Initial commit

.formatter.exs

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+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

.gitignore

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+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where 3rd-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+frenzy-*.tar
+
+# Files matching config/*.secret.exs pattern contain sensitive
+# data and you should not commit them into version control.
+#
+# Alternatively, you may comment the line below and commit the
+# secrets files as long as you replace their contents by environment
+# variables.
+/config/*.secret.exs

README.md

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+# Gemini
+
+**TODO: Add description**
+
+## Installation
+
+If [available in Hex](https://hex.pm/docs/publish), the package can be installed
+by adding `gemini` to your list of dependencies in `mix.exs`:
+
+```elixir
+def deps do
+  [
+    {:gemini, "~> 0.1.0"}
+  ]
+end
+```
+
+Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
+and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
+be found at [https://hexdocs.pm/gemini](https://hexdocs.pm/gemini).
+

lib/gemini.ex

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+defmodule Gemini do
+  @moduledoc """
+  Documentation for `Gemini`.
+  """
+
+  @spec request(URI.t() | String.t()) :: {:ok, Gemini.Response.t()} | {:error, term()}
+  @doc """
+  Sends a Gemini request to the given URI.
+  """
+  def request(uri) when is_binary(uri) do
+    request(URI.parse(uri))
+  end
+
+  def request(%URI{host: host} = uri) do
+    port = gemini_port(uri)
+
+    case Socket.SSL.connect(host, port) do
+      {:error, reason} ->
+        {:error, reason}
+
+      {:ok, sock} ->
+        Socket.Stream.send(sock, "#{URI.to_string(uri)}\r\n")
+
+        case Socket.Stream.recv(sock) do
+          {:error, reason} ->
+            {:error, reason}
+
+          {:ok, data} ->
+            Gemini.Response.parse(data)
+        end
+    end
+  end
+
+  defp gemini_port(%URI{scheme: "gemini", port: nil}), do: 1965
+  defp gemini_port(%URI{scheme: "gemini", port: port}), do: port
+
+  @type line ::
+          {:text, String.t()}
+          | {:link, URI.t(), String.t() | nil}
+          | {:preformatted, String.t(), String.t() | nil}
+          | {:heading, String.t(), 1 | 2 | 3}
+          | {:list_item, String.t()}
+          | {:quoted, String.t()}
+
+  @link_line_regex ~r/\s*([^\s]+)(?:\s+([^\s]+))?/
+
+  @spec parse(String.t()) :: [line()]
+
+  def parse(doc) do
+    {lines, _, _} =
+      doc
+      |> String.split("\n")
+      |> Enum.reduce({[], false, nil}, fn line, {lines, in_preformatting, preformatting_alt} ->
+        preformatting_toggle = match?("```" <> _, line)
+
+        cond do
+          preformatting_toggle && in_preformatting ->
+            {lines, false, nil}
+
+          preformatting_toggle && !in_preformatting ->
+            "```" <> alt = line
+            {lines, true, alt}
+
+          in_preformatting ->
+            {[{:preformatted, line, preformatting_alt} | lines], true, preformatting_alt}
+
+          true ->
+            case line do
+              "=>" <> rest ->
+                {link, text} =
+                  case Regex.run(@link_line_regex, rest) do
+                    [_, link] -> {link, nil}
+                    [_, link, text] -> {link, text}
+                  end
+
+                {[{:link, URI.parse(link), text} | lines], false, nil}
+
+              "###" <> rest ->
+                {[{:heading, String.trim(rest), 3} | lines], false, nil}
+
+              "##" <> rest ->
+                {[{:heading, String.trim(rest), 2} | lines], false, nil}
+
+              "#" <> rest ->
+                {[{:heading, String.trim(rest), 1} | lines], false, nil}
+
+              "* " <> rest ->
+                {[{:list_item, String.trim(rest)} | lines], false, nil}
+
+              ">" <> rest ->
+                {[{:quoted, String.trim(rest)} | rest], false, nil}
+
+              line ->
+                {[{:text, line} | lines], false, nil}
+            end
+        end
+      end)
+
+    lines
+  end
+end

lib/gemini/response.ex

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+defmodule Gemini.Response do
+  @moduledoc """
+  A response to a Gemini protocol request.
+  """
+
+  @enforce_keys [:status, :meta]
+  defstruct [:status, :meta, :body]
+
+  @type t :: %__MODULE__{
+          status: integer(),
+          meta: String.t(),
+          body: nil | binary()
+        }
+
+  @spec parse(data :: binary()) :: {:ok, t()} | {:error, term()}
+
+  @doc """
+  Parse a Gemini response from the given data.
+  """
+  def parse(<<status::binary-size(2), " ", rest::binary>>) do
+    status = String.to_integer(status)
+
+    case parse_meta(rest) do
+      {:error, reason} ->
+        {:error, reason}
+
+      {:ok, meta, body} ->
+        {
+          :ok,
+          %__MODULE__{
+            status: status,
+            meta: meta,
+            body: body
+          }
+        }
+    end
+  end
+
+  def parse(_) do
+    {:error, "Expected Gemini response to begin with two digit status code and space"}
+  end
+
+  defp parse_meta(data, acc \\ [], length \\ 0)
+
+  defp parse_meta(<<"\r\n", rest::binary>>, acc, _length) do
+    {
+      :ok,
+      acc
+      |> Enum.reverse()
+      |> :erlang.list_to_binary(),
+      rest
+    }
+  end
+
+  defp parse_meta(_data, _acc, 1024) do
+    {:error, "Expected meta string in Gemini response to be no longer than 1024 bytes"}
+  end
+
+  defp parse_meta(<<c::binary-size(1), rest::binary>>, acc, length) do
+    parse_meta(rest, [c | acc], length + 1)
+  end
+end

mix.exs

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+defmodule Gemini.MixProject do
+  use Mix.Project
+
+  def project do
+    [
+      app: :gemini,
+      version: "0.1.0",
+      elixir: "~> 1.10",
+      start_permanent: Mix.env() == :prod,
+      deps: deps()
+    ]
+  end
+
+  # Run "mix help compile.app" to learn about applications.
+  def application do
+    [
+      extra_applications: [:logger]
+    ]
+  end
+
+  # Run "mix help deps" to learn about dependencies.
+  defp deps do
+    [
+      {:socket, "~> 0.3.13"}
+    ]
+  end
+end

mix.lock

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+%{
+  "socket": {:hex, :socket, "0.3.13", "98a2ab20ce17f95fb512c5cadddba32b57273e0d2dba2d2e5f976c5969d0c632", [:mix], [], "hexpm", "f82ea9833ef49dde272e6568ab8aac657a636acb4cf44a7de8a935acb8957c2e"},
+}

test/gemini_test.exs

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+defmodule GeminiTest do
+  use ExUnit.Case
+  doctest Gemini
+
+  test "greets the world" do
+    assert Gemini.hello() == :world
+  end
+end

test/test_helper.exs

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+ExUnit.start()