Add CLI interface

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## v0.6.0
+
+* Add CLI interface
+
 ## v0.5.1
 
 ### Bug fixes

README.md

@@ -132,6 +132,28 @@ have any JavaScript, you will get warnings from validation tools such as
 
 See `BUPE.Builder`, `BUPE.Config`, and `BUPE.Item` for more details.
 
+### Using the builder via command line
+
+You can build EPUB documents using the command line as follows:
+
+1. Install `BUPE` as an escript:
+
+```console
+mix escript.install hex bupe
+```
+
+2. Then you are ready to use it in your projects:
+
+```console
+bupe "EPUB_TITLE" -p egg.xhtml -p bacon.xhtml -l path/to/logo.png
+```
+
+For more details about using the command line tool, review the usage guide:
+
+```console
+bupe --help
+```
+
 ### Parser
 
 If you want to parse an EPUB file you can do the following:

lib/bupe/cli.ex

@@ -0,0 +1,107 @@
+defmodule BUPE.CLI do
+  @moduledoc """
+  CLI interface for BUPE.
+  """
+
+  @aliases [
+    h: :help,
+    l: :logo,
+    o: :output,
+    p: :page,
+    v: :version
+  ]
+
+  @switches [
+    help: :boolean,
+    language: :string,
+    logo: :string,
+    output: :string,
+    page: :keep,
+    version: :boolean
+  ]
+
+  def main(args, builder \\ &BUPE.Builder.run/3) do
+    {opts, args, _invalid} = OptionParser.parse(args, aliases: @aliases, switches: @switches)
+
+    cond do
+      Keyword.has_key?(opts, :version) ->
+        print_version()
+
+      Keyword.has_key?(opts, :help) ->
+        print_usage()
+
+      true ->
+        generate(args, opts, builder)
+    end
+  end
+
+  defp generate([], _, _) do
+    IO.puts("Too few arguments.\n")
+    print_usage()
+    exit({:shutdown, 1})
+  end
+
+  defp generate([title], opts, builder) do
+    opts =
+      opts
+      |> Keyword.put(:title, title)
+      |> parse_pages()
+
+    name = parse_output(opts, title)
+
+    with {:ok, path} <- BUPE.Config |> struct(opts) |> builder.(name, []) do
+      IO.puts("EPUB successfully generated:")
+      path |> Path.relative_to_cwd() |> IO.puts()
+    end
+  end
+
+  def parse_pages(opts) do
+    case Keyword.get_values(opts, :page) do
+      [] ->
+        IO.puts("At least one page is required\n")
+        print_usage()
+        exit({:shutdown, 1})
+
+      pages ->
+        opts
+        |> Keyword.delete(:page)
+        |> Keyword.put(:pages, pages)
+    end
+  end
+
+  def parse_output(opts, title) do
+    Keyword.get_lazy(opts, :output, fn ->
+      title
+      |> String.downcase()
+      |> String.replace(" ", "_")
+      |> Kernel.<>(".epub")
+    end)
+  end
+
+  defp print_version do
+    IO.puts("BUPE v#{BUPE.version()}")
+  end
+
+  defp print_usage do
+    IO.puts(~S"""
+    Usage:
+      bupe EPUB_TITLE [OPTIONS]
+
+    Examples:
+      bupe "Ode to Food" -p egg.xhtml -p bacon.xhtml
+
+    Options:
+      EPUB_TITLE      EPUB title
+      -p, --page      Path to a page (e.g. XHTML) file that will be copied
+                      to the EPUB file. May be given multiple times
+      --language      Identify the primary language of the EPUB document, its
+                      value must be a valid [BCP 47](https://tools.ietf.org/html/bcp47)
+                      language tag, default: "en"
+      -l, --logo      Path to the image logo of the EPUB document
+      -v, --version   Print BUPE version
+      -o, --output    Path to output EPUB document.
+      -h, --help      Print this usage
+
+    """)
+  end
+end

mix.exs

@@ -1,7 +1,7 @@
 defmodule BUPE.Mixfile do
   use Mix.Project
 
-  @version "0.5.2-dev"
+  @version "0.6.0"
 
   def project do
     [
@@ -19,11 +19,8 @@ defmodule BUPE.Mixfile do
       docs: docs(),
       package: package(),
       deps: deps(),
-      dialyzer: [
-        plt_add_apps: [:mix, :ex_unit, :xmerl],
-        check_plt: true,
-        flags: [:error_handling, :race_conditions, :underspecs]
-      ]
+      dialyzer: dialyzer(),
+      escript: escript()
     ]
   end
 
@@ -34,6 +31,18 @@ defmodule BUPE.Mixfile do
     [applications: []]
   end
 
+  def dialyzer do
+    [
+      plt_add_apps: [:mix, :ex_unit, :xmerl],
+      check_plt: true,
+      flags: [:error_handling, :race_conditions, :underspecs]
+    ]
+  end
+
+  def escript do
+    [main_module: BUPE.CLI]
+  end
+
   defp deps do
     [
       {:ex_doc, "~> 0.19", only: :dev},

test/bupe/cli_test.exs

@@ -0,0 +1,55 @@
+defmodule BUPE.CLITest do
+  use ExUnit.Case, async: true
+
+  alias BUPE.CLI
+
+  import ExUnit.CaptureIO
+
+  defp builder(_config, name, _opts) do
+    {:ok, name}
+  end
+
+  test "minimum command-line options" do
+    fun = fn ->
+      CLI.main(["sample", "--page", "egg.xhtml"], &builder/3)
+    end
+
+    assert "EPUB successfully generated:\nsample.epub\n" == capture_io(fun)
+  end
+
+  test "at least one page is required" do
+    fun = fn ->
+      CLI.main(["sample"])
+    end
+
+    assert catch_exit(capture_io(fun)) == {:shutdown, 1}
+  end
+
+  test "too few arguments" do
+    fun = fn ->
+      CLI.main(["--page", "egg.xhtml"])
+    end
+
+    assert catch_exit(capture_io(fun)) == {:shutdown, 1}
+  end
+
+  test "version" do
+    assert capture_io(fn ->
+             CLI.main(["--version"])
+           end) == "BUPE v#{BUPE.version()}\n"
+
+    assert capture_io(fn ->
+             CLI.main(["-v"])
+           end) == "BUPE v#{BUPE.version()}\n"
+  end
+
+  test "help" do
+    assert capture_io(fn ->
+             CLI.main(["--help"])
+           end) =~ "Usage:\n"
+
+    assert capture_io(fn ->
+             CLI.main(["-h"])
+           end) =~ "Usage:\n"
+  end
+end