#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
#import "WebViewController.h" //创建webview

static const char *kScanQRCodeQueueName = "ScanQRCodeQueue"; //自定义线程的名字

@interface ViewController ()<AVCaptureMetadataOutputObjectsDelegate>

@property (weak, nonatomic) IBOutlet UIView *sanFrameView; //扫描窗口

@property (weak, nonatomic) IBOutlet UIButton *lightButton; //灯按钮

@property (weak, nonatomic) IBOutlet UIButton *captureButton; //开始扫描按钮

@property (nonatomic) AVCaptureSession *captureSession; //会话，用于添加输入流和输出流
@property (nonatomic) AVCaptureVideoPreviewLayer *videoPreviewLayer; //输出对象
@property (nonatomic) BOOL lastResult;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    /**
     基本逻辑：
     扫描二维码，将扫描到的网址二维码直接扔到webview中进行显示
     */
    
    [self.lightButton setTitle:@"打开照明" forState:UIControlStateNormal]; //设置灯按钮的初始状态
    [self.captureButton setTitle:@"开始" forState:UIControlStateNormal]; //设置扫描按钮的状态
    self.lastResult = YES; //初始化判断
    
}

#pragma mark **************扫描部分 begin*****************
#pragma mark 扫描按钮点击事件
- (IBAction)captureButtonClick:(UIButton *)sender {
    
    if ([self.captureButton.titleLabel.text isEqualToString:@"开始"]) {
        [self startReading];
    } else {
        [self stopReading];
    }
}


#pragma mrak 开始扫描方法
- (BOOL)startReading {
    
    [self.captureButton setTitle:@"停止" forState:UIControlStateNormal];
    
#pragma mark 获取设备实例
    NSError *error;
    AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    
#pragma mark 创建会话
    self.captureSession = [[AVCaptureSession alloc] init];
    
#pragma mark 创建输入流
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];
    //如果设备输入流不存在，直接返回
    if (!input) {
        NSLog(@"%@",[error localizedDescription]);
        return NO;
    }
    
    [self.captureSession addInput:input]; //会话添加输入流
    
#pragma mark 创建输出流
    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
    [self.captureSession addOutput:output]; //会话添加输出流
    
#pragma mark 添加输出代理，用于接收输出的数据
    dispatch_queue_t dispatchQueue = dispatch_queue_create(kScanQRCodeQueueName, NULL);
    [output setMetadataObjectsDelegate:self queue:dispatchQueue];
    
#pragma mark 设置输出的元数据类型 AVMetadataObjectTypeQRCode 二维码类型
    [output setMetadataObjectTypes:[NSArray arrayWithObject:AVMetadataObjectTypeQRCode]];
    
#pragma mark 根据会话设置创建输出对象
    self.videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:self.captureSession];
    [self.videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
    self.videoPreviewLayer.frame = self.sanFrameView.layer.bounds;
    [self.sanFrameView.layer addSublayer:self.videoPreviewLayer];
    //设置完成，开始会话
    [self.captureSession startRunning];
    
    return YES;
}

#pragma mark 停止扫描方法
- (void)stopReading {
    [self.captureButton setTitle:@"开始" forState:UIControlStateNormal];
    [self.captureSession stopRunning];
    self.captureSession = nil;
}

#pragma mark 输出流代理方法
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection {
    
    if (metadataObjects != nil && metadataObjects.count) {
        
        AVMetadataMachineReadableCodeObject *metadataObject = [metadataObjects objectAtIndex:0];
        NSString *result;
        if ([[metadataObject type] isEqualToString:AVMetadataObjectTypeQRCode]) {
            result = metadataObject.stringValue;
        } else {
            NSLog(@"不是二维码");
        }
        //将结果带到主线程，进行确认
        [self performSelectorOnMainThread:@selector(outputResult:) withObject:result waitUntilDone:NO];
    }
}

#pragma mark 接收扫描的内容
- (void)outputResult:(NSString *)result {
    
    [self stopReading]; //得到结果，结束读取
    if (!_lastResult) {
        return;
    }
    
    NSLog(@"result = %@",result);
    _lastResult = NO;
    
#pragma mark 创建一个警告controller
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"二维码扫描" message:result preferredStyle:UIAlertControllerStyleAlert];
#pragma mark 创建取消按钮
    UIAlertAction *concelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil];
    
#pragma mark 添加一个确认按钮 实现按钮的点击事件
    UIAlertAction *getAction = [UIAlertAction actionWithTitle:@"确认" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        
        WebViewController *webview = [[WebViewController alloc] init];
        webview.url = result;
        [self.navigationController pushViewController:webview animated:YES];
        
        NSLog(@"将内容推出去");
    }];
    [alertController addAction:concelAction]; //添加取消按钮
    [alertController addAction:getAction]; //添加确认按钮
#pragma mark 模态视图出现
    [self presentViewController:alertController animated:YES completion:nil];
    
    _lastResult = YES;
}

#pragma mark **************扫描部分 end*******************

#pragma mark **************灯 begin*******************
#pragma mark 灯按钮的点击事件
- (IBAction)lightButtonClick:(UIButton *)sender {
    
    if ([self.lightButton.titleLabel.text isEqualToString:@"打开照明"]) {
        [self systemLightSwith:YES];
    } else {
        [self systemLightSwith:NO];
    }

}

#pragma mark 灯触发事件
- (void)systemLightSwith:(BOOL)open {
    
    //改变按钮的状态
    if (open) {
        [self.lightButton setTitle:@"关闭" forState:UIControlStateNormal];
    } else {
        [self.lightButton setTitle:@"打开照明" forState:UIControlStateNormal];
    }
    
    //获取当前的设备
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    //如果存在设备，设置
    if ([device hasTorch]) {
        [device lockForConfiguration:nil];
        
        if (open) { //打开
            [device setTorchMode:AVCaptureTorchModeOn];
        } else { //关闭
            [device setTorchMode:AVCaptureTorchModeOff];
        }
        
        [device unlockForConfiguration];
    } else {
        NSLog(@"不存在照明设备");
    }
    
}
#pragma mark **************灯 end*******************

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

@end