From 7265fd0f0dc9a813a11de7020086b6a188c535d4 Mon Sep 17 00:00:00 2001
From: Christoph Hagen <christoph@spacemasters.eu>
Date: Wed, 1 Dec 2021 12:45:42 +0100
Subject: [PATCH] Persist registrations on disk

---
 Resources/.gitkeep                       |  1 +
 Sources/App/Model/Database.swift         |  6 +-
 Sources/App/Model/PlayerManagement.swift | 74 +++++++++++++++++++++++-
 Sources/App/configure.swift              |  4 +-
 4 files changed, 80 insertions(+), 5 deletions(-)
 create mode 100644 Resources/.gitkeep

diff --git a/Resources/.gitkeep b/Resources/.gitkeep
new file mode 100644
index 0000000..8d1c8b6
--- /dev/null
+++ b/Resources/.gitkeep
@@ -0,0 +1 @@
+ 
diff --git a/Sources/App/Model/Database.swift b/Sources/App/Model/Database.swift
index 61e708c..1103a06 100644
--- a/Sources/App/Model/Database.swift
+++ b/Sources/App/Model/Database.swift
@@ -7,10 +7,10 @@ final class Database {
 
     private let tables: TableManagement
 
-    init() {
-        self.players = PlayerManagement()
+    init(storageFolder: URL) throws {
+        self.players = try PlayerManagement(storageFolder: storageFolder)
         self.tables = TableManagement()
-        // TODO: Load server data from disk
+        // TODO: Load table data from disk
         // TODO: Save data to disk
     }
 
diff --git a/Sources/App/Model/PlayerManagement.swift b/Sources/App/Model/PlayerManagement.swift
index b6b037f..5bdf65a 100644
--- a/Sources/App/Model/PlayerManagement.swift
+++ b/Sources/App/Model/PlayerManagement.swift
@@ -15,9 +15,75 @@ final class PlayerManagement {
 
     /// A reverse mapping between generated access tokens and player name
     private var playerNameForToken = [SessionToken: PlayerName]()
+    
+    private let passwordFile: FileHandle
+    
+    private let passwordFileUrl: URL
 
-    init() {
+    init(storageFolder: URL) throws {
+        let url = storageFolder.appendingPathComponent("passwords.txt")
         
+        if !FileManager.default.fileExists(atPath: url.path) {
+            try Data().write(to: url)
+        }
+        
+        passwordFile = try FileHandle(forUpdating: url)
+        passwordFileUrl = url
+        
+        if #available(macOS 10.15.4, *) {
+            guard let data = try passwordFile.readToEnd() else {
+                try passwordFile.seekToEnd()
+                return
+            }
+            try loadPasswords(data: data)
+        } else {
+            let data = passwordFile.readDataToEndOfFile()
+            try loadPasswords(data: data)
+        }
+        print("Loaded \(playerPasswordHashes.count) players")
+    }
+    
+    private func loadPasswords(data: Data) throws {
+        String(data: data, encoding: .utf8)!
+            .components(separatedBy: "\n")
+            .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
+            .filter { $0 != "" }
+            .forEach { line in
+                let parts = line.components(separatedBy: ":")
+                // Token may contain the separator
+                guard parts.count >= 2 else {
+                    print("Invalid line in password file")
+                    return
+                }
+                let name = parts[0]
+                let token = parts.dropFirst().joined(separator: ":")
+                if token == "" {
+                    playerPasswordHashes[name] = nil
+                } else {
+                    playerPasswordHashes[name] = token
+                }
+            }
+    }
+    
+    private func save(password: PasswordHash, forPlayer player: PlayerName) -> Bool {
+        let entry = player + ":" + password + "\n"
+        let data = entry.data(using: .utf8)!
+        do {
+            if #available(macOS 10.15.4, *) {
+                try passwordFile.write(contentsOf: data)
+            } else {
+                passwordFile.write(data)
+            }
+            try passwordFile.synchronize()
+            return true
+        } catch {
+            print("Failed to save password to disk: \(error)")
+            return false
+        }
+    }
+    
+    private func deletePassword(forPlayer player: PlayerName) -> Bool {
+        save(password: "", forPlayer: player)
     }
 
     /**
@@ -48,6 +114,9 @@ final class PlayerManagement {
         guard !hasRegisteredPlayer(named: name) else {
             return nil
         }
+        guard save(password: hash, forPlayer: name) else {
+            return nil
+        }
         self.playerPasswordHashes[name] = hash
         return startNewSessionForRegisteredPlayer(named: name)
     }
@@ -58,6 +127,9 @@ final class PlayerManagement {
      - Returns: The session token of the current player, if one exists
      */
     func deletePlayer(named name: PlayerName) -> SessionToken? {
+        guard deletePassword(forPlayer: name) else {
+            return nil
+        }
         playerPasswordHashes.removeValue(forKey: name)
         guard let sessionToken = sessionTokenForPlayer.removeValue(forKey: name) else {
             return nil
diff --git a/Sources/App/configure.swift b/Sources/App/configure.swift
index 78f9455..8b8b873 100644
--- a/Sources/App/configure.swift
+++ b/Sources/App/configure.swift
@@ -7,7 +7,9 @@ public func configure(_ app: Application) throws {
     // serve files from /Public folder
     app.middleware.use(FileMiddleware(publicDirectory: app.directory.publicDirectory))
 
-    database = Database()
+    let storageFolder = URL(fileURLWithPath: app.directory.resourcesDirectory)
+    database = try Database(storageFolder: storageFolder)
+    
     // register routes
     try routes(app)
 }