#!/usr/bin/env ruby
# detective
# Tests by asking the user questions
#
# NOTE: requires ruby 1.9.2 and the rainbow gem.
#
# Usage:
#   detective [list of ruby test files]
#
# Syntax:
#   describe "A test" do
#     instruct "Go to google"
#     ask("What is written on the first button?").expect("Google Search")
#   end
#
#
require 'fiber'
require 'rainbow'

module Detective
  # Ask question. e.g.
  #   ask "Where were you last night?"
  def ask(question)
    @last_question = question
    @last_result = Fiber.yield [:ask, question]
    return self
  end

  # Instruct the user. e.g.
  #    instruct "You have the right to remain silent"
  def instruct(question)
    Fiber.yield [:instruct, question]
    return self
  end

  # Expect a result from the last question. e.g.
  #    ask("When did you last see M. Ratchett alive?").expect("last evening")
  def expect(result)
    if (@last_result||'').strip != result.to_s.downcase
      Fiber.yield [:fail, @last_question, @last_result, result]
    end
  end

  # Describe a test. e.g.
  #    describe("The suspect") { ask("How many fingers am i holding up?").expect(1) }
  def describe test, &block
    Fiber.yield [:describe, test]
    yield
    Fiber.yield [:describe_end, test]
  end

  alias_method :it, :describe
end

def run_suite(files)
  fib = Fiber.new do
    include Detective
    files.each { |f| require f }
  end

  total_test = 0
  total_pass = 0
  test_results = []

  begin
    result = nil
    describe_stack = []
    while (command = fib.resume(result)) and !command.nil? and command != :end
      result = nil
      case command[0]
      when :instruct
        if describe_stack[-1][1]
          puts "#{command[1]} [press RETURN to continue]"
          result = STDIN.readline
        end
      when :ask
        if describe_stack[-1][1]
          puts "#{command[1]}: "
          result = STDIN.readline.downcase
        end
      when :describe
        describe_stack << [command[1], true]
        puts "\n#{describe_stack.map{|d|d[0]}.join(' ')}.\n"
        total_test += 1
      when :describe_end
        test_results << ["#{describe_stack.map{|d|d[0]}.join(' ')}.", describe_stack[-1][1]]
        total_pass += 1 if describe_stack.pop[1]
      when :fail
        describe_stack[-1][1] = false
      end
    end
  rescue FiberError
  rescue Exception => e
    puts e.inspect
    puts e.backtrace
  end

  puts "\n"
  test_results.reverse.each do |test|
    puts test[0].color(test[1] ? :green : :red)
  end
  puts "\n#{total_pass} / #{total_test} Tests passed".color(total_pass == total_test ? :green : :red)

  exit total_pass == total_test ? 0 : 1
end

run_suite(ARGV)