#import <AVFoundation/AVFoundation.h>
#import <UIKit/UIKit.h>

@interface NativeCameraController : NSObject <AVCaptureMetadataOutputObjectsDelegate>
@property (nonatomic, strong) AVCaptureSession *session;
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *previewLayer;
@property (nonatomic, copy) NSString *gameObjectName;
@property (nonatomic, assign) BOOL hasScanned;
@end

@implementation NativeCameraController

- (void)startWithName:(NSString *)goName
{
    self.gameObjectName = goName;
    self.hasScanned = NO;

    // 1. 创建 session
    self.session = [[AVCaptureSession alloc] init];
    self.session.sessionPreset = AVCaptureSessionPresetHigh;

    // 2. 获取后置摄像头
    AVCaptureDevice *device = [self findRearCamera];
    if (!device) {
        [self sendToUnity:@"ERROR:NO_CAMERA"];
        return;
    }

    NSLog(@"[NativeCamera] 使用摄像头: %@", device.localizedName);

    // 3. 配置连续自动对焦
    NSError *error = nil;
    if ([device lockForConfiguration:&error]) {
        if ([device isFocusModeSupported:AVCaptureFocusModeContinuousAutoFocus]) {
            device.focusMode = AVCaptureFocusModeContinuousAutoFocus;
        }
        if ([device isExposureModeSupported:AVCaptureExposureModeContinuousAutoExposure]) {
            device.exposureMode = AVCaptureExposureModeContinuousAutoExposure;
        }
        if ([device respondsToSelector:@selector(isAutoFocusRangeRestrictionSupported)] &&
            [device isAutoFocusRangeRestrictionSupported]) {
            device.autoFocusRangeRestriction = AVCaptureAutoFocusRangeRestrictionNear;
        }
        [device unlockForConfiguration];
        NSLog(@"[NativeCamera] 已启用连续自动对焦");
    } else {
        NSLog(@"[NativeCamera] 配置摄像头失败: %@", error.localizedDescription);
    }

    // 4. 输入
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
    if (!input) {
        [self sendToUnity:[NSString stringWithFormat:@"ERROR:INPUT:%@", error.localizedDescription]];
        return;
    }
    [self.session addInput:input];

    // 5. 元数据输出（二维码检测）
    AVCaptureMetadataOutput *metadataOutput = [[AVCaptureMetadataOutput alloc] init];
    [self.session addOutput:metadataOutput];
    [metadataOutput setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    metadataOutput.metadataObjectTypes = @[AVMetadataObjectTypeQRCode];

    // 6. 预览层 — 插入到 Unity 视图底层
    UIViewController *rootVC = UnityGetGLViewController();
    self.previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
    self.previewLayer.frame = rootVC.view.bounds;
    self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    // 插入到最底层，Unity UI 正常渲染在上层
    [rootVC.view.layer insertSublayer:self.previewLayer atIndex:0];

    // 7. 启动 session
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [self.session startRunning];
        dispatch_async(dispatch_get_main_queue(), ^{
            [self sendToUnity:@"CAMERA_READY"];
        });
    });
}

/// 选择后置主摄（排除超广角/长焦）
- (AVCaptureDevice *)findRearCamera
{
    if (@available(iOS 10.0, *)) {
        AVCaptureDeviceDiscoverySession *session = [AVCaptureDeviceDiscoverySession
            discoverySessionWithDeviceTypes:@[AVCaptureDeviceTypeBuiltInWideAngleCamera,
                                              AVCaptureDeviceTypeBuiltInTelephotoCamera,
                                              AVCaptureDeviceTypeBuiltInUltraWideCamera]
                                  mediaType:AVMediaTypeVideo
                                   position:AVCaptureDevicePositionBack];
        // 优先宽角（主摄）
        for (AVCaptureDevice *d in session.devices) {
            if (d.deviceType == AVCaptureDeviceTypeBuiltInWideAngleCamera) {
                return d;
            }
        }
        // 兜底：返回第一个
        return session.devices.firstObject;
    }
    return [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
}

- (void)stop
{
    self.hasScanned = YES;
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [self.session stopRunning];
    });
    [self.previewLayer removeFromSuperlayer];
    self.previewLayer = nil;
    self.session = nil;
}

- (void)sendToUnity:(NSString *)msg
{
    if (self.gameObjectName) {
        UnitySendMessage([self.gameObjectName UTF8String], "OnNativeScanResult", [msg UTF8String]);
    }
}

#pragma mark - AVCaptureMetadataOutputObjectsDelegate

- (void)captureOutput:(AVCaptureOutput *)output
didOutputMetadataObjects:(NSArray<__kindof AVMetadataObject *> *)metadataObjects
          fromConnection:(AVCaptureConnection *)connection
{
    if (self.hasScanned) return;
    if (metadataObjects.count == 0) return;

    AVMetadataMachineReadableCodeObject *code = metadataObjects.firstObject;
    if (![code isKindOfClass:[AVMetadataMachineReadableCodeObject class]]) return;
    if (!code.stringValue) return;

    self.hasScanned = YES;
    NSLog(@"[NativeCamera] 扫描到二维码: %@", code.stringValue);

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [self.session stopRunning];
    });

    [self sendToUnity:code.stringValue];
}

@end

// ──── 单例管理 ────
static NativeCameraController *g_cameraController = nil;

extern "C" {

    void _StartNativeCamera(const char *gameObjectName)
    {
        if (g_cameraController) {
            [g_cameraController stop];
            g_cameraController = nil;
        }

        // 权限请求
        AVAuthorizationStatus status = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
        if (status == AVAuthorizationStatusNotDetermined) {
            [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
                if (granted) {
                    g_cameraController = [[NativeCameraController alloc] init];
                    NSString *goName = [NSString stringWithUTF8String:gameObjectName];
                    [g_cameraController startWithName:goName];
                } else {
                    UnitySendMessage((char *)gameObjectName, "OnNativeScanResult", "ERROR:PERMISSION_DENIED");
                }
            }];
            return;
        }

        if (status != AVAuthorizationStatusAuthorized) {
            UnitySendMessage((char *)gameObjectName, "OnNativeScanResult", "ERROR:PERMISSION_DENIED");
            return;
        }

        g_cameraController = [[NativeCameraController alloc] init];
        NSString *goName = [NSString stringWithUTF8String:gameObjectName];
        [g_cameraController startWithName:goName];
    }

    void _StopNativeCamera()
    {
        if (g_cameraController) {
            [g_cameraController stop];
            g_cameraController = nil;
        }
    }

}