codex_sdk

defmodule Codex.Auth do
  @moduledoc false

  @spec codex_home() :: String.t()
  def codex_home do
    System.get_env("CODEX_HOME") || Path.join(System.user_home!(), ".codex")
  end

  @spec auth_paths() :: [String.t()]
  def auth_paths do
    codex_home = codex_home()

    base_paths = [
      Path.join(codex_home, "auth.json"),
      Path.join(codex_home, ".credentials.json")
    ]

    if System.get_env("CODEX_HOME") do
      base_paths
    else
      (base_paths ++
         [
           Path.join(System.user_home!(), ".config/codex/credentials.json"),
           Path.join(System.user_home!(), ".config/openai/codex.json"),
           Path.join(System.user_home!(), ".codex/credentials.json")
         ])
      |> Enum.uniq()
    end
  end

  @spec infer_auth_mode() :: :api | :chatgpt
  def infer_auth_mode do
    if api_key_env?() || openai_api_key_from_auth() do
      :api
    else
      :chatgpt
    end
  end

  @spec api_key() :: String.t() | nil
  def api_key do
    api_key_env() || openai_api_key_from_auth()
  end

  @spec chatgpt_access_token() :: String.t() | nil
  def chatgpt_access_token do
    auth_paths()
    |> Enum.find_value(&read_chatgpt_access_token/1)
  end

  defp api_key_env? do
    case api_key_env() do
      value when is_binary(value) and value != "" -> true
      _ -> false
    end
  end

  defp api_key_env do
    System.get_env("CODEX_API_KEY")
    |> normalize_string()
  end

  defp openai_api_key_from_auth do
    auth_paths()
    |> Enum.find_value(&read_openai_api_key/1)
  end

  defp read_openai_api_key(path) do
    case read_auth_json(path) do
      %{} = decoded -> extract_openai_api_key(decoded)
      _ -> nil
    end
  end

  defp read_chatgpt_access_token(path) do
    case read_auth_json(path) do
      %{} = decoded -> extract_chatgpt_access_token(decoded)
      _ -> nil
    end
  end

  defp read_auth_json(path) do
    with true <- File.exists?(path),
         {:ok, contents} <- File.read(path),
         {:ok, decoded} <- Jason.decode(contents) do
      decoded
    else
      _ -> nil
    end
  end

  defp extract_openai_api_key(%{"OPENAI_API_KEY" => key}) when is_binary(key) and key != "" do
    String.trim(key)
  end

  defp extract_openai_api_key(%{"openai_api_key" => key}) when is_binary(key) and key != "" do
    String.trim(key)
  end

  defp extract_openai_api_key(_), do: nil

  defp extract_chatgpt_access_token(%{"tokens" => %{"access_token" => token}})
       when is_binary(token) and token != "" do
    String.trim(token)
  end

  defp extract_chatgpt_access_token(%{"tokens" => %{"token" => token}})
       when is_binary(token) and token != "" do
    String.trim(token)
  end

  defp extract_chatgpt_access_token(%{"access_token" => token})
       when is_binary(token) and token != "" do
    String.trim(token)
  end

  defp extract_chatgpt_access_token(%{"token" => token}) when is_binary(token) and token != "" do
    String.trim(token)
  end

  defp extract_chatgpt_access_token(_), do: nil

  defp normalize_string(nil), do: nil

  defp normalize_string(value) when is_binary(value) do
    value = String.trim(value)
    if value == "", do: nil, else: value
  end
end