Tusker/Tusker/Models/CompositionAttachmentData.s...

209 lines
8.1 KiB
Swift

//
// CompositionAttachmentData.swift
// Tusker
//
// Created by Shadowfacts on 1/1/20.
// Copyright © 2020 Shadowfacts. All rights reserved.
//
import UIKit
import Photos
import MobileCoreServices
import PencilKit
enum CompositionAttachmentData {
case asset(PHAsset)
case image(UIImage)
case video(URL)
case drawing(PKDrawing)
var type: AttachmentType {
switch self {
case let .asset(asset):
return asset.attachmentType!
case .image(_):
return .image
case .video(_):
return .video
case .drawing(_):
return .image
}
}
var isAsset: Bool {
switch self {
case .asset(_):
return true
default:
return false
}
}
var canSaveToDraft: Bool {
switch self {
case .video(_):
return false
default:
return true
}
}
func getData(completion: @escaping (_ data: Data, _ mimeType: String) -> Void) {
switch self {
case let .image(image):
// Export as JPEG instead of PNG, otherweise photos straight from the camera are too large
// for Mastodon in its default configuration (max of 10MB).
// The quality of 0.8 was chosen completely arbitrarily, it may need to be tuned in the future.
completion(image.jpegData(compressionQuality: 0.8)!, "image/jpeg")
case let .asset(asset):
if asset.mediaType == .image {
let options = PHImageRequestOptions()
options.version = .current
options.deliveryMode = .highQualityFormat
options.resizeMode = .none
options.isNetworkAccessAllowed = true
PHImageManager.default().requestImageDataAndOrientation(for: asset, options: options) { (data, dataUTI, orientation, info) in
guard var data = data, let dataUTI = dataUTI else { fatalError() }
let mimeType: String
if dataUTI == "public.heic" {
// neither Mastodon nor Pleroma handles HEIC well, so convert to JPEG
let image = CIImage(data: data)!
let context = CIContext()
let colorSpace = image.colorSpace ?? CGColorSpace(name: CGColorSpace.sRGB)!
data = context.jpegRepresentation(of: image, colorSpace: colorSpace, options: [:])!
mimeType = "image/jpeg"
} else {
mimeType = UTTypeCopyPreferredTagWithClass(dataUTI as CFString, kUTTagClassMIMEType)!.takeRetainedValue() as String
}
completion(data, mimeType)
}
} else if asset.mediaType == .video {
let options = PHVideoRequestOptions()
options.deliveryMode = .automatic
options.isNetworkAccessAllowed = true
options.version = .current
PHImageManager.default().requestExportSession(forVideo: asset, options: options, exportPreset: AVAssetExportPresetHighestQuality) { (exportSession, info) in
guard let exportSession = exportSession else { fatalError("failed to create export session") }
CompositionAttachmentData.exportVideoData(session: exportSession, completion: completion)
}
} else {
fatalError("assetType must be either image or video")
}
case let .video(url):
let asset = AVURLAsset(url: url)
guard let session = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetHighestQuality) else {
fatalError("failed to create export session")
}
CompositionAttachmentData.exportVideoData(session: session, completion: completion)
case let .drawing(drawing):
let image = drawing.imageInLightMode(from: drawing.bounds, scale: 1)
completion(image.pngData()!, "image/png")
}
}
private static func exportVideoData(session: AVAssetExportSession, completion: @escaping (Data, String) -> Void) {
session.outputFileType = .mp4
session.outputURL = FileManager.default.temporaryDirectory.appendingPathComponent("exported_video_\(UUID())").appendingPathExtension("mp4")
session.exportAsynchronously {
guard session.status == .completed else { fatalError("video export failed: \(String(describing: session.error))") }
do {
let data = try Data(contentsOf: session.outputURL!)
completion(data, "video/mp4")
} catch {
fatalError("Unable to load video: \(error)")
}
}
}
enum AttachmentType {
case image, video
}
}
extension PHAsset {
var attachmentType: CompositionAttachmentData.AttachmentType? {
switch self.mediaType {
case .image:
return .image
case .video:
return .video
default:
return nil
}
}
}
extension CompositionAttachmentData: Codable {
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
switch self {
case let .asset(asset):
try container.encode("asset", forKey: .type)
try container.encode(asset.localIdentifier, forKey: .assetIdentifier)
case let .image(image):
try container.encode("image", forKey: .type)
try container.encode(image.pngData()!, forKey: .imageData)
case .video(_):
throw EncodingError.invalidValue(self, EncodingError.Context(codingPath: [], debugDescription: "video CompositionAttachments cannot be encoded"))
case let .drawing(drawing):
try container.encode("drawing", forKey: .type)
let drawingData = drawing.dataRepresentation()
try container.encode(drawingData, forKey: .drawing)
}
}
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
switch try container.decode(String.self, forKey: .type) {
case "asset":
let identifier = try container.decode(String.self, forKey: .assetIdentifier)
guard let asset = PHAsset.fetchAssets(withLocalIdentifiers: [identifier], options: nil).firstObject else {
throw DecodingError.dataCorruptedError(forKey: .assetIdentifier, in: container, debugDescription: "Could not fetch asset with local identifier")
}
self = .asset(asset)
case "image":
guard let image = UIImage(data: try container.decode(Data.self, forKey: .imageData)) else {
throw DecodingError.dataCorruptedError(forKey: .imageData, in: container, debugDescription: "Could not decode UIImage from image data")
}
self = .image(image)
case "drawing":
let drawingData = try container.decode(Data.self, forKey: .drawing)
let drawing = try PKDrawing(data: drawingData)
self = .drawing(drawing)
default:
throw DecodingError.dataCorruptedError(forKey: .type, in: container, debugDescription: "CompositionAttachment type must be one of 'image' or 'asset'")
}
}
enum CodingKeys: CodingKey {
case type
case imageData
/// The local identifier of the PHAsset for this attachment
case assetIdentifier
/// The PKDrawing object for this attachment.
case drawing
}
}
extension CompositionAttachmentData: Equatable {
static func ==(lhs: CompositionAttachmentData, rhs: CompositionAttachmentData) -> Bool {
switch (lhs, rhs) {
case let (.asset(a), .asset(b)):
return a.localIdentifier == b.localIdentifier
case let (.image(a), .image(b)):
return a == b
case let (.video(a), .video(b)):
return a == b
case let (.drawing(a), .drawing(b)):
return a == b
default:
return false
}
}
}