defmodule Platem do
  @moduledoc """
  This module provides a simple interface to the Platem.
  This module is also the main supervisor and it should be included in the main supervision tree.
  """

  use DynamicSupervisor
  alias Platem.Populator
  alias Platem.PageManager
  alias Platem.Publisher

  @doc false
  def start_link(_args) do
    DynamicSupervisor.start_link(__MODULE__, [], name: __MODULE__)
  end

  @doc false
  def start_manager() do
    spec = {PageManager, []}
    DynamicSupervisor.start_child(__MODULE__, spec)
  end

  @doc false
  def start_populator(template, values) do
    spec = {Populator, {template, values}}
    DynamicSupervisor.start_child(__MODULE__, spec)
  end

  @doc """
  Populates a template with the given values.

  # Example
      iex> Populator.populate(%Template{template: "{{name}}", fields: [%Field{name: "name", default: "default"}]}, clause: {"{{", "}}"}, [%Value{name: "name", value: "value"}])
      %Template{template: "value", fields: [%Field{name: "name", default: "name"}]}
  """
  def populate(template, values) do
    case start_populator(template, values) do
      {:ok, pid} ->
        pid |> GenServer.call(:populate)

      {:error, reason} ->
        raise reason
    end
  end

  @doc """
  This function saves a page to the filesystem, and then adds it to the manager.
  """
  def publish(page, folder, name) do
    page
    |> Map.put(:folder, folder)
    |> Map.put(:name, name)
    |> Publisher.save()
    |> Publisher.add_to_manager()
  end

  @doc """
  This function retrieves all of the pages from the manager.
  """
  def get_pages() do
    Publisher.get_pages()
  end

  @impl true
  def init(_args) do
    DynamicSupervisor.init(strategy: :one_for_one)
  end
end