# SPDX-FileCopyrightText: 2025 ash_neo4j contributors <https://github.com/diffo-dev/ash_neo4j/graphs.contributors>
#
# SPDX-License-Identifier: MIT

defmodule AshNeo4j.Verifiers.VerifyLabelPascalCase do
  @moduledoc "Verifies that the label is PascalCase"
  use Spark.Dsl.Verifier

  alias Spark.Dsl.Verifier
  alias Spark.Error.DslError
  @regex ~r/^[A-Z][a-zA-Z0-9]*$/

  @impl true
  def verify(dsl) do
    resource = Verifier.get_persisted(dsl, :module)
    module = String.to_atom(List.last(Module.split(resource)))
    label = Verifier.get_option(dsl, [:neo4j], :label, module)

    cond do
      label == nil ->
        {:error,
         DslError.exception(
           module: resource,
           message: "label: missing"
         )}

      Regex.match?(@regex, Atom.to_string(label)) ->
        :ok

      true ->
        {:error,
         DslError.exception(
           module: resource,
           message: "label: neo4j label must be PascalCase"
         )}
    end
  end
end