import UniformTypeIdentifiers
import SwiftUI
import CoreGraphics

struct GifRenderer {
  static func render(_ images: [CGImage], at fps: Int, to url: URL) async {
    let framedelay = String(format: "%.3f", 1.0 / Double(fps))
    let fileProperties = [kCGImagePropertyGIFDictionary as String: [kCGImagePropertyGIFLoopCount as String: 0]]
    let gifProperties = [kCGImagePropertyGIFDictionary as String: [kCGImagePropertyGIFUnclampedDelayTime as String: framedelay]]
    let cfURL = url as CFURL
    if let destination = CGImageDestinationCreateWithURL(cfURL, UTType.gif.identifier as CFString, images.count, nil) {
      CGImageDestinationSetProperties(destination, fileProperties as CFDictionary?)
      for image in images {
        CGImageDestinationAddImage(destination, image, gifProperties as CFDictionary?)
      }
      CGImageDestinationFinalize(destination)
    }
  }
}