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

  ## Features
  - Create new members with personal information
  - Edit existing member details
  - Grouped sections for better organization
  - Tab navigation (Payments tab disabled, coming soon)
  - Manage custom properties (dynamic fields, displayed sorted by name)
  - Real-time validation with visual feedback

  ## Form Sections
  - Personal Data: Name, address, contact information, membership dates, notes
  - Custom Fields: Dynamic fields in uniform grid layout (displayed sorted by name)
  - Payment Data: Mockup section (not editable)

  ## Events
  - `validate` - Real-time form validation
  - `save` - Submit form (create or update member)
  """
  use MvWeb, :live_view

  @impl true
  def render(assigns) do
    # Sort custom fields by name for display only
    sorted_custom_fields = Enum.sort_by(assigns.custom_fields, & &1.name)
    assigns = assign(assigns, :sorted_custom_fields, sorted_custom_fields)

    ~H"""
    <Layouts.app flash={@flash} current_user={@current_user}>
      <.form for={@form} id="member-form" phx-change="validate" phx-submit="save">
        <%!-- Header with Back button, Name display, and Save button --%>
        <div class="flex items-center justify-between gap-4 pb-4">
          <.button navigate={return_path(@return_to, @member)} type="button">
            <.icon name="hero-arrow-left" class="size-4" />
            {gettext("Back")}
          </.button>

          <h1 class="text-2xl font-bold text-center flex-1">
            <%= if @member do %>
              {@member.first_name} {@member.last_name}
            <% else %>
              {gettext("New Member")}
            <% end %>
          </h1>

          <.button phx-disable-with={gettext("Saving...")} variant="primary" type="submit">
            {gettext("Save")}
          </.button>
        </div>

        <%!-- Tab Navigation --%>
        <div role="tablist" class="tabs tabs-bordered mb-6">
          <button type="button" role="tab" class="tab tab-active" aria-selected="true">
            <.icon name="hero-identification" class="size-4 mr-2" />
            {gettext("Contact Data")}
          </button>
          <button
            type="button"
            role="tab"
            class="tab"
            disabled
            aria-disabled="true"
            title={gettext("Coming soon")}
          >
            <.icon name="hero-credit-card" class="size-4 mr-2" />
            {gettext("Payments")}
          </button>
        </div>

        <%!-- Personal Data and Custom Fields Row --%>
        <div class="grid grid-cols-1 lg:grid-cols-2 gap-6 mb-6">
          <%!-- Personal Data Section --%>
          <div>
            <.form_section title={gettext("Personal Data")}>
              <div class="space-y-4">
                <%!-- Name Row --%>
                <div class="flex gap-4">
                  <div class="w-48">
                    <.input field={@form[:first_name]} label={gettext("First Name")} required />
                  </div>
                  <div class="w-48">
                    <.input field={@form[:last_name]} label={gettext("Last Name")} required />
                  </div>
                </div>

                <%!-- Address Row --%>
                <div class="flex gap-4">
                  <div class="flex-1">
                    <.input field={@form[:street]} label={gettext("Street")} />
                  </div>
                  <div class="w-16">
                    <.input field={@form[:house_number]} label={gettext("Nr.")} />
                  </div>
                  <div class="w-24">
                    <.input field={@form[:postal_code]} label={gettext("Postal Code")} />
                  </div>
                  <div class="w-32">
                    <.input field={@form[:city]} label={gettext("City")} />
                  </div>
                </div>

                <%!-- Email --%>
                <div>
                  <.input field={@form[:email]} label={gettext("Email")} required type="email" />
                </div>

                <%!-- Phone --%>
                <div>
                  <.input field={@form[:phone_number]} label={gettext("Phone")} type="tel" />
                </div>

                <%!-- Membership Dates Row --%>
                <div class="flex gap-4">
                  <div class="w-36">
                    <.input field={@form[:join_date]} label={gettext("Join Date")} type="date" />
                  </div>
                  <div class="w-36">
                    <.input field={@form[:exit_date]} label={gettext("Exit Date")} type="date" />
                  </div>
                </div>

                <%!-- Notes --%>
                <div>
                  <.input field={@form[:notes]} label={gettext("Notes")} type="textarea" />
                </div>
              </div>
            </.form_section>
          </div>

          <%!-- Custom Fields Section --%>
          <%= if Enum.any?(@custom_fields) do %>
            <div>
              <.form_section title={gettext("Custom Fields")}>
                <div class="grid grid-cols-2 gap-4">
                  <%!-- Render in sorted order by finding the form for each sorted custom field --%>
                  <%= for cf <- @sorted_custom_fields do %>
                    <.inputs_for :let={f_cfv} field={@form[:custom_field_values]}>
                      <%= if f_cfv[:custom_field_id].value == cf.id do %>
                        <div class={if cf.value_type == :boolean, do: "flex items-end", else: ""}>
                          <.inputs_for :let={value_form} field={f_cfv[:value]}>
                            <.input
                              field={value_form[:value]}
                              label={cf.name}
                              type={custom_field_input_type(cf.value_type)}
                            />
                          </.inputs_for>
                          <input
                            type="hidden"
                            name={f_cfv[:custom_field_id].name}
                            value={f_cfv[:custom_field_id].value}
                          />
                        </div>
                      <% end %>
                    </.inputs_for>
                  <% end %>
                </div>
              </.form_section>
            </div>
          <% end %>
        </div>

        <%!-- Payment Data Section (Mockup) --%>
        <div class="max-w-xl">
          <.form_section title={gettext("Payment Data")}>
            <div role="alert" class="alert alert-info mb-4">
              <.icon name="hero-information-circle" class="size-5" />
              <span>{gettext("This data is for demonstration purposes only (mockup).")}</span>
            </div>

            <div class="flex gap-8">
              <div class="w-24">
                <label for="mock-contribution" class="label text-sm font-medium">
                  {gettext("Contribution")}
                </label>
                <input
                  type="text"
                  id="mock-contribution"
                  value="72 €"
                  disabled
                  class="input input-bordered w-full bg-base-200"
                />
              </div>
              <div class="w-40">
                <label class="label text-sm font-medium">{gettext("Payment Cycle")}</label>
                <div class="flex gap-3 mt-2">
                  <label class="flex items-center gap-1 cursor-not-allowed opacity-60">
                    <input type="radio" name="mock_cycle" checked disabled class="radio radio-sm" />
                    <span class="text-sm">{gettext("monthly")}</span>
                  </label>
                  <label class="flex items-center gap-1 cursor-not-allowed opacity-60">
                    <input type="radio" name="mock_cycle" disabled class="radio radio-sm" />
                    <span class="text-sm">{gettext("yearly")}</span>
                  </label>
                </div>
              </div>
              <div class="w-24 flex items-end">
                <.input field={@form[:paid]} label={gettext("Paid")} type="checkbox" />
              </div>
            </div>
          </.form_section>
        </div>

        <%!-- Bottom Action Buttons --%>
        <div class="flex justify-end gap-4 mt-6">
          <.button navigate={return_path(@return_to, @member)} type="button">
            {gettext("Cancel")}
          </.button>
          <.button phx-disable-with={gettext("Saving...")} variant="primary" type="submit">
            {gettext("Save Member")}
          </.button>
        </div>
      </.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: gettext("New"), else: gettext("Edit")
    page_title = "#{action} #{gettext("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", nil), do: ~p"/members"
  defp return_path("show", member), do: ~p"/members/#{member.id}"

  # -----------------------------------------------------------------
  # Helper Components
  # -----------------------------------------------------------------

  # Renders a form section box with border and title.
  attr :title, :string, required: true
  slot :inner_block, required: true

  defp form_section(assigns) do
    ~H"""
    <section class="mb-6">
      <h2 class="text-lg font-semibold mb-3">{@title}</h2>
      <div class="border border-base-300 rounded-lg p-4 bg-base-100">
        {render_slot(@inner_block)}
      </div>
    </section>
    """
  end

  # -----------------------------------------------------------------
  # Helper Functions for Custom Fields
  # -----------------------------------------------------------------

  # Returns input type for custom field based on value type
  defp custom_field_input_type(:string), do: "text"
  defp custom_field_input_type(:integer), do: "number"
  defp custom_field_input_type(:boolean), do: "checkbox"
  defp custom_field_input_type(:date), do: "date"
  defp custom_field_input_type(:email), do: "email"
  defp custom_field_input_type(_), do: "text"
end