//
//  CameraController.swift
//  CapFinder
//
//  Created by User on 22.02.18.
//  Copyright © 2018 User. All rights reserved.
//

import UIKit

protocol CameraControllerDelegate {
    
    func didCapture(image: UIImage)
    
    func didCancel()
}

class CameraController: UIViewController {

    private let imageSize = 299 // New for XCode models, 227/229 for turicreate

    // MARK: Outlets

    @IBOutlet weak var imageButton: RoundedButton!

    @IBOutlet weak var cropView: CropView!

    @IBOutlet weak var cancelButton: RoundedButton!

    @IBOutlet weak var cameraView: CameraView! {
        didSet {
            cameraView.configure()
        }
    }
    
    var delegate: CameraControllerDelegate?
    
    override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
        return .portrait
    }
    
    override var preferredInterfaceOrientationForPresentation: UIInterfaceOrientation {
        return .portrait
    }
    
    override var shouldAutorotate: Bool {
        return false
    }

    // MARK: Actions

    @IBAction func backButtonPressed() {
        self.giveFeedback(.medium)
        delegate?.didCancel()
        self.dismiss(animated: true)
    }

    @IBAction func imageButtonPressed() {
        self.giveFeedback(.medium)
        imageButton.isEnabled = false
        cameraView.capture()
    }

    // MARK: Life cycle

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        cameraView.delegate = self
        imageButton.imageView?.image = UIImage.templateImage(named: "camera")
        setTintColor()

        cameraView.launch { success, error in
            guard let err = error else {
                return
            }
            switch err {
            case "No camera access": self.showNoCameraAccessAlert()
            case "Camera error": self.showAlert("Unable to capture media")
            default: self.showAlert("Error in camera setup")
            }
        }
        self.imageButton.isEnabled = true
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        cameraView.complete()
    }

    private func setTintColor() {
        let tint = AppDelegate.tintColor
        cropView.lineColor = tint
        imageButton.borderColor = tint
        imageButton.imageView?.tintColor = tint
        cancelButton.borderColor = tint
        cancelButton.set(template: "cancel", with: tint)
    }
    
    private func giveFeedback(_ style: UIImpactFeedbackGenerator.FeedbackStyle) {
        let generator = UIImpactFeedbackGenerator(style: style)
        generator.impactOccurred()
    }

    // MARK: Alerts
    
    private func showNoCameraAccessAlert() {
        let alert = UIAlertController(title: "Unable to access the Camera",
                                      message: "To enable access, go to Settings > Privacy > Camera and turn on Camera access for this app.",
                                      preferredStyle: .alert,
                                      blurStyle: .dark)

        let okAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
        alert.addAction(okAction)

        let settingsAction = UIAlertAction(title: "Settings", style: .default, handler: { _ in
            // Take the user to Settings app to possibly change permission.
            guard let settingsUrl = URL(string: UIApplication.openSettingsURLString) else { return }
            if UIApplication.shared.canOpenURL(settingsUrl) {
                UIApplication.shared.open(settingsUrl, completionHandler: nil)
            }
        })
        alert.addAction(settingsAction)
        self.present(alert, animated: true, completion: nil)
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        cameraView.didReceiveTouch(touches.first!)
    }
}

extension CameraController: PhotoCaptureHandlerDelegate {

    func didCapture(_ image: UIImage?) {
        event("Image captured")
        let factor = CGFloat(cropView.relativeSize)
        self.dismiss(animated: true)
        let size = CGSize(width: imageSize, height: imageSize)
        guard let img = image else {
            self.error("No image captured")
            return
        }
        
        guard delegate != nil else {
            self.error("No delegate")
            return
        }
        
        guard let masked = img.crop(factor: factor).circleMasked else {
            self.error("Could not mask image")
            return
        }
        
        // Only use 227 x 227 image
        let scaled = masked.resize(to: size)
        
        delegate!.didCapture(image: scaled)
    }
}

extension CameraController: Logger {

    static var logToken = "[Camera]"
}