defmodule ToweropsWeb.UserSettingsLive.Helpers do
  @moduledoc """
  Helper functions for formatting and displaying user settings data.
  """

  @doc """
  Checks if a session matches the current token ID.
  """
  def current_session?(session, current_token_id) do
    session.user_token_id == current_token_id
  end

  @doc """
  Formats a UTC datetime in the user's timezone.
  """
  def format_timestamp_in_timezone(datetime, timezone, time_format \\ "24h") do
    case DateTime.shift_zone(datetime, timezone) do
      {:ok, shifted} ->
        time_str = format_time_for_display(shifted, time_format)
        Calendar.strftime(shifted, "%b %d, %Y #{time_str} %Z")

      {:error, _} ->
        # Fallback to UTC if timezone conversion fails
        time_str = format_time_for_display(datetime, time_format)
        Calendar.strftime(datetime, "%b %d, %Y #{time_str} UTC")
    end
  end

  defp format_time_for_display(datetime, "12h") do
    Calendar.strftime(datetime, "%I:%M %p")
  end

  defp format_time_for_display(datetime, _time_format) do
    Calendar.strftime(datetime, "%H:%M:%S")
  end

  @doc """
  Formats browser information from a session for display.
  """
  def format_browser_info(session) do
    case {session.browser_name, session.browser_version, session.os_name} do
      {nil, _, _} -> session.device_name || "Unknown Browser"
      {browser, nil, nil} -> browser
      {browser, version, nil} -> "#{browser} #{version}"
      {browser, nil, os} -> "#{browser} on #{os}"
      {browser, version, os} -> "#{browser} #{version} on #{os}"
    end
  end

  @doc """
  Formats location information from GeoIP data.
  """
  def format_location(record) do
    case {record.city_name, record.subdivision_1_name, record.country_name} do
      {nil, nil, nil} ->
        "Unknown Location"

      {city, state, country} when not is_nil(city) and not is_nil(state) and not is_nil(country) ->
        "#{city}, #{state}, #{country}"

      {city, nil, country} when not is_nil(city) and not is_nil(country) ->
        "#{city}, #{country}"

      {nil, nil, country} when not is_nil(country) ->
        country

      _ ->
        "Unknown Location"
    end
  end

  @doc """
  Formats a datetime as a relative time string (e.g., "5 minutes ago").
  """
  def format_relative_time(datetime) do
    now = DateTime.utc_now()
    diff = DateTime.diff(now, datetime, :second)

    cond do
      diff < 60 -> "Just now"
      diff < 3600 -> "#{div(diff, 60)} minutes ago"
      diff < 86_400 -> "#{div(diff, 3600)} hours ago"
      diff < 604_800 -> "#{div(diff, 86_400)} days ago"
      true -> Calendar.strftime(datetime, "%b %d, %Y")
    end
  end

  @doc """
  Returns icon name and display label for a login method.
  """
  def login_method_info(method) do
    case method do
      "password" -> {"hero-lock-closed", "Password"}
      "magic_link" -> {"hero-envelope", "Magic Link"}
      "mobile_qr" -> {"hero-device-phone-mobile", "Mobile QR"}
      _ -> {"hero-question-mark-circle", method}
    end
  end

  @doc """
  Generates pagination range with ellipsis for large page counts.

  Shows: [1] ... [4] [5] [6] ... [20] when on page 5 of 20
  """
  def pagination_range(current_page, total_pages) do
    cond do
      total_pages <= 7 ->
        # Show all pages if 7 or fewer
        Enum.to_list(1..total_pages)

      current_page <= 4 ->
        # Near the start
        [1, 2, 3, 4, 5, :ellipsis, total_pages]

      current_page >= total_pages - 3 ->
        # Near the end
        [1, :ellipsis, total_pages - 4, total_pages - 3, total_pages - 2, total_pages - 1, total_pages]

      true ->
        # In the middle
        [1, :ellipsis, current_page - 1, current_page, current_page + 1, :ellipsis, total_pages]
    end
  end
end