ecto_context

  @doc """
  Creates a `<%= inspect(schema) %>` associated to the given parent via `assoc_atom`.

  The foreign key is always set from `assoc_atom` + `parent_id`, overriding any value in `attrs`.

  Returns `{:ok, <%= singular %>}` on success, `{:error, :unauthorized}` if the scope
  lacks permission, or `{:error, changeset}` on validation failure.

  Permission is checked via `permission(:create, %<%= inspect(schema) %>{}, scope)`.
  Add a `permission(:create, %<%= inspect(schema) %>{}, scope)` clause to control who
  may create records.

  ## Options

    * `:changeset` - changeset function to use (default: `:changeset`)

  If a `changeset_permission/2` function is exported by the calling module,
  it is consulted whenever a non-default `:changeset` is passed.  Return
  `true` to allow or `false` to deny (results in `{:error, :unauthorized}`).

  """
  def create_for(scope, assoc_atom, parent_id, attrs, opts \\ []) when is_map(scope) do
    EctoContext.Validate.validate_opts!(opts, [:changeset])

    changeset_fn = Keyword.get(opts, :changeset, <%= inspect(default_changeset) %>)
    parent_key = <%= inspect(schema) %>.__schema__(:association, assoc_atom).owner_key

    with true <- (changeset_fn == <%= inspect(default_changeset) %> or
                  not function_exported?(__MODULE__, :changeset_permission, 2) or
                  apply(__MODULE__, :changeset_permission, [changeset_fn, scope])) || {:error, :unauthorized},
         true <- permission(:create, %<%= inspect(schema) %>{}, scope) || {:error, :unauthorized} do
      changeset =
        apply(<%= inspect(schema) %>, changeset_fn, [%<%= inspect(schema) %>{}, attrs, scope])
        |> Ecto.Changeset.put_change(parent_key, parent_id)

      with {:ok, <%= singular %> = %<%= inspect(schema) %>{}} <-
              <%= inspect(repo) %>.insert(changeset) do

        if function_exported?(__MODULE__, :broadcast, 2) do
          apply(__MODULE__, :broadcast, [scope, {:created, <%= singular %>}])
        end
        {:ok, <%= singular %>}
      end
    end
  end