import Foundation
import Postbox
import SwiftSignalKit
import LegacyComponents
import FFMpeg

private final class AVURLAssetCopyItem: MediaResourceDataFetchCopyLocalItem {
    private let url: URL
    
    init(url: URL) {
        self.url = url
    }
    
    func copyTo(url: URL) -> Bool {
        var success = true
        do {
            try FileManager.default.copyItem(at: self.url, to: url)
        } catch {
            success = false
        }
        return success
    }
}

class VideoConversionWatcher: TGMediaVideoFileWatcher {
    private let update: (String, Int) -> Void
    private var path: String?
    
    init(update: @escaping (String, Int) -> Void) {
        self.update = update
        
        super.init()
    }
    
    override func setup(withFileURL fileURL: URL!) {
        self.path = fileURL?.path
        super.setup(withFileURL: fileURL)
    }
    
    override func fileUpdated(_ completed: Bool) -> Any! {
        if let path = self.path {
            var value = stat()
            if stat(path, &value) == 0 {
                self.update(path, Int(value.st_size))
            }
        }
        
        return super.fileUpdated(completed)
    }
}

public func fetchVideoLibraryMediaResource(resource: VideoLibraryMediaResource) -> Signal<MediaResourceDataFetchResult, MediaResourceDataFetchError> {
    return Signal { subscriber in
        subscriber.putNext(.reset)
        
        let fetchResult = PHAsset.fetchAssets(withLocalIdentifiers: [resource.localIdentifier], options: nil)
        var requestId: PHImageRequestID?
        let disposable = MetaDisposable()
        if fetchResult.count != 0 {
            let asset = fetchResult.object(at: 0)
            let option = PHVideoRequestOptions()
            option.isNetworkAccessAllowed = true
            option.deliveryMode = .highQualityFormat
            
            let alreadyReceivedAsset = Atomic<Bool>(value: false)
            requestId = PHImageManager.default().requestAVAsset(forVideo: asset, options: option, resultHandler: { avAsset, _, _ in
                if avAsset == nil {
                    return
                }
                
                if alreadyReceivedAsset.swap(true) {
                    return
                }
                
                var adjustments: TGVideoEditAdjustments?
                switch resource.conversion {
                    case .passthrough:
                        if let asset = avAsset as? AVURLAsset {
                            var value = stat()
                            if stat(asset.url.path, &value) == 0 {
                                subscriber.putNext(.copyLocalItem(AVURLAssetCopyItem(url: asset.url)))
                                subscriber.putCompletion()
                            } else {
                                subscriber.putError(.generic)
                            }
                            return
                        } else {
                            adjustments = nil
                        }
                    case let .compress(adjustmentsValue):
                        if let adjustmentsValue = adjustmentsValue {
                            if let dict = NSKeyedUnarchiver.unarchiveObject(with: adjustmentsValue.data.makeData()) as? [AnyHashable : Any] {
                                adjustments = TGVideoEditAdjustments(dictionary: dict)
                            }
                        }
                }
                let updatedSize = Atomic<Int>(value: 0)
                let signal = TGMediaVideoConverter.convert(avAsset, adjustments: adjustments, watcher: VideoConversionWatcher(update: { path, size in
                    var value = stat()
                    if stat(path, &value) == 0 {
                        /*if let data = try? Data(contentsOf: URL(fileURLWithPath: path), options: [.mappedRead]) {
                            var range: Range<Int>?
                            let _ = updatedSize.modify { updatedSize in
                                range = updatedSize ..< Int(value.st_size)
                                return Int(value.st_size)
                            }
                            //print("size = \(Int(value.st_size)), range: \(range!)")
                            subscriber.putNext(.dataPart(resourceOffset: range!.lowerBound, data: data, range: range!, complete: false))
                        }*/
                    }
                }))!
                let signalDisposable = signal.start(next: { next in
                    if let result = next as? TGMediaVideoConversionResult {
                        var value = stat()
                        if stat(result.fileURL.path, &value) == 0 {
                            /*let tempFile = TempBox.shared.tempFile(fileName: "video.mp4")
                            if FFMpegRemuxer.remux(result.fileURL.path, to: tempFile.path) {
                                let _ = try? FileManager.default.removeItem(atPath: result.fileURL.path)
                                subscriber.putNext(.moveTempFile(file: tempFile))
                            } else {
                                TempBox.shared.dispose(tempFile)*/
                                subscriber.putNext(.moveLocalFile(path: result.fileURL.path))
                            //}
                            /*if let data = try? Data(contentsOf: result.fileURL, options: [.mappedRead]) {
                                var range: Range<Int>?
                                let _ = updatedSize.modify { updatedSize in
                                    range = updatedSize ..< Int(value.st_size)
                                    return Int(value.st_size)
                                }
                                //print("finish size = \(Int(value.st_size)), range: \(range!)")
                                subscriber.putNext(.dataPart(resourceOffset: range!.lowerBound, data: data, range: range!, complete: false))
                                subscriber.putNext(.replaceHeader(data: data, range: 0 ..< 1024))
                                subscriber.putNext(.dataPart(resourceOffset: data.count, data: Data(), range: 0 ..< 0, complete: true))
                            }*/
                            subscriber.putNext(.moveLocalFile(path: result.fileURL.path))
                        } else {
                            subscriber.putError(.generic)
                        }
                        subscriber.putCompletion()
                    }
                }, error: { _ in
                    subscriber.putError(.generic)
                }, completed: nil)
                disposable.set(ActionDisposable {
                    signalDisposable?.dispose()
                })
            })
        }
        
        return ActionDisposable {
            if let requestId = requestId {
                PHImageManager.default().cancelImageRequest(requestId)
            }
            disposable.dispose()
        }
    }
}

func fetchLocalFileVideoMediaResource(resource: LocalFileVideoMediaResource) -> Signal<MediaResourceDataFetchResult, MediaResourceDataFetchError> {
    return Signal { subscriber in
        subscriber.putNext(.reset)
        
        let avAsset = AVURLAsset(url: URL(fileURLWithPath: resource.path))
        var adjustments: TGVideoEditAdjustments?
        if let videoAdjustments = resource.adjustments {
            if let dict = NSKeyedUnarchiver.unarchiveObject(with: videoAdjustments.data.makeData()) as? [AnyHashable : Any] {
                adjustments = TGVideoEditAdjustments(dictionary: dict)
            }
        }
        let updatedSize = Atomic<Int>(value: 0)
        let signal = TGMediaVideoConverter.convert(avAsset, adjustments: adjustments, watcher: VideoConversionWatcher(update: { path, size in
            var value = stat()
            if stat(path, &value) == 0 {
                /*if let data = try? Data(contentsOf: URL(fileURLWithPath: path), options: [.mappedRead]) {
                    var range: Range<Int>?
                    let _ = updatedSize.modify { updatedSize in
                        range = updatedSize ..< Int(value.st_size)
                        return Int(value.st_size)
                    }
                    //print("size = \(Int(value.st_size)), range: \(range!)")
                    subscriber.putNext(.dataPart(resourceOffset: range!.lowerBound, data: data, range: range!, complete: false))
                }*/
            }
        }))!
        let signalDisposable = signal.start(next: { next in
            if let result = next as? TGMediaVideoConversionResult {
                var value = stat()
                if stat(result.fileURL.path, &value) == 0 {
                    subscriber.putNext(.moveLocalFile(path: result.fileURL.path))
                    /*if let data = try? Data(contentsOf: result.fileURL, options: [.mappedRead]) {
                        var range: Range<Int>?
                        let _ = updatedSize.modify { updatedSize in
                            range = updatedSize ..< Int(value.st_size)
                            return Int(value.st_size)
                        }
                        //print("finish size = \(Int(value.st_size)), range: \(range!)")
                        subscriber.putNext(.dataPart(resourceOffset: range!.lowerBound, data: data, range: range!, complete: false))
                        subscriber.putNext(.replaceHeader(data: data, range: 0 ..< 1024))
                        subscriber.putNext(.dataPart(resourceOffset: 0, data: Data(), range: 0 ..< 0, complete: true))
                    }*/
                }
                subscriber.putCompletion()
            }
        }, error: { _ in
        }, completed: nil)
        
        let disposable = ActionDisposable {
            signalDisposable?.dispose()
        }
        
        return ActionDisposable {
            disposable.dispose()
        }
    }
}

public func fetchVideoLibraryMediaResourceHash(resource: VideoLibraryMediaResource) -> Signal<Data?, NoError> {
    return Signal { subscriber in
        let fetchResult = PHAsset.fetchAssets(withLocalIdentifiers: [resource.localIdentifier], options: nil)
        var requestId: PHImageRequestID?
        let disposable = MetaDisposable()
        if fetchResult.count != 0 {
            let asset = fetchResult.object(at: 0)
            let option = PHVideoRequestOptions()
            option.isNetworkAccessAllowed = true
            option.deliveryMode = .highQualityFormat
            
            let alreadyReceivedAsset = Atomic<Bool>(value: false)
            requestId = PHImageManager.default().requestAVAsset(forVideo: asset, options: option, resultHandler: { avAsset, _, info in
                if avAsset == nil {
                    subscriber.putNext(nil)
                    subscriber.putCompletion()
                    return
                }
                
                if alreadyReceivedAsset.swap(true) {
                    return
                }
                
                var adjustments: TGVideoEditAdjustments?
                var isPassthrough = false
                switch resource.conversion {
                    case .passthrough:
                        isPassthrough = true
                        adjustments = nil
                    case let .compress(adjustmentsValue):
                        if let adjustmentsValue = adjustmentsValue {
                            if let dict = NSKeyedUnarchiver.unarchiveObject(with: adjustmentsValue.data.makeData()) as? [AnyHashable : Any] {
                                adjustments = TGVideoEditAdjustments(dictionary: dict)
                            }
                        }
                }
                let signal = TGMediaVideoConverter.hash(for: avAsset, adjustments: adjustments)!
                let signalDisposable = signal.start(next: { next in
                    if let next = next as? String, let data = next.data(using: .utf8) {
                        var updatedData = data
                        if isPassthrough {
                            updatedData.reverse()
                        }
                        subscriber.putNext(updatedData)
                    } else {
                        subscriber.putNext(nil)
                    }
                    subscriber.putCompletion()
                }, error: { _ in
                }, completed: nil)
                disposable.set(ActionDisposable {
                    signalDisposable?.dispose()
                })
            })
        }
        
        return ActionDisposable {
            if let requestId = requestId {
                PHImageManager.default().cancelImageRequest(requestId)
            }
            disposable.dispose()
        }
    }
}

func fetchLocalFileGifMediaResource(resource: LocalFileGifMediaResource) -> Signal<MediaResourceDataFetchResult, MediaResourceDataFetchError> {
    return Signal { subscriber in
        subscriber.putNext(.reset)
        
        let disposable = MetaDisposable()
        if let data = try? Data(contentsOf: URL(fileURLWithPath: resource.path), options: Data.ReadingOptions.mappedIfSafe) {
            let updatedSize = Atomic<Int>(value: 0)
            let signal = TGGifConverter.convertGif(toMp4: data)!
            let signalDisposable = signal.start(next: { next in
                if let result = next as? NSDictionary, let path = result["path"] as? String {
                    var value = stat()
                    if stat(path, &value) == 0 {
                        subscriber.putNext(.moveLocalFile(path: path))
                        /*if let data = try? Data(contentsOf: result.fileURL, options: [.mappedRead]) {
                         var range: Range<Int>?
                         let _ = updatedSize.modify { updatedSize in
                         range = updatedSize ..< Int(value.st_size)
                         return Int(value.st_size)
                         }
                         //print("finish size = \(Int(value.st_size)), range: \(range!)")
                         subscriber.putNext(.dataPart(resourceOffset: range!.lowerBound, data: data, range: range!, complete: false))
                         subscriber.putNext(.replaceHeader(data: data, range: 0 ..< 1024))
                         subscriber.putNext(.dataPart(resourceOffset: 0, data: Data(), range: 0 ..< 0, complete: true))
                         }*/
                    }
                    subscriber.putCompletion()
                }
            }, error: { _ in
            }, completed: nil)
            
            disposable.set(ActionDisposable {
                signalDisposable?.dispose()
            })
        }
        
        return ActionDisposable {
            disposable.dispose()
        }
    }
}