got assignment template variables and replacement working

Management/Management.csproj

@@ -7,6 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Markdig" Version="0.31.0" />
     <PackageReference Include="RestSharp" Version="108.0.3" />
     <PackageReference Include="YamlDotNet" Version="13.1.1" />
   </ItemGroup>

Management/Models/Local/AssignmentTemplate.cs

@@ -15,4 +15,16 @@ public record AssignmentTemplate
 
     return matches.Select(match => match.Groups[1].Value);
   }
+  public static string GetHtml(AssignmentTemplate template, LocalAssignment assignment) 
+  {
+
+    var html = Markdig.Markdown.ToHtml(template.Markdown);
+
+    foreach (KeyValuePair<string, string> entry in assignment.template_variables)
+    {
+      html = html.Replace($"%7B%7B{entry.Key}%7D%7D", entry.Value);
+    }
+    return html;
+  } 
+  
 }

Management/Services/ICanvasTokenManagement.cs

@@ -1,5 +0,0 @@
-public interface ICanvasTokenManagement
-{
-  Task<string?> GetCanvasToken();
-  Task SaveCanvasToken(string token);
-}

Management/Services/WebRequestor.cs

@@ -3,46 +3,33 @@ using RestSharp;
 public class WebRequestor : IWebRequestor
 {
   private const string BaseUrl = "https://snow.instructure.com/api/v1/";
-  private bool tokenSet = false;
+  private string token;
   private RestClient client;
 
-  private ICanvasTokenManagement tokenManagement { get; }
-
-  public WebRequestor(ICanvasTokenManagement tokenManagement)
+  public WebRequestor()
   {
+    token =
+      Environment.GetEnvironmentVariable("CANVAS_TOKEN")
+      ?? throw new Exception("CANVAS_TOKEN not in environment");
     client = new RestClient(BaseUrl);
-    this.tokenManagement = tokenManagement;
+    client.AddDefaultHeader("Authorization", $"Bearer {token}");
   }
 
-  private async Task EnsureCanvasTokenSet()
-  {
-    if (tokenSet)
-      return;
-    
-    var newToken = await tokenManagement.GetCanvasToken();
-    if(newToken == null)
-      throw new Exception("cannot request canvas, no token in storage");
-    
-    client.AddDefaultHeader("Authorization", $"Bearer {newToken}");
-    tokenSet = true;
-  }
+
   public async Task<(T[]?, RestResponse)> GetManyAsync<T>(RestRequest request)
   {
-    await EnsureCanvasTokenSet();
     var response = await client.ExecuteGetAsync(request);
     return (Deserialize<T[]>(response), response);
   }
 
   public async Task<(T?, RestResponse)> GetAsync<T>(RestRequest request)
   {
-    await EnsureCanvasTokenSet();
     var response = await client.ExecuteGetAsync(request);
     return (Deserialize<T>(response), response);
   }
 
   public async Task<RestResponse> PostAsync(RestRequest request)
   {
-    await EnsureCanvasTokenSet();
     var response = await client.ExecutePostAsync(request);
     if (!response.IsSuccessful)
     {
@@ -56,7 +43,6 @@ public class WebRequestor : IWebRequestor
 
   public async Task<(T?, RestResponse)> PostAsync<T>(RestRequest request)
   {
-    await EnsureCanvasTokenSet();
     var response = await client.ExecutePostAsync(request);
     return (Deserialize<T>(response), response);
   }