require 'appbundler/version'
require 'appbundler/app'
require 'mixlib/cli'

module Appbundler
  class CLI
    include Mixlib::CLI

    banner(<<-BANNER)
Usage: appbundler APPLICATION_DIR BINSTUB_DIR

  APPLICATION_DIR is the root directory to a working copy of your app
  BINSTUB_DIR is the directory where you want generated executables to be written

Your bundled application must already be gem installed.  Generated binstubs
will point to the gem, not your working copy.
BANNER

    option :version,
      :short => '-v',
      :long => '--version',
      :description => 'Show appbundler version',
      :boolean => true,
      :proc => lambda {|v| $stdout.puts("Appbundler Version: #{::Appbundler::VERSION}")},
      :exit => 0

    option :help,
      :short => "-h",
      :long => "--help",
      :description => "Show this message",
      :on => :tail,
      :boolean => true,
      :show_options => true,
      :exit => 0

    def self.run(argv)
      cli = new(argv)
      cli.handle_options
      cli.validate!
      cli.run
    end

    attr_reader :argv

    attr_reader :app_path
    attr_reader :bin_path

    def initialize(argv)
      @argv = argv
      super()
    end

    def handle_options
      parse_options(@argv)
    end

    def validate!
      if cli_arguments.size != 2
        usage_and_exit!
      else
        @app_path = File.expand_path(cli_arguments[0])
        @bin_path = File.expand_path(cli_arguments[1])
        verify_app_path
        verify_bin_path
        verify_gem_installed
      end
    end

    def verify_app_path
      if !File.directory?(app_path)
        err("APPLICATION_DIR `#{app_path}' is not a directory or doesn't exist")
        usage_and_exit!
      elsif !File.exist?(File.join(app_path, "Gemfile.lock"))
        err("APPLICATION_DIR does not contain required Gemfile.lock")
        usage_and_exit!
      end
    end

    def verify_bin_path
      if !File.directory?(bin_path)
        err("BINSTUB_DIR `#{bin_path}' is not a directory or doesn't exist")
        usage_and_exit!
      end
    end

    def verify_gem_installed
      app = App.new(app_path, bin_path)
      app.app_gemspec
    rescue Gem::LoadError
      err("Unable to find #{app.app_spec.name} #{app.app_spec.version} installed as a gem")
      err("You must install the top-level app as a gem before calling app-bundler")
      usage_and_exit!
    end

    def run
      app = App.new(app_path, bin_path)
      created_stubs = app.write_executable_stubs
      created_stubs.each do |real_executable_path, stub_path|
        $stdout.puts "Generated binstub #{stub_path} => #{real_executable_path}"
      end
      app.copy_bundler_env
    end

    def err(message)
      $stderr.print("#{message}\n")
    end

    def usage_and_exit!
      err(banner)
      exit 1
    end
  end
end