Implement mix update script

lib/heroicons.ex

@@ -16,4 +16,120 @@ defmodule Heroicons do
 
   Heroicons are designed by [Steve Schoger](https://twitter.com/steveschoger)
   """
+
+  # https://github.com/tailwindlabs/heroicons/releases
+  @latest_version "2.0.0"
+
+  @tmp_dir_name "heroicons-elixir"
+
+  require Logger
+
+  @doc false
+  # Latest known version at the time of publishing.
+  def latest_version, do: @latest_version
+
+  @doc """
+  Returns the configured Heroicons version.
+  """
+  def configured_version do
+    Application.get_env(:heroicons, :version, latest_version())
+  end
+
+  @doc false
+  def svgs_path, do: Path.join(:code.priv_dir(:heroicons), "icons")
+
+  def icons_path(style), do: Path.join(svgs_path(), style)
+
+  def update do
+    version = configured_version()
+    tmp_dir = Path.join(System.tmp_dir!(), @tmp_dir_name)
+
+    File.rm_rf!(tmp_dir)
+    File.mkdir_p!(tmp_dir)
+
+    url = "https://github.com/tailwindlabs/heroicons/archive/refs/tags/v#{version}.zip"
+    archive = fetch_body!(url)
+
+    case unpack_archive(".zip", archive, tmp_dir) do
+      :ok -> :ok
+      other -> raise "couldn't unpack archive: #{inspect(other)}"
+    end
+
+    # Copy icon styles, mini, outline and solid, to priv folder
+    Path.join([tmp_dir, "heroicons-#{version}", "optimized"])
+    |> File.ls!()
+    |> Enum.each(fn size ->
+      case size do
+        "20" -> copy_svg_files(size, "solid", "mini")
+        "24" -> Enum.each(File.ls!(), fn style -> copy_svg_files(size, style, style) end)
+        _ -> true
+      end
+    end)
+  end
+
+  defp copy_svg_files(icons_size, src_dir_name, output_dir_name) do
+    tmp_dir = Path.join(System.tmp_dir!(), @tmp_dir_name)
+    svgs_temp_dir = Path.join([tmp_dir, "heroicons-#{configured_version()}", "optimized"])
+
+    File.cp_r!(Path.join([svgs_temp_dir, icons_size, src_dir_name]), icons_path(output_dir_name))
+  end
+
+  defp fetch_body!(url) do
+    url = String.to_charlist(url)
+    Logger.debug("Downloading heroicons from #{url}")
+
+    {:ok, _} = Application.ensure_all_started(:inets)
+    {:ok, _} = Application.ensure_all_started(:ssl)
+
+    if proxy = System.get_env("HTTP_PROXY") || System.get_env("http_proxy") do
+      Logger.debug("Using HTTP_PROXY: #{proxy}")
+      %{host: host, port: port} = URI.parse(proxy)
+      :httpc.set_options([{:proxy, {{String.to_charlist(host), port}, []}}])
+    end
+
+    if proxy = System.get_env("HTTPS_PROXY") || System.get_env("https_proxy") do
+      Logger.debug("Using HTTPS_PROXY: #{proxy}")
+      %{host: host, port: port} = URI.parse(proxy)
+      :httpc.set_options([{:https_proxy, {{String.to_charlist(host), port}, []}}])
+    end
+
+    # https://erlef.github.io/security-wg/secure_coding_and_deployment_hardening/inets
+    cacertfile = CAStore.file_path() |> String.to_charlist()
+
+    http_options = [
+      ssl: [
+        verify: :verify_peer,
+        cacertfile: cacertfile,
+        depth: 2,
+        customize_hostname_check: [
+          match_fun: :public_key.pkix_verify_hostname_match_fun(:https)
+        ],
+        versions: protocol_versions()
+      ]
+    ]
+
+    options = [body_format: :binary]
+
+    case :httpc.request(:get, {url, []}, http_options, options) do
+      {:ok, {{_, 200, _}, _headers, body}} ->
+        body
+
+      other ->
+        raise "couldn't fetch #{url}: #{inspect(other)}"
+    end
+  end
+
+  defp protocol_versions do
+    if otp_version() < 25, do: [:"tlsv1.2"], else: [:"tlsv1.2", :"tlsv1.3"]
+  end
+
+  defp otp_version, do: :erlang.system_info(:otp_release) |> List.to_integer()
+
+  defp unpack_archive(".zip", zip, cwd) do
+    with {:ok, _} <- :zip.unzip(zip, cwd: to_charlist(cwd)), do: :ok
+  end
+
+  defp unpack_archive(_, tar, cwd) do
+    :erl_tar.extract({:binary, tar}, [:compressed, cwd: to_charlist(cwd)])
+  end
 end