defmodule MvWeb.CustomFieldLive.Form do
  @moduledoc """
  LiveView form for creating and editing custom fields (admin).

  ## Features
  - Create new custom field definitions
  - Edit existing custom fields
  - Select value type from supported types
  - Set immutable and required flags
  - Real-time validation

  ## Form Fields
  **Required:**
  - name - Unique identifier (e.g., "phone_mobile", "emergency_contact")
  - value_type - Data type (:string, :integer, :boolean, :date, :email)

  **Optional:**
  - description - Human-readable explanation
  - immutable - If true, values cannot be changed after creation (default: false)
  - required - If true, all members must have this custom field (default: false)

  ## Value Type Selection
  - `:string` - Text data (unlimited length)
  - `:integer` - Numeric data
  - `:boolean` - True/false flags
  - `:date` - Date values
  - `:email` - Validated email addresses

  ## Events
  - `validate` - Real-time form validation
  - `save` - Submit form (create or update custom field)

  ## Security
  Custom field management is restricted to admin users.
  """
  use MvWeb, :live_view

  @impl true
  def render(assigns) do
    ~H"""
    <Layouts.app flash={@flash} current_user={@current_user}>
      <.header>
        {@page_title}
        <:subtitle>
          {gettext("Use this form to manage custom_field records in your database.")}
        </:subtitle>
      </.header>

      <.form for={@form} id="custom_field-form" phx-change="validate" phx-submit="save">
        <.input field={@form[:name]} type="text" label={gettext("Name")} />

        <.input
          field={@form[:value_type]}
          type="select"
          label={gettext("Value type")}
          options={
            Ash.Resource.Info.attribute(Mv.Membership.CustomField, :value_type).constraints[:one_of]
          }
        />
        <.input field={@form[:description]} type="text" label={gettext("Description")} />
        <.input field={@form[:immutable]} type="checkbox" label={gettext("Immutable")} />
        <.input field={@form[:required]} type="checkbox" label={gettext("Required")} />

        <.button phx-disable-with={gettext("Saving...")} variant="primary">
          {gettext("Save Custom field")}
        </.button>
        <.button navigate={return_path(@return_to, @custom_field)}>{gettext("Cancel")}</.button>
      </.form>
    </Layouts.app>
    """
  end

  @impl true
  def mount(params, _session, socket) do
    custom_field =
      case params["id"] do
        nil -> nil
        id -> Ash.get!(Mv.Membership.CustomField, id)
      end

    action = if is_nil(custom_field), do: "New", else: "Edit"
    page_title = action <> " " <> "Custom field"

    {:ok,
     socket
     |> assign(:return_to, return_to(params["return_to"]))
     |> assign(custom_field: custom_field)
     |> assign(:page_title, page_title)
     |> assign_form()}
  end

  defp return_to("show"), do: "show"
  defp return_to(_), do: "index"

  @impl true
  def handle_event("validate", %{"custom_field" => custom_field_params}, socket) do
    {:noreply,
     assign(socket, form: AshPhoenix.Form.validate(socket.assigns.form, custom_field_params))}
  end

  def handle_event("save", %{"custom_field" => custom_field_params}, socket) do
    case AshPhoenix.Form.submit(socket.assigns.form, params: custom_field_params) do
      {:ok, custom_field} ->
        notify_parent({:saved, custom_field})

        action =
          case socket.assigns.form.source.type do
            :create -> gettext("create")
            :update -> gettext("update")
            other -> to_string(other)
          end

        socket =
          socket
          |> put_flash(:info, gettext("Custom field %{action} successfully", action: action))
          |> push_navigate(to: return_path(socket.assigns.return_to, custom_field))

        {:noreply, socket}

      {:error, form} ->
        {:noreply, assign(socket, form: form)}
    end
  end

  defp notify_parent(msg), do: send(self(), {__MODULE__, msg})

  defp assign_form(%{assigns: %{custom_field: custom_field}} = socket) do
    form =
      if custom_field do
        AshPhoenix.Form.for_update(custom_field, :update, as: "custom_field")
      else
        AshPhoenix.Form.for_create(Mv.Membership.CustomField, :create, as: "custom_field")
      end

    assign(socket, form: to_form(form))
  end

  defp return_path("index", _custom_field), do: ~p"/custom_fields"
  defp return_path("show", custom_field), do: ~p"/custom_fields/#{custom_field.id}"
end