defmodule MvWeb.MemberLive.Form do
  @moduledoc """
  LiveView form for creating and editing members.

  ## Features
  - Create new members with personal information
  - Edit existing member details
  - Manage custom properties (dynamic fields)
  - Real-time validation with visual feedback
  - Link/unlink user accounts

  ## Form Fields
  **Required:**
  - first_name, last_name, email

  **Optional:**
  - birth_date, phone_number, address fields (city, street, house_number, postal_code)
  - join_date, exit_date
  - paid status
  - notes

  ## Custom Field Values
  Members can have dynamic custom field values defined by CustomFields.
  The form dynamically renders inputs based on available CustomFields.

  ## Events
  - `validate` - Real-time form validation
  - `save` - Submit form (create or update member)
  - Custom field value management events for adding/removing custom fields
  """
  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 member records and their properties.")}
        </:subtitle>
      </.header>

      <.form for={@form} id="member-form" phx-change="validate" phx-submit="save">
        <.input field={@form[:first_name]} label={gettext("First Name")} required />
        <.input field={@form[:last_name]} label={gettext("Last Name")} required />
        <.input field={@form[:email]} label={gettext("Email")} required type="email" />
        <.input field={@form[:birth_date]} label={gettext("Birth Date")} type="date" />
        <.input field={@form[:paid]} label={gettext("Paid")} type="checkbox" />
        <.input field={@form[:phone_number]} label={gettext("Phone Number")} />
        <.input field={@form[:join_date]} label={gettext("Join Date")} type="date" />
        <.input field={@form[:exit_date]} label={gettext("Exit Date")} type="date" />
        <.input field={@form[:notes]} label={gettext("Notes")} />
        <.input field={@form[:city]} label={gettext("City")} />
        <.input field={@form[:street]} label={gettext("Street")} />
        <.input field={@form[:house_number]} label={gettext("House Number")} />
        <.input field={@form[:postal_code]} label={gettext("Postal Code")} />

        <h3 class="mt-8 mb-2 text-lg font-semibold">{gettext("Custom Field Values")}</h3>
        <.inputs_for :let={f_custom_field_value} field={@form[:custom_field_values]}>
          <% type =
            Enum.find(@custom_fields, &(&1.id == f_custom_field_value[:custom_field_id].value)) %>
          <.inputs_for :let={value_form} field={f_custom_field_value[:value]}>
            <% input_type =
              cond do
                type && type.value_type == :boolean -> "checkbox"
                type && type.value_type == :date -> :date
                true -> :text
              end %>
            <.input field={value_form[:value]} label={type && type.name} type={input_type} />
          </.inputs_for>
          <input
            type="hidden"
            name={f_custom_field_value[:custom_field_id].name}
            value={f_custom_field_value[:custom_field_id].value}
          />
        </.inputs_for>

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

  @impl true
  def mount(params, _session, socket) do
    {:ok, custom_fields} = Mv.Membership.list_custom_fields()

    initial_custom_field_values =
      Enum.map(custom_fields, fn cf ->
        %{
          "custom_field_id" => cf.id,
          "value" => %{
            "type" => cf.value_type,
            "value" => nil,
            "_union_type" => Atom.to_string(cf.value_type)
          }
        }
      end)

    member =
      case params["id"] do
        nil -> nil
        id -> Ash.get!(Mv.Membership.Member, id)
      end

    action = if is_nil(member), do: "New", else: "Edit"
    page_title = action <> " " <> "Member"

    {:ok,
     socket
     |> assign(:return_to, return_to(params["return_to"]))
     |> assign(:custom_fields, custom_fields)
     |> assign(:initial_custom_field_values, initial_custom_field_values)
     |> assign(member: member)
     |> 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", %{"member" => member_params}, socket) do
    {:noreply, assign(socket, form: AshPhoenix.Form.validate(socket.assigns.form, member_params))}
  end

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

        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("Member %{action} successfully", action: action))
          |> push_navigate(to: return_path(socket.assigns.return_to, member))

        {:noreply, socket}

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

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

  defp assign_form(%{assigns: %{member: member}} = socket) do
    form =
      if member do
        {:ok, member} = Ash.load(member, custom_field_values: [:custom_field])

        existing_custom_field_values =
          member.custom_field_values
          |> Enum.map(& &1.custom_field_id)

        is_missing_custom_field_value = fn i ->
          not Enum.member?(existing_custom_field_values, Map.get(i, "custom_field_id"))
        end

        params = %{
          "custom_field_values" =>
            Enum.map(member.custom_field_values, fn cfv ->
              %{
                "custom_field_id" => cfv.custom_field_id,
                "value" => %{
                  "_union_type" => Atom.to_string(cfv.value.type),
                  "type" => cfv.value.type,
                  "value" => cfv.value.value
                }
              }
            end)
        }

        form =
          AshPhoenix.Form.for_update(
            member,
            :update_member,
            api: Mv.Membership,
            as: "member",
            params: params,
            forms: [auto?: true]
          )

        missing_custom_field_values =
          Enum.filter(socket.assigns[:initial_custom_field_values], is_missing_custom_field_value)

        Enum.reduce(
          missing_custom_field_values,
          form,
          &AshPhoenix.Form.add_form(&2, [:custom_field_values], params: &1)
        )
      else
        AshPhoenix.Form.for_create(
          Mv.Membership.Member,
          :create_member,
          api: Mv.Membership,
          as: "member",
          params: %{"custom_field_values" => socket.assigns[:initial_custom_field_values]},
          forms: [auto?: true]
        )
      end

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

  defp return_path("index", _member), do: ~p"/members"
  defp return_path("show", member), do: ~p"/members/#{member.id}"
end