lib/selector: Add selector library, apply to jdk and hunspell (#7473)

* Add selector library, apply to `jdk` and `hunspell`

* Make rubocop happy

* Fix syntax error

* jdk: Fetch version from packages

* Auto update version number

* hunspell: wrap with `ARGV.include?`

* Fix syntax error

* Make rubocop happy

* jdk: use `Dir[]`

* Generate options dynamically

lib/selector.rb

@@ -0,0 +1,93 @@
+# selector.rb: Prompt user to choose an option in a list of options
+# See packages/hunspell.rb for example usage
+require_relative 'color'
+
+class Selector
+  @@default_prompt = {
+      heading: 'There are %{total_opts} provider(s) for this package: ',
+    countdown: 'Default selected in %%2.2i second(s). Enter your choice [1 = %{default}]: '
+  }
+
+  def initialize(options, prompt = @@default_prompt, timeout = 10)
+    @options = options
+    @timeout = timeout
+
+    # substitute expressions in the message ("%{variable}")
+    @prompt = prompt.transform_values {|p| format(p, { total_opts: @options.size, default: @options[0][:value] }) }
+  end
+
+  def show_prompt
+    # show_prompt(): Show prompt based on given options
+    warn "#{@prompt[:heading]}\n\n"
+
+    @options.each_with_index do |opt, i|
+      $stderr.print "  #{i + 1}: #{opt[:value]}"
+      $stderr.print " (#{opt[:description]})" if opt[:description]
+      $stderr.print "\n"
+    end
+
+    warn "\n"
+
+    # only show prompt when crew is running in an interactive terminal
+    if $stdin.isatty
+      begin
+        fire_timer { Thread.kill(@io_read) }
+        start_reading
+
+        @io_read.join
+      ensure
+        Thread.kill(@countdown)
+      end
+    end
+
+    if @io_read.nil? || @io_read[:input].to_s.chomp.empty?
+      # empty input or timeout
+      warn "Selected \"#{@options[0][:value]}\" by default.".yellow
+      choice = 1
+    elsif Integer(@io_read[:input], exception: false)&.between?(1, @options.size)
+      # when input is valid (is an integer and in range)
+      choice = @io_read[:input].to_i
+    else
+      # invalid input
+      warn <<~EOT.yellow
+        I don't understand "#{@io_read[:input]}". :(
+
+        Selected "#{@options[0][:value]}" by default.
+      EOT
+      choice = 1
+    end
+
+    # return result
+    return @options[choice - 1][:value]
+  end
+
+  private
+
+  def fire_timer(&when_timeout)
+    # fire_timer(): start a timer in separate thread
+    @countdown = Thread.new do
+      @timeout.downto(0).each do |remaining_time|
+        # print current countdown
+        $stderr.print "\r#{format(@prompt[:countdown], remaining_time)}"
+
+        if remaining_time.zero?
+          warn "\nTime expired.\n".yellow
+          when_timeout.call
+        else
+          sleep 1
+        end
+      end
+    end
+  end
+
+  def start_reading
+    # start_reading(): read from terminal in separate thread
+    @io_read = Thread.new do
+      # discard any input in the input buffer
+      $stdin.read_nonblock(1024)
+    rescue IO::WaitReadable
+    ensure
+      Thread.current[:input] = $stdin.getc
+    end
+  end
+end