generating tokens with mix

lib/pleroma/user_invite_token.ex

@@ -6,34 +6,54 @@ defmodule Pleroma.UserInviteToken do
   use Ecto.Schema
 
   import Ecto.Changeset
-
+  import Ecto.Query
   alias Pleroma.Repo
   alias Pleroma.UserInviteToken
 
+  @type token :: String.t()
+
   schema "user_invite_tokens" do
     field(:token, :string)
     field(:used, :boolean, default: false)
+    field(:max_use, :integer)
+    field(:expire_at, :date)
+    field(:uses, :integer)
+    field(:token_type)
 
     timestamps()
   end
 
-  def create_token do
+  def create_token(options \\ []) do
     token = :crypto.strong_rand_bytes(32) |> Base.url_encode64()
 
-    token = %UserInviteToken{
-      used: false,
-      token: token
-    }
+    max_use = options[:max_use]
+    expire_at = options[:expire_at]
+
+    token =
+      %UserInviteToken{
+        used: false,
+        token: token,
+        max_use: max_use,
+        expire_at: expire_at,
+        uses: 0
+      }
+      |> token_type()
 
     Repo.insert(token)
   end
 
+  def list_invites do
+    query = from(u in UserInviteToken, order_by: u.id)
+    Repo.all(query)
+  end
+
   def used_changeset(struct) do
     struct
     |> cast(%{}, [])
     |> put_change(:used, true)
   end
 
+  @spec mark_as_used(token()) :: {:ok, UserInviteToken.t()} | {:error, token()}
   def mark_as_used(token) do
     with %{used: false} = token <- Repo.get_by(UserInviteToken, %{token: token}),
          {:ok, token} <- Repo.update(used_changeset(token)) do
@@ -42,4 +62,61 @@ defmodule Pleroma.UserInviteToken do
       _e -> {:error, token}
     end
   end
+
+  defp token_type(%{expire_at: nil, max_use: nil} = token), do: %{token | token_type: "one_time"}
+
+  defp token_type(%{expire_at: _expire_at, max_use: nil} = token),
+    do: %{token | token_type: "date_limited"}
+
+  defp token_type(%{expire_at: nil, max_use: _max_use} = token),
+    do: %{token | token_type: "reusable"}
+
+  defp token_type(%{expire_at: _expire_at, max_use: _max_use} = token),
+    do: %{token | token_type: "reusable_date_limited"}
+
+  @spec valid_token?(UserInviteToken.t()) :: boolean()
+  def valid_token?(%{token_type: "one_time"} = token) do
+    not token.used
+  end
+
+  def valid_token?(%{token_type: "date_limited"} = token) do
+    not_overdue_date?(token) and not token.used
+  end
+
+  def valid_token?(%{token_type: "reusable"} = token) do
+    token.uses < token.max_use and not token.used
+  end
+
+  def valid_token?(%{token_type: "reusable_date_limited"} = token) do
+    not_overdue_date?(token) and token.uses < token.max_use and not token.used
+  end
+
+  defp not_overdue_date?(%{expire_at: expire_at} = token) do
+    Date.compare(Date.utc_today(), expire_at) in [:lt, :eq] ||
+      (Repo.update!(change(token, used: true)) && false)
+  end
+
+  def update_usage(%{token_type: "date_limited"}), do: nil
+
+  def update_usage(%{token_type: "one_time"} = token) do
+    UserInviteToken.mark_as_used(token.token)
+  end
+
+  def update_usage(%{token_type: token_type} = token)
+      when token_type == "reusable" or token_type == "reusable_date_limited" do
+    new_uses = token.uses + 1
+
+    changes = %{
+      uses: new_uses
+    }
+
+    changes =
+      if new_uses >= token.max_use do
+        Map.put(changes, :used, true)
+      else
+        changes
+      end
+
+    change(token, changes) |> Repo.update!()
+  end
 end