import AVKit

let fileURL = Bundle.main.url(forResource: "1", withExtension: "mp4")
let fileURL1 = Bundle.main.url(forResource: "2", withExtension: "mp4")
let fileURL2 = Bundle.main.url(forResource: "3", withExtension: "MOV")
let fileURL3 = Bundle.main.url(forResource: "4", withExtension: "mp4")
let fileURLs = [fileURL, fileURL1, fileURL2, fileURL3]


/// Multiple videos merge in one video with manage scale & aspect ratio
/// - Parameters:
///   - videoFileURLs: Video file path URLs, Array of videos that going to merge
///   - videoResolution: Output video resolution, (defult:  CGSize(width: -1, height: -1), find max width and height from provided videos)
///   - videoQuality: AVAssetExportPresetMediumQuality(default) , AVAssetExportPresetLowQuality , AVAssetExportPresetHighestQuality
///   - completion: Completion give  2 optional  values, 1)mergedVideoURL: URL path of successfully merged video   2)error: Gives Error object if some error occur in videos merging process
///   - mergedVideoURL: URL path of successfully merged video
///   - error: Gives Error object if some error occur in videos merging process
DPVideoMerger().mergeVideos(withFileURLs: fileURLs as! [URL], completion: {(_ mergedVideoFile: URL?, _ error: Error?) -> Void in
    if error != nil {
        let errorMessage = "Could not merge videos: \(error?.localizedDescription ?? "error")"
        let alert = UIAlertController(title: "Error", message: errorMessage, preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { (a) in
        }))
        self.present(alert, animated: true) {() -> Void in }
        return
    }
    let objAVPlayerVC = AVPlayerViewController()
    objAVPlayerVC.player = AVPlayer(url: mergedVideoFile!)
    self.present(objAVPlayerVC, animated: true, completion: {() -> Void in
        objAVPlayerVC.player?.play()
    }) 
})


/// Merge  videos to grid matrix layout
/// - Parameters:
///   - videoFileURLs: Video file path URLs, Array of videos that going to grid merge
///   - matrix: Video matrix position (eg 3x3, 4x2, 1x3, ...) (default:- 2x2)
///   - audioFileURL: Optional audio file for Merged Video
///   - videoResolution: Output video resolution
///   - isRepeatVideo: Repeat Video on grid if one or more video have shorter duartion time then output video duration
///   - isRepeatAudio: Repeat Audio if Merged video have longer duartion time then provided Audio duration
///   - isAudio: Allow Audio for grid video (default :- true)
///   - videoDuration: Output video duration (defult:  -1, find max duration from provided  videos)
///   - videoQuality: AVAssetExportPresetMediumQuality(default) , AVAssetExportPresetLowQuality , AVAssetExportPresetHighestQuality
///   - completion: completion give  2 optional  values, 1)mergedVideoURL: URL path of successfully grid merged video  2)error: gives Error object if some error occur in videos merging process
///   - mergedVideoURL: URL path of successfully grid merged video
///   - error: gives Error object if some error occur in videos merging process
DPVideoMerger().gridMergeVideos(withFileURLs: fileURLs, videoResolution: CGSize(width: 1000, height: 1000), completion: {(_ mergedVideoFile: URL?, _ error: Error?) -> Void in
    if error != nil {
        let errorMessage = "Could not merge videos: \(error?.localizedDescription ?? "error")"
        let alert = UIAlertController(title: "Error", message: errorMessage, preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "OK", style: .default, handler: { (a) in
        }))
        self.present(alert, animated: true) {() -> Void in }
        return
    }
    let objAVPlayerVC = AVPlayerViewController()
    objAVPlayerVC.player = AVPlayer(url: mergedVideoFile!)
    self.present(objAVPlayerVC, animated: true, completion: {() -> Void in
        objAVPlayerVC.player?.play()
    })
})