defmodule WorkloadService.Aggregates.SolicitationTask do
  use WorkloadService.Aggregates.Task,
    task_type: "solicitation",
    commands: WorkloadService.Commands.SolicitationTask,
    submission_type: map()

  def validate_submission(submission) when is_map(submission) do
    with {:ok, provider_policy_number} <- validate_required_string(submission, "provider_policy_number"),
         {:ok, effective_date} <- validate_date_string(submission, "effective_date"),
         {:ok, expiry_date} <- validate_date_string(submission, "expiry_date"),
         {:ok, _} <- validate_expiry_after_effective(effective_date, expiry_date) do
      :ok
    end
  end

  def validate_submission(_), do: {:error, :invalid_submission_format}

  defp validate_required_string(submission, field) do
    case Map.get(submission, field) do
      nil -> {:error, {:missing_field, field}}
      value when is_binary(value) and byte_size(value) > 0 -> {:ok, value}
      _ -> {:error, {:invalid_field, field}}
    end
  end

  defp validate_date_string(submission, field) do
    case Map.get(submission, field) do
      nil -> {:error, {:missing_field, field}}
      value when is_binary(value) ->
        case Date.from_iso8601(value) do
          {:ok, _date} -> {:ok, value}
          {:error, _} -> {:error, {:invalid_date_format, field}}
        end
      _ -> {:error, {:invalid_field, field}}
    end
  end

  defp validate_expiry_after_effective(effective_date, expiry_date) do
    case {Date.from_iso8601(effective_date), Date.from_iso8601(expiry_date)} do
      {{:ok, effective}, {:ok, expiry}} ->
        if Date.compare(expiry, effective) == :gt do
          {:ok, :valid_date_range}
        else
          {:error, :expiry_must_be_after_effective}
        end
      _ ->
        {:error, :invalid_date_comparison}
    end
  end
end