feat: add cross-engine platform services

Runtime/ShrinkSave.cs

@@ -4,7 +4,9 @@ using System.IO;
 using System.Threading;
 using Cysharp.Threading.Tasks;
 using Newtonsoft.Json.Linq;
+#if UNITY_5_3_OR_NEWER
 using UnityEngine;
+#endif
 
 namespace ShrinkDataSaver
 {
@@ -141,7 +143,7 @@ namespace ShrinkDataSaver
                 }
                 catch (Exception e)
                 {
-                    Debug.LogWarning($"[ShrinkDataSaver] 读取元数据失败 slot_{slotIndex}: {e.Message}");
+                    ShrinkDataSaverPlatform.Warning($"[ShrinkDataSaver] 读取元数据失败 slot_{slotIndex}: {e.Message}");
                 }
             }
 
@@ -200,7 +202,11 @@ namespace ShrinkDataSaver
                     }
                 };
 
+#if UNITY_5_3_OR_NEWER
                 if (options.Screenshot || options.CaptureScreenshot)
+#else
+                if (options.Screenshot != null || options.CaptureScreenshot)
+#endif
                 {
                     packet.Meta.ScreenshotBase64 = await CaptureScreenshotAsync(options, ct);
                 }
@@ -223,7 +229,7 @@ namespace ShrinkDataSaver
                             throw new InvalidOperationException($"关键模块 '{module.Key}' 序列化失败: {e.Message}", e);
                         }
 
-                        Debug.LogError($"[ShrinkDataSaver] 模块 '{module.Key}' 序列化失败（已跳过）: {e.Message}");
+                        ShrinkDataSaverPlatform.Error($"[ShrinkDataSaver] 模块 '{module.Key}' 序列化失败（已跳过）: {e.Message}");
                     }
                 }
 
@@ -252,7 +258,7 @@ namespace ShrinkDataSaver
                     ModuleNames = moduleNames.ToArray(),
                     Timestamp = timestamp
                 });
-                Debug.Log($"[ShrinkDataSaver] 槽位 {slotIndex} 已保存。({moduleNames.Count} 个模块)");
+                ShrinkDataSaverPlatform.Info($"[ShrinkDataSaver] 槽位 {slotIndex} 已保存。({moduleNames.Count} 个模块)");
             }
             catch (Exception e)
             {
@@ -293,13 +299,13 @@ namespace ShrinkDataSaver
                     }
                     catch (Exception e)
                     {
-                        Debug.LogError($"[ShrinkDataSaver] 反序列化模块 '{module.Key}' 失败: {e.Message}");
+                        ShrinkDataSaverPlatform.Error($"[ShrinkDataSaver] 反序列化模块 '{module.Key}' 失败: {e.Message}");
                     }
                 }
 
                 _loadedSlot = slotIndex;
                 _storedPlaytime = packet.Meta.PlaytimeSeconds;
-                _sessionStart = Time.realtimeSinceStartup;
+                _sessionStart = (float)ShrinkDataSaverPlatform.TimeSeconds;
                 await PersistRecentSlotIndexAsync(slotIndex, ct);
 
                 OnLoadCompleted?.Invoke(new LoadCompletedEventArgs
@@ -309,7 +315,7 @@ namespace ShrinkDataSaver
                     Version = packet.Meta.SaveVersion,
                     Timestamp = timestamp
                 });
-                Debug.Log($"[ShrinkDataSaver] 槽位 {slotIndex} 已加载。(v{packet.Meta.SaveVersion}, {moduleNames.Count} 个模块)");
+                ShrinkDataSaverPlatform.Info($"[ShrinkDataSaver] 槽位 {slotIndex} 已加载。(v{packet.Meta.SaveVersion}, {moduleNames.Count} 个模块)");
             }
             catch (Exception e)
             {
@@ -344,7 +350,7 @@ namespace ShrinkDataSaver
             }
 
             OnDeleteCompleted?.Invoke(new SlotDeletedEventArgs { SlotIndex = slotIndex });
-            Debug.Log($"[ShrinkDataSaver] 槽位 {slotIndex} 已删除。");
+            ShrinkDataSaverPlatform.Info($"[ShrinkDataSaver] 槽位 {slotIndex} 已删除。");
         }
 
         public static float GetMinAutoSaveInterval()
@@ -355,7 +361,7 @@ namespace ShrinkDataSaver
             {
                 if (cfg.AutoSaveIntervalSeconds > 0f)
                 {
-                    min = Mathf.Min(min, cfg.AutoSaveIntervalSeconds);
+                    min = Math.Min(min, cfg.AutoSaveIntervalSeconds);
                     hasAny = true;
                 }
             }
@@ -406,7 +412,11 @@ namespace ShrinkDataSaver
                 throw new ArgumentOutOfRangeException(nameof(slotIndex), "槽位索引不能为负数。");
             }
 
+#if UNITY_5_3_OR_NEWER
             var max = ShrinkDataSaverSettings.Instance.maxSlots;
+#else
+            var max = ShrinkDataSaverPlatform.MaxSlots;
+#endif
             if (max > 0 && slotIndex >= max)
             {
                 throw new ArgumentOutOfRangeException(nameof(slotIndex), $"超出最大槽位数 ({max})。");
@@ -529,7 +539,7 @@ namespace ShrinkDataSaver
 
                     if (!string.Equals(candidatePath, primaryPath, StringComparison.Ordinal))
                     {
-                        Debug.LogWarning($"[ShrinkDataSaver] 槽位 {slotIndex} 主文件损坏或缺失，已从备份恢复：{candidatePath}");
+                        ShrinkDataSaverPlatform.Warning($"[ShrinkDataSaver] 槽位 {slotIndex} 主文件损坏或缺失，已从备份恢复：{candidatePath}");
                         await _storage.WriteAsync(primaryPath, bytes, ct);
                     }
 
@@ -538,7 +548,7 @@ namespace ShrinkDataSaver
                 catch (Exception ex)
                 {
                     lastError = ex;
-                    Debug.LogWarning($"[ShrinkDataSaver] 读取槽位副本失败：{candidatePath} / {ex.Message}");
+                    ShrinkDataSaverPlatform.Warning($"[ShrinkDataSaver] 读取槽位副本失败：{candidatePath} / {ex.Message}");
                 }
             }
 
@@ -612,7 +622,7 @@ namespace ShrinkDataSaver
 
                     if (!string.Equals(candidatePath, primaryPath, StringComparison.Ordinal))
                     {
-                        Debug.LogWarning($"[ShrinkDataSaver] 槽位 {slotIndex} 主文件损坏或缺失，已从备份恢复：{candidatePath}");
+                        ShrinkDataSaverPlatform.Warning($"[ShrinkDataSaver] 槽位 {slotIndex} 主文件损坏或缺失，已从备份恢复：{candidatePath}");
                         await _storage.WriteAsync(primaryPath, bytes, ct);
                     }
 
@@ -621,7 +631,7 @@ namespace ShrinkDataSaver
                 catch (Exception ex)
                 {
                     lastError = ex;
-                    Debug.LogWarning($"[ShrinkDataSaver] 加载槽位副本失败：{candidatePath} / {ex.Message}");
+                    ShrinkDataSaverPlatform.Warning($"[ShrinkDataSaver] 加载槽位副本失败：{candidatePath} / {ex.Message}");
                 }
             }
 
@@ -633,10 +643,11 @@ namespace ShrinkDataSaver
             throw new FileNotFoundException($"槽位 {slotIndex} 不存在。");
         }
 
-        private static float GetCurrentPlaytime() => _loadedSlot < 0 ? 0f : _storedPlaytime + (Time.realtimeSinceStartup - _sessionStart);
+        private static float GetCurrentPlaytime() => _loadedSlot < 0 ? 0f : _storedPlaytime + ((float)ShrinkDataSaverPlatform.TimeSeconds - _sessionStart);
 
         private static async UniTask<string> CaptureScreenshotAsync(SaveOptions options, CancellationToken ct)
         {
+#if UNITY_5_3_OR_NEWER
             var tex = options.Screenshot;
             if (!tex && options.CaptureScreenshot)
             {
@@ -668,6 +679,16 @@ namespace ShrinkDataSaver
             }
 
             return Convert.ToBase64String(tex.EncodeToJPG(75));
+#else
+            var pngBytes = options.Screenshot;
+            if (pngBytes == null && options.CaptureScreenshot)
+            {
+                var provider = ShrinkDataSaverPlatform.Screenshots ??
+                    throw new InvalidOperationException("Screenshot capture was requested but no platform provider is configured.");
+                pngBytes = await provider.CapturePngAsync(ct);
+            }
+            return pngBytes == null ? string.Empty : Convert.ToBase64String(pngBytes);
+#endif
         }
     }
 }