import CoreGraphics
import SwiftUI
/*
 Copyright (C) 2024 Rubén Beltrán del Río

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program. If not, see https://captura.tranquil.systems.
 */
import UniformTypeIdentifiers

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)
    }
  }
}