Available versions endpoint

lib/schema_web/controllers/schema_controller.ex

@@ -43,6 +43,19 @@ defmodule SchemaWeb.SchemaController do
             version: "1.0.0"
           })
         end,
+      Versions:
+        swagger_schema do
+          title("Versions")
+          description("Schema versions, using Semantic Versioning Specification (SemVer) format.")
+
+          properties do
+            versions(:string, "Version numbers", required: true)
+          end
+
+          example(%{
+            versions: ["1.0.0", "1.1.0"]
+          })
+        end,
       ClassDesc:
         swagger_schema do
           title("Class Descriptor")
@@ -122,6 +135,45 @@ defmodule SchemaWeb.SchemaController do
     send_json_resp(conn, version)
   end
 
+  @doc """
+  Get available OCSF schema versions.
+  """
+  swagger_path :versions do
+    get("/api/versions")
+    summary("Versions")
+    description("Get available OCSF schema versions.")
+    produces("application/json")
+    tag("Schema")
+    response(200, "Success", :Versions)
+  end
+
+  @spec versions(Plug.Conn.t(), any) :: Plug.Conn.t()
+  def versions(conn, _params) do
+
+    url = Application.get_env(:schema_server, SchemaWeb.Endpoint)[:url]
+
+    base_url = "#{conn.scheme}://#{Keyword.fetch!(url, :host)}:#{Keyword.fetch!(url, :port)}"
+
+    available_versions = Schemas.versions()
+    |> Enum.map(fn {version, _} -> version end)
+
+    default_version = %{:version => Schema.version(), :url => "#{base_url}/api"}
+
+    versions_response = case available_versions do
+      [] ->
+        # If there is no response, we only provide a single schema
+        %{:versions => [default_version], :default => default_version}
+
+      [_head | _tail] ->
+        available_versions_objects = available_versions
+        |> Enum.map(fn version -> %{:version => version, :url => "#{base_url}/#{version}/api"} end)
+        %{:versions => available_versions_objects, :default => default_version}
+
+    end
+
+    send_json_resp(conn, versions_response)
+  end
+
   @doc """
   Get the schema data types.
   """

lib/schema_web/router.ex

@@ -38,7 +38,7 @@ defmodule SchemaWeb.Router do
     get "/classes", PageController, :classes
     get "/classes/:id", PageController, :classes
     get "/classes/:extension/:id", PageController, :classes
-    
+
     get "/class/graph/:id", PageController, :class_graph
     get "/class/graph/:extension/:id", PageController, :class_graph
 
@@ -51,7 +51,7 @@ defmodule SchemaWeb.Router do
 
     get "/object/graph/:id", PageController, :object_graph
     get "/object/graph/:extension/:id", PageController, :object_graph
-    
+
     get "/data_types", PageController, :data_types
     get "/guidelines", PageController, :guidelines
   end
@@ -61,6 +61,8 @@ defmodule SchemaWeb.Router do
     pipe_through :api
 
     get "/version", SchemaController, :version
+    get "/versions", SchemaController, :versions
+
     get "/profiles", SchemaController, :profiles
     get "/extensions", SchemaController, :extensions
 
@@ -94,7 +96,7 @@ defmodule SchemaWeb.Router do
 
     get "/classes/:id", SchemaController, :json_class
     get "/classes/:extension/:id", SchemaController, :json_class
-    
+
     get "/objects/:id", SchemaController, :json_object
     get "/objects/:extension/:id", SchemaController, :json_object
   end