defmodule ExSQL.AST.CreateIndex do
  @moduledoc "A `CREATE [UNIQUE] INDEX [IF NOT EXISTS] name ON table(cols) [WHERE expr]` statement."

  defstruct name: nil,
            schema: nil,
            table: nil,
            columns: [],
            unique: false,
            if_not_exists: false,
            where: nil

  @type index_column :: %{
          name: String.t() | nil,
          expr: term() | nil,
          direction: :asc | :desc,
          collate: String.t() | nil
        }

  @type t :: %__MODULE__{
          name: String.t(),
          schema: String.t() | nil,
          table: String.t(),
          columns: [index_column()],
          unique: boolean(),
          if_not_exists: boolean(),
          where: ExSQL.Parser.expr() | nil
        }
end