//
//  UIImageExtensions.swift
//  CapFinder
//
//  Created by User on 13.02.18.
//  Copyright © 2018 User. All rights reserved.
//

import Foundation
import UIKit

extension UIImage {

    static func templateImage(named: String) -> UIImage {
        return UIImage(named: named)!.withRenderingMode(.alwaysTemplate)
    }

    /**
     Resize an image to the target size
     */
    func resize(to targetSize: CGSize) -> UIImage {
        let rect = CGRect(x: 0, y: 0, width: targetSize.width, height: targetSize.height)

        UIGraphicsBeginImageContextWithOptions(targetSize, false, 1.0)
        self.draw(in: rect)
        let newImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return newImage!
    }

    /**
     Crop an image to a square, centered around the middle of the frame
     - parameter factor: The crop factor of the resulting image
     - returns: The cropped image
     */
    func crop(factor: CGFloat) -> UIImage {
        let width = self.size.width * factor
        return crop(to: width)
    }

    /**
     Crop an image to a square, centered around the middle of the frame
     - parameter size: The height and width of the resulting image
     - returns: The cropped image
     */
    func crop(to size: CGFloat) -> UIImage {
        var rect = CGRect(
            x: (self.size.height - size) / 2,
            y: (self.size.width - size) / 2,
            width: size,
            height: size)
        rect.origin.x *= scale
        rect.origin.y *= scale
        rect.size.width *= scale
        rect.size.height *= scale

        let imageRef = cgImage!.cropping(to: rect)
        return UIImage(cgImage: imageRef!, scale: scale, orientation: imageOrientation)
    }

    /// The (circular) image masked by a circle
    var circleMasked: UIImage? {
        let width = size.width
        let height = size.height
        let isPortrait = height > width
        let breadth = min(width, height)
        let breadthSize = CGSize(width: breadth, height: breadth)
        let breadthRect = CGRect(origin: .zero, size: breadthSize)
        UIGraphicsBeginImageContextWithOptions(breadthSize, false, scale)
        defer { UIGraphicsEndImageContext() }

        let x = isPortrait ? 0 : floor((width - height) / 2)
        let y = isPortrait ? floor((height - width) / 2) : 0
        let rect = CGRect(origin: CGPoint( x: x, y: y), size: breadthSize)
        guard let cgImage = cgImage?.cropping(to: rect) else {
            return nil
        }
        UIBezierPath(ovalIn: breadthRect).addClip()
        UIImage(cgImage: cgImage, scale: 1, orientation: imageOrientation).draw(in: breadthRect)
        return UIGraphicsGetImageFromCurrentImageContext()
    }
}