defmodule PhoenixKit.Modules.Billing.Web.Settings do
  @moduledoc """
  Billing settings LiveView for the billing module.

  Provides configuration interface for billing module settings.
  Company and bank information is now managed in Organization Settings.
  """

  use Phoenix.LiveView
  use Gettext, backend: PhoenixKitWeb.Gettext
  import PhoenixKitWeb.Components.Core.AdminPageHeader
  import PhoenixKitWeb.Components.Core.Icon

  alias PhoenixKit.Modules.Billing
  alias PhoenixKit.Settings
  alias PhoenixKit.Utils.CountryData

  @impl true
  def mount(_params, _session, socket) do
    project_title = Settings.get_project_title()
    billing_enabled = Billing.enabled?()

    socket =
      socket
      |> assign(:page_title, "Billing Settings")
      |> assign(:project_title, project_title)
      |> assign(:billing_enabled, billing_enabled)
      |> load_settings()

    {:ok, socket}
  end

  @impl true
  def handle_params(_params, _url, socket) do
    {:noreply, socket}
  end

  defp load_settings(socket) do
    # Get company info from consolidated Settings (with fallback to legacy keys)
    company_info = CountryData.get_company_info()
    bank_details = CountryData.get_bank_details()
    company_country = company_info["country"] || ""

    socket
    # General settings
    |> assign(:default_currency, Settings.get_setting("billing_default_currency", "EUR"))
    |> assign(:invoice_prefix, Settings.get_setting("billing_invoice_prefix", "INV"))
    |> assign(:order_prefix, Settings.get_setting("billing_order_prefix", "ORD"))
    |> assign(:receipt_prefix, Settings.get_setting("billing_receipt_prefix", "RCP"))
    |> assign(:invoice_due_days, Settings.get_setting("billing_invoice_due_days", "14"))
    |> assign(:tax_enabled, Settings.get_setting("billing_tax_enabled", "false") == "true")
    |> assign(:tax_rate, Settings.get_setting("billing_default_tax_rate", "0"))
    # Company info (from consolidated source)
    |> assign(:company_info, company_info)
    |> assign(:company_address_formatted, CountryData.format_company_address())
    |> assign(:company_country_name, get_country_name(company_country))
    |> assign(:company_country, company_country)
    # For suggested tax rate
    |> assign_suggested_tax_rate()
    # Bank details (from consolidated source)
    |> assign(:bank_details, bank_details)
  end

  # Helper to get country name from code
  defp get_country_name(""), do: ""
  defp get_country_name(nil), do: ""

  defp get_country_name(country_code) do
    case BeamLabCountries.get(country_code) do
      nil -> country_code
      country -> country.name
    end
  end

  @impl true
  def handle_event("save_general", params, socket) do
    # Convert checkbox value to "true"/"false" string
    tax_enabled = if params["tax_enabled"] == "true", do: "true", else: "false"

    settings = [
      {"billing_default_currency", params["default_currency"]},
      {"billing_invoice_prefix", params["invoice_prefix"]},
      {"billing_order_prefix", params["order_prefix"]},
      {"billing_receipt_prefix", params["receipt_prefix"]},
      {"billing_invoice_due_days", params["invoice_due_days"]},
      {"billing_tax_enabled", tax_enabled},
      {"billing_default_tax_rate", params["tax_rate"]}
    ]

    Enum.each(settings, fn {key, value} ->
      Settings.update_setting(key, value)
    end)

    {:noreply,
     socket
     |> load_settings()
     |> put_flash(:info, "General settings saved")}
  end

  @impl true
  def handle_event("tax_rate_changed", %{"tax_rate" => tax_rate}, socket) do
    current_rate = parse_tax_rate(tax_rate)
    country_code = socket.assigns.company_country

    suggested_rate =
      if country_code != "" do
        rate = CountryData.get_standard_vat_percent(country_code)
        if rate == current_rate, do: nil, else: rate
      else
        nil
      end

    {:noreply,
     socket
     |> assign(:tax_rate, tax_rate)
     |> assign(:suggested_tax_rate, suggested_rate)}
  end

  @impl true
  def handle_event("apply_suggested_tax", _params, socket) do
    case socket.assigns.suggested_tax_rate do
      nil ->
        {:noreply, socket}

      rate ->
        {:noreply,
         socket
         |> assign(:tax_rate, to_string(rate))
         |> assign(:suggested_tax_rate, nil)}
    end
  end

  # Suggested tax rate helper

  defp assign_suggested_tax_rate(socket) do
    country_code = socket.assigns.company_country
    current_rate = parse_tax_rate(socket.assigns.tax_rate)

    suggested_rate =
      if country_code != "" do
        rate = CountryData.get_standard_vat_percent(country_code)
        # Hide suggestion if it matches current rate
        if rate == current_rate, do: nil, else: rate
      else
        nil
      end

    assign(socket, :suggested_tax_rate, suggested_rate)
  end

  defp parse_tax_rate(rate) when is_binary(rate) do
    case Float.parse(rate) do
      {value, _} -> if value == trunc(value), do: trunc(value), else: value
      :error -> 0
    end
  end

  defp parse_tax_rate(rate) when is_number(rate), do: rate
  defp parse_tax_rate(_), do: 0
end