Async Sync IO...

CLI/CLI/main.swift

@@ -4,6 +4,8 @@ import Model
 import CustomTypes
 import Persistance
 
+var game: Game? = nil
+
 enum EnumRules: String, CaseIterable {
     case FourInARow = "Four in a row"
     case TicTacToe = "Tic Tac Toe"
@@ -15,8 +17,8 @@ func enumPrompt<E: RawRepresentable<String> & CaseIterable>(prompt: String) -> E
         print("\t\(index + 1). \(variant.rawValue)")
     }
     
-    guard let rawInput = readLine(strippingNewline: true),
-          let index = Int(rawInput), index >= 1, index <= E.allCases.count
+    guard let rawInput = readLine(strippingNewline: true) else { exit(EXIT_SUCCESS) }
+    guard let index = Int(rawInput), index >= 1, index <= E.allCases.count
     else {
         fatalError("Invalid variant number")
     }
@@ -24,14 +26,13 @@ func enumPrompt<E: RawRepresentable<String> & CaseIterable>(prompt: String) -> E
     return E.allCases[index - 1]
 }
 
-let gameType: EnumRules = enumPrompt(prompt: "Choose a game type")
-
 enum PlayerType: String, CaseIterable {
     case AIRandom = "(AI) Random"
     case Human = "Player"
 }
 
-func playerPrompt(allowed_moves: [Move.Action], board: Board) -> Move.Action {
+@MainActor
+func playerPrompt(allowed_moves: [Move.Action], board: Board) async -> Move.Action {
     for (i, action) in allowed_moves.enumerated() {
         let text = switch action {
         case .InsertAt(let at): "Place piece at \(at.col):\(at.row)"
@@ -40,13 +41,24 @@ func playerPrompt(allowed_moves: [Move.Action], board: Board) -> Move.Action {
         print("\(i + 1). \(text)")
     }
     
-    guard let rawInput = readLine(strippingNewline: true),
-          let index = Int(rawInput), index >= 1, index <= allowed_moves.count
-    else {
-        fatalError("Invalid move number")
+    if let rawInput = readLine(strippingNewline: true) {
+        guard let index = Int(rawInput), index >= 1, index <= allowed_moves.count
+        else {
+            fatalError("Invalid move number")
+        }
+        
+        return allowed_moves[index - 1]
+    } else {
+        // dump game to disk
+        
+        do {
+            try await Storage.save(game: game!, finished: false)
+        } catch {
+            fatalError("Failed to save game: \(error)")
+        }
+        
+        exit(EXIT_SUCCESS)
     }
-    
-    return allowed_moves[index - 1]
 }
 
 func createPlayer(type: PlayerType, playing pieces: PieceType, named name: String) -> Player {
@@ -58,31 +70,52 @@ func createPlayer(type: PlayerType, playing pieces: PieceType, named name: Strin
     }
 }
 
-let players: [Player] = PieceType.allCases.map { type in
-    let ptype: PlayerType = enumPrompt(prompt: "Player playing pieces \(type)")
+if let unfinished = try await Storage.loadUnfinishedGame(callbackFactory: { name, type in playerPrompt }) {
+    print("There was an unfinished game. Resume? [Y/n]")
+    
+    guard let answer = readLine(strippingNewline: true) else {
+        exit(EXIT_SUCCESS)
+    }
     
-    print("Enter player name:")
-    guard let playerName = readLine(strippingNewline: true) else {
-        fatalError("Player name unspecified")
+    switch answer.lowercased() {
+    case "", "y", "yes":
+        game = unfinished
+    default:
+        break;
     }
     
-    return createPlayer(type: ptype, playing: type, named: playerName)
+    try await Storage.clearUnfinished()
 }
 
-let rules: any Rules = switch gameType {
-case .FourInARow: FourInARowRules(players: players)!
-case .TicTacToe: TicTacToeRules(players: players)!
-}
+if game == nil {
+    let gameType: EnumRules = enumPrompt(prompt: "Choose a game type")
 
-var game = Game(players: players, rules: rules)
+    let players: [Player] = PieceType.allCases.map { type in
+        let ptype: PlayerType = enumPrompt(prompt: "Player playing pieces \(type)")
+        
+        print("Enter player name:")
+        guard let playerName = readLine(strippingNewline: true) else {
+            fatalError("Player name unspecified")
+        }
+        
+        return createPlayer(type: ptype, playing: type, named: playerName)
+    }
 
-game.boardChanged.add { board in
+    let rules: any Rules = switch gameType {
+    case .FourInARow: FourInARowRules(players: players)!
+    case .TicTacToe: TicTacToeRules(players: players)!
+    }
+    
+    game = Game(players: players, rules: rules)
+}
+
+game!.boardChanged.add { board in
     print(board)
 }
-game.moveIsInvalid.add { move in
+game!.moveIsInvalid.add { move in
     print("\(move.player.name), this move is invalid according to the rules.")
 }
-game.gameStateChanged.add { state in
+game!.gameStateChanged.add { state in
     switch state {
     case .Playing(let player):
         print("\(player.name) turn.")
@@ -96,16 +129,6 @@ game.gameStateChanged.add { state in
     }
 }
 
-game.play()
-
-var encoder = JSONEncoder()
-encoder.outputFormatting = .prettyPrinted
-encoder.userInfo[.gameDecodingContext] = CodableContext()
-
-let data = try encoder.encode(CodableGameWrapper(of: game))
-
-var decoder = JSONDecoder()
-decoder.userInfo[.gameDecodingContext] = CodableContext(creatingCallbacks: { name, type in playerPrompt })
-let game2 = (try decoder.decode(CodableGameWrapper.self, from: data)).game
+await game!.play()
 
-assert(game == game2, "Games are not equals!")
+try await Storage.save(game: game!, finished: true)

Model/Sources/Model/Game.swift

@@ -32,8 +32,9 @@ public class Game: Equatable {
         self.rules = rules
         self.board = board
     }
-        
-    public func play() {
+    
+    @MainActor
+    public func play() async {
         switch state {
         case .Playing:
             break
@@ -52,7 +53,7 @@ public class Game: Equatable {
                 player_turn.skipMove(board: board)
             } else {
                 while true {
-                    let choosen_action = player_turn.chooseMove(allowed_moves: valid_moves, board: board)
+                    let choosen_action = await player_turn.chooseMove(allowed_moves: valid_moves, board: board)
                     let move = Move(player: player_turn, action: choosen_action)
                     
                     guard rules.isValid(board: board, move: move) else {

Model/Sources/Model/Players/HumanPlayer.swift

@@ -1,4 +1,4 @@
-public typealias MoveCallback = ([Move.Action], Board) -> Move.Action
+public typealias MoveCallback = ([Move.Action], Board) async -> Move.Action
 
 public class HumanPlayer : Player {
     private let callback: MoveCallback
@@ -11,7 +11,7 @@ public class HumanPlayer : Player {
         super.init(name: name, piece_type: piece_type)
     }
 
-    public override func chooseMove(allowed_moves moves: [Move.Action], board: Board) -> Move.Action {
-        callback(moves, board)
+    public override func chooseMove(allowed_moves moves: [Move.Action], board: Board) async -> Move.Action {
+        await callback(moves, board)
     }
 }

Model/Sources/Model/Players/Player.swift

@@ -9,7 +9,7 @@ public class Player : Equatable {
         self.piece_type = piece_type
     }
 
-    public func chooseMove(allowed_moves moves: [Move.Action], board: Board) -> Move.Action {
+    public func chooseMove(allowed_moves moves: [Move.Action], board: Board) async -> Move.Action {
         fatalError("abstract method not implemented")
     }
     

Model/Sources/Model/Players/RandomPlayer.swift

@@ -1,6 +1,6 @@
 public class RandomPlayer : Player {
     public override var type: PlayerType { .AIRandom }
-    public override func chooseMove(allowed_moves moves: [Move.Action], board: Board) -> Move.Action {
+    public override func chooseMove(allowed_moves moves: [Move.Action], board: Board) async -> Move.Action {
         moves[Int.random(in: moves.indices)]
     }
 }

Persistance/Sources/Persistance/Game.swift

@@ -61,7 +61,7 @@ extension GameState: Codable {
         
         self = switch (try container.decode(CodableEnum<VariantCodingKeys>.self, forKey: .type)).variant {
         case .Playing:
-            .Playing(turn: (try CodablePlayerWrapper(from: decoder)).player)
+            .Playing(turn: (try (try decoder.container(keyedBy: ExtraCodingKeys.self)).decode(CodablePlayerReferenceWrapper.self, forKey: .player)).player)
         case .Win:
             try Self.decodeWin(from: decoder)
         case .Draw:

Persistance/Sources/Persistance/Storage.swift

@@ -0,0 +1,61 @@
+import Foundation
+import Model
+
+@available(macOS 13.0, *)
+public struct Storage {
+    private static let gameDirectory = try! URL(for: .applicationDirectory, in: .userDomainMask).appending(path: "Connect4")
+    private static let unfinishedGame = gameDirectory.appending(path: "unfinished.json")
+    private static let finishedGameDirectory = gameDirectory.appending(path: "finished")
+    
+    /* func hasUnfinishedGame() -> Bool {
+     return FileManager.default.fileExists(atPath: unfinishedGameDirectory.path)
+     } */
+    
+    public static func loadUnfinishedGame(callbackFactory: @escaping (_ name: String, _ type: PieceType) -> MoveCallback) async throws -> Game? {
+        // Will read the file asynchronously
+        let content = await Task {
+            if FileManager.default.fileExists(atPath: unfinishedGame.path) {
+                return FileManager.default.contents(atPath: unfinishedGame.path)
+            } else {
+                return nil
+            }
+        }.value
+        guard let content = content else { return nil }
+        
+        let decoder = JSONDecoder()
+        decoder.userInfo[.gameDecodingContext] = CodableContext(creatingCallbacks: callbackFactory)
+        
+        return (try decoder.decode(CodableGameWrapper.self, from: content)).game
+    }
+    
+    public static func save(game: Game, finished: Bool) async throws {
+        let (directory, file) = if finished {
+            (
+                finishedGameDirectory.path,
+                finishedGameDirectory
+                    .appending(path: "\(Date())")
+                    .appendingPathExtension(".json")
+            )
+        } else {
+            (gameDirectory.path, unfinishedGame)
+        }
+        
+        let encoder = JSONEncoder()
+        encoder.outputFormatting = .prettyPrinted
+        encoder.userInfo[.gameDecodingContext] = CodableContext()
+        
+        let data = try encoder.encode(CodableGameWrapper(of: game))
+        
+        // Does Swift have true async IO natively???
+        try await Task {
+            try FileManager.default.createDirectory(atPath: directory, withIntermediateDirectories: true)
+            try data.write(to: file)
+        }.value
+    }
+    
+    public static func clearUnfinished() async throws {
+        try await Task {
+            try FileManager.default.removeItem(at: unfinishedGame)
+        }.value
+    }
+}