attachment params validation

Section

Mix.install([{:ecto, "~> 3.0"}])

doc = %{
  "data" => %{
    "attributes" => %{
      "filename" => "file_name.Jpg",
      "filesize" => 500_000,
      "customer-id" => 1
    },
    "type" => "note-attachment",
    "relationships" => %{}
  }
}

defmodule AttachmentParams do
  use Ecto.Schema
  import Ecto.Changeset

  @allowed_extensions ~w(jpg jpeg png)
  embedded_schema do
    field(:file_size, :integer)
    field(:customer_id, :integer)
    field(:file_type, :string)
    field(:file_name, :string)
    field(:filename, :string, virtual: true)
    field(:filesize, :integer, virtual: true)
    field(:"customer-id", :integer, virtual: true)
  end

  def changeset(attachment, params \\ %{}) do
    attachment
    |> cast(params, [:filename, :filesize, :"customer-id"])
    |> validate_required([:filename, :filesize, :"customer-id"])
    |> validate_number(:filesize, less_than: 10_000_000)
    |> validate_format(:filename, ~r/\./, message: "file name needs to have extension")
    |> put_required_fields()
    |> delete_virtual_fields([:filename, :filesize, :"customer-id"])
    |> validate_length(:file_type, min: 2, max: 5)
    |> validate_length(:file_name, min: 2, max: 100)
    |> validate_inclusion(:file_type, @allowed_extensions, message: "file extension not supported")
  end

  defp put_required_fields(
         %Ecto.Changeset{
           changes: %{
             "customer-id": customer_id,
             filename: full_file_name,
             filesize: file_size
           }
         } = changeset
       ) do
    {file_name, file_type} = split_filename(full_file_name)

    changeset
    |> put_change(:file_name, file_name)
    |> put_change(:file_type, file_type)
    |> put_change(:file_size, file_size)
    |> put_change(:customer_id, customer_id)
  end

  defp delete_virtual_fields(changeset, virtual_fields) do
    Enum.reduce(virtual_fields, changeset, &delete_change(&2, &1))
  end

  defp split_filename(full_file_name) do
    unstandarized_file_type = Path.extname(full_file_name)
    file_name = Path.basename(full_file_name, unstandarized_file_type)
    file_type = standarize_extension(unstandarized_file_type)
    {file_name, file_type}
  end

  defp standarize_extension(ext) do
    ext
    |> strip_dot_from_extension()
    |> String.downcase()
  end

  defp strip_dot_from_extension("." <> ext), do: ext
  defp strip_dot_from_extension(ext), do: ext
end

AttachmentParams.changeset(%AttachmentParams{}, doc["data"]["attributes"])

defmodule AttachmentParamsSchemaless do
  import Ecto.Changeset

  @allowed_extensions ~w(jpg jpeg png)
  @types %{
    :"customer-id" => :integer,
    file_size: :integer,
    customer_id: :integer,
    file_type: :string,
    file_name: :string,
    filename: :string,
    filesize: :integer
  }

  def changeset(params \\ %{}) do
    {params, @types}
    |> cast(params, [:filename, :filesize, :"customer-id"])
    |> validate_required([:filename, :filesize, :"customer-id"])
    |> validate_number(:filesize, less_than: 10_000_000)
    |> validate_format(:filename, ~r/\./, message: "file name needs to have extension")
    |> put_required_fields()
    |> delete_virtual_fields([:filename, :filesize, :"customer-id"])
    |> validate_length(:file_type, min: 2, max: 5)
    |> validate_length(:file_name, min: 2, max: 100)
    |> validate_inclusion(:file_type, @allowed_extensions, message: "file extension not supported")
  end

  defp put_required_fields(
         %Ecto.Changeset{
           changes: %{
             "customer-id": customer_id,
             filename: full_file_name,
             filesize: file_size
           }
         } = changeset
       ) do
    {file_name, file_type} = split_filename(full_file_name)

    changeset
    |> put_change(:file_name, file_name)
    |> put_change(:file_type, file_type)
    |> put_change(:file_size, file_size)
    |> put_change(:customer_id, customer_id)
  end

  defp delete_virtual_fields(changeset, virtual_fields) do
    Enum.reduce(virtual_fields, changeset, &delete_change(&2, &1))
  end

  defp split_filename(full_file_name) do
    unstandarized_file_type = Path.extname(full_file_name)
    file_name = Path.basename(full_file_name, unstandarized_file_type)
    file_type = standarize_extension(unstandarized_file_type)
    {file_name, file_type}
  end

  defp standarize_extension(ext) do
    ext
    |> strip_dot_from_extension()
    |> String.downcase()
  end

  defp strip_dot_from_extension("." <> ext), do: ext
  defp strip_dot_from_extension(ext), do: ext
end

AttachmentParamsSchemaless.changeset(doc["data"]["attributes"])