defmodule MvWeb.MemberLive.Show do
  @moduledoc """
  LiveView for displaying a single member's details.

  ## Features
  - Display all member information in grouped sections
  - Tab navigation for future features (Payments)
  - Show custom field values with type-based formatting
  - Navigate to edit form
  - Return to member list

  ## Sections
  - Personal Data: Name, address, contact information, membership dates, notes
  - Custom Fields: Dynamic fields in uniform grid layout (sorted by name)
  - Payment Data: Mockup section with placeholder data

  ## Navigation
  - Back to member list
  - Edit member (with return_to parameter for back navigation)
  """
  use MvWeb, :live_view
  import Ash.Query

  @impl true
  def render(assigns) do
    ~H"""
    <Layouts.app flash={@flash} current_user={@current_user}>
      <%!-- Header with Back button, Name, and Edit button --%>
      <div class="flex items-center justify-between gap-4 pb-4">
        <.button navigate={~p"/members"} aria-label={gettext("Back to members list")}>
          <.icon name="hero-arrow-left" class="size-4" />
          {gettext("Back")}
        </.button>

        <h1 class="text-2xl font-bold text-center flex-1">
          {@member.first_name} {@member.last_name}
        </h1>

        <.button variant="primary" navigate={~p"/members/#{@member}/edit?return_to=show"}>
          {gettext("Edit Member")}
        </.button>
      </div>

      <%!-- Tab Navigation --%>
      <div role="tablist" class="tabs tabs-bordered mb-6">
        <button role="tab" class="tab tab-active" aria-selected="true">
          <.icon name="hero-identification" class="size-4 mr-2" />
          {gettext("Contact Data")}
        </button>
        <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>
          <.section_box title={gettext("Personal Data")}>
            <div class="space-y-4">
              <%!-- Name Row --%>
              <div class="flex gap-6">
                <.data_field label={gettext("First Name")} value={@member.first_name} class="w-48" />
                <.data_field label={gettext("Last Name")} value={@member.last_name} class="w-48" />
              </div>

              <%!-- Address --%>
              <div>
                <.data_field label={gettext("Address")} value={format_address(@member)} />
              </div>

              <%!-- Email --%>
              <div>
                <.data_field label={gettext("Email")}>
                  <a
                    href={"mailto:#{MvWeb.MemberLive.Index.format_member_email(@member)}"}
                    class="text-blue-700 hover:text-blue-800 underline"
                  >
                    {@member.email}
                  </a>
                </.data_field>
              </div>

              <%!-- Phone --%>
              <div>
                <.data_field label={gettext("Phone")} value={@member.phone_number} />
              </div>

              <%!-- Membership Dates Row --%>
              <div class="flex gap-6">
                <.data_field
                  label={gettext("Join Date")}
                  value={format_date(@member.join_date)}
                  class="w-28"
                />
                <.data_field
                  label={gettext("Exit Date")}
                  value={format_date(@member.exit_date)}
                  class="w-28"
                />
              </div>

              <%!-- Linked User --%>
              <div>
                <.data_field label={gettext("Linked User")}>
                  <%= if @member.user do %>
                    <.link
                      navigate={~p"/users/#{@member.user}"}
                      class="text-blue-700 hover:text-blue-800 underline inline-flex items-center gap-1"
                    >
                      <.icon name="hero-user" class="size-4" />
                      {@member.user.email}
                    </.link>
                  <% else %>
                    <span class="text-base-content/70 italic">{gettext("No user linked")}</span>
                  <% end %>
                </.data_field>
              </div>

              <%!-- Notes --%>
              <%= if @member.notes && String.trim(@member.notes) != "" do %>
                <div>
                  <.data_field label={gettext("Notes")}>
                    <p class="whitespace-pre-wrap text-base-content/80">{@member.notes}</p>
                  </.data_field>
                </div>
              <% end %>
            </div>
          </.section_box>
        </div>

        <%!-- Custom Fields Section --%>
        <%= if Enum.any?(@member.custom_field_values) do %>
          <div>
            <.section_box title={gettext("Custom Fields")}>
              <div class="grid grid-cols-2 gap-4">
                <%= for cfv <- sort_custom_field_values(@member.custom_field_values) do %>
                  <% custom_field = cfv.custom_field %>
                  <% value_type = custom_field && custom_field.value_type %>
                  <.data_field label={custom_field && custom_field.name}>
                    {format_custom_field_value(cfv.value, value_type)}
                  </.data_field>
                <% end %>
              </div>
            </.section_box>
          </div>
        <% end %>
      </div>

      <%!-- Payment Data Section (Mockup) --%>
      <div class="max-w-xl">
        <.section_box 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-6">
            <.data_field label={gettext("Contribution")} value="72 €" class="w-24" />
            <.data_field label={gettext("Payment Cycle")} value={gettext("monthly")} class="w-28" />
            <.data_field label={gettext("Paid")} class="w-24">
              <%= if @member.paid do %>
                <span class="badge badge-success">{gettext("Paid")}</span>
              <% else %>
                <span class="badge badge-warning">{gettext("Pending")}</span>
              <% end %>
            </.data_field>
          </div>
        </.section_box>
      </div>
    </Layouts.app>
    """
  end

  @impl true
  def mount(_params, _session, socket) do
    {:ok, socket}
  end

  @impl true
  def handle_params(%{"id" => id}, _, socket) do
    query =
      Mv.Membership.Member
      |> filter(id == ^id)
      |> load([:user, custom_field_values: [:custom_field]])

    member = Ash.read_one!(query)

    {:noreply,
     socket
     |> assign(:page_title, page_title(socket.assigns.live_action))
     |> assign(:member, member)}
  end

  defp page_title(:show), do: gettext("Show Member")
  defp page_title(:edit), do: gettext("Edit Member")

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

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

  defp section_box(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

  # Renders a labeled data field.
  attr :label, :string, required: true
  attr :value, :string, default: nil
  attr :class, :string, default: ""
  slot :inner_block

  defp data_field(assigns) do
    ~H"""
    <dl class={@class}>
      <dt class="text-sm font-medium text-base-content/70">{@label}</dt>
      <dd class="mt-1 text-base-content">
        <%= if @inner_block != [] do %>
          {render_slot(@inner_block)}
        <% else %>
          {display_value(@value)}
        <% end %>
      </dd>
    </dl>
    """
  end

  # -----------------------------------------------------------------
  # Helper Functions
  # -----------------------------------------------------------------

  defp display_value(nil), do: ""
  defp display_value(""), do: ""
  defp display_value(value), do: value

  defp format_address(member) do
    street_part =
      [member.street, member.house_number]
      |> Enum.filter(&(&1 && &1 != ""))
      |> Enum.join(" ")

    city_part =
      [member.postal_code, member.city]
      |> Enum.filter(&(&1 && &1 != ""))
      |> Enum.join(" ")

    [street_part, city_part]
    |> Enum.filter(&(&1 != ""))
    |> Enum.join(", ")
    |> case do
      "" -> nil
      address -> address
    end
  end

  defp format_date(nil), do: nil

  defp format_date(%Date{} = date) do
    Calendar.strftime(date, "%d.%m.%Y")
  end

  defp format_date(date), do: to_string(date)

  # Sorts custom field values by custom field name
  defp sort_custom_field_values(custom_field_values) do
    Enum.sort_by(custom_field_values, fn cfv ->
      (cfv.custom_field && cfv.custom_field.name) || ""
    end)
  end

  # Formats custom field value based on type
  defp format_custom_field_value(%Ash.Union{value: value, type: type}, _expected_type) do
    format_custom_field_value(value, type)
  end

  defp format_custom_field_value(nil, _type), do: "—"

  defp format_custom_field_value(value, :boolean) when is_boolean(value) do
    if value, do: gettext("Yes"), else: gettext("No")
  end

  defp format_custom_field_value(%Date{} = date, :date) do
    Calendar.strftime(date, "%d.%m.%Y")
  end

  defp format_custom_field_value(value, :email) when is_binary(value) do
    assigns = %{email: value}

    ~H"""
    <a href={"mailto:#{@email}"} class="text-blue-700 hover:text-blue-800 underline">{@email}</a>
    """
  end

  defp format_custom_field_value(value, :integer) when is_integer(value) do
    Integer.to_string(value)
  end

  defp format_custom_field_value(value, _type) when is_binary(value) do
    if String.trim(value) == "", do: "—", else: value
  end

  defp format_custom_field_value(value, _type), do: to_string(value)
end