Implement core game functionality with AppRoot, SaveClient, PlayerRepository, and LevelRepository classes

data/SaveClient.cs

@@ -0,0 +1,103 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Godot;
+using Godot.Collections;
+using Mr.BrickAdventures.game.repositories;
+
+namespace Mr.BrickAdventures.data;
+
+public sealed class SaveClient
+{
+    private readonly string _path;
+    private readonly int _version;
+
+    public SaveClient(string path, int version) { _path = path; _version = version; }
+
+    public bool Exists() => FileAccess.FileExists(_path);
+
+    public bool TryLoad(out PlayerState player, out LevelState level) {
+        player = null!; level = null!;
+        if (!Exists()) return false;
+
+        using var f = FileAccess.Open(_path, FileAccess.ModeFlags.Read);
+        var dict = (Dictionary)f.GetVar();
+
+        if ((int)dict.GetValueOrDefault("version", -1) != _version) return false;
+
+        player = ToPlayer((Dictionary)dict["player"]);
+        level  = ToLevel((Dictionary)dict["level"]);
+        return true;
+    }
+    
+    // Strict load: requires version + player_state + level_state.
+    // If anything is off, delete the file and act as "no save".
+    public bool TryLoadStrict(out PlayerState player, out LevelState level) {
+        player = default!;
+        level  = default!;
+
+        if (!Exists()) return false;
+
+        try {
+            using var f = FileAccess.Open(_path, FileAccess.ModeFlags.Read);
+            if (f == null) { Delete(); return false; }
+
+            var dictionary = (Dictionary)f.GetVar();
+            
+
+            if (!dictionary.TryGetValue("version", out var v) || (int)v != _version) { Delete(); return false; }
+
+            if (!dictionary.TryGetValue("player_state", out var pObj) || (Dictionary)pObj is not { } p) { Delete(); return false; }
+            if (!dictionary.TryGetValue("level_state",  out var lObj) || (Dictionary)lObj is not { } l) { Delete(); return false; }
+
+            player = ToPlayer(p);
+            level  = ToLevel(l);
+            return true;
+        }
+        catch (Exception e) {
+            GD.PushWarning($"SaveClient: load failed — deleting bad save. {e.GetType().Name}: {e.Message}");
+            Delete();
+            return false;
+        }
+    }
+
+    public void Save(PlayerState player, LevelState level) {
+        using var f = FileAccess.Open(_path, FileAccess.ModeFlags.Write);
+        var dict = new Dictionary {
+            { "version", _version },
+            { "player", FromPlayer(player) },
+            { "level",  FromLevel(level) }
+        };
+        f.StoreVar(dict);
+    }
+    
+    public void Delete() {
+        if (!Exists()) return;
+        var abs = ProjectSettings.GlobalizePath(_path);
+        var ok = DirAccess.RemoveAbsolute(abs);
+        if (ok != Error.Ok) GD.PushWarning($"SaveClient: failed to delete {_path}: {ok}");
+    }
+
+    private static Dictionary FromPlayer(PlayerState s) => new() { { "coins", s.Coins }, { "lives", s.Lives } };
+    private static PlayerState ToPlayer(Dictionary d) => new() {
+        Coins = d.TryGetValue("coins", out var c) ? (int)c : 0,
+        Lives = d.TryGetValue("lives", out var l) ? (int)l : 3
+    };
+
+    private static Dictionary FromLevel(LevelState s) => new() {
+        { "current",   s.Current },
+        { "unlocked",  new Array<int>(s.Unlocked) },
+        { "completed", new Array<int>(s.Completed) },
+    };
+
+    private static LevelState ToLevel(Dictionary d) => new() {
+        Current   = d.TryGetValue("current", out var cur) ? (int)cur : 0,
+        Unlocked  = d.TryGetValue("unlocked", out var ul) && (Array<int>)ul is { } a1 ? a1.ToArray() : [0],
+        Completed = d.TryGetValue("completed", out var cl) && (Array<int>)cl is { } a2 ? a2.ToArray() : [],
+    };
+}
+
+public record SaveSnapshot {
+    public required PlayerState PlayerState { get; init; }
+    public required LevelState  LevelState  { get; init; }
+}