add "dm/messages/get" request

LarpixServer/Account/Requests.cs

@@ -631,11 +631,17 @@ public class Requests
                             , password));
                     break;
                 case "user/dm/create":
-                    await context.Response.WriteAsync(
+                    await context.Response.WriteAsync(Encryption.Encryption.EncryptString(await Room.Requests.DmCreate(id, serializedBody.string2), password));
-                        Encryption.Encryption.EncryptString(
-                            await Room.Requests.DmCreate(id, serializedBody.string2)
-                            , password));
                     break;
+                case "dm/messages/get":
+                    {
+                        Universal3String msgGet = JsonSerializer.Deserialize(
+                            serializedBody.string2,
+                            AppJsonSerializerContext.Default.Universal3String
+                        );
+                        await context.Response.WriteAsync(Encryption.Encryption.EncryptString(await Room.Requests.GetDmMessages(id, msgGet.string1, msgGet.string3, msgGet.string2), password));
+                        break;
+                    }
                 case "dm/key/get":
                     await context.Response.WriteAsync(
                         Encryption.Encryption.EncryptString(

LarpixServer/Filesystem/Fs.cs

@@ -160,11 +160,15 @@ public class Fs
 
         try
         {
-            var dir = Path.GetDirectoryName(path);
+            var dir = Path.GetDirectoryName(path)?.Replace("\\", "/");
-            if (!string.IsNullOrEmpty(dir) && !Directory.Exists(dir))
+            if (!string.IsNullOrEmpty(dir))
+            {
+                existCache[dir] = true;
+                if (!Directory.Exists(dir))
                 {
                     CreateDirectory(dir);
                 }
+            }
 
             await File.WriteAllBytesAsync(path, content);
             existCache[path] = true;

LarpixServer/Room/Requests.cs

@@ -29,6 +29,49 @@ public class Requests
         string memberPath = $"{ROOMS_DIR}/dms/{DOMAIN}/{dmId}/members/{id};{DOMAIN}";
         return Fs.Exists(memberPath);
     }
+    public static async Task<string> GetDmMessages(string id, string dmId, string startOffset, string countStr)
+    {
+        if (!await IsMemberOfDm(id, dmId)) return "error:forbidden";
+        
+        string msgDir = $"{ROOMS_DIR}/dms/{DOMAIN}/{dmId}/messages";
+        if (!Fs.Exists(msgDir)) return "{}";
+        
+        long last = 0;
+        if (Fs.Exists($"{msgDir}/last")) 
+        {
+            string lastStr = Encoding.UTF8.GetString(await Fs.ReadFile($"{msgDir}/last"));
+            long.TryParse(lastStr, out last);
+        }
+        
+        long start = last;
+        if (!string.IsNullOrEmpty(startOffset) && long.TryParse(startOffset, out long s))
+        {
+            start = s;
+        }
+        
+        int count = 50;
+        if (!string.IsNullOrEmpty(countStr) && int.TryParse(countStr, out int c))
+        {
+            count = Math.Min(c, 100);
+        }
+
+        StringBuilder sb = new StringBuilder("{");
+        int fetched = 0;
+        for (long i = start; i >= 0 && fetched < count; i--)
+        {
+            string p = $"{msgDir}/{i}";
+            if (Fs.Exists(p))
+            {
+                if (fetched > 0) sb.Append(',');
+                sb.Append($"\"{i}\":");
+                sb.Append(Encoding.UTF8.GetString(await Fs.ReadFile(p)));
+                fetched++;
+            }
+        }
+        sb.Append("}");
+        return sb.ToString();
+    }
+
 
     public static async Task<string> GetDmKey(string id, string dmId)
     {