Swiftgram/submodules/SaveToCameraRoll/Sources/SaveToCameraRoll.swift

import Foundation
import UIKit
import SwiftSignalKit
import Postbox
import TelegramCore
import Photos
import Display
import MobileCoreServices
import DeviceAccess
import AccountContext
import LegacyComponents

public enum FetchMediaDataState {
    case progress(Float)
    case data(MediaResourceData)
}

public func fetchMediaData(context: AccountContext, postbox: Postbox, mediaReference: AnyMediaReference) -> Signal<(FetchMediaDataState, Bool), NoError> {
    var resource: MediaResource?
    var isImage = true
    var fileExtension: String?
    if let image = mediaReference.media as? TelegramMediaImage {
        if let representation = largestImageRepresentation(image.representations) {
            resource = representation.resource
        }
    } else if let file = mediaReference.media as? TelegramMediaFile {
        resource = file.resource
        if file.isVideo || file.mimeType.hasPrefix("video/") {
            isImage = false
        }
        let maybeExtension = ((file.fileName ?? "") as NSString).pathExtension
        if !maybeExtension.isEmpty {
            fileExtension = maybeExtension
        }
    } else if let webpage = mediaReference.media as? TelegramMediaWebpage, case let .Loaded(content) = webpage.content {
        if let file = content.file {
            resource = file.resource
            if file.isVideo {
                isImage = false
            }
        } else if let image = content.image {
            if let representation = largestImageRepresentation(image.representations) {
                resource = representation.resource
            }
        }
    }
    
    if let resource = resource {
        let fetchedData: Signal<FetchMediaDataState, NoError> = Signal { subscriber in
            let fetched = fetchedMediaResource(mediaBox: postbox.mediaBox, reference: mediaReference.resourceReference(resource)).start()
            let status = postbox.mediaBox.resourceStatus(resource).start(next: { status in
                switch status {
                    case .Local:
                        subscriber.putNext(.progress(1.0))
                    case .Remote:
                        subscriber.putNext(.progress(0.0))
                    case let .Fetching(_, progress):
                        subscriber.putNext(.progress(progress))
                    case let .Paused(progress):
                        subscriber.putNext(.progress(progress))
                }
            })
            let data = postbox.mediaBox.resourceData(resource, pathExtension: fileExtension, option: .complete(waitUntilFetchStatus: true)).start(next: { next in
                subscriber.putNext(.data(next))
            }, completed: {
                subscriber.putCompletion()
            })
            return ActionDisposable {
                fetched.dispose()
                status.dispose()
                data.dispose()
            }
        }
        return fetchedData
        |> map { data in
            return (data, isImage)
        }
    } else {
        return .complete()
    }
}

public func saveToCameraRoll(context: AccountContext, postbox: Postbox, mediaReference: AnyMediaReference) -> Signal<Float, NoError> {
    return fetchMediaData(context: context, postbox: postbox, mediaReference: mediaReference)
    |> mapToSignal { state, isImage -> Signal<Float, NoError> in
        switch state {
            case let .progress(value):
                return .single(value)
            case let .data(data):
                if data.complete {
                    return Signal<Float, NoError> { subscriber in
                        DeviceAccess.authorizeAccess(to: .mediaLibrary(.save), presentationData: context.sharedContext.currentPresentationData.with { $0 }, present: { c, a in
                            context.sharedContext.presentGlobalController(c, a)
                        }, openSettings: context.sharedContext.applicationBindings.openSettings, { authorized in
                            if !authorized {
                                subscriber.putCompletion()
                                return
                            }
                            
                            let tempVideoPath = NSTemporaryDirectory() + "\(Int64.random(in: Int64.min ... Int64.max)).mp4"
                            PHPhotoLibrary.shared().performChanges({
                                if isImage {
                                    if let fileData = try? Data(contentsOf: URL(fileURLWithPath: data.path)) {
                                        if #available(iOSApplicationExtension 9.0, iOS 9.0, *) {
                                            PHAssetCreationRequest.forAsset().addResource(with: .photo, data: fileData, options: nil)
                                        } else {
                                            if let image = UIImage(data: fileData) {
                                                PHAssetChangeRequest.creationRequestForAsset(from: image)
                                            }
                                        }
                                    }
                                } else {
                                    if let _ = try? FileManager.default.copyItem(atPath: data.path, toPath: tempVideoPath) {
                                        PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: URL(fileURLWithPath: tempVideoPath))
                                    }
                                }
                            }, completionHandler: { _, error in
                                if let error = error {
                                    print("\(error)")
                                }
                                let _ = try? FileManager.default.removeItem(atPath: tempVideoPath)
                                subscriber.putNext(1.0)
                                subscriber.putCompletion()
                            })
                        })
                        
                        return ActionDisposable {
                        }
                    }
                } else {
                    return .complete()
                }
        }
    }
}

public func copyToPasteboard(context: AccountContext, postbox: Postbox, mediaReference: AnyMediaReference) -> Signal<Void, NoError> {
    return fetchMediaData(context: context, postbox: postbox, mediaReference: mediaReference)
    |> mapToSignal { state, isImage -> Signal<Void, NoError> in
        if case let .data(data) = state, data.complete {
            return Signal<Void, NoError> { subscriber in
                let pasteboard = UIPasteboard.general
                
                if mediaReference.media is TelegramMediaImage {
                    if let fileData = try? Data(contentsOf: URL(fileURLWithPath: data.path), options: .mappedIfSafe) {
                        pasteboard.setData(fileData, forPasteboardType: kUTTypeJPEG as String)
                    }
                }
                subscriber.putNext(Void())
                subscriber.putCompletion()
                
                return EmptyDisposable
            }
        } else {
            return .complete()
        }
    }
    |> mapToSignal { _ -> Signal<Void, NoError> in return .complete() }
}