3 files changed, 233 insertions, 0 deletions
diff --git a/lib/pleroma/docs/generator.ex b/lib/pleroma/docs/generator.ex
new file mode 100644
index 000000000..6b12dcdd9
--- /dev/null
+++ b/lib/pleroma/docs/generator.ex
@@ -0,0 +1,121 @@
+defmodule Pleroma.Docs.Generator do
+  @callback process(keyword()) :: {:ok, String.t()}
+
+  @spec process(module(), keyword()) :: {:ok, String.t()}
+  def process(implementation, descriptions) do
+    implementation.process(descriptions)
+  end
+
+  @spec list_modules_in_dir(String.t(), String.t()) :: [module()]
+  def list_modules_in_dir(dir, start) do
+    with {:ok, files} <- File.ls(dir) do
+      files
+      |> Enum.filter(&String.ends_with?(&1, ".ex"))
+      |> Enum.map(fn filename ->
+        module = filename |> String.trim_trailing(".ex") |> Macro.camelize()
+        String.to_existing_atom(start <> module)
+      end)
+    end
+  end
+
+  @doc """
+  Converts:
+  - atoms to strings with leading `:`
+  - module names to strings, without leading `Elixir.`
+  - add humanized labels to `keys` if label is not defined, e.g. `:instance` -> `Instance`
+  """
+  @spec convert_to_strings([map()]) :: [map()]
+  def convert_to_strings(descriptions) do
+    Enum.map(descriptions, &format_entity(&1))
+  end
+
+  defp format_entity(entity) do
+    entity
+    |> format_key()
+    |> Map.put(:group, atom_to_string(entity[:group]))
+    |> format_children()
+  end
+
+  defp format_key(%{key: key} = entity) do
+    entity
+    |> Map.put(:key, atom_to_string(key))
+    |> Map.put(:label, entity[:label] || humanize(key))
+  end
+
+  defp format_key(%{group: group} = entity) do
+    Map.put(entity, :label, entity[:label] || humanize(group))
+  end
+
+  defp format_key(entity), do: entity
+
+  defp format_children(%{children: children} = entity) do
+    Map.put(entity, :children, Enum.map(children, &format_child(&1)))
+  end
+
+  defp format_children(entity), do: entity
+
+  defp format_child(%{suggestions: suggestions} = entity) do
+    entity
+    |> Map.put(:suggestions, format_suggestions(suggestions))
+    |> format_key()
+    |> format_group()
+    |> format_children()
+  end
+
+  defp format_child(entity) do
+    entity
+    |> format_key()
+    |> format_group()
+    |> format_children()
+  end
+
+  defp format_group(%{group: group} = entity) do
+    Map.put(entity, :group, format_suggestion(group))
+  end
+
+  defp format_group(entity), do: entity
+
+  defp atom_to_string(entity) when is_binary(entity), do: entity
+
+  defp atom_to_string(entity) when is_atom(entity), do: inspect(entity)
+
+  defp humanize(entity) do
+    string = inspect(entity)
+
+    if String.starts_with?(string, ":"),
+      do: Phoenix.Naming.humanize(entity),
+      else: string
+  end
+
+  defp format_suggestions([]), do: []
+
+  defp format_suggestions([suggestion | tail]) do
+    [format_suggestion(suggestion) | format_suggestions(tail)]
+  end
+
+  defp format_suggestion(entity) when is_atom(entity) do
+    atom_to_string(entity)
+  end
+
+  defp format_suggestion([head | tail] = entity) when is_list(entity) do
+    [format_suggestion(head) | format_suggestions(tail)]
+  end
+
+  defp format_suggestion(entity) when is_tuple(entity) do
+    format_suggestions(Tuple.to_list(entity)) |> List.to_tuple()
+  end
+
+  defp format_suggestion(entity), do: entity
+end
+
+defimpl Jason.Encoder, for: Tuple do
+  def encode(tuple, opts), do: Jason.Encode.list(Tuple.to_list(tuple), opts)
+end
+
+defimpl Jason.Encoder, for: [Regex, Function] do
+  def encode(term, opts), do: Jason.Encode.string(inspect(term), opts)
+end
+
+defimpl String.Chars, for: Regex do
+  def to_string(term), do: inspect(term)
+end
diff --git a/lib/pleroma/docs/json.ex b/lib/pleroma/docs/json.ex
new file mode 100644
index 000000000..6508a7bdb
--- /dev/null
+++ b/lib/pleroma/docs/json.ex
@@ -0,0 +1,24 @@
+defmodule Pleroma.Docs.JSON do
+  @behaviour Pleroma.Docs.Generator
+
+  @spec process(keyword()) :: {:ok, String.t()}
+  def process(descriptions) do
+    with path <- "docs/generated_config.json",
+         {:ok, file} <- File.open(path, [:write, :utf8]),
+         formatted_descriptions <-
+           Pleroma.Docs.Generator.convert_to_strings(descriptions),
+         json <- Jason.encode!(formatted_descriptions),
+         :ok <- IO.write(file, json),
+         :ok <- File.close(file) do
+      {:ok, path}
+    end
+  end
+
+  def compile do
+    with config <- Pleroma.Config.Loader.load("config/description.exs") do
+      config[:pleroma][:config_description]
+      |> Pleroma.Docs.Generator.convert_to_strings()
+      |> Jason.encode!()
+    end
+  end
+end
diff --git a/lib/pleroma/docs/markdown.ex b/lib/pleroma/docs/markdown.ex
new file mode 100644
index 000000000..68b106499
--- /dev/null
+++ b/lib/pleroma/docs/markdown.ex
@@ -0,0 +1,88 @@
+defmodule Pleroma.Docs.Markdown do
+  @behaviour Pleroma.Docs.Generator
+
+  @spec process(keyword()) :: {:ok, String.t()}
+  def process(descriptions) do
+    config_path = "docs/generated_config.md"
+    {:ok, file} = File.open(config_path, [:utf8, :write])
+    IO.write(file, "# Generated configuration\n")
+    IO.write(file, "Date of generation: #{Date.utc_today()}\n\n")
+
+    IO.write(
+      file,
+      "This file describe the configuration, it is recommended to edit the relevant `*.secret.exs` file instead of the others founds in the ``config`` directory.\n\n" <>
+        "If you run Pleroma with ``MIX_ENV=prod`` the file is ``prod.secret.exs``, otherwise it is ``dev.secret.exs``.\n\n"
+    )
+
+    for group <- descriptions do
+      if is_nil(group[:key]) do
+        IO.write(file, "## #{inspect(group[:group])}\n")
+      else
+        IO.write(file, "## #{inspect(group[:key])}\n")
+      end
+
+      IO.write(file, "#{group[:description]}\n")
+
+      for child <- group[:children] || [] do
+        print_child_header(file, child)
+
+        print_suggestions(file, child[:suggestions])
+
+        if child[:children] do
+          for subchild <- child[:children] do
+            print_child_header(file, subchild)
+
+            print_suggestions(file, subchild[:suggestions])
+          end
+        end
+      end
+
+      IO.write(file, "\n")
+    end
+
+    :ok = File.close(file)
+    {:ok, config_path}
+  end
+
+  defp print_child_header(file, %{key: key, type: type, description: description} = _child) do
+    IO.write(
+      file,
+      "- `#{inspect(key)}` (`#{inspect(type)}`): #{description}  \n"
+    )
+  end
+
+  defp print_child_header(file, %{key: key, type: type} = _child) do
+    IO.write(file, "- `#{inspect(key)}` (`#{inspect(type)}`)  \n")
+  end
+
+  defp print_suggestion(file, suggestion) when is_list(suggestion) do
+    IO.write(file, "  `#{inspect(suggestion)}`\n")
+  end
+
+  defp print_suggestion(file, suggestion) when is_function(suggestion) do
+    IO.write(file, "  `#{inspect(suggestion.())}`\n")
+  end
+
+  defp print_suggestion(file, suggestion, as_list \\ false) do
+    list_mark = if as_list, do: "- ", else: ""
+    IO.write(file, "  #{list_mark}`#{inspect(suggestion)}`\n")
+  end
+
+  defp print_suggestions(_file, nil), do: nil
+
+  defp print_suggestions(_file, ""), do: nil
+
+  defp print_suggestions(file, suggestions) do
+    if length(suggestions) > 1 do
+      IO.write(file, "Suggestions:\n")
+
+      for suggestion <- suggestions do
+        print_suggestion(file, suggestion, true)
+      end
+    else
+      IO.write(file, "  Suggestion: ")
+
+      print_suggestion(file, List.first(suggestions))
+    end
+  end
+end