refactor&fix: 重构将maidata中的lv映射为游戏中的难度的逻辑。

之前的逻辑是在ImportChartCheck和ImportChart中分别写的，甚至对同时标准难度和lv_8这种非标准难度的情况下，两边的处理甚至还不一致，造成ImportChartCheck返回给前端的信息和实际导入的结果不一致。

Author: Starrah

MaiChartManager/Controllers/Charts/ImportChartController.cs

@@ -42,60 +42,56 @@ public ImportChartCheckResult ImportChartCheck(IFormFile file, [FromForm] bool i
                 fatal = true;
             }
 
-            var levels = new bool[5];
             var allChartText = new Dictionary<int, string>();
-
-            for (var i = 0; i < 5; i++)
+            for (var i = 2; i < 9; i++)
             {
-                // maidata 里 2 是绿谱，6 是白谱
-                if (!string.IsNullOrWhiteSpace(maiData.GetValueOrDefault($"inote_{i + 2}")))
+                if (!string.IsNullOrWhiteSpace(maiData.GetValueOrDefault($"inote_{i}")))
                 {
-                    levels[i] = true;
-                    allChartText.Add(i + 2, maiData.GetValueOrDefault($"inote_{i + 2}"));
+                    allChartText.Add(i, maiData.GetValueOrDefault($"inote_{i}"));
                 }
             }
 
-            if (levels.Any(it => it))
+            if (!string.IsNullOrWhiteSpace(maiData.GetValueOrDefault("inote_0")))
             {
-                string[] levelNames = [Locale.DifficultyBasic, Locale.DifficultyAdvanced, Locale.DifficultyExpert, Locale.DifficultyMaster, Locale.DifficultyReMaster];
-                var message = Locale.ImportingDifficulties;
-                for (var i = 0; i < 5; i++)
-                {
-                    if (levels[i])
-                    {
-                        message += levelNames[i] + " ";
-                    }
-                }
-
-                errors.Add(new ImportChartMessage(message, MessageLevel.Info));
+                allChartText.Add(0, maiData.GetValueOrDefault($"inote_0"));
             }
-
-            foreach (var i in (int[])[7, 8, 0])
+            var targetLevelMap = importService.mapMaidataLevelToGame(allChartText.Keys.ToList());
+
+            # region 向前端返回，关于导入谱面的inote_映射到游戏中的难度的提示信息
+            string[] levelNames = [Locale.DifficultyBasic, Locale.DifficultyAdvanced, Locale.DifficultyExpert, Locale.DifficultyMaster, Locale.DifficultyReMaster];
+            string[] importAsMessages = [Locale.DifficultyImportedAsBasic, null, null, Locale.DifficultyImportedAsMaster, Locale.DifficultyImportedAsReMaster];
+            
+            string generalImportMessage = ""; // “将导入以下难度：” 的默认信息
+            var extraImportMessages = new List<string>(); // “有一个难度为 {0} 的谱面，将导入为XX谱 ” 的信息
+            foreach (var (lv, _) in allChartText)
             {
-                if (string.IsNullOrWhiteSpace(maiData.GetValueOrDefault($"inote_{i}"))) continue;
-                allChartText.Add(i, maiData.GetValueOrDefault($"inote_{i}"));
-                if (!levels[3])
-                {
-                    levels[3] = true;
-                    errors.Add(new ImportChartMessage(string.Format(Locale.DifficultyImportedAsMaster, i), MessageLevel.Warning));
+                if (!targetLevelMap.TryGetValue(lv, out var targetLevel))
+                { // 根据targetLevelMap返回的结果，该谱面应被忽略
+                    extraImportMessages.Add(string.Format(Locale.DifficultyIgnored, lv));
+                    continue;
                 }
-                else if (!levels[4])
+                if (2 <= lv && lv <= 6)
                 {
-                    levels[4] = true;
-                    errors.Add(new ImportChartMessage(string.Format(Locale.DifficultyImportedAsReMaster, i), MessageLevel.Warning));
-                }
-                else if (!levels[0])
-                {
-                    levels[0] = true;
-                    errors.Add(new ImportChartMessage(string.Format(Locale.DifficultyImportedAsBasic, i), MessageLevel.Warning));
+                    generalImportMessage += levelNames[targetLevel] + " ";
                 }
                 else
                 {
-                    errors.Add(new ImportChartMessage(string.Format(Locale.DifficultyIgnored, i), MessageLevel.Warning));
+                    extraImportMessages.Add(string.Format(importAsMessages[targetLevel], lv));
                 }
             }
+            
+            if (!string.IsNullOrEmpty(generalImportMessage))
+            {
+                errors.Add(new ImportChartMessage(Locale.ImportingDifficulties + generalImportMessage, MessageLevel.Info));
+            }
+
+            foreach (var message in extraImportMessages)
+            {
+                errors.Add(new ImportChartMessage(message, MessageLevel.Warning));
+            }
+            # endregion
 
-            if (!levels.Any(it => it))
+            if (targetLevelMap.Count == 0) // 没有能够被映射的谱面
             {
                 errors.Add(new ImportChartMessage(Locale.MusicNoCharts, MessageLevel.Fatal));
                 fatal = true;

MaiChartManager/Services/MaidataImportService.cs

@@ -257,6 +257,54 @@ public static Dictionary<ShiftMethod, float> CalcChartPadding(List<MaiChart> cha
 
     private record AllChartsEntry(string chartText, MaiChart simaiSharpChart);
 
+    /** 根据maidata中定义的所有难度，将其映射到游戏中的难度。 **/
+    public Dictionary<int, int> mapMaidataLevelToGame(List<int> maidataLevels)
+    {
+        var result = new Dictionary<int, int>();
+        var gameLevels = new bool[5];
+        
+        // 先映射标准难度谱面 绿红黄紫白
+        for (int lv = 2; lv <= 6; lv++)
+        {
+            if (!maidataLevels.Contains(lv)) continue;
+            var targetLevel = lv - 2;
+            result.Add(lv, targetLevel);
+            gameLevels[targetLevel] = true;
+        }
+
+        // 再映射78
+        foreach (var lv in (int[])[7,8])
+        {
+            if (!maidataLevels.Contains(lv)) continue;
+            foreach (var targetLevel in (int[])[3,4,0]) // 匹配顺序：紫，白，绿
+            {
+                if (!gameLevels[targetLevel])
+                {
+                    result.Add(lv, targetLevel);
+                    gameLevels[targetLevel] = true;
+                    break;
+                }
+            }
+        }
+        
+        // 再映射0
+        foreach (var lv in (int[])[0])
+        {
+            if (!maidataLevels.Contains(lv)) continue;
+            foreach (var targetLevel in (int[])[0,3,4]) // 匹配顺序：绿，紫，白
+            {
+                if (!gameLevels[targetLevel])
+                {
+                    result.Add(lv, targetLevel);
+                    gameLevels[targetLevel] = true;
+                    break;
+                }
+            }
+        }
+
+        return result;
+    }
+    
     public ImportChartResult ImportMaidata(
         MusicXml music,
         IFormFile file,
@@ -313,6 +361,7 @@ public ImportChartResult ImportMaidata(
         }
 
         float bpm = 0f;
+        var targetLevelMap = mapMaidataLevelToGame(allCharts.Keys.ToList());
         foreach (var (level, chart) in allCharts)
         {
             // 宴会场只导入第一个谱面
@@ -323,36 +372,9 @@ public ImportChartResult ImportMaidata(
             // 一个小节多少秒
             var bar = 60 / bpm * 4;
 
-            # region 设定 targetLevel
-
-            var targetLevel = level - 2;
-
-            // 处理非标准难度
-            if (level is > 6 or < 1)
-            {
-                // 分给 3 4 0
-                if (!music.Charts[3].Enable)
-                {
-                    targetLevel = 3;
-                }
-                else if (!music.Charts[4].Enable)
-                {
-                    targetLevel = 4;
-                }
-                else if (!music.Charts[0].Enable)
-                {
-                    targetLevel = 0;
-                }
-                else
-                {
-                    continue;
-                }
-            }
-
+            if (!targetLevelMap.TryGetValue(level, out var targetLevel)) continue; // 字典里没查到、说明这个难度是“被忽略的难度”
             if (isUtage) targetLevel = 0;
 
-            # endregion
-
             var targetChart = music.Charts[targetLevel];
             targetChart.Path = $"{id:000000}_0{targetLevel}.ma2";
             var levelNumStr = maiData.GetValueOrDefault($"lv_{level}");