From 874688b43ff611cc62b7c3f6d69570a9b0619269 Mon Sep 17 00:00:00 2001 From: Christoph Hagen Date: Mon, 23 Oct 2023 16:49:56 +0200 Subject: [PATCH] Improve error handling and printing --- Sources/ClassifierCreator.swift | 296 +++++++++++++++----------------- Sources/Configuration.swift | 3 +- Sources/ConfigurationFile.swift | 9 +- Sources/TrainingError.swift | 131 ++++++++++++-- 4 files changed, 262 insertions(+), 177 deletions(-) diff --git a/Sources/ClassifierCreator.swift b/Sources/ClassifierCreator.swift index b5f7c28..50a61be 100644 --- a/Sources/ClassifierCreator.swift +++ b/Sources/ClassifierCreator.swift @@ -18,6 +18,9 @@ final class ClassifierCreator { let df = DateFormatter() + private func print(info: String) { + Swift.print("[INFO] " + info) + } // MARK: Step 1: Load configuration @@ -39,40 +42,42 @@ final class ClassifierCreator { let (classes, changedImageCount, changedMainImages) = try await loadImages() guard !classes.isEmpty else { - print("[INFO] No image classes found, exiting...") + print(info: "No image classes found, exiting...") return } guard changedImageCount > 0 else { - print("[INFO] No changed images, so no new classifier trained") - await createThumbnails(changed: changedMainImages) - print("[INFO] Done") + print(info: "No changed images, so no new classifier trained") + try await createThumbnails(changed: changedMainImages) + print(info: "Done") return } let classifierVersion = try await getClassifierVersion() let newVersion = classifierVersion + 1 - print("[INFO] Image directory: \(imageDirectory.absoluteURL.path)") - print("[INFO] Model path: \(classifierUrl.path)") - print("[INFO] Version: \(newVersion)") - print("[INFO] Classes: \(classes.count)") - print("[INFO] Iterations: \(configuration.trainingIterations)") + print(info: "Image directory: \(imageDirectory.absoluteURL.path)") + print(info: "Model path: \(classifierUrl.path)") + print(info: "Version: \(newVersion)") + print(info: "Classes: \(classes.count)") + print(info: "Iterations: \(configuration.trainingIterations)") try await trainAndSaveModel() try await uploadModel(version: newVersion) try await upload(classes: classes, lastUpdate: imagesSnapshotDate) - await createThumbnails(changed: changedMainImages) - print("[INFO] Done") + try await createThumbnails(changed: changedMainImages) + print(info: "Done") } // MARK: Step 2: Load changed images func loadImages() async throws -> (classes: [Int], changedImageCount: Int, changedMainImages: [Int]) { - guard createFolderIfMissing(imageDirectory) else { - throw TrainingError.mainImageFolderNotCreated + do { + try createFolderIfMissing(imageDirectory) + } catch { + throw TrainingError.mainImageFolderNotCreated(error) } - let imageCounts = await getImageCounts() + let imageCounts = try await getImageCounts() let missingImageList: [CapImage] = imageCounts .sorted { $0.key < $1.key } .reduce(into: []) { list, pair in @@ -87,9 +92,9 @@ final class ClassifierCreator { list.append(contentsOf: missingImagesForCap) } if missingImageList.isEmpty { - print("[INFO] No missing images to load") + print(info: "No missing images to load") } else { - print("[INFO] Loading \(missingImageList.count) missing images...") + print(info: "Loading \(missingImageList.count) missing images...") try await loadImages(missingImageList) } @@ -102,9 +107,9 @@ final class ClassifierCreator { let imagesAlreadyLoad = changedImageList.count - filteredChangeList.count let suffix = imagesAlreadyLoad > 0 ? " (\(imagesAlreadyLoad) already loaded)" : "" if filteredChangeList.isEmpty { - print("[INFO] No changed images to load" + suffix) + print(info: "No changed images to load" + suffix) } else { - print("[INFO] Loading \(filteredChangeList.count) changed images" + suffix) + print(info: "Loading \(filteredChangeList.count) changed images" + suffix) try await loadImages(filteredChangeList) } @@ -117,16 +122,19 @@ final class ClassifierCreator { return (classes, missingImageList.count + changedImageList.count, changedMainImages) } - private func getImageCounts() async -> [Int : Int] { - guard let data: Data = await get(server.appendingPathComponent("caps.json")) else { - return [:] + private func getImageCounts() async throws -> [Int : Int] { + let data: Data + do { + data = try await get(server.appendingPathComponent("caps.json")) + } catch { + throw TrainingError.failedToGetCapDatabase(error) } do { - return try JSONDecoder().decode([Cap].self, from: data) + return try JSONDecoder() + .decode([Cap].self, from: data) .reduce(into: [:]) { $0[$1.id] = $1.count } } catch { - print("[ERROR] Failed to decode cap database: \(error)") - return [:] + throw TrainingError.failedToDecodeCapDatabase(error) } } @@ -136,8 +144,7 @@ final class ClassifierCreator { do { folders = try FileManager.default.contentsOfDirectory(atPath: imageDirectory.path) } catch { - print("[ERROR] Failed to get list of image folders: \(error)") - throw TrainingError.failedToGetListOfImageFolders + throw TrainingError.failedToGetListOfImageFolders(error) } for folder in folders { if validNames.contains(folder) { @@ -148,10 +155,9 @@ final class ClassifierCreator { let url = imageDirectory.appendingPathComponent(folder) do { try FileManager.default.removeItem(at: url) - print("[INFO] Removed unused image folder '\(folder)'") + print(info: "Removed unused image folder '\(folder)'") } catch { - print("[ERROR] Failed to delete unused image folder \(folder): \(error)") - throw TrainingError.failedToRemoveImageFolder + throw TrainingError.failedToRemoveImageFolder(folder, error) } } } @@ -160,22 +166,22 @@ final class ClassifierCreator { base.appendingPathComponent(String(format: "%04d/%04d-%02d.jpg", image.cap, image.cap, image.image)) } - private func load(image: CapImage) async -> Bool { - guard createFolderIfMissing(imageDirectory.appendingPathComponent(String(format: "%04d", image.cap))) else { - return false + private func load(image: CapImage) async throws { + do { + try createFolderIfMissing(imageDirectory.appendingPathComponent(String(format: "%04d", image.cap))) + } catch { + throw TrainingError.failedToCreateImageFolder(image.cap, error) } let url = imageUrl(base: server.appendingPathComponent("images"), image: image) let tempFile: URL, response: URLResponse do { (tempFile, response) = try await URLSession.shared.download(from: url) } catch { - print("[ERROR] Failed to load \(image): \(error)") - return false + throw TrainingError.failedToLoadImage(image, error) } let responseCode = (response as! HTTPURLResponse).statusCode guard responseCode == 200 else { - print("[ERROR] Failed to load \(image): Response \(responseCode)") - return false + throw TrainingError.invalidImageRequestResponse(image, responseCode) } do { let localUrl = imageUrl(base: imageDirectory, image: image) @@ -183,60 +189,62 @@ final class ClassifierCreator { try FileManager.default.removeItem(at: localUrl) } try FileManager.default.moveItem(at: tempFile, to: localUrl) - return true } catch { - print("[ERROR] Failed to save \(image): \(error)") - return false + throw TrainingError.failedToSaveImage(image, error) } } private func loadImages(_ list: [CapImage]) async throws { - var loadedImages = 0 - await withTaskGroup(of: Bool.self) { group in + var loadedImageCount = 0 + var errors = [Error]() + await withTaskGroup(of: Error?.self) { group in for image in list { group.addTask { - await self.load(image: image) + do { + try await self.load(image: image) + return nil + } catch { + return error + } } } - for await loaded in group { - if loaded { - loadedImages += 1 + for await error in group { + if let error { + errors.append(error) + } else { + loadedImageCount += 1 } } } - if loadedImages != list.count { - print("[ERROR] Only \(loadedImages) of \(list.count) images loaded") - throw TrainingError.failedToLoadImages + for error in errors { + Swift.print(error.localizedDescription) + } + let expectedCount = list.count + + if loadedImageCount != expectedCount { + throw TrainingError.failedToLoadImages(expected: list.count, loaded: loadedImageCount) } } func getChangedImageList() async throws -> [CapImage] { - guard let string: String = await get(server.appendingPathComponent("changes.txt")) else { - print("[ERROR] Failed to get list of changed images") - throw TrainingError.failedToGetChangedImagesList + let string: String + do { + string = try await get(server.appendingPathComponent("changes.txt")) + } catch { + throw TrainingError.failedToGetChangedImagesList(error) } - return string + return try string .components(separatedBy: "\n") + .map { $0.trimmingCharacters(in: .whitespaces) } .filter { $0 != "" } .compactMap { let parts = $0.components(separatedBy: ":") - guard parts.count == 3 else { - return nil - } - /* - guard let date = df.date(from: parts[0]) else { - print("[WARN] Invalid date \(parts[0]) in change list") - return nil - } - */ - guard let cap = Int(parts[1]) else { - print("[WARN] Invalid cap id \(parts[1]) in change list") - return nil - } - guard let image = Int(parts[2]) else { - print("[WARN] Invalid image id \(parts[2]) in change list") - return nil + guard parts.count == 3, + let _ = df.date(from: parts[0]), + let cap = Int(parts[1]), + let image = Int(parts[2]) else { + throw TrainingError.invalidEntryInChangeList($0) } return CapImage(cap: cap, image: image) } @@ -245,12 +253,13 @@ final class ClassifierCreator { // MARK: Step 3: Compute version func getClassifierVersion() async throws -> Int { - guard let string: String = await get(server.appendingPathComponent("version")) else { - print("[ERROR] Failed to get classifier version") - throw TrainingError.failedToGetClassifierVersion + let string: String + do { + string = try await get(server.appendingPathComponent("version")) + } catch { + throw TrainingError.failedToGetClassifierVersion(error) } guard let version = Int(string) else { - print("[ERROR] Invalid classifier version \(string)") throw TrainingError.invalidClassifierVersion(string) } return version @@ -284,13 +293,13 @@ final class ClassifierCreator { parameters: params, sessionParameters: sessionParameters) } catch { - throw TrainingError.failedToCreateClassifier + throw TrainingError.failedToCreateClassifier("\(error)") } job.progress .publisher(for: \.fractionCompleted) .sink { completed in - print(String(format: " %.1f %% completed", completed * 100), terminator: "\r") + Swift.print(String(format: " %.1f %% completed", completed * 100), terminator: "\r") fflush(stdout) //guard let progress = MLProgress(progress: job.progress) else { @@ -305,11 +314,10 @@ final class ClassifierCreator { return try await withCheckedThrowingContinuation { continuation in // Register a sink to receive the resulting model. job.result.sink { result in - print("[ERROR] \(result)") - continuation.resume(throwing: TrainingError.failedToCreateClassifier) - } receiveValue: { model in + continuation.resume(throwing: TrainingError.failedToCreateClassifier("\(result)")) + } receiveValue: { [weak self] model in // Use model - print("[INFO] Created model") + self?.print(info: "Created model") continuation.resume(returning: model) } .store(in: &subscriptions) @@ -326,18 +334,16 @@ final class ClassifierCreator { trainingData: .labeledDirectories(at: imageDirectory), parameters: params) } catch { - print("[ERROR] Failed to create classifier: \(error)") - throw TrainingError.failedToCreateClassifier + throw TrainingError.failedToCreateClassifier("\(error)") } } private func save(model: MLImageClassifier) throws { - print("[INFO] Saving classifier...") + print(info: "Saving classifier...") do { try model.write(to: classifierUrl) } catch { - print("[ERROR] Failed to save model to file: \(error)") throw TrainingError.failedToWriteClassifier(error) } } @@ -345,83 +351,81 @@ final class ClassifierCreator { // MARK: Step 5: Upload classifier func uploadModel(version: Int) async throws { - print("[INFO] Uploading classifier...") + print(info: "Uploading classifier...") let modelData: Data do { modelData = try Data(contentsOf: classifierUrl) } catch { - print("[ERROR] Failed to read classifier data: \(error)") throw TrainingError.failedToReadClassifierData(error) } - let success = await post( - url: server.appendingPathComponent("classifier/\(version)"), - body: modelData) - guard success else { - throw TrainingError.failedToUploadClassifier + let url = server.appendingPathComponent("classifier/\(version)") + do { + try await post(url: url, body: modelData) + } catch { + throw TrainingError.failedToUploadClassifier(error) } } // MARK: Step 6: Update classes func upload(classes: [Int], lastUpdate: Date) async throws { - print("[INFO] Uploading trained classes...") + print(info: "Uploading trained classes...") let dateString = df.string(from: lastUpdate) let url = server.appendingPathComponent("classes/\(dateString)") let body = classes.map(String.init).joined(separator: ",").data(using: .utf8)! - guard await post(url: url, body: body) else { - throw TrainingError.failedToUploadClassifierClasses + do { + try await post(url: url, body: body) + } catch { + throw TrainingError.failedToUploadClassifierClasses(error) } } // MARK: Step 7: Create thumbnails - func createThumbnails(changed: [Int]) async { - guard checkMagickAvailability() else { - return + func createThumbnails(changed: [Int]) async throws { + try ensureMagickAvailability() + do { + try createFolderIfMissing(thumbnailDirectory) + } catch { + throw TrainingError.failedToCreateThumbnailFolder(error) } - guard createFolderIfMissing(thumbnailDirectory) else { - print("[ERROR] Failed to create folder for thumbnails") - return - } - let capIdsOfMissingThumbnails = await getMissingThumbnailIds() + let capIdsOfMissingThumbnails = try await getMissingThumbnailIds() let all = Set(capIdsOfMissingThumbnails).union(changed) - print("[INFO] Creating \(all.count) thumbnails...") + print(info: "Creating \(all.count) thumbnails...") for cap in all { - await createThumbnail(for: cap) + try await createThumbnail(for: cap) } } - func checkMagickAvailability() -> Bool { + func ensureMagickAvailability() throws { do { let (code, output) = try safeShell("magick --version") guard code == 0, let version = output.components(separatedBy: "ImageMagick ").dropFirst().first? .components(separatedBy: " ").first else { - print("[ERROR] Magick not found, install using 'brew install imagemagick'") - return false + throw TrainingError.magickDependencyNotFound } - print("[INFO] Using magick \(version)") + print(info: "Using magick \(version)") } catch { - print("[ERROR] Failed to get version of magick: (\(error))") - return false + throw TrainingError.magickDependencyCheckFailed(error) } - return true } - private func getMissingThumbnailIds() async -> [Int] { - guard let string: String = await get(server.appendingPathComponent("thumbnails/missing")) else { - print("[ERROR] Failed to get missing thumbnails") - return [] + private func getMissingThumbnailIds() async throws -> [Int] { + let string: String + do { + string = try await get(server.appendingPathComponent("thumbnails/missing")) + } catch { + throw TrainingError.failedToGetMissingThumbnailIds(error) } return string.components(separatedBy: ",").compactMap(Int.init) } - private func createThumbnail(for cap: Int) async { + private func createThumbnail(for cap: Int) async throws { let mainImage = CapImage(cap: cap, image: 0) let inputUrl = imageUrl(base: imageDirectory, image: mainImage) guard FileManager.default.fileExists(atPath: inputUrl.path) else { - print("[ERROR] Local main image not found for cap \(cap): \(inputUrl.path)") - return + throw TrainingError.missingMainImage(cap) } let output = thumbnailDirectory.appendingPathComponent(String(format: "%04d.jpg", cap)) @@ -429,24 +433,22 @@ final class ClassifierCreator { let command = "magick convert \(inputUrl.path) -quality 70% -resize 100x100 \(output.path)" let (code, output) = try safeShell(command) if code != 0 { - print("Failed to create thumbnail for cap \(cap): \(output)") - return + throw TrainingError.failedToCreateThumbnail(cap, output) } } catch { - print("Failed to read created thumbnail for cap \(cap): \(error)") - return + throw TrainingError.failedToCreateThumbnail(cap, "\(error)") } let data: Data do { data = try Data(contentsOf: output) } catch { - print("Failed to read created thumbnail for cap \(cap): \(error)") - return + throw TrainingError.failedToReadCreatedThumbnail(cap, error) } - guard await post(url: server.appendingPathComponent("thumbnails/\(cap)"), body: data) else { - print("Failed to upload thumbnail for cap \(cap)") - return + do { + try await post(url: server.appendingPathComponent("thumbnails/\(cap)"), body: data) + } catch { + throw TrainingError.failedToUploadCreatedThumbnail(cap, error) } } @@ -472,57 +474,41 @@ final class ClassifierCreator { } - private func createFolderIfMissing(_ folder: URL) -> Bool { + private func createFolderIfMissing(_ folder: URL) throws { guard !FileManager.default.fileExists(atPath: folder.path) else { - return true - } - do { - try FileManager.default.createDirectory(at: folder, withIntermediateDirectories: true) - return true - } catch { - print("[ERROR] Failed to create directory \(folder.path): \(error)") - return false + return } + try FileManager.default.createDirectory(at: folder, withIntermediateDirectories: true) } // MARK: Requests - private func post(url: URL, body: Data) async -> Bool { + private func post(url: URL, body: Data) async throws { var request = URLRequest(url: url) request.httpMethod = "POST" request.httpBody = body request.addValue(configuration.authenticationToken, forHTTPHeaderField: "key") - return await perform(request) != nil + _ = try await perform(request) } - private func perform(_ request: URLRequest) async -> Data? { - let data: Data - let response: URLResponse - do { - (data, response) = try await URLSession.shared.data(for: request) - } catch { - print("[ERROR] Request to \(request.url!.absoluteString) failed: \(error)") - return nil - } + private func perform(_ request: URLRequest) async throws -> Data { + let (data, response) = try await URLSession.shared.data(for: request) let code = (response as! HTTPURLResponse).statusCode guard code == 200 else { - print("[ERROR] Request to \(request.url!.absoluteString): Invalid response \(code)") - return nil + throw TrainingError.invalidResponse(request.url!, code) } return data } - private func get(_ url: URL) async -> Data? { - await perform(URLRequest(url: url)) + private func get(_ url: URL) async throws -> Data { + try await perform(URLRequest(url: url)) } - private func get(_ url: URL) async -> String? { - guard let data: Data = await get(url) else { - return nil - } + private func get(_ url: URL) async throws -> String { + let data: Data = try await get(url) + guard let string = String(data: data, encoding: .utf8) else { - print("[ERROR] Invalid string response \(data)") - return nil + throw TrainingError.invalidGetResponseData(data.count) } return string } diff --git a/Sources/Configuration.swift b/Sources/Configuration.swift index fffb3e0..9895ebc 100644 --- a/Sources/Configuration.swift +++ b/Sources/Configuration.swift @@ -15,8 +15,7 @@ extension Configuration { func serverUrl() throws -> URL { guard let serverUrl = URL(string: serverPath) else { - print("[ERROR] Configuration: Invalid server path \(serverPath)") - throw TrainingError.invalidServerPath + throw TrainingError.invalidServerPath(serverPath) } return serverUrl } diff --git a/Sources/ConfigurationFile.swift b/Sources/ConfigurationFile.swift index 46f1c8b..333aa8e 100644 --- a/Sources/ConfigurationFile.swift +++ b/Sources/ConfigurationFile.swift @@ -19,21 +19,18 @@ extension ConfigurationFile { init(at url: URL) throws { guard FileManager.default.fileExists(atPath: url.path) else { - print("[ERROR] No configuration at \(url.absoluteURL.path)") - throw TrainingError.configurationFileMissing + throw TrainingError.configurationFileMissing(url) } let data: Data do { data = try Data(contentsOf: url) } catch { - print("[ERROR] Failed to load configuration data at \(url.absoluteURL.path): \(error)") - throw TrainingError.configurationFileUnreadable + throw TrainingError.configurationFileUnreadable(url, error) } do { self = try JSONDecoder().decode(ConfigurationFile.self, from: data) } catch { - print("[ERROR] Failed to decode configuration at \(url.absoluteURL.path): \(error)") - throw TrainingError.configurationFileDecodingFailed + throw TrainingError.configurationFileDecodingFailed(url, error) } } } diff --git a/Sources/TrainingError.swift b/Sources/TrainingError.swift index ea27c24..e7a5388 100644 --- a/Sources/TrainingError.swift +++ b/Sources/TrainingError.swift @@ -1,29 +1,132 @@ import Foundation enum TrainingError: Error { + case invalidGetResponseData(Int) + case invalidResponse(URL, Int) case missingArguments - case configurationFileMissing - case configurationFileUnreadable - case configurationFileDecodingFailed - case invalidServerPath - case mainImageFolderNotCreated - case failedToLoadImages + case configurationFileMissing(URL) + case configurationFileUnreadable(URL, Error) + case configurationFileDecodingFailed(URL, Error) + case invalidServerPath(String) + case mainImageFolderNotCreated(Error) - case failedToGetListOfImageFolders - case failedToRemoveImageFolder + case failedToGetCapDatabase(Error) + case failedToDecodeCapDatabase(Error) - case failedToGetClassifierVersion + case failedToLoadImage(CapImage, Error) + case failedToCreateImageFolder(Int, Error) + case invalidImageRequestResponse(CapImage, Int) + case failedToSaveImage(CapImage, Error) + case failedToLoadImages(expected: Int, loaded: Int) + + case failedToGetChangedImagesList(Error) + case invalidEntryInChangeList(String) + + + case failedToGetListOfImageFolders(Error) + case failedToRemoveImageFolder(String, Error) + + case failedToGetClassifierVersion(Error) case invalidClassifierVersion(String) - case failedToCreateClassifier + case failedToCreateClassifier(String) case failedToWriteClassifier(Error) - case failedToGetChangedImagesList - case failedToReadClassifierData(Error) - case failedToUploadClassifier + case failedToUploadClassifier(Error) - case failedToUploadClassifierClasses + case failedToUploadClassifierClasses(Error) + + case magickDependencyCheckFailed(Error) + case magickDependencyNotFound + case failedToCreateThumbnailFolder(Error) + case failedToGetMissingThumbnailIds(Error) + case missingMainImage(Int) + case failedToCreateThumbnail(Int, String) + case failedToReadCreatedThumbnail(Int, Error) + case failedToUploadCreatedThumbnail(Int, Error) +} + +extension TrainingError: CustomStringConvertible { + + var description: String { + switch self { + case .missingArguments: + return "Missing arguments" + case .configurationFileMissing(let url): + return "No configuration at \(url.absoluteURL.path)" + case .configurationFileUnreadable(let url, let error): + return "Failed to load configuration data at \(url.absoluteURL.path): \(error)" + case .configurationFileDecodingFailed(let url, let error): + return "Failed to decode configuration at \(url.absoluteURL.path): \(error)" + case .invalidServerPath(let path): + return "Configuration: Invalid server path \(path)" + case .mainImageFolderNotCreated(let error): + return "Failed to create main image folder: \(error)" + + case .failedToGetCapDatabase(let error): + return "Failed to get cap database from server: \(error)" + case .failedToDecodeCapDatabase(let error): + return "Failed to decode cap database: \(error)" + + case .failedToGetListOfImageFolders(let error): + return "Failed to get list of image folders: \(error)" + case .failedToRemoveImageFolder(let folder, let error): + return "Failed to delete unused image folder \(folder): \(error)" + case .failedToCreateImageFolder(let cap, let error): + return "Failed to create image folder for cap \(cap): \(error)" + case .failedToLoadImage(let image, let error): + return "Failed to load \(image): \(error)" + case .invalidImageRequestResponse(let image, let responseCode): + return "Failed to load \(image): Response \(responseCode)" + case .failedToSaveImage(let image, let error): + return "Failed to save \(image): \(error)" + case .failedToLoadImages(let expected, let loaded): + return "Only \(expected) of \(loaded) images loaded" + + case .failedToGetChangedImagesList(let error): + return "Failed to get list of changed images: \(error)" + case .invalidEntryInChangeList(let entry): + return "Invalid change list entry: '\(entry)'" + + case .failedToGetClassifierVersion(let error): + return "Failed to get classifier version: \(error)" + case .invalidClassifierVersion(let string): + return "Invalid classifier version \(string)" + case .failedToCreateClassifier(let result): + return "Failed to create classifier: \(result)" + case .failedToWriteClassifier(let error): + return "Failed to save model to file: \(error)" + case .failedToReadClassifierData(let error): + return "Failed to read classifier data: \(error)" + case .failedToUploadClassifier(let error): + return "Failed to upload classifier: \(error)" + case .failedToUploadClassifierClasses(let error): + return "Failed to upload classifier classes: \(error)" + + case .magickDependencyCheckFailed(let error): + return "Failed to get version of magick: (\(error))" + case .magickDependencyNotFound: + return "Magick not found, install using 'brew install imagemagick'" + case .failedToCreateThumbnailFolder(let error): + return "Failed to create folder for thumbnails: \(error)" + case .failedToGetMissingThumbnailIds(let error): + return "Failed to get missing thumbnails ids: \(error)" + case .missingMainImage(let cap): + return "Local main image not found for cap \(cap)" + case .failedToCreateThumbnail(let cap, let message): + return "Failed to read created thumbnail for cap \(cap): \(message)" + case .failedToReadCreatedThumbnail(let cap, let error): + return "Failed to read created thumbnail for cap \(cap): \(error)" + case .failedToUploadCreatedThumbnail(let cap, let error): + return "Failed to upload thumbnail for cap \(cap): \(error)" + + case .invalidGetResponseData(let count): + return "Response (\(count) bytes) is not a valid string" + case .invalidResponse(let url, let code): + return "Invalid response \(code) to \(url.absoluteString)" + } + } }