Caps-Server/Sources/App/CapServer.swift
2022-12-16 13:32:33 +01:00

300 lines
9.1 KiB
Swift

import Foundation
import Vapor
final class CapServer {
// MARK: Paths
private let imageFolder: URL
/// The file where the database of caps is stored
private let dbFile: URL
/// The file to store the HTML info of the cap count
private let htmlFile: URL
private let classifierVersionFile: URL
private let classifierFile: URL
private let fm = FileManager.default
// MARK: Caps
private var writers: Set<String>
var classifierVersion: Int {
get {
do {
let content = try String(contentsOf: classifierVersionFile)
.trimmingCharacters(in: .whitespacesAndNewlines)
guard let value = Int(content) else {
log("Invalid classifier version: \(content)")
return 0
}
return value
} catch {
log("Failed to read classifier version file: \(error)")
return 0
}
}
set {
do {
try "\(newValue)".data(using: .utf8)!
.write(to: classifierVersionFile)
} catch {
log("Failed to save classifier version: \(error)")
}
}
}
/**
The time to wait for changes to be written to disk.
This delay is used to prevent file writes for each small update to the caps.
*/
private let saveDelay: TimeInterval = 1
/**
The time when a save should occur.
No save is necessary if this property is `nil`.
*/
private var nextSaveTime: Date?
private var caps = [Int: Cap]() {
didSet { scheduleSave() }
}
var nextClassifierVersion: Int {
caps.values.compactMap { $0.classifierVersion }.max() ?? 1
}
init(in folder: URL, writers: [String]) throws {
self.imageFolder = folder.appendingPathComponent("images")
self.dbFile = folder.appendingPathComponent("caps.json")
self.htmlFile = folder.appendingPathComponent("count.html")
self.classifierVersionFile = folder.appendingPathComponent("classifier.version")
self.classifierFile = folder.appendingPathComponent("classifier.mlmodel")
self.writers = Set(writers)
var isDirectory: ObjCBool = false
guard fm.fileExists(atPath: folder.path, isDirectory: &isDirectory),
isDirectory.boolValue else {
log("Public directory \(folder.path) is not a folder, or doesn't exist")
throw CapError.invalidConfiguration
}
try loadCaps()
try updateCounts()
saveCapCountHTML()
}
private func loadCaps() throws {
do {
let data = try Data(contentsOf: dbFile)
caps = try JSONDecoder().decode([Cap].self, from: data)
.reduce(into: [:]) { $0[$1.id] = $1 }
} catch {
log("Failed to load caps: \(error)")
throw error
}
log("\(caps.count) caps loaded")
}
private func scheduleSave() {
nextSaveTime = Date().addingTimeInterval(saveDelay)
DispatchQueue.global().asyncAfter(deadline: .now() + saveDelay) {
self.performScheduledSave()
}
}
private func performScheduledSave() {
guard let date = nextSaveTime else {
// No save necessary, or already saved
return
}
guard date < Date() else {
// Save pushed to future
return
}
do {
try saveCaps()
nextSaveTime = nil
} catch {
// Attempt save again
scheduleSave()
}
}
private func saveCaps() throws {
let data = try JSONEncoder().encode(caps.values.sorted())
try data.write(to: dbFile)
}
private func saveCapCountHTML() {
let count = caps.count
let content =
"""
<body style="margin: 0;">
<div style="display: flex; justify-content: center;">
<div style="font-size: 60px; font-family: 'SF Pro Display',-apple-system,BlinkMacSystemFont,Helvetica,sans-serif; -webkit-font-smoothing: antialiased;">\(count)</div>
</div>
</body>
"""
try? content.data(using: .utf8)!.write(to: htmlFile)
}
// MARK: Paths
func folder(of cap: Int) -> URL {
imageFolder.appendingPathComponent(String(format: "%04d", cap))
}
func file(of cap: Int, version: Int) -> URL {
folder(of: cap).appendingPathComponent(String(format: "%04d-%02d.jpg", cap, version))
}
// MARK: Authentication
func hasAuthorization(for key: String) -> Bool {
// Note: This is not a constant-time compare, so there may be an opportunity
// for timing attack here. Sets perform hashed lookups, so this may be less of an issue,
// and we're not doing anything critical in this application.
// Worst case, an unauthorized person with a lot of free time and energy to hack this system
// is able to change contents of the database, which are backed up in any case.
writers.contains(key)
}
// MARK: Counts
private func updateCounts() throws {
do {
caps = try caps.mapValues {
var cap = $0
cap.count = try count(of: $0.id)
return cap
}
} catch {
log("Failed to update counts: \(error)")
throw error
}
}
func countImages(in folder: URL) throws -> Int {
try fm.contentsOfDirectory(at: folder, includingPropertiesForKeys: nil)
.filter({ $0.pathExtension == "jpg" }).count
}
/**
Get the image count of a cap.
*/
func count(of cap: Int) throws -> Int {
let f = folder(of: cap)
guard fm.fileExists(atPath: f.path) else {
return 0
}
return try countImages(in: f)
}
// MARK: Images
/**
Save a cap image to disk.
Automatically creates the image name with the current image count.
- Parameter data: The image data
- Parameter cap: The id of the cap.
- Throws: `CapError.unknownId`, if the cap doesn't exist. `CapError.dataInconsistency` if an image already exists for the current count.
*/
func save(image data: Data, for cap: Int) throws {
guard caps[cap] != nil else {
throw CapError.unknownId
}
var id = 0
let capFolder = folder(of: cap)
var f = file(of: cap, version: id)
if fm.fileExists(atPath: capFolder.path) {
while fm.fileExists(atPath: f.path) {
id += 1
f = file(of: cap, version: id)
}
} else {
try fm.createDirectory(at: capFolder, withIntermediateDirectories: true)
}
try data.write(to: f)
caps[cap]!.count = try count(of: cap)
log("Added image \(id) for cap \(cap)")
}
func switchMainImage(to version: Int, for cap: Int) throws {
let file2 = file(of: cap, version: version)
guard fm.fileExists(atPath: file2.path) else {
log("No image \(version) for cap \(cap)")
throw CapError.invalidFile
}
caps[cap]?.mainImage = version
log("Switched cap \(cap) to version \(version)")
}
func addOrUpdate(_ cap: Cap) throws {
if let existingCap = caps[cap.id] {
update(existingCap, with: cap)
} else {
try add(cap)
}
}
private func add(_ cap: Cap) throws {
guard cap.mainImage == 0 else {
throw CapError.invalidData
}
var cap = cap
cap.count = 0
cap.classifierVersion = nextClassifierVersion
caps[cap.id] = cap
saveCapCountHTML()
log("Added cap \(cap.id) '\(cap.name)'")
}
private func update(_ existingCap: Cap, with cap: Cap) {
var updatedCap = existingCap
if cap.name != "" {
updatedCap.name = cap.name
}
let url = file(of: existingCap.id, version: cap.mainImage)
if fm.fileExists(atPath: url.path) {
updatedCap.mainImage = cap.mainImage
}
if let color = cap.color {
updatedCap.color = color
}
caps[existingCap.id] = updatedCap
log("Updated cap \(existingCap.id)")
}
func updateTrainedClasses(content: String) {
let trainedCaps = content
.components(separatedBy: "\n")
.compactMap(Int.init)
let version = classifierVersion
for cap in trainedCaps {
if caps[cap]?.classifierVersion == nil {
caps[cap]?.classifierVersion = version
}
}
log("Updated \(trainedCaps.count) classifier classes")
}
func save(classifier: Data, version: Int) throws {
do {
try classifier.write(to: classifierFile)
} catch {
log("Failed to write classifier: \(error)")
throw Abort(.internalServerError)
}
classifierVersion = version
log("Updated classifier to version \(version)")
}
}