//

//  ViewController.swift

//  QrCodeTest

//

//  Created by XuAlvin on 2/2/16.

//  Copyright © 2016年 XuAlvin. All rights reserved.

//

import UIKit

import AVFoundation

class ViewController: UIViewController,AVCaptureMetadataOutputObjectsDelegate {

    var session:AVCaptureSession?

    override func viewDidLoad() {

        super.viewDidLoad()

        //获取摄像设备,注意是Video而不是Audio

        let device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)

        //初始化AV Session来协调和处理AV的输入和输出流

        let session = AVCaptureSession()

        //创建输入流

        let input:AVCaptureDeviceInput? = try! AVCaptureDeviceInput(device: device)

        if session.canAddInput(input){

            session.addInput(input)

        }

        //创建输出流

        let output:AVCaptureMetadataOutput = AVCaptureMetadataOutput()

        if session.canAddOutput(output){

            session.addOutput(output)

            //设置输出流代理，从接收端收到的所有元数据都会被传送到delegate方法，所有delegate方法均在queue中执行

            output.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())

            //设置元数据的类型，这里是二维码QRCode

            output.metadataObjectTypes = [AVMetadataObjectTypeQRCode]

        }

        //创建视频设备拍摄视频区域，本例中是全屏

        let layer:AVCaptureVideoPreviewLayer = AVCaptureVideoPreviewLayer.init(session: session)

        layer.videoGravity = AVLayerVideoGravityResizeAspectFill

        layer.frame=self.view.layer.bounds

        self.view.layer.insertSublayer(layer, atIndex: 0)

        //开始采集视频数据

        session.startRunning()

        }

        //实现AVCaptureMetadataOutputObjectsDelegate的成员方法来处理二维码信息

        func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {

            session?.stopRunning()

            //获取二维码信息元数据

            if let metadataObjects = metadataObjects.first{

                let readableObject = metadataObjects as! AVMetadataMachineReadableCodeObject

                //添加震动

                AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))

                //弹出二维码信息

                let alertCtl : UIAlertController = UIAlertController(title: "二维码信息", message: readableObject.stringValue, preferredStyle: UIAlertControllerStyle.Alert)

                //添加action到uialertcontroller，action是UIalertcontroller上的按钮操作，建议至少添加一个，如果不添加，alertcontroller就没有相应的按钮退出

                let alertAction : UIAlertAction = UIAlertAction(title: "Action", style: UIAlertActionStyle.Default, handler: { (param : UIAlertAction!) -> Void in

                    print("I am alert action")

                })

                alertCtl.addAction(alertAction)

                //显示alert controller

                self.presentViewController(alertCtl, animated: true, completion: nil)

            }

        }

}