Support for Elixir configuration file #1208

Contribution for Google Summer of code 2016 by Gabriel Gatu

1 files changed, 94 insertions, 0 deletions

diff --git a/lib/mix/tasks/deps.tree.ex b/lib/mix/tasks/deps.tree.ex
new file mode 100644
index 000000000..94cb85a50
--- /dev/null
+++ b/lib/mix/tasks/deps.tree.ex
@@ -0,0 +1,94 @@
+defmodule Mix.Tasks.Ejabberd.Deps.Tree do
+  use Mix.Task
+
+  alias Ejabberd.Config.EjabberdModule
+
+  @shortdoc "Lists all ejabberd modules and their dependencies"
+
+  @moduledoc """
+  Lists all ejabberd modules and their dependencies.
+
+  The project must have ejabberd as a dependency.
+  """
+
+  def run(_argv) do
+    # First we need to start manually the store to be available
+    # during the compilation of the config file.
+    Ejabberd.Config.Store.start_link
+    Ejabberd.Config.init(:ejabberd_config.get_ejabberd_config_path())
+
+    Mix.shell.info "ejabberd modules"
+
+    Ejabberd.Config.Store.get(:modules)
+    |> Enum.reverse # Because of how mods are stored inside the store
+    |> format_mods
+    |> Mix.shell.info
+  end
+
+  defp format_mods(mods) when is_list(mods) do
+    deps_tree = build_dependency_tree(mods)
+    mods_used_as_dependency = get_mods_used_as_dependency(deps_tree)
+
+    keep_only_mods_not_used_as_dep(deps_tree, mods_used_as_dependency)
+    |> format_mods_into_string
+  end
+
+  defp build_dependency_tree(mods) do
+    Enum.map mods, fn %EjabberdModule{module: mod, attrs: attrs} ->
+      deps = attrs[:dependency]
+      build_dependency_tree(mods, mod, deps)
+    end
+  end
+
+  defp build_dependency_tree(mods, mod, []), do: %{module: mod, dependency: []}
+  defp build_dependency_tree(mods, mod, deps) when is_list(deps) do
+    dependencies = Enum.map deps, fn dep ->
+      dep_deps = get_dependencies_of_mod(mods, dep)
+      build_dependency_tree(mods, dep, dep_deps)
+    end
+
+    %{module: mod, dependency: dependencies}
+  end
+
+  defp get_mods_used_as_dependency(mods) when is_list(mods) do
+    Enum.reduce mods, [], fn(mod, acc) ->
+      case mod do
+        %{dependency: []} -> acc
+        %{dependency: deps} -> get_mod_names(deps) ++ acc
+      end
+    end
+  end
+
+  defp get_mod_names([]), do: []
+  defp get_mod_names(mods) when is_list(mods), do: Enum.map(mods, &get_mod_names/1) |> List.flatten
+  defp get_mod_names(%{module: mod, dependency: deps}), do: [mod | get_mod_names(deps)]
+
+  defp keep_only_mods_not_used_as_dep(mods, mods_used_as_dep) do
+    Enum.filter mods, fn %{module: mod} ->
+      not mod in mods_used_as_dep
+    end
+  end
+
+  defp get_dependencies_of_mod(deps, mod_name) do
+    Enum.find(deps, &(Map.get(&1, :module) == mod_name))
+    |> Map.get(:attrs)
+    |> Keyword.get(:dependency)
+  end
+
+  defp format_mods_into_string(mods), do: format_mods_into_string(mods, 0)
+  defp format_mods_into_string([], _indentation), do: ""
+  defp format_mods_into_string(mods, indentation) when is_list(mods) do
+    Enum.reduce mods, "", fn(mod, acc) ->
+      acc <> format_mods_into_string(mod, indentation)
+    end
+  end
+
+  defp format_mods_into_string(%{module: mod, dependency: deps}, 0) do
+    "\n├── #{mod}" <> format_mods_into_string(deps,  2)
+  end
+
+  defp format_mods_into_string(%{module: mod, dependency: deps}, indentation) do
+    spaces = Enum.reduce 0..indentation, "", fn(_, acc) -> " " <> acc end
+    "\n│#{spaces}└── #{mod}" <> format_mods_into_string(deps, indentation + 4)
+  end
+end