Cherry-pick IVLE changes from PR #73

Author: ning-y

lib/cadet/accounts/ivle.ex

@@ -8,7 +8,7 @@ defmodule Cadet.Accounts.IVLE do
   [this link](http://ivle.nus.edu.sg/LAPI/default.aspx).
   """
 
-  @api_url "https://ivle.nus.edu.sg/api/Lapi.svc"
+  @api_url "https://ivle.nus.edu.sg/api/Lapi.svc/"
   @api_key Dotenv.load().values["IVLE_KEY"]
 
   @doc """
@@ -30,7 +30,7 @@ defmodule Cadet.Accounts.IVLE do
       {:ok, "e012345"}
 
   """
-  def fetch_nusnet_id(token), do: api_fetch("UserID_Get", token)
+  def fetch_nusnet_id(token), do: api_fetch("UserID_Get", Token: token)
 
   @doc """
   Get the full name of the user corresponding to this token.
@@ -51,10 +51,51 @@ defmodule Cadet.Accounts.IVLE do
       {:ok, "LEE NING YUAN"}
 
   """
-  def fetch_name(token), do: api_fetch("UserName_Get", token)
+  def fetch_name(token), do: api_fetch("UserName_Get", Token: token)
 
-  defp api_fetch(path, token) do
-    case HTTPoison.get(api_url(path, token)) do
+  @doc """
+  Get the role of the user corresponding to this token.
+
+  returns...
+
+    - {:ok, :student} - valid token, permission "S"
+    - {:ok, :admin} - valid token, permission "O"
+    - {:ok, :staff} - valid token, permissions "F", "M", "R"
+    - {:error, :bad_request} - invalid token, or not taking the module
+
+  This function assumes that inactive modules have an ID of 
+  `"00000000-0000-0000-0000-000000000000"`, and that there is only one active
+  module with the course code `"CS1101S"`. (So far, these assumptions have been
+  true).
+  """
+  def fetch_role(token) do
+    {:ok, modules} = api_fetch("Modules", AuthToken: token, CourseID: "CS1101S")
+
+    cs1101s =
+      modules["Results"]
+      |> Enum.filter(fn module ->
+        module["CourseCode"] == "CS1101S" and
+          module["ID"] != "00000000-0000-0000-0000-000000000000"
+      end)
+      |> List.first()
+
+    case cs1101s do
+      %{"Permission" => "S"} ->
+        {:ok, :student}
+
+      %{"Permission" => "O"} ->
+        {:ok, :admin}
+
+      %{"Permission" => _} ->
+        {:ok, :staff}
+
+      _ ->
+        {:error, :bad_request}
+    end
+  end
+
+  defp api_fetch(method, queries) do
+    case HTTPoison.get(api_url(method, queries)) do
       {:ok, %{body: body, status_code: 200}} when body != ~s("") ->
         {:ok, Poison.decode!(body)}
 
@@ -68,8 +109,17 @@ defmodule Cadet.Accounts.IVLE do
     end
   end
 
-  defp api_url(path, token) do
-    # construct a valid URL with the module attributes, and given params
-    "#{@api_url}/#{path}?APIKey=#{@api_key}&Token=#{token}"
+  # Construct a valid URL with the module attributes, and given params
+  # token_param_key is specified as some api calls use ...&Token={token},
+  # but other calls use ...&AuthToken={token}
+  defp api_url(method, queries) do
+    queries = [APIKey: @api_key] ++ queries
+
+    url =
+      @api_url
+      |> URI.merge(method)
+      |> (&"#{&1}?#{URI.encode_query(queries)}").()
+
+    url
   end
 end

test/cadet/accounts/ivle_test.exs

@@ -57,4 +57,19 @@ defmodule Cadet.Accounts.IVLETest do
       end
     end
   end
+
+  describe "Fetch a role" do
+    test "Using a valid token" do
+      use_cassette "ivle/fetch_role#1" do
+        assert {:ok, role} = IVLE.fetch_role(@token)
+        assert Enum.member?([:student, :staff, :admin], role)
+      end
+    end
+
+    test "Using an invalid token" do
+      use_cassette "ivle/fetch_role#2" do
+        assert {:error, :bad_request} = IVLE.fetch_role(@token <> "Z")
+      end
+    end
+  end
 end

test/fixtures/vcr_cassettes/ivle/fetch_role#1.json

@@ -0,0 +1,29 @@
+[
+  {
+    "request": {
+      "body": "",
+      "headers": [],
+      "method": "get",
+      "options": [],
+      "request_body": "",
+      "url": "https://ivle.nus.edu.sg/api/Lapi.svc/Modules"
+    },
+    "response": {
+      "binary": false,
+      "body": "{\"Results\":[{\"Announcements\":[],\"Forums\":[],\"Workbins\":[],\"Webcasts\":[],\"Gradebooks\":[],\"Polls\":[],\"Multimedia\":[],\"LessonPlan\":[],\"ID\":\"a6579f36-4d7d-41fb-b394-92a00b78148b\",\"CourseLevel\":\"1\",\"CourseCode\":\"CS1101S\",\"CourseName\":\"PROGRAMMING METHODOLOGY\",\"CourseDepartment\":\"\",\"CourseSemester\":\"Semester 1\",\"CourseAcadYear\":\"2018/2019\",\"CourseOpenDate\":\"\\/Date(1526486400000+0800)\\/\",\"CourseOpenDate_js\":\"2018-05-17T00:00:00\",\"CourseCloseDate\":\"\\/Date(1545494340000+0800)\\/\",\"CourseCloseDate_js\":\"2018-12-22T23:59:00\",\"CourseMC\":\"0\",\"isActive\":\"Y\",\"Permission\":\"S\",\"Creator\":{\"UserID\":\"dcsmjh\",\"Name\":\"Martin Henz\",\"Email\":null,\"Title\":null,\"UserGuid\":\"4dce39fc-432c-4e4c-aef1-8bb187fcbcc0\",\"AccountType\":null,\"Photo\":null},\"hasGradebookItems\":false,\"hasTimetableItems\":false,\"hasGroupsItems\":false,\"hasClassGroupsForSignUp\":false,\"hasGuestRosterItems\":false,\"hasClassRosterItems\":false,\"hasWeblinkItems\":false,\"hasLecturerItems\":false,\"hasDescriptionItems\":false,\"hasReadingItems\":false,\"hasAnnouncementItems\":false,\"hasProjectGroupItems\":false,\"hasProjectGroupsForSignUp\":false,\"hasConsultationItems\":false,\"hasConsultationSlotsForSignUp\":false,\"hasLessonPlanItems\":false,\"Badge\":3,\"BadgeAnnouncement\":3,\"WebLinks\":[],\"Lecturers\":[],\"Descriptions\":[],\"ReadingFormatted\":[],\"ReadingUnformatted\":[]}],\"Comments\":\"Valid login!\",\"LastUpdate\":\"\\/Date(1529925360661+0800)\\/\",\"LastUpdate_js\":\"2018-06-25T19:16:00.6613434+08:00\"}",
+      "headers": {
+        "Cache-Control": "private",
+        "Content-Type": "application/json",
+        "Server": "Microsoft-IIS/8.5",
+        "Request-Context": "appId=cid-v1:9bebd252-0be2-48b7-a1db-8e2b70524944",
+        "Set-Cookie": "ASP.NET_SessionId=45zj2hcegu2tf01cjxe2tljv; path=/; HttpOnly",
+        "X-AspNet-Version": "4.0.30319",
+        "X-Powered-By": "ASP.NET",
+        "Date": "Mon, 25 Jun 2018 11:16:00 GMT",
+        "Content-Length": "1423"
+      },
+      "status_code": 200,
+      "type": "ok"
+    }
+  }
+]

test/fixtures/vcr_cassettes/ivle/fetch_role#2.json

@@ -0,0 +1,29 @@
+[
+  {
+    "request": {
+      "body": "",
+      "headers": [],
+      "method": "get",
+      "options": [],
+      "request_body": "",
+      "url": "https://ivle.nus.edu.sg/api/Lapi.svc/Modules"
+    },
+    "response": {
+      "binary": false,
+      "body": "{\"Results\":[],\"Comments\":\"Invalid login!\",\"LastUpdate\":\"\\/Date(1529925361303+0800)\\/\",\"LastUpdate_js\":\"2018-06-25T19:16:01.3037465+08:00\"}",
+      "headers": {
+        "Cache-Control": "private",
+        "Content-Type": "application/json",
+        "Server": "Microsoft-IIS/8.5",
+        "Request-Context": "appId=cid-v1:9bebd252-0be2-48b7-a1db-8e2b70524944",
+        "Set-Cookie": "ASP.NET_SessionId=lrv1epzits2rh4hhkxg1uv2w; path=/; HttpOnly",
+        "X-AspNet-Version": "4.0.30319",
+        "X-Powered-By": "ASP.NET",
+        "Date": "Mon, 25 Jun 2018 11:16:00 GMT",
+        "Content-Length": "138"
+      },
+      "status_code": 200,
+      "type": "ok"
+    }
+  }
+]