#!/usr/bin/env ruby

require 'optparse'
require 'ostruct'
require 'shellwords'
require 'tempfile'

RUBY_VERSIONS = %W[1.9.3 2.1.2]
RAILS_VERSIONS = %W[3.2 4.0 4.1]

o = OpenStruct.new
o.ruby_versions = RUBY_VERSIONS
o.rails_versions = RAILS_VERSIONS

OptionParser.new do |opts|
    opts.banner = "Usage: #{$0} [options]"

    opts.on("-n", "--dry-run", "Do a dry run without executing actions") do |v|
        o.dry_run = true
    end

    opts.on("--update", "Update gem dependencies") do |v|
        o.update = v
    end

    opts.on("--install", "Install gem dependencies") do |v|
        o.install = v
    end

    opts.on("--ruby version", String, "Choose which version(s) of ruby to run.  Default is: #{o.ruby_versions.join(' ')}") do |ruby|
        o.ruby_versions = ruby.split(' ')
    end

    opts.on("--rails version", String, "Choose which version(s) of rails to run.  Default is: #{o.rails_versions.join(' ')}") do |rails|
        o.rails_versions = rails.split(' ')
    end

    opts.on("--quick", "quick run ruby #{RUBY_VERSIONS.last} and rails #{RAILS_VERSIONS.last}") do
      o.ruby_versions  = [RUBY_VERSIONS.last]
      o.rails_versions = [RAILS_VERSIONS.last]
    end

    opts.on("--rspec", "run rspec rather than rake") do |v|
        o.rspec = v
    end

end.parse!


Combo = Struct.new(:ruby, :rails)

combos = o.ruby_versions.product(o.rails_versions).map{|product| Combo.new(*product)}.select {|combo|
    case
    when combo.rails >= "3.2" && combo.ruby <= "1.8.7" then false  # no longer happens, just keeping it as an example
    else true
    end
}

if system("which -s rvm")
    # using rvm
    def ruby_version_selector(ruby)
        "rvm #{ruby} do"
    end
else
    # using rbenv.
    #
    # because we're running within a ruby program that was launched by
    # rbenv, we already have various environment variables set up.  need
    # strip those out so that the forked shell can run a diifferent ruby
    # version than the one we're in now.
    ENV['PATH'] = ENV['PATH'].split(':').reject{|dir| dir =~ %r{/\.?rbenv/(?!shims)}}.join(':')
    ENV['GEM_PATH'] = ENV['GEM_PATH'].split(':').reject{|dir| dir =~ %r{/\.?rbenv}}.join(':') unless ENV['GEM_PATH'].nil?
    ENV['RBENV_DIR'] = nil
    ENV['RBENV_HOOK_PATH'] = nil

    def ruby_version_selector(ruby)
        @versions ||= `rbenv versions --bare`.split
        version = @versions.select{|v| v.start_with? ruby}.last || abort("no ruby version '#{ruby}' installed in rbenv")
        "RBENV_VERSION=#{version}"
    end
end

GEMFILES_DIR = File.expand_path('../gemfiles', __FILE__)
errs = []
combos.each_with_index do |combo, n|
    ruby = combo.ruby
    rails = combo.rails

    cmd = case
          when o.update
              "bundle update"
          when o.install
              "bundle install"
          when o.rspec
              "bundle exec rspec"
          else
              "bundle exec rake spec"
          end

    command = %Q{BUNDLE_GEMFILE="#{File.join(GEMFILES_DIR, "Gemfile.rails-#{rails}")}" #{ruby_version_selector(ruby)} #{cmd} #{Shellwords.join(ARGV)}}

    puts "\n\n*** ruby version #{ruby} - rails version #{rails}  [#{n+1} of #{combos.size}]\n\n#{command}"

        next if o.dry_run

    Tempfile.open('runspecs') do |file|
        system("(#{command}) 2>&1 | tee #{file.path}")
        file.rewind
        errs << "ruby #{ruby}, rails #{rails}" if file.readlines.grep(/(^Failed examples)|(rake aborted)/).any?
    end
end
puts errs.any? ?  "\n*** #{errs.size} failures:\n\t#{errs.join("\n\t")}" : "\n*** #{combos.size > 1 ? 'all versions' : 'spec'} succeeded ***" unless o.dry_run
exit !errs.any?