# 
# parse_dependencies_for
# 
def parse_project_gemfile
  required_gems = []    
  gem_file = "#{project_dir}/lib/#{project[:name]}/gems.rb"
  if File.exist? gem_file
    # puts "Parsing gemfile #{gem_file}"
    
    code = File.open(gem_file){|f| f.read}
    
    stub_class = Class.new
    stub_class.send(:define_method, :gem){|*args| required_gems << args}
    stub = stub_class.new      
    stub.instance_eval code, __FILE__, __LINE__
  end
  required_gems
end


# 
# Install gems
# 
namespace :gem do
  desc "Install gem required by project"
  task :install do
    gems = parse_project_gemfile    
    gems.each do |name, version|
      puts "Installing gem #{name} #{version}"
      %x(gem install #{name} #{"-v #{version}" if version})
    end
  end
end


# 
# Gem Spec, for sample look at Rakefile
# 
require 'rake/clean'
require 'rake/gempackagetask'
require 'tmpdir'

namespace :gem do
  spec = Gem::Specification.new do |s|
    gems = parse_project_gemfile
    gems.each{|name_version| s.add_dependency *name_version}

    options = project.clone

    options.delete(:name)
    s.name = options.delete(:gem_name)
    s.platform = options.delete(:platform) || Gem::Platform::RUBY
    s.has_rdoc = options.delete(:has_rdoc) == nil ? false : true
    s.require_path = options.delete(:lib) || "lib"
    s.files = options.delete(:files) || (%w{Rakefile readme.md} + Dir.glob("{lib,spec}/**/*"))

    # s.name = options[:name)
    # s.author = options[:author)
    # s.homepage = options[:homepage)

    options.each{|k, v| s.send "#{k}=", v}    
  end

  package_dir = Dir.tmpdir + "/#{project[:gem_name]}_tmp"
  Rake::GemPackageTask.new(spec) do |p|
    p.need_tar = true if RUBY_PLATFORM !~ /mswin/
    p.need_zip = true
    p.package_dir = package_dir
  end

  task :push do
    gem_file = Dir.glob("#{package_dir}/#{project[:gem_name]}*.gem").first
    system "gem push #{gem_file}"
  end

  task :clean do
    system "rm -r #{package_dir}"
  end
  
  desc "List all gems required by project"
  task :list do
    puts "Gems required for #{project[:gem_name]}:"
    puts parse_project_gemfile
  end
    
  desc "Build and publish project as gem"
  task :release => [:gem, :push, :clean]
end