adjusted file service, added get all notes method

Services/FileNoteService.cs

@@ -3,10 +3,12 @@
     public class FileNoteService : INoteService
     {
         private readonly string? defaultFileName;
+        private readonly string? filePath;
 
         public FileNoteService(IConfiguration configuration)
         {
-            defaultFileName = configuration["ContentFilePath"];
+            defaultFileName = configuration["DefaultContentFileName"].Trim().ToLower();
+            filePath = configuration["ContentFilePath"].Trim();
 
             CheckFile(defaultFileName);
         }
@@ -15,25 +17,37 @@
         {
             CheckFile(noteName);
 
-            return File.ReadAllText(GetFileName(noteName));
+            return File.ReadAllText(GetFilePath(noteName));
+        }
+
+        public ICollection<string> GetNoteNames()
+        {
+            return Directory.GetFiles(filePath);
         }
 
         public void Save(string content, string? noteName)
         {
-            File.WriteAllText(GetFileName(noteName), content);
+            File.WriteAllText(GetFilePath(noteName), content);
         }
 
         private void CheckFile(string noteName)
         {
-            var fileName = GetFileName(noteName);
+            var filePath = GetFilePath(noteName);
 
             // ensure initialized
-            if (!File.Exists(fileName))
+            if (!File.Exists(filePath))
             {
-                Save("Hi! Feel free to start typing. Everything will be saved soon after you are done typing.", fileName);
+                Save("Hi! Feel free to start typing. Everything will be saved soon after you are done typing.", noteName);
             }
         }
 
-        private string GetFileName(string? noteName) => string.IsNullOrWhiteSpace(noteName) ? defaultFileName : noteName;
+        private string GetFilePath(string? noteName)
+        {
+            noteName = string.IsNullOrWhiteSpace(noteName) ? defaultFileName : noteName;
+            
+            noteName = noteName.Trim().ToLower();
+
+            return Path.Combine(filePath, noteName);
+        }
     }
 }

Services/INoteService.cs

@@ -2,6 +2,7 @@
 {
     public interface INoteService
     {
+        ICollection<string> GetNoteNames();
         string Get(string? noteName);
         void Save(string content, string? noteName);
     }

appsettings.json

@@ -6,5 +6,6 @@
     }
   },
   "AllowedHosts": "*",
-  "ContentFilePath": "content"
+  "DefaultContentFileName": "content",
+  "ContentFilePath": "notes"
 }