feat: csv generation

lib/safira/event.ex

@@ -2,6 +2,7 @@ defmodule Safira.Event do
   @moduledoc """
   The event context.
   """
+  alias Safira.Accounts
   alias Safira.Constants
 
   @doc """

lib/safira_web/controllers/csv_controller.ex

@@ -0,0 +1,44 @@
+defmodule SafiraWeb.CSVController do
+  use SafiraWeb, :controller
+  alias NimbleCSV.RFC4180, as: CSV
+
+  alias Safira.Accounts
+
+  def final_draw(conn, _params) do
+    if user_authorized?(conn.assigns.current_user) do
+      conn =
+        conn
+        |> put_resp_content_type("text/csv")
+        |> put_resp_header("content-disposition", "attachment; filename=\"large_data.csv\"")
+        |> send_chunked(200)
+
+      # Stream the data
+      Accounts.list_attendees()
+      |> Stream.flat_map(&final_draw_lines/1)
+      |> Stream.map(&CSV.dump_to_iodata(&1))
+      |> Enum.reduce(conn, fn chunk, conn ->
+        case chunk(conn, chunk) do
+          {:ok, conn} -> conn
+          {:error, _reason} -> conn
+        end
+      end)
+    else
+      conn
+      |> put_flash(:error, "You do not have permission to view this resource")
+      |> put_status(403)
+      |> redirect(to: ~p"/dashboard")
+      |> halt()
+    end
+  end
+
+  defp user_authorized?(user) do
+    not is_nil(user.staff) and
+      Enum.member?(Map.get(user.staff.role.permissions, "statistics"), "show")
+  end
+
+  defp final_draw_lines(attendee) do
+    for _ <- 1..attendee.attendee.entries do
+      [[attendee.id, attendee.name, attendee.handle]]
+    end
+  end
+end

lib/safira_web/router.ex

@@ -95,9 +95,12 @@ defmodule SafiraWeb.Router do
         live "/vault", VaultLive.Index, :index
       end
 
-      scope "/dashboard", Backoffice do
-        pipe_through :require_staff_user
+      scope "/downloads" do
+        pipe_through [:require_staff_user]
+        get "/final_draw", CSVController, :final_draw
+      end
 
+      scope "/dashboard", Backoffice do
         scope "/attendees", AttendeeLive do
           live "/", Index, :index
           live "/:id", Show, :show

mix.exs

@@ -83,6 +83,7 @@ defmodule Safira.MixProject do
       {:jason, "~> 1.2"},
       {:lua, "~> 0.0.14"},
       {:timex, "~> 3.7.11"},
+      {:nimble_csv, "~>1.1"},
 
       # server
       {:bandit, "~> 1.2"},

mix.lock

@@ -36,6 +36,7 @@
   "mime": {:hex, :mime, "2.0.6", "8f18486773d9b15f95f4f4f1e39b710045fa1de891fada4516559967276e4dc2", [:mix], [], "hexpm", "c9945363a6b26d747389aac3643f8e0e09d30499a138ad64fe8fd1d13d9b153e"},
   "mimerl": {:hex, :mimerl, "1.3.0", "d0cd9fc04b9061f82490f6581e0128379830e78535e017f7780f37fea7545726", [:rebar3], [], "hexpm", "a1e15a50d1887217de95f0b9b0793e32853f7c258a5cd227650889b38839fe9d"},
   "mint": {:hex, :mint, "1.6.2", "af6d97a4051eee4f05b5500671d47c3a67dac7386045d87a904126fd4bbcea2e", [:mix], [{:castore, "~> 0.1.0 or ~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:hpax, "~> 0.1.1 or ~> 0.2.0 or ~> 1.0", [hex: :hpax, repo: "hexpm", optional: false]}], "hexpm", "5ee441dffc1892f1ae59127f74afe8fd82fda6587794278d924e4d90ea3d63f9"},
+  "nimble_csv": {:hex, :nimble_csv, "1.2.0", "4e26385d260c61eba9d4412c71cea34421f296d5353f914afe3f2e71cce97722", [:mix], [], "hexpm", "d0628117fcc2148178b034044c55359b26966c6eaa8e2ce15777be3bbc91b12a"},
   "nimble_options": {:hex, :nimble_options, "1.1.1", "e3a492d54d85fc3fd7c5baf411d9d2852922f66e69476317787a7b2bb000a61b", [:mix], [], "hexpm", "821b2470ca9442c4b6984882fe9bb0389371b8ddec4d45a9504f00a66f650b44"},
   "nimble_pool": {:hex, :nimble_pool, "1.1.0", "bf9c29fbdcba3564a8b800d1eeb5a3c58f36e1e11d7b7fb2e084a643f645f06b", [:mix], [], "hexpm", "af2e4e6b34197db81f7aad230c1118eac993acc0dae6bc83bac0126d4ae0813a"},
   "parse_trans": {:hex, :parse_trans, "3.4.1", "6e6aa8167cb44cc8f39441d05193be6e6f4e7c2946cb2759f015f8c56b76e5ff", [:rebar3], [], "hexpm", "620a406ce75dada827b82e453c19cf06776be266f5a67cff34e1ef2cbb60e49a"},