#!/usr/bin/env ruby


# This script is used to generate test applications for testing with various
# versions of Rails.
#
# Refer to spec/applications/README for a full understanding of test
# applications.


require 'fileutils'
require 'rake' # in order to get the nice sh method, which allows system
               # command output to be streamed in real time
include FileUtils

#*******************************************************************************
#  CHECK ARGUMENTS

if ARGV.size != 2
  puts "Usage: create_test_app [app name] [Rails version]"
  puts "  both arguments are required"
  puts "  app name: the name of an application living in spec/applications"
  puts "  Rails version: the gem version, such as 3.1.11 or 4.0.0.beta"
  puts
  puts "  Read spec/applications/README for a full understanding of test apps."
  exit
end

app_name = ARGV[0]
rails_version = ARGV[1]

installed_rails_versions = %x{ gem list rails }
if installed_rails_versions =~ /rails\s\((.+)\)/
  versions = $1.split(',').map(&:strip)
  if !versions.include?(rails_version)
    abort "Rails version '#{rails_version}' is not installed. First install this version of Rails before continuing."
  end
else
  abort "Rails is not installed. First install the version of Rails you wish to use."
end

test_app_dir = File.expand_path('../../spec/applications', __FILE__)
test_app_dirs = Dir[test_app_dir+'/*'].select{|f| File.directory?(f)}
test_app_names = test_app_dirs.map{|x| x.split('/').last}.select{|f| f != 'universal'}
if !test_app_names.include?(app_name)
  abort "Could not find test app named '#{app_name}' in spec/applications. Read spec/applications/README for a full understanding of test apps."
end

#*******************************************************************************
#  INVOKE RAILS TEMPLATE

app_dir = File.expand_path("../../spec/applications/#{app_name}/" + 'rails_' + rails_version.gsub('.', '-'), __FILE__)
if File.exists?(app_dir)
  FileUtils.remove_dir(app_dir, true)
end

app_template_path = File.expand_path("../../spec/applications/#{app_name}/application_template.rb", __FILE__)

app_generation_command = "TEST_APP_RAILS_VERSION='#{rails_version}' rails _#{rails_version}_ new #{app_dir} -m #{app_template_path} --old-style-hash"
puts "Generating a new rails app:"
puts

rails_executable_version = %x{ rails _#{rails_version}_ -v }
if rails_executable_version !~ %r{#{rails_version}}
  puts "Accessing the executable for rails version #{rails_version} failed."
  puts "  The rails gem with version #{rails_version} appears to be installed."
  puts "  However, running 'rails _#{rails_version}_ -v' did not produce the right version of Rails."
  puts
  puts "  Refer to spec/applications/README for a better understanding of this issue."
  abort
end

sh "#{app_generation_command}"