se350-question-writer

#!/usr/bin/env ruby

require 'rubygems'
require 'json'
require 'erb'
require 'tmpdir'

# Check for official validator
def validator?; system('which question-validator > /dev/null 2>&1'); end
if !validator?
  $stderr.puts("WARNING: Did not detect 'official' validator installed on your system. This script " +
    "WILL work but, to be safe, you should probably install it from " +
    "https://github.com/jcpetkovich/App-QuestionValidator/.")
end

# First, we extract the input from stdin
$stderr.puts("Reading input...")
input = $stdin.read
questions = JSON.parse(input, :symbolize_names => true)

$stderr.puts("Validating input...")
raise 'Questions must be provided as a JSON array' unless questions.is_a?(Array)
$stderr.puts 'WARNING: You should submit 4 questions' unless questions.length == 4

# Turn each JSON question into a d2l question
outputs = []
questions.each_with_index do |question, index|
  # Validate all required question fields are present
  $stderr.puts("\nValidating question #{index}...")
  [:title, :question, :options].each do |field|
    raise "'#{field}' field must be non-null for questions" if question[field].nil?
  end

  # Validating all required option fields are present
  question[:options].each do |option|
    [:points, :answer].each do |field|
      raise "'#{field}' field must be non-null for options" if option[field].nil?
    end
  end

  # All questions must be multiple choice questions with four possible answers.
  raise "You must provide exactly 4 options for each question" unless question[:options].length == 4
  # Ensure all point values are integers between 0 and 100
  raise "All option 'point' values must be integers" unless question[:options].count {|o| !(0..100).include?(o[:points])} == 0
  # At most one answer must give full points.
  raise "Exactly one option must give 100 points" unless question[:options].count {|o| o[:points] == 100} == 1
  # At least two answers must give zero points.
  raise "At least two options must give 0 points" unless question[:options].count {|o| o[:points] == 0} >= 2
  # One question may give zero to fifty percent of the points.
  raise "At most one option may give 1 to 50 points" unless question[:options].count {|o| (1..50).include?(o[:points])} <= 1

  # This is the template required for the d2l import
  def escape(input); input.to_s.gsub('"', '\\"'); end
  template = ERB.new <<-eos
NewQuestion,MC,
Title,"<%=escape question[:title] %>",
QuestionText,"\n<%=escape question[:question] %>\n",
<% question[:options].each do |option| %><%#
  %>Option,<%= option[:points] %>,"<%=escape option[:answer] %>",,"<%=escape option[:feedback] %>"
<% end %><%#
%>Feedback,"<%=escape question[:feedback] %>",,,,
  eos

  # Generate output
  $stderr.puts("Generating output for question #{index}...")
  output = template.result(binding)

  # Run through the prof's question validator, if it is installed.
  if validator?
    $stderr.puts("Running question #{index} through official validator...")
    o = `echo "#{escape(output)}" | question-validator 2>&1`
    $stderr.print(o)
    throw "Question #{index} did not pass official validator" unless $? == 0 && o == ''
  end

  # Save out the d2l formatted question if everything worked!
  $stderr.puts("Question #{index} successfully generated!")
  outputs.push(output)
end

$stderr.puts("\nCreating tmp dir...")
Dir.mktmpdir("se350") do |tmpdir|
  dirname = 'questions'
  dir = File.join(tmpdir, dirname)
  Dir.mkdir(dir)

  # Write each d2l question into its own file
  outputs.each_with_index do |output, index|
    $stderr.puts("Writing question #{index} to disk...")
    File.open(File.join(dir, "#{index}.csv"), "w") do |file|
      file << output
    end
  end

  # Tar the tmpdir together
  $stderr.puts("Taring all files together...")
  $stdout.print `tar -C #{tmpdir} -cz #{dirname}`

  $stderr.puts("Done!")
end