import Foundation

final class FileStore {
    static let shared = FileStore()

    static var fileFolder: URL {
        // swiftlint:disable:next force_unwrapping
        let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let subdirectoryURL = documentsURL.appendingPathComponent(Const.fileFolder)
        if !FileManager.default.fileExists(atPath: subdirectoryURL.path) {
            try? FileManager.default.createDirectory(at: subdirectoryURL, withIntermediateDirectories: true, attributes: nil)
        }
        return subdirectoryURL
    }

    func storeCaptured(messageId: String, _ data: Data, _ type: GalleryMediaType) async throws -> (String, AttachmentType) {
        try await Task {
            // local name
            let fileId = UUID().uuidString
            let localName: String
            let msgType: AttachmentType
            switch type {
            case .photo:
                localName = "\(messageId)_\(fileId).jpg"
                msgType = .image

            case .video:
                localName = "\(messageId)_\(fileId).mov"
                msgType = .video
            }

            // save
            let localUrl = FileStore.fileFolder.appendingPathComponent(localName)
            try data.write(to: localUrl)
            return (localName, msgType)
        }.value
    }
}

// import Foundation
// import Photos
// import UIKit
//
// final class FileProcessing {
//     static let shared = FileProcessing()
//
//     static var fileFolder: URL {
//         // swiftlint:disable:next force_unwrapping
//         let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
//         let subdirectoryURL = documentsURL.appendingPathComponent(Const.fileFolder)
//         if !FileManager.default.fileExists(atPath: subdirectoryURL.path) {
//             try? FileManager.default.createDirectory(at: subdirectoryURL, withIntermediateDirectories: true, attributes: nil)
//         }
//         return subdirectoryURL
//     }
//
//     func createThumbnail(localName: String) -> String? {
//         let thumbnailFileName = "thumb_\(localName)"
//         let thumbnailUrl = FileProcessing.fileFolder.appendingPathComponent(thumbnailFileName)
//         let localUrl = FileProcessing.fileFolder.appendingPathComponent(localName)
//
//         // check if thumbnail already exists
//         if FileManager.default.fileExists(atPath: thumbnailUrl.path) {
//             return thumbnailFileName
//         }
//
//         // create thumbnail if not exists
//         switch localName.attachmentType {
//         case .image:
//             guard let image = UIImage(contentsOfFile: localUrl.path) else {
//                 print("FileProcessing: Error loading image: \(localUrl)")
//                 return nil
//             }
//             let targetSize = CGSize(width: Const.attachmentPreviewSize, height: Const.attachmentPreviewSize)
//             guard let thumbnail = scaleAndCropImage(image, targetSize) else {
//                 print("FileProcessing: Error scaling image: \(localUrl)")
//                 return nil
//             }
//             guard let data = thumbnail.pngData() else {
//                 print("FileProcessing: Error converting thumbnail of \(localUrl) to data")
//                 return nil
//             }
//             do {
//                 try data.write(to: thumbnailUrl)
//                 return thumbnailFileName
//             } catch {
//                 print("FileProcessing: Error writing thumbnail: \(error)")
//                 return nil
//             }
//
//         default:
//             return nil
//         }
//     }
//
//     func fetchGallery() -> [SharingGalleryItem] {
//         let items = syncGalleryEnumerate()
//             .map {
//                 SharingGalleryItem(
//                     id: $0.localIdentifier,
//                     type: $0.mediaType == .image ? .photo : .video,
//                     duration: $0.mediaType == .video ? $0.duration.minAndSec : nil
//                 )
//             }
//         return items
//     }
//
//     func fillGalleryItemsThumbnails(items: [SharingGalleryItem]) -> [SharingGalleryItem] {
//         let ids = items
//             .filter { $0.thumbnail == nil }
//             .map { $0.id }
//
//         let assets = syncGalleryEnumerate(ids)
//         return assets.compactMap { asset in
//             if asset.mediaType == .image {
//                 return syncGalleryProcessImage(asset) { [weak self] image in
//                     if let thumbnail = self?.scaleAndCropImage(image, CGSize(width: Const.galleryGridSize, height: Const.galleryGridSize)) {
//                         let data = thumbnail.jpegData(compressionQuality: 1.0) ?? Data()
//                         return SharingGalleryItem(id: asset.localIdentifier, type: .photo, thumbnail: data)
//                     } else {
//                         return nil
//                     }
//                 }
//             } else if asset.mediaType == .video {
//                 return syncGalleryProcessVideo(asset) { [weak self] avAsset in
//                     // swiftlint:disable:next force_cast
//                     let assetURL = avAsset as! AVURLAsset
//                     let url = assetURL.url
//                     if let thumbnail = self?.generateVideoThumbnail(url, CGSize(width: Const.galleryGridSize, height: Const.galleryGridSize)) {
//                         let data = thumbnail.jpegData(compressionQuality: 1.0) ?? Data()
//                         return SharingGalleryItem(
//                             id: asset.localIdentifier,
//                             type: .video,
//                             thumbnail: data,
//                             duration: asset.duration.minAndSec
//                         )
//                     } else {
//                         return nil
//                     }
//                 }
//             } else {
//                 return nil
//             }
//         }
//     }
//
//     // This function also creates new ids for messages for each new attachment
//     func copyGalleryItemsForUploading(items: [SharingGalleryItem]) -> [(String, String)] {
//         let assets = syncGalleryEnumerate(items.map { $0.id })
//         return assets
//             .compactMap { asset in
//                 let newMessageId = UUID().uuidString
//                 let fileId = UUID().uuidString
//                 if asset.mediaType == .image {
//                     return syncGalleryProcessImage(asset) { image in
//                         let localName = "\(newMessageId)_\(fileId).jpg"
//                         let localUrl = FileProcessing.fileFolder.appendingPathComponent(localName)
//                         if let data = image.jpegData(compressionQuality: 1.0) {
//                             do {
//                                 try data.write(to: localUrl)
//                                 return (newMessageId, localName)
//                             } catch {
//                                 return nil
//                             }
//                         } else {
//                             return nil
//                         }
//                     }
//                 } else if asset.mediaType == .video {
//                     return syncGalleryProcessVideo(asset) { avAsset in
//                         // swiftlint:disable:next force_cast
//                         let assetURL = avAsset as! AVURLAsset
//                         let url = assetURL.url
//                         let localName = "\(newMessageId)_\(fileId).mov"
//                         let localUrl = FileProcessing.fileFolder.appendingPathComponent(localName)
//                         do {
//                             try FileManager.default.copyItem(at: url, to: localUrl)
//                             return (newMessageId, localName)
//                         } catch {
//                             return nil
//                         }
//                     }
//                 } else {
//                     return nil
//                 }
//             }
//     }
//
//     // This function also creates new id for file from camera capturing
//     func copyCameraCapturedForUploading(media: Data, type: SharingCameraMediaType) -> (String, String)? {
//         let newMessageId = UUID().uuidString
//         let fileId = UUID().uuidString
//         let localName: String
//         switch type {
//         case .photo:
//             localName = "\(newMessageId)_\(fileId).jpg"
//         case .video:
//             localName = "\(newMessageId)_\(fileId).mov"
//         }
//         let localUrl = FileProcessing.fileFolder.appendingPathComponent(localName)
//         do {
//             try media.write(to: localUrl)
//             return (newMessageId, localName)
//         } catch {
//             return nil
//         }
//     }
//
//     // This function also creates new id for file from document sharing
//     func copyDocumentsForUploading(data: [Data], extensions: [String]) -> [(String, String)] {
//         data.enumerated().compactMap { index, data in
//             let newMessageId = UUID().uuidString
//             let fileId = UUID().uuidString
//             let localName = "\(newMessageId)_\(fileId).\(extensions[index])"
//             let localUrl = FileProcessing.fileFolder.appendingPathComponent(localName)
//             do {
//                 try data.write(to: localUrl)
//                 return (newMessageId, localName)
//             } catch {
//                 print("FileProcessing: Error writing document: \(error)")
//                 return nil
//             }
//         }
//     }
// }
//
// private extension FileProcessing {
//     func scaleAndCropImage(_ img: UIImage, _ size: CGSize) -> UIImage? {
//         let aspect = img.size.width / img.size.height
//         let targetAspect = size.width / size.height
//         var newWidth: CGFloat
//         var newHeight: CGFloat
//         if aspect < targetAspect {
//             newWidth = size.width
//             newHeight = size.width / aspect
//         } else {
//             newHeight = size.height
//             newWidth = size.height * aspect
//         }
//
//         UIGraphicsBeginImageContextWithOptions(size, false, 0.0)
//         img.draw(in: CGRect(x: (size.width - newWidth) / 2, y: (size.height - newHeight) / 2, width: newWidth, height: newHeight))
//         let newImage = UIGraphicsGetImageFromCurrentImageContext()
//         UIGraphicsEndImageContext()
//
//         return newImage
//     }
//
//     func syncGalleryEnumerate(_ ids: [String]? = nil) -> [PHAsset] {
//         var result: [PHAsset] = []
//
//         let group = DispatchGroup()
//         DispatchQueue.global(qos: .userInitiated).sync {
//             let fetchOptions = PHFetchOptions()
//             fetchOptions.sortDescriptors = [NSSortDescriptor(key: "creationDate", ascending: false)]
//             if let ids {
//                 fetchOptions.predicate = NSPredicate(format: "localIdentifier IN %@", ids)
//             }
//             let assets = PHAsset.fetchAssets(with: fetchOptions)
//             assets.enumerateObjects { asset, _, _ in
//                 group.enter()
//                 result.append(asset)
//                 group.leave()
//             }
//         }
//         group.wait()
//         return result
//     }
//
//     func syncGalleryProcess<T>(_ assets: [PHAsset], _ block: @escaping (PHAsset) -> T) -> [T] {
//         var result: [T] = []
//         let group = DispatchGroup()
//         DispatchQueue.global(qos: .userInitiated).sync {
//             for asset in assets {
//                 group.enter()
//                 let res = block(asset)
//                 result.append(res)
//                 group.leave()
//             }
//         }
//         group.wait()
//         return result
//     }
//
//     func syncGalleryProcessImage<T>(_ asset: PHAsset, _ block: @escaping (UIImage) -> T?) -> T? {
//         var result: T?
//         let semaphore = DispatchSemaphore(value: 0)
//         DispatchQueue.global(qos: .userInitiated).sync {
//             let options = PHImageRequestOptions()
//             options.version = .original
//             options.isSynchronous = true
//             PHImageManager.default().requestImage(
//                 for: asset,
//                 targetSize: PHImageManagerMaximumSize,
//                 contentMode: .aspectFill,
//                 options: options
//             ) { image, _ in
//                 if let image {
//                     result = block(image)
//                 } else {
//                     result = nil
//                 }
//                 semaphore.signal()
//             }
//         }
//         semaphore.wait()
//         return result
//     }
//
//     func syncGalleryProcessVideo<T>(_ asset: PHAsset, _ block: @escaping (AVAsset) -> T?) -> T? {
//         var result: T?
//         let semaphore = DispatchSemaphore(value: 0)
//         _ = DispatchQueue.global(qos: .userInitiated).sync {
//             PHImageManager.default().requestAVAsset(forVideo: asset, options: nil) { avAsset, _, _ in
//                 if let avAsset {
//                     result = block(avAsset)
//                 } else {
//                     result = nil
//                 }
//                 semaphore.signal()
//             }
//         }
//         semaphore.wait()
//         return result
//     }
//
//     func generateVideoThumbnail(_ url: URL, _ size: CGSize) -> UIImage? {
//         let asset = AVAsset(url: url)
//         let assetImgGenerate = AVAssetImageGenerator(asset: asset)
//         assetImgGenerate.appliesPreferredTrackTransform = true
//         let time = CMTimeMakeWithSeconds(Float64(1), preferredTimescale: 600)
//         do {
//             let cgImage = try assetImgGenerate.copyCGImage(at: time, actualTime: nil)
//             let image = UIImage(cgImage: cgImage)
//             return scaleAndCropImage(image, size)
//         } catch {
//             return nil
//         }
//     }
// }

// import Foundation
//
// final class DownloadManager {
//     static let shared = DownloadManager()
//
//     private let urlSession: URLSession
//     private let downloadQueue = DispatchQueue(label: "com.example.downloadQueue")
//     private var activeDownloads = Set<URL>()
//
//     init() {
//         let configuration = URLSessionConfiguration.default
//         urlSession = URLSession(configuration: configuration)
//     }
//
//     func enqueueDownload(from url: URL, to localUrl: URL, completion: @escaping (Error?) -> Void) {
//         downloadQueue.async {
//             if self.activeDownloads.contains(url) {
//                 print("Download for this file is already in queue.")
//                 return
//             }
//
//             self.activeDownloads.insert(url)
//
//             let task = self.urlSession.downloadTask(with: url) { tempLocalUrl, _, error in
//                 self.downloadQueue.async {
//                     self.activeDownloads.remove(url)
//
//                     guard let tempLocalUrl = tempLocalUrl, error == nil else {
//                         completion(error)
//                         return
//                     }
//
//                     do {
//                         if FileManager.default.fileExists(atPath: localUrl.path) {
//                             try FileManager.default.removeItem(at: localUrl)
//                         }
//                         let data = try Data(contentsOf: tempLocalUrl)
//                         try data.write(to: localUrl)
//                         completion(nil)
//                     } catch let writeError {
//                         completion(writeError)
//                     }
//                 }
//             }
//             task.resume()
//         }
//     }
// }