//
//  SPFadeEdgeImageView.swift
//  ThimraTV
//
//  Created by 佳尔 on 2025/4/28.
//

import UIKit

class SPFadeEdgeImageView: UIImageView {
    
    
    private var blurredImage: UIImage?
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        applyCircularFade()
    }
    
    /// 给当前视图添加一个圆形渐隐遮罩
    func applyCircularFade(radius: CGFloat? = nil) {
        let maskLayer = CALayer()
        maskLayer.frame = bounds
        
        // 渲染一个径向渐变图像
        UIGraphicsBeginImageContextWithOptions(bounds.size, false, 0)
        guard let ctx = UIGraphicsGetCurrentContext() else { return }
        
        let center = CGPoint(x: bounds.midX, y: bounds.midY)
        let maxRadius = radius ?? min(bounds.width, bounds.height) / 2
        
        let colorSpace = CGColorSpaceCreateDeviceGray()
        let colors: [CGFloat] = [1, 1, 0, 0] // 中心透明度1，边缘透明度0
        let locations: [CGFloat] = [0, 1]
        
        if let gradient = CGGradient(colorSpace: colorSpace, colorComponents: colors, locations: locations, count: 2) {
            ctx.drawRadialGradient(
                gradient,
                startCenter: center, startRadius: 0,
                endCenter: center, endRadius: maxRadius,
                options: .drawsAfterEndLocation
            )
        }
        
        let maskImage = UIGraphicsGetImageFromCurrentImageContext()?.cgImage
        UIGraphicsEndImageContext()
        
        maskLayer.contents = maskImage
        self.layer.mask = maskLayer
    }
    
}