pageantry

defmodule Pageantry.Field do
  @moduledoc """
  Field definition for sorting/filtering.

  ## Fields

  * `field`
  : Field name (in schema), eg `:inserted_at`.
  * `relation`
  : If field is not directly in schema, how the field is related.
  * `repo`
  : HACK this can be removed when `Pageantry.Page.build_subquery_condition/3`
    no longer needs it.
  * `sort`
  : True if sortable (defaults to true).
  * `filter`
  : Filter type:
    * `:false`: Cannot be used as filter.
    * `:equal`: Filter value must be exactly equal to field value.
    * `:like`: Filter value matched to field value with SQL `LIKE`.
    * `:boolean`: Filter and field values casted to boolean and matched.
      For cases where you want to filter on whether an optional field has been set
      (eg "has_address=yes").
  * `all`
  : True if included in special `:ALL` filter (defaults to true).
  """

  alias Ecto.Repo
  alias Pageantry.FieldRelation

  @enforce_keys [:field]
  defstruct [:field, :relation, :repo, sort: true, filter: :equal, all: true]
  @type filter :: false | :equal | :like | :boolean
  @type t :: %__MODULE__{
          field: atom,
          relation: FieldRelation.t(),
          repo: Repo.t(),
          sort: boolean,
          filter: filter,
          all: boolean
        }
end