Files
mediaplayer/ios/OralTrainer/Services/SentenceExplanationStore.swift

68 lines
3.1 KiB
Swift

import Foundation
final class SentenceExplanationStore {
static let shared = SentenceExplanationStore()
private let root: URL
init() {
let documents = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
root = documents.appendingPathComponent("SentenceExplanations", isDirectory: true)
try? FileManager.default.createDirectory(at: root, withIntermediateDirectories: true)
}
func load(mediaId: String, sentenceIndex: Int) -> String? {
let url = fileURL(mediaId: mediaId, sentenceIndex: sentenceIndex)
guard FileManager.default.fileExists(atPath: url.path) else { return nil }
let text = try? String(contentsOf: url, encoding: .utf8)
let trimmed = text?.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
return trimmed.isEmpty ? nil : trimmed
}
@discardableResult
func save(mediaId: String, sentenceIndex: Int, explanation: String) -> Bool {
let trimmed = explanation.trimmingCharacters(in: .whitespacesAndNewlines)
guard !trimmed.isEmpty else { return false }
let url = fileURL(mediaId: mediaId, sentenceIndex: sentenceIndex)
try? FileManager.default.createDirectory(at: url.deletingLastPathComponent(), withIntermediateDirectories: true)
do {
try trimmed.write(to: url, atomically: true, encoding: .utf8)
return true
} catch {
return false
}
}
func sync(mediaId: String, sentences: [SentenceBoundary]) {
guard !sentences.isEmpty else { return }
let directory = root.appendingPathComponent(Self.sanitize(mediaId), isDirectory: true)
let revision = Self.revision(for: sentences)
let marker = directory.appendingPathComponent("revision.txt")
let previous = (try? String(contentsOf: marker, encoding: .utf8))?
.trimmingCharacters(in: .whitespacesAndNewlines) ?? ""
guard previous != revision else { return }
try? FileManager.default.removeItem(at: directory)
try? FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true)
try? revision.write(to: marker, atomically: true, encoding: .utf8)
}
private func fileURL(mediaId: String, sentenceIndex: Int) -> URL {
let directory = root.appendingPathComponent(Self.sanitize(mediaId), isDirectory: true)
return directory.appendingPathComponent("\(sentenceIndex).txt")
}
static func revision(for sentences: [SentenceBoundary]) -> String {
sentences.map { sentence in
let text = (sentence.text ?? "").trimmingCharacters(in: .whitespacesAndNewlines)
return "\(sentence.index)\t\(text)"
}.joined(separator: "\n")
}
static func sanitize(_ mediaId: String) -> String {
let allowed = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "._-"))
let filtered = mediaId.lowercased().unicodeScalars.map { allowed.contains($0) ? Character($0) : "_" }
let value = String(filtered).trimmingCharacters(in: CharacterSet(charactersIn: "_"))
return value.isEmpty || value == "." || value == ".." ? "unknown" : value
}
}