defmodule PhoenixKitEcommerce.Web.Carts do
  @moduledoc """
  Carts admin list LiveView for E-Commerce module.
  """

  use PhoenixKitEcommerce.Web, :live_view

  import PhoenixKitWeb.Components.Core.TableDefault

  alias PhoenixKit.Utils.Routes
  alias PhoenixKitBilling.Currency
  alias PhoenixKitEcommerce, as: Shop

  @per_page 25

  # Last-resort currency symbol used only when no default currency is
  # configured in Billing (i.e. `@currency` resolved to nil at mount).
  # When a currency struct is present we always defer to its own symbol.
  @default_currency_symbol "$"

  @impl true
  def mount(_params, _session, socket) do
    {carts, total} = Shop.list_carts_with_count(per_page: @per_page)
    currency = Shop.get_default_currency()

    socket =
      socket
      |> assign(:page_title, "Shopping Carts")
      |> assign(:carts, carts)
      |> assign(:total, total)
      |> assign(:page, 1)
      |> assign(:per_page, @per_page)
      |> assign(:status_filter, nil)
      |> assign(:search, "")
      |> assign(:currency, currency)

    {:ok, socket}
  end

  @impl true
  def handle_params(params, _uri, socket) do
    page = String.to_integer(params["page"] || "1")
    status = params["status"]
    search = params["search"] || ""

    {carts, total} =
      Shop.list_carts_with_count(
        page: page,
        per_page: @per_page,
        status: status,
        search: search
      )

    socket =
      socket
      |> assign(:carts, carts)
      |> assign(:total, total)
      |> assign(:page, page)
      |> assign(:status_filter, status)
      |> assign(:search, search)

    {:noreply, socket}
  end

  @impl true
  def handle_event("filter_status", %{"status" => status}, socket) do
    status = if status == "", do: nil, else: status
    {:noreply, push_patch(socket, to: build_url(socket.assigns, status: status, page: 1))}
  end

  @impl true
  def handle_event("search", %{"search" => search}, socket) do
    {:noreply, push_patch(socket, to: build_url(socket.assigns, search: search, page: 1))}
  end

  defp build_url(assigns, overrides) do
    params =
      %{
        status: Keyword.get(overrides, :status, assigns.status_filter),
        search: Keyword.get(overrides, :search, assigns.search),
        page: Keyword.get(overrides, :page, assigns.page)
      }
      |> Enum.filter(fn {_k, v} -> v && v != "" end)
      |> URI.encode_query()

    if params == "" do
      Routes.path("/admin/shop/carts")
    else
      Routes.path("/admin/shop/carts?#{params}")
    end
  end

  @impl true
  def render(assigns) do
    ~H"""
      <div class="container flex-col mx-auto px-4 py-6 max-w-7xl">
        <.admin_page_header back={Routes.path("/admin/shop")}>
          <h1 class="text-xl sm:text-2xl lg:text-3xl font-bold text-base-content">Shopping Carts</h1>
          <p class="text-sm sm:text-base text-base-content/60 mt-0.5">{@total} carts total</p>
        </.admin_page_header>

        <%!-- Controls Bar --%>
        <div class="bg-base-200 rounded-lg p-6 mb-6">
          <div class="flex flex-col lg:flex-row gap-4">
            <%!-- Search --%>
            <div class="flex-1">
              <label class="label"><span class="label-text">Search</span></label>
              <form phx-submit="search" phx-change="search">
                <input
                  type="text"
                  name="search"
                  value={@search}
                  placeholder="Search by email or session ID..."
                  class="input input-bordered w-full focus:input-primary"
                  phx-debounce="300"
                />
              </form>
            </div>

            <%!-- Status Filter --%>
            <div class="w-full lg:w-48">
              <label class="label"><span class="label-text">Status</span></label>
              <select
                class="select select-bordered w-full focus:select-primary"
                phx-change="filter_status"
                name="status"
              >
                <option value="" selected={is_nil(@status_filter)}>All Status</option>
                <option value="active" selected={@status_filter == "active"}>Active</option>
                <option value="converted" selected={@status_filter == "converted"}>Converted</option>
                <option value="abandoned" selected={@status_filter == "abandoned"}>Abandoned</option>
                <option value="expired" selected={@status_filter == "expired"}>Expired</option>
                <option value="merged" selected={@status_filter == "merged"}>Merged</option>
              </select>
            </div>
          </div>
        </div>

        <%!-- Carts Table --%>
        <.table_default id="carts-table" variant="zebra" class="w-full" toggleable={true} items={@carts}
          card_fields={fn cart -> [
            %{label: "Items", value: "#{cart.items_count || 0} items"},
            %{label: "Total", value: if(cart.total, do: Decimal.to_string(Decimal.round(cart.total, 2)), else: "-")},
            %{label: "Status", value: cart.status || "-"},
            %{label: "Updated", value: Calendar.strftime(cart.updated_at, "%Y-%m-%d %H:%M")}
          ] end}>

          <:card_header :let={cart}>
            <div class="font-bold">
              <%= if cart.user do %>
                {cart.user.email}
              <% else %>
                Guest — {String.slice(cart.session_id || "", 0, 16)}...
              <% end %>
            </div>
          </:card_header>

          <.table_default_header>
            <.table_default_row>
              <.table_default_header_cell>Customer</.table_default_header_cell>
              <.table_default_header_cell>Items</.table_default_header_cell>
              <.table_default_header_cell class="text-right">Total</.table_default_header_cell>
              <.table_default_header_cell>Status</.table_default_header_cell>
              <.table_default_header_cell>Updated</.table_default_header_cell>
            </.table_default_row>
          </.table_default_header>

          <.table_default_body>
            <%= if @carts == [] do %>
              <.table_default_row>
                <.table_default_cell class="text-center py-12 text-base-content/50">
                  <.icon name="hero-shopping-cart" class="w-12 h-12 mx-auto mb-3 opacity-50" />
                  <p class="text-lg">No carts found</p>
                  <p class="text-sm">Carts will appear here when customers add items</p>
                </.table_default_cell>
              </.table_default_row>
            <% else %>
              <%= for cart <- @carts do %>
                <.table_default_row class="hover">
                  <.table_default_cell>
                    <%= if cart.user do %>
                      <div class="font-medium">{cart.user.email}</div>
                      <div class="text-xs text-base-content/50">User UUID: {cart.user.uuid}</div>
                    <% else %>
                      <div class="text-base-content/60">Guest</div>
                      <div class="text-xs text-base-content/40 font-mono">
                        {String.slice(cart.session_id || "", 0, 16)}...
                      </div>
                    <% end %>
                  </.table_default_cell>
                  <.table_default_cell>
                    <span class="badge badge-neutral">{cart.items_count || 0} items</span>
                    <%= if cart.total_weight_grams && cart.total_weight_grams > 0 do %>
                      <span class="text-xs text-base-content/50 ml-2">
                        {format_weight(cart.total_weight_grams)}
                      </span>
                    <% end %>
                  </.table_default_cell>
                  <.table_default_cell class="text-right">
                    <div class="font-semibold">{format_price(cart.total, @currency)}</div>
                    <%= if Decimal.compare(cart.subtotal || Decimal.new("0"), cart.total || Decimal.new("0")) != :eq do %>
                      <div class="text-xs text-base-content/50">
                        Subtotal: {format_price(cart.subtotal, @currency)}
                      </div>
                    <% end %>
                  </.table_default_cell>
                  <.table_default_cell>
                    <span class={status_badge_class(cart.status)}>{cart.status}</span>
                  </.table_default_cell>
                  <.table_default_cell>
                    <div class="text-sm">{format_datetime(cart.updated_at)}</div>
                    <%= if cart.expires_at do %>
                      <div class="text-xs text-base-content/50">
                        Expires: {format_datetime(cart.expires_at)}
                      </div>
                    <% end %>
                  </.table_default_cell>
                </.table_default_row>
              <% end %>
            <% end %>
          </.table_default_body>
        </.table_default>

        <%!-- Pagination --%>
        <%= if @total > @per_page do %>
          <div class="flex justify-center mt-6">
            <div class="join">
              <%= for page_num <- 1..ceil(@total / @per_page) do %>
                <.link
                  patch={build_url(assigns, page: page_num)}
                  class={["join-item btn btn-sm", if(@page == page_num, do: "btn-active")]}
                >
                  {page_num}
                </.link>
              <% end %>
            </div>
          </div>
        <% end %>
      </div>
    """
  end

  defp status_badge_class("active"), do: "badge badge-success"
  defp status_badge_class("converted"), do: "badge badge-info"
  defp status_badge_class("abandoned"), do: "badge badge-warning"
  defp status_badge_class("expired"), do: "badge badge-neutral"
  defp status_badge_class("merged"), do: "badge badge-secondary"
  defp status_badge_class(_), do: "badge"

  defp format_price(nil, _currency), do: "-"

  defp format_price(amount, nil) do
    "#{@default_currency_symbol}#{Decimal.round(amount, 2)}"
  end

  defp format_price(amount, currency) do
    Currency.format_amount(amount, currency)
  end

  defp format_weight(grams) when grams >= 1000, do: "#{Float.round(grams / 1000, 1)} kg"
  defp format_weight(grams), do: "#{grams} g"

  defp format_datetime(nil), do: "-"

  defp format_datetime(datetime) do
    Calendar.strftime(datetime, "%Y-%m-%d %H:%M")
  end
end