationStatusAuthorized: {
            RARCH_LOG("[Camera]: Camera access already authorized\n");
            completion(YES);
            break;
        }

        case AVAuthorizationStatusNotDetermined: {

            RARCH_LOG("[Camera]: Requesting camera authorization...\n");
            [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo
                                     completionHandler:^(BOOL granted) {
                RARCH_LOG("[Camera]: Authorization %s\n", granted ? "granted" : "denied");
                completion(granted);
            }];
            break;
        }

        case AVAuthorizationStatusDenied: {
            RARCH_ERR("[Camera]: Camera access denied by user\n");
            completion(NO);
            break;
        }

        case AVAuthorizationStatusRestricted: {
            RARCH_ERR("[Camera]: Camera access restricted (parental controls?)\n");
            completion(NO);
            break;
        }

        default: {
            RARCH_ERR("[Camera]: Unknown authorization status\n");
            completion(NO);
            break;
        }
    }
}

- (void)captureOutput:(AVCaptureOutput *)output
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection {
    @autoreleasepool {
        if (!self.frameBuffer)
            return;

        CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
        if (!imageBuffer) {
            RARCH_ERR("[Camera]: Failed to get image buffer\n");
            return;
        }

        CVPixelBufferLockBaseAddress(imageBuffer, 0);

        size_t sourceWidth = CVPixelBufferGetWidth(imageBuffer);
        size_t sourceHeight = CVPixelBufferGetHeight(imageBuffer);
        OSType pixelFormat = CVPixelBufferGetPixelFormatType(imageBuffer);

#ifdef DEBUG
        RARCH_LOG("[Camera]: Processing frame %zux%zu format: %u\n", sourceWidth, sourceHeight, (unsigned int)pixelFormat);
#endif
        // Create intermediate buffer for full-size converted image
        uint32_t *intermediateBuffer = (uint32_t*)malloc(sourceWidth * sourceHeight * 4);
        if (!intermediateBuffer) {
            RARCH_ERR("[Camera]: Failed to allocate intermediate buffer\n");
            CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
            return;
        }

        vImage_Buffer srcBuffer = {}, intermediateVBuffer = {}, dstBuffer = {};
        vImage_Error err = kvImageNoError;

        // Setup intermediate buffer
        intermediateVBuffer.data = intermediateBuffer;
        intermediateVBuffer.width = sourceWidth;
        intermediateVBuffer.height = sourceHeight;
        intermediateVBuffer.rowBytes = sourceWidth * 4;

        // Setup destination buffer
        dstBuffer.data = self.frameBuffer;
        dstBuffer.width = self.width;
        dstBuffer.height = self.height;
        dstBuffer.rowBytes = self.width * 4;

        // Convert source format to RGBA
        switch (pixelFormat) {
            case kCVPixelFormatType_32BGRA: {
                srcBuffer.data = CVPixelBufferGetBaseAddress(imageBuffer);
                srcBuffer.width = sourceWidth;
                srcBuffer.height = sourceHeight;
                srcBuffer.rowBytes = CVPixelBufferGetBytesPerRow(imageBuffer);

                uint8_t permuteMap[4] = {2, 1, 0, 3}; // BGRA -> RGBA
                err = vImagePermuteChannels_ARGB8888(&srcBuffer, &intermediateVBuffer, permuteMap, kvImageNoFlags);
                break;
            }

            case kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange:
            case kCVPixelFormatType_420YpCbCr8BiPlanarFullRange: {
                // YUV to RGB conversion
                vImage_Buffer srcY = {}, srcCbCr = {};

                srcY.data = CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 0);
                srcY.width = sourceWidth;
                srcY.height = sourceHeight;
                srcY.rowBytes = CVPixelBufferGetBytesPerRowOfPlane(imageBuffer, 0);

                srcCbCr.data = CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 1);
                srcCbCr.width = sourceWidth / 2;
                srcCbCr.height = sourceHeight / 2;
                srcCbCr.rowBytes = CVPixelBufferGetBytesPerRowOfPlane(imageBuffer, 1);

                vImage_YpCbCrToARGB info;
                vImage_YpCbCrPixelRange pixelRange =
                    (pixelFormat == kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange) ?
                        (vImage_YpCbCrPixelRange){16, 128, 235, 240} :  // Video range
                        (vImage_YpCbCrPixelRange){0, 128, 255, 255};    // Full range

                err = vImageConvert_YpCbCrToARGB_GenerateConversion(kvImage_YpCbCrToARGBMatrix_ITU_R_601_4,
                                                                   &pixelRange,
                                                                   &info,
                                                                   kvImage420Yp8_CbCr8,
                                                                   kvImageARGB8888,
                                                                   kvImageNoFlags);

                if (err == kvImageNoError) {
                    err = vImageConvert_420Yp8_CbCr8ToARGB8888(&srcY,
                                                              &srcCbCr,
                                                              &intermediateVBuffer,
                                                              &info,
                                                              NULL,
                                                              255,
                                                              kvImageNoFlags);
                }
                break;
            }

            default:
                RARCH_ERR("[Camera]: Unsupported pixel format: %u\n", (unsigned int)pixelFormat);
                free(intermediateBuffer);
                CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
                return;
        }

        if (err != kvImageNoError) {
            RARCH_ERR("[Camera]: Error converting color format: %ld\n", err);
            free(intermediateBuffer);
            CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
            return;
        }

        // Determine rotation based on platform and camera type
#if TARGET_OS_OSX
        int rotationDegrees = 0; // Default 180-degree rotation for most cases
        bool shouldMirror = true;
#else
        int rotationDegrees = 180; // Default 180-degree rotation for most cases
        bool shouldMirror = false;

        /// For camera rotation detection
        UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
        if (orientation == UIDeviceOrientationPortrait ||
            orientation == UIDeviceOrientationPortraitUpsideDown) {
            // In portrait mode, adjust rotation based on camera type
            if (self.input.device.position == AVCaptureDevicePositionFront) {
                rotationDegrees = 270;
                #if CAMERA_MIRROR_FRONT_CAMERA
                // TODO: Add an API to retroarch to allow for mirroring of front camera
                shouldMirror = true; // Mirror front camera
                #endif
                RARCH_LOG("[Camera]: Using 270-degree rotation with mirroring for front camera in portrait mode\n");
            }
        }
#endif

        // Rotate image
        vImage_Buffer rotatedBuffer = {};
        rotatedBuffer.data = malloc(sourceWidth * sourceHeight * 4);
        if (!rotatedBuffer.data) {
            RARCH_ERR("[Camera]: Failed to allocate rotation buffer\n");
            free(intermediateBuffer);
            CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
            return;
        }

        // Set dimensions based on rotation angle
        if (rotationDegrees == 90 || rotationDegrees == 270) {
            rotatedBuffer.width = sourceHeight;
            rotatedBuffer.height = sourceWidth;
        } else {
            rotatedBuffer.width = sourceWidth;
            rotatedBuffer.height = sourceHeight;
        }
        rotatedBuffer.rowBytes = rotatedBuffer.width * 4;

        const Pixel_8888 backgroundColor = {0, 0, 0, 255};

        err = vImageRotate90_ARGB8888(&intermediateVBuffer,
                                     &rotatedBuffer,
                                     rotationDegrees / 90,
                                     backgroundColor,
                                     kvImageNoFlags);

        if (err != kvImageNoError) {
            RARCH_ERR("[Camera]: Error rotating image: %ld\n", err);
            free(rotatedBuffer.data);
            free(intermediateBuffer);
            CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
            return;
        }

        // Mirror the image if needed
        if (shouldMirror) {
            vImage_Buffer mirroredBuffer = {};
            mirroredBuffer.data = malloc(rotatedBuffer.height * rotatedBuffer.rowBytes);
            if (!mirroredBuffer.data) {
                RARCH_ERR("[Camera]: Failed to allocate mirror buffer\n");
                free(rotatedBuffer.data);
                free(intermediateBuffer);
                CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
                return;
            }

            mirroredBuffer.width = rotatedBuffer.width;
            mirroredBuffer.height = rotatedBuffer.height;
            mirroredBuffer.rowBytes = rotatedBuffer.rowBytes;

            err = vImageHorizontalReflect_ARGB8888(&rotatedBuffer, &mirroredBuffer, kvImageNoFlags);

            if (err == kvImageNoError) {
                // Free rotated buffer and use mirrored buffer for scaling
                free(rotatedBuffer.data);
                rotatedBuffer = mirroredBuffer;
            } else {
                RARCH_ERR("[Camera]: Error mirroring image: %ld\n", err);
                free(mirroredBuffer.data);
            }
        }

        // Calculate aspect fill scaling
        float sourceAspect = (float)rotatedBuffer.width / rotatedBuffer.height;
        float targetAspect = (float)self.width / self.height;

        vImage_Buffer scaledBuffer = {};
        size_t scaledWidth, scaledHeight;

        if (sourceAspect > targetAspect) {
            // Source is wider - scale to match height
            scaledHeight = self.height;
            scaledWidth = (size_t)(self.height * sourceAspect);
        } else {
            // Source is taller - scale to match width
            scaledWidth = self.width;
            scaledHeight = (size_t)(self.width / sourceAspect);
        }

        RARCH_LOG("[Camera]: Aspect fill scaling from %zux%zu to %zux%zu\n",
                  rotatedBuffer.width, rotatedBuffer.height, scaledWidth, scaledHeight);

        scaledBuffer.data = malloc(scaledWidth * scaledHeight * 4);
        if (!scaledBuffer.data) {
            RARCH_ERR("[Camera]: Failed to allocate scaled buffer\n");
            free(rotatedBuffer.data);
            free(intermediateBuffer);
            CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
            return;
        }

        scaledBuffer.width = scaledWidth;
        scaledBuffer.height = scaledHeight;
        scaledBuffer.rowBytes = scaledWidth * 4;

        // Scale maintaining aspect ratio
        err = vImageScale_ARGB8888(&rotatedBuffer, &scaledBuffer, NULL, kvImageHighQualityResampling);

        if (err != kvImageNoError) {
            RARCH_ERR("[Camera]: Error scaling image: %ld\n", err);
            free(scaledBuffer.data);
            free(rotatedBuffer.data);
            free(intermediateBuffer);
            CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
            return;
        }

        // Center crop the scaled image into the destination buffer
        size_t xOffset = (scaledWidth > self.width) ? (scaledWidth - self.width) / 2 : 0;
        size_t yOffset = (scaledHeight > self.height) ? (scaledHeight - self.height) / 2 : 0;

        // Copy the centered portion to the destination buffer
        uint32_t *srcPtr = (uint32_t *)scaledBuffer.data;
        uint32_t *dstPtr = (uint32_t *)self.frameBuffer;

        for (size_t y = 0; y < self.height; y++) {
            memcpy(dstPtr + y * self.width,
                   srcPtr + (y + yOffset) * scaledWidth + xOffset,
                   self.width * 4);
        }

        // Clean up
        free(scaledBuffer.data);
        free(rotatedBuffer.data);
        free(intermediateBuffer);
        CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
    } // End of autorelease pool
}

- (AVCaptureDevice *)selectCameraDevice {
    RARCH_LOG("[Camera]: Selecting camera device\n");

    NSArray<AVCaptureDevice *> *devices;

#if TARGET_OS_OSX
    // On macOS, use default discovery method
    // Could probably due the same as iOS but need to test.
    devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
#else
    // On iOS/tvOS use modern discovery session
    NSArray<AVCaptureDeviceType> *deviceTypes;
    if (@available(iOS 17.0, *)) {
        deviceTypes = @[
            AVCaptureDeviceTypeExternal,
            AVCaptureDeviceTypeBuiltInWideAngleCamera,
            AVCaptureDeviceTypeBuiltInTelephotoCamera,
            AVCaptureDeviceTypeBuiltInUltraWideCamera,
            //        AVCaptureDeviceTypeBuiltInDualCamera,
            //        AVCaptureDeviceTypeBuiltInDualWideCamera,
            //        AVCaptureDeviceTypeBuiltInTripleCamera,
            //        AVCaptureDeviceTypeBuiltInTrueDepthCamera,
            //        AVCaptureDeviceTypeBuiltInLiDARDepthCamera,
            //        AVCaptureDeviceTypeContinuityCamera,
        ];
    } else {
        deviceTypes = @[
            AVCaptureDeviceTypeBuiltInWideAngleCamera,
            AVCaptureDeviceTypeBuiltInTelephotoCamera,
            AVCaptureDeviceTypeBuiltInUltraWideCamera,
            //        AVCaptureDeviceTypeBuiltInDualCamera,
            //        AVCaptureDeviceTypeBuiltInDualWideCamera,
            //        AVCaptureDeviceTypeBuiltInTripleCamera,
            //        AVCaptureDeviceTypeBuiltInTrueDepthCamera,
            //        AVCaptureDeviceTypeBuiltInLiDARDepthCamera,
            //        AVCaptureDeviceTypeContinuityCamera,
        ];
    }
    AVCaptureDeviceDiscoverySession *discoverySession = [AVCaptureDeviceDiscoverySession
                                                         discoverySessionWithDeviceTypes:deviceTypes
                                                         mediaType:AVMediaTypeVideo
                                                         position:AVCaptureDevicePositionUnspecified];

    devices = discoverySession.devices;
#endif

    if (devices.count == 0) {
        RARCH_ERR("[Camera]: No camera devices found\n");
        return nil;
    }

    // Log available devices
    for (AVCaptureDevice *device in devices) {
        RARCH_LOG("[Camera]: Found device: %s - Position: %d\n",
                  [device.localizedName UTF8String],
                  (int)device.position);
    }

#if TARGET_OS_OSX
    // macOS: Just use the first available camera if only one exists
    if (devices.count == 1) {
        RARCH_LOG("[Camera]: Using only available camera: %s\n",
                  [devices.firstObject.localizedName UTF8String]);
        return devices.firstObject;
    }

    // Try to match by name for built-in cameras
    for (AVCaptureDevice *device in devices) {
        BOOL isFrontFacing = [device.localizedName containsString:@"FaceTime"] ||
                            [device.localizedName containsString:@"Front"];
        if (CAMERA_PREFER_FRONTFACING == isFrontFacing) {
            RARCH_LOG("[Camera]: Selected macOS camera: %s\n",
                      [device.localizedName UTF8String]);
            return device;
        }
    }
#else
    // iOS: Use position property
    AVCaptureDevicePosition preferredPosition = CAMERA_PREFER_FRONTFACING ?
        AVCaptureDevicePositionFront : AVCaptureDevicePositionBack;

    // Try to find preferred camera
    for (AVCaptureDevice *device in devices) {
        if (device.position == preferredPosition) {
            RARCH_LOG("[Camera]: Selected iOS camera position: %d\n",
                      (int)preferredPosition);
            return device;
        }
    }
#endif

    // Fallback to first available camera
    RARCH_LOG("[Camera]: Using fallback camera: %s\n",
              [devices.firstObject.localizedName UTF8String]);
    return devices.firstObject;
}

- (bool)setupCameraSession {
    // Initialize capture session
    self.session = [[AVCaptureSession alloc] init];

    // Get camera device
    AVCaptureDevice *device = [self selectCameraDevice];
    if (!device) {
        RARCH_ERR("[Camera]: No camera device found\n");
        return false;
    }

    // Create device input
    NSError *error = nil;
    self.input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
    if (error) {
        RARCH_ERR("[Camera]: Failed to create device input: %s\n",
                  [error.localizedDescription UTF8String]);
        return false;
    }

    if ([self.session canAddInput:self.input]) {
        [self.session addInput:self.input];
        RARCH_LOG("[Camera]: Added camera input to session\n");
    }

    // Create and configure video output
    self.output = [[AVCaptureVideoDataOutput alloc] init];
    self.output.videoSettings = @{
        (NSString*)kCVPixelBufferPixelFormatTypeKey: @(kCVPixelFormatType_32BGRA)
    };
    [self.output setSampleBufferDelegate:self queue:dispatch_get_main_queue()];

    if ([self.session canAddOutput:self.output]) {
        [self.session addOutput:self.output];
        RARCH_LOG("[Camera]: Added video output to session\n");
    }

    return true;
}

@end

typedef struct
{
    AVCameraManager *manager;
    unsigned width;
    unsigned height;
} avfoundation_t;

static void generateColorBars(uint32_t *buffer, size_t width, size_t height) {
    const uint32_t colors[] = {
        0xFFFFFFFF,  // White
        0xFFFFFF00,  // Yellow
        0xFF00FFFF,  // Cyan
        0xFF00FF00,  // Green
        0xFFFF00FF,  // Magenta
        0xFFFF0000,  // Red
        0xFF0000FF,  // Blue
        0xFF000000   // Black
    };

    size_t barWidth = width / 8;
    for (size_t y = 0; y < height; y++) {
        for (size_t x = 0; x < width; x++) {
            size_t colorIndex = x / barWidth;
            buffer[y * width + x] = colors[colorIndex];
        }
    }
}

static void *avfoundation_init(const char *device, uint64_t caps,
                             unsigned width, unsigned height)
{
    avfoundation_t *avf = (avfoundation_t*)calloc(1, sizeof(avfoundation_t));
    RARCH_LOG("[Camera]: Initializing AVFoundation camera %ux%u\n", width, height);
    if (!avf)
    {
        RARCH_ERR("[Camera]: Failed to allocate avfoundation_t\n");
        return NULL;
    }

    avf->manager        = [AVCameraManager sharedInstance];
    avf->width          = width;
    avf->height         = height;
    avf->manager.width  = width;
    avf->manager.height = height;

    /* Check if we're on the main thread */
    if ([NSThread isMainThread])
    {
        RARCH_LOG("[Camera]: Initializing on main thread\n");
        /* Direct initialization on main thread */
        [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
            AVAuthorizationStatus status = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
            if (status != AVAuthorizationStatusAuthorized)
            {
                RARCH_ERR("[Camera]: Camera access not authorized (status: %d)\n", (int)status);
                free(avf);
                return;
            }
        }];
    }
    else 
    {
        RARCH_LOG("[Camera]: Initializing on background thread\n");
        /* Use dispatch_sync to run authorization check on main thread */
        __block AVAuthorizationStatus status;
        dispatch_sync(dispatch_get_main_queue(), ^{
            status = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
        });

        if (status != AVAuthorizationStatusAuthorized)
        {
            RARCH_ERR("[Camera]: Camera access not authorized (status: %d)\n", (int)status);
            free(avf);
            return NULL;
        }
    }

    /* Allocate frame buffer */
    avf->manager.frameBuffer = (uint32_t*)calloc(width * height, sizeof(uint32_t));
    if (!avf->manager.frameBuffer)
    {
        RARCH_ERR("[Camera]: Failed to allocate frame buffer\n");
        free(avf);
        return NULL;
    }

    /* Initialize capture session on main thread */
    __block bool setupSuccess = false;

    if ([NSThread isMainThread])
    {
        @autoreleasepool {
            setupSuccess = [avf->manager setupCameraSession];
            if (setupSuccess) {
                [avf->manager.session startRunning];
                RARCH_LOG("[Camera]: Started camera session\n");
            }
        }
    }
    else
    {
        dispatch_sync(dispatch_get_main_queue(), ^{
            @autoreleasepool {
                setupSuccess = [avf->manager setupCameraSession];
                if (setupSuccess) {
                    [avf->manager.session startRunning];
                    RARCH_LOG("[Camera]: Started camera session\n");
                }
            }
        });
    }

    if (!setupSuccess)
    {
        RARCH_ERR("[Camera]: Failed to setup camera\n");
        free(avf->manager.frameBuffer);
        free(avf);
        return NULL;
    }

    /* Add a check to verify the session is actually running */
    if (!avf->manager.session.isRunning)
    {
        RARCH_ERR("[Camera]: Failed to start camera session\n");
        free(avf->manager.frameBuffer);
        free(avf);
        return NULL;
    }

    RARCH_LOG("[Camera]: AVFoundation camera initialized and started successfully\n");
    return avf;
}

static void avfoundation_free(void *data)
{
    avfoundation_t *avf = (avfoundation_t*)data;
    if (!avf)
        return;

    RARCH_LOG("[Camera]: Freeing AVFoundation camera\n");

    if (avf->manager.session)
        [avf->manager.session stopRunning];

    if (avf->manager.frameBuffer)
    {
        free(avf->manager.frameBuffer);
        avf->manager.frameBuffer = NULL;
    }

    free(avf);
    RARCH_LOG("[Camera]: AVFoundation camera freed\n");
}

static bool avfoundation_start(void *data)
{
    bool isRunning;
    avfoundation_t *avf = (avfoundation_t*)data;
    if (!avf || !avf->manager.session)
    {
        RARCH_ERR("[Camera]: Cannot start - invalid data\n");
        return false;
    }

    RARCH_LOG("[Camera]: Starting AVFoundation camera\n");

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [avf->manager.session startRunning];
        RARCH_LOG("[Camera]: Camera session started on background thread\n");
    });

    /* Give the session a moment to start */
    usleep(100000); /* 100ms */

    isRunning = avf->manager.session.isRunning;
    RARCH_LOG("[Camera]: Camera session running: %s\n", isRunning ? "YES" : "NO");
    return isRunning;
}

static void avfoundation_stop(void *data)
{
    avfoundation_t *avf = (avfoundation_t*)data;
    if (!avf || !avf->manager.session)
        return;

    RARCH_LOG("[Camera]: Stopping AVFoundation camera\n");

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [avf->manager.session stopRunning];
        RARCH_LOG("[Camera]: Camera session stopped on background thread\n");
    });
}

static bool avfoundation_poll(void *data,
      retro_camera_frame_raw_framebuffer_t frame_raw_cb,
      retro_camera_frame_opengl_texture_t frame_gl_cb)
{
    avfoundation_t *avf = (avfoundation_t*)data;
    if (!avf || !frame_raw_cb)
    {
        RARCH_ERR("[Camera]: Cannot poll - invalid data or callback\n");
        return false;
    }

    if (!avf->manager.session.isRunning)
    {
        RARCH_LOG("[Camera]: Camera not running, generating color bars\n");
        uint32_t *tempBuffer = (uint32_t*)calloc(avf->width * avf->height, sizeof(uint32_t));
        if (tempBuffer)
        {
            generateColorBars(tempBuffer, avf->width, avf->height);
            frame_raw_cb(tempBuffer, avf->width, avf->height, avf->width * 4);
            free(tempBuffer);
            return true;
        }
        return false;
    }

#ifdef DEBUG
    RARCH_LOG("[Camera]: Delivering camera frame\n");
#endif
    frame_raw_cb(avf->manager.frameBuffer, avf->width, avf->height, avf->width * 4);
    return true;
}

camera_driver_t camera_avfoundation = {
   avfoundation_init,
   avfoundation_free,
   avfoundation_start,
   avfoundation_stop,
   avfoundation_poll,
   "avfoundation"
};