MLViewController

//
//  AppDelegate.swift
//  ImageClassifierApp
//
//  Created by Nav Singh on 10/5/20.
//  Copyright © 2020 Nav Singh . All rights reserved.
//

import UIKit
import CoreML
import Vision

class ViewController: UIViewController {

    @IBOutlet weak var classifyButton: UIBarButtonItem!
    @IBOutlet weak var imageView: UIImageView!
    @IBOutlet weak var classifyLabel: UILabel!
    @IBOutlet weak var imageSizeConstraint: NSLayoutConstraint?

    //image classifying code here!
    @IBAction func didTapClassify(_ sender: Any) {
       guard  let model = try? VNCoreMLModel(for: MyImageClassifier_2().model) else {return}
        let request = VNCoreMLRequest(model: model, completionHandler: {request, error in
            guard let results = request.results else { return }
            print(results)
            guard let firstResult = results.first as? VNClassificationObservation else {return}
            self.classifyLabel.text = firstResult.identifier
        })
        
        guard let image = imageView.image else {return}   
        let handler = VNImageRequestHandler(cgImage: image.cgImage!, orientation: .up)        
        try? handler.perform([request])
    }
}

extension ViewController: UIImagePickerControllerDelegate, UINavigationControllerDelegate {

    @IBAction func didTapChoose(_ sender: Any) {
        // Present an image picker view controller
        let imagePicker = UIImagePickerController()
        imagePicker.sourceType = .photoLibrary
        imagePicker.allowsEditing = false
        imagePicker.delegate = self
        self.present(imagePicker, animated: true, completion: nil)
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

        // Set the image to our image view
        guard let image = info[.originalImage] as? UIImage else { return }
        imageView.image = image

        // Change the aspect ratio of the image to match
        if let imageView = imageView {
            if let constraint = imageSizeConstraint {
                imageView.removeConstraint(constraint)
            }
            let aspectRatio = image.size.height / image.size.width
            let constraint = NSLayoutConstraint(item: imageView, attribute: .height,
                                       relatedBy: .equal,
                                       toItem: imageView, attribute: .width,
                                       multiplier: aspectRatio, constant: 0)
            imageView.addConstraint(constraint)
            self.imageSizeConstraint = constraint
        }

        // Dismiss the image picker
        dismiss(animated: true, completion: nil)

        // Enable the classify button
        //reset the state of label
        self.classifyLabel.text = "...."
        classifyButton.isEnabled = true
    }
}