miosa

defmodule Miosa.Usage do
  @moduledoc """
  Usage — current period summary, per-session metering, and report queries.

  ## Example

      client = Miosa.client(System.fetch_env!("MIOSA_API_KEY"))

      {:ok, summary} = Miosa.Usage.current(client)
      {:ok, sessions} = Miosa.Usage.sessions(client, %{limit: 100})
  """

  alias Miosa.Client

  @doc "Get the current period usage summary."
  @spec current(Client.t()) :: Client.result(map())
  def current(client) do
    Client.get(client, "/usage/summary")
  end

  @doc """
  List per-session metering events.

  Accepts optional filters as a keyword list or map (e.g. `:limit`, `:cursor`,
  `:computer_id`).
  """
  @spec sessions(Client.t(), keyword() | map()) :: Client.result(map())
  def sessions(client, filters \\ []) do
    query = filters |> normalize() |> build_query()
    Client.get(client, "/usage/sessions" <> query)
  end

  @doc """
  Get a usage report for a period.

  Options: `:period_start` and `:period_end` (ISO 8601 strings), plus any
  additional filters accepted by the API.
  """
  @spec report(Client.t(), keyword() | map()) :: Client.result(map())
  def report(client, filters \\ []) do
    query = filters |> normalize() |> build_query()
    Client.get(client, "/usage/summary" <> query)
  end

  # ── Helpers ───────────────────────────────────────────────────────────────────

  defp normalize(filters) when is_list(filters), do: Map.new(filters)
  defp normalize(filters) when is_map(filters), do: filters

  defp build_query(filters) when filters == %{}, do: ""

  defp build_query(filters) do
    "?" <>
      (filters
       |> Enum.reject(fn {_k, v} -> is_nil(v) end)
       |> Enum.map(fn {k, v} -> "#{k}=#{URI.encode_www_form(to_string(v))}" end)
       |> Enum.join("&"))
  end
end