#import <AVFoundation/AVFoundation.h>
#import "YXKPhotoController.h"
#import "AVPlayerDemoPlaybackView.h"
#import "VideoCore.h"
#import "YXKPublishController.h"

@interface YXKPhotoController () <UIImagePickerControllerDelegate, UINavigationControllerDelegate>
{
    __weak IBOutlet UIView *photoView;
    __weak IBOutlet UIButton *turnCameraButton;
    __weak IBOutlet UIButton *lightningButton;
    __weak IBOutlet UIButton *cancleButton;
    __weak IBOutlet UIButton *photoButton;
    __weak IBOutlet UIButton *addPhotoButton;
    AVCaptureSession *AVSession;
}

@property (nonatomic, strong) AVCaptureSession *session;
@property (nonatomic) BOOL isFlashLight;
@property (nonatomic, strong) AVCaptureDeviceInput *videoInput;
@property (nonatomic, strong) AVCaptureStillImageOutput *stillImageOutput;
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *previewLayer;

@end

@implementation YXKPhotoController

- (void) viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    self.tabBarController.tabBar.hidden = NO;
}

- (void) viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    self.tabBarController.tabBar.hidden = YES;
}

#pragma mark -- 加载预览图层
- (void) setUpCameraLayer
{
    if (self.previewLayer == nil) {
        self.previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.session];
        UIView * view = photoView;
        CALayer * viewLayer = [view layer];
        [viewLayer setMasksToBounds:YES];
       
        CGRect bounds = [view bounds];
        [self.previewLayer setFrame:bounds];
        [self.previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
       
        [viewLayer insertSublayer:self.previewLayer below:[[viewLayer sublayers] objectAtIndex:0]];
       
    }
}

- (void) viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    if(self.session)
    {
        [self.session startRunning];
    }
}

- (void)viewDidLoad {
    [super viewDidLoad];
    [self checkDeviceAuthorizationStatus];
    self.isFlashLight = NO;
    //这个方法的执行我放在init方法里了
    self.session = [[AVCaptureSession alloc] init];
    self.videoInput = [[AVCaptureDeviceInput alloc] initWithDevice:[self backCamera] error:nil];
    //[self fronCamera]方法会返回一个AVCaptureDevice对象，因为我初始化时是采用前摄像头，所以这么写，具体的实现方法后面会介绍
    self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
    NSDictionary * outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey, nil];
    //这是输出流的设置参数AVVideoCodecJPEG参数表示以JPEG的图片格式输出图片
    [self.stillImageOutput setOutputSettings:outputSettings];
   
    if ([self.session canAddInput:self.videoInput]) {
        [self.session addInput:self.videoInput];
    }
    if ([self.session canAddOutput:self.stillImageOutput]) {
        [self.session addOutput:self.stillImageOutput];
    }
   
}

#pragma mark -- 打开闪光灯
- (IBAction)turnButtonClick:(id)sender
{
    self.isFlashLight = !self.isFlashLight;
    if(self.isFlashLight)
    {
        [lightningButton setImage:[UIImage imageNamed:@"picker_flash_sel.png"] forState:UIControlStateNormal];
    }
    else
    {
        [lightningButton setImage:[UIImage imageNamed:@"picker_flash.png"] forState:UIControlStateNormal];
        [self closeFlashLight];
    }
}

-(void)openFlashLight
{
    AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    if (device.torchMode == AVCaptureTorchModeOff) {
        //Create an AV session
        AVCaptureSession * session = [[AVCaptureSession alloc]init];
       
        // Create device input and add to current session
        AVCaptureDeviceInput * input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
        [session addInput:input];
       
        // Create video output and add to current session
        AVCaptureVideoDataOutput * output = [[AVCaptureVideoDataOutput alloc]init];
        [session addOutput:output];
       
        // Start session configuration
        [session beginConfiguration];
        [device lockForConfiguration:nil];
       
        // Set torch to on
        [device setTorchMode:AVCaptureTorchModeOn];
       
        [device unlockForConfiguration];
        [session commitConfiguration];
       
        // Start the session
        [session startRunning];
       
        // Keep the session around
        [self setSession:self.session];
    }
}

- (void) closeFlashLight
{
   
}

#pragma mark -- 反转摄像头
- (IBAction)turnCameraButtonClick:(id)sender
{
    [self toggleCamera];
}

#pragma mark --  翻转摄像头
- (void)toggleCamera {
    // p判断设备上有几个摄像头
    NSUInteger cameraCount = [[AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo] count];
   
    if (cameraCount > 1) {
        NSError *error;
        AVCaptureDeviceInput *newVideoInput;
        // 获取当前的摄像头是前置还是后置
        AVCaptureDevicePosition position = [[_videoInput device] position];
       
        if (position == AVCaptureDevicePositionBack)
            newVideoInput = [[AVCaptureDeviceInput alloc] initWithDevice:[self frontCamera] error:&error];
        else if (position == AVCaptureDevicePositionFront)
            newVideoInput = [[AVCaptureDeviceInput alloc] initWithDevice:[self backCamera] error:&error];
        else
            return;
       
        if (newVideoInput != nil) {
            // 改变回话的配置前,一定要开启配置,配置完成后提交配置改变
            [self.session beginConfiguration];
            [self.session removeInput:self.videoInput];
            if ([self.session canAddInput:newVideoInput]) {
                [self.session addInput:newVideoInput];
                [self setVideoInput:newVideoInput];
            } else {
                [self.session addInput:self.videoInput];
            }
            // 提交新的配置信息
            [self.session commitConfiguration];
        } else if (error) {
            NSLog(@"toggle carema failed, error = %@", error);
        }
    }
}

- (IBAction)cancleButtonClick:(id)sender
{
    self.tabBarController.selectedIndex =  0;
}

#pragma mark -- 调用摄像头拍照,并且跳转到发布界面
- (IBAction)photoButtonClick:(id)sender
{
    [self readImageFromCamera];
}

#pragma mark -- 从摄像头获取照片
- (void) readImageFromCamera
{
    AVCaptureConnection * videoConnection = [self.stillImageOutput connectionWithMediaType:AVMediaTypeVideo];
    if (!videoConnection) {
        NSLog(@"take photo failed!");
        return;
    }
   
    [self.stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
        if (imageDataSampleBuffer == NULL) {
            return;
        }
      
       
        NSData * imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
        UIImage * image = [UIImage imageWithData:imageData];
        NSLog(@"image size = %@",NSStringFromCGSize(image.size));
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.03 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                if(self.session)
                {
                    if(self.isFlashLight)
                    {
                        [self openFlashLight];
                    }
                    [self.session stopRunning];
                }
            YXKPublishController *publish = [[YXKPublishController alloc] init];
            publish.image = image;
            [self.navigationController pushViewController:publish animated:YES];
        });
    }];
}

#pragma mark -- 访问本地照片库
- (IBAction)addPhotoButtonClick:(id)sender
{
    [self readImageFromAlbum];
}

#pragma mark -- 从本地读取相册
- (void) readImageFromAlbum
{
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
    // 设置类型, 表示仅仅从相册中获取照片
    imagePicker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    imagePicker.delegate = self;
    // 设置照片是否允许用户编辑
    imagePicker.allowsEditing = NO;
   
    [self presentViewController:imagePicker animated:YES completion:nil];
}

#pragma mark -- 图片完成处理后提交,代理方法UIPickerControllerDelegate
- (void) imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary<NSString *,id> *)editingInfo
{
    YXKPublishController *publish = [[YXKPublishController alloc] init];
    publish.image = image;
    [self.navigationController pushViewController:publish animated:YES];
}

#pragma mark -- 这是获取前后摄像头对象的方法
- (AVCaptureDevice *)cameraWithPosition:(AVCaptureDevicePosition) position {
    NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];
    for (AVCaptureDevice *device in devices) {
        if ([device position] == position) {
            return device;
        }
    }
    return nil;
}

- (AVCaptureDevice *)frontCamera {
    return [self cameraWithPosition:AVCaptureDevicePositionFront];
}

- (AVCaptureDevice *)backCamera {
    return [self cameraWithPosition:AVCaptureDevicePositionBack];
}

#pragma mark -- 是否拥有使用摄像头的权限
- (void)checkDeviceAuthorizationStatus
{
    [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
        if (granted) {
            dispatch_async(dispatch_get_main_queue(), ^{
                [self setUpCameraLayer];
            });
        }
        else {
            dispatch_async(dispatch_get_main_queue(), ^{
                UIAlertController * alert = [UIAlertController alertControllerWithTitle:nil
                                                                                message:@"No permission to use Camera, please change privacy settings" preferredStyle:UIAlertControllerStyleAlert];
                [alert addAction:[UIAlertAction actionWithTitle:@"Cancel"
                                                          style:UIAlertActionStyleCancel
                                                        handler:^(UIAlertAction * _Nonnull action) {
                                                            [self cancleButtonClick:nil];
                                                        }]];
               
                [self presentViewController:alert animated:YES completion:nil];
            });
        }
    }];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end