require "erb"
require "fileutils"

module GGem

  class Template

    def initialize(ggem)
      @gem = ggem
    end

    def save
      save_folder # (gem root path)
      save_folder ".circleci"
      save_folder "lib/#{@gem.ruby_name}"
      save_folder "test/support"
      save_folder "test/system"
      save_folder "test/unit"
      save_folder "log"
      save_folder "tmp"

      save_file("circleci_config.yml.erb", ".circleci/config.yml")

      save_file("gitignore.erb", ".gitignore")
      save_file("Gemfile.erb",   "Gemfile")
      save_file("gemspec.erb",   "#{@gem.name}.gemspec")
      save_file("README.md.erb", "README.md")
      save_file("LICENSE.erb",   "LICENSE")

      save_file("lib.rb.erb",         "lib/#{@gem.ruby_name}.rb")
      save_file("lib_version.rb.erb", "lib/#{@gem.ruby_name}/version.rb")

      save_file("test_helper.rb.erb",          "test/helper.rb")
      save_file("test_support_factory.rb.erb", "test/support/factory.rb")

      save_empty_file("log/.gitkeep")
      save_empty_file("test/system/.gitkeep")
      save_empty_file("test/unit/.gitkeep")
      save_empty_file("tmp/.gitkeep")
    end

    private

    def save_folder(relative_path=nil)
      path = File.join([@gem.path, relative_path].compact)
      FileUtils.mkdir_p(path)
    end

    def save_empty_file(relative_path)
      path = File.join(@gem.path, relative_path)
      FileUtils.touch(path)
    end

    def save_file(source, output)
      source_file = File.join(File.dirname(__FILE__), "template_file", source)
      output_file = File.join(@gem.root_path, @gem.name, output)

      if File.exists?(source_file)
        FileUtils.mkdir_p(File.dirname(output_file))
        erb = ERB.new(File.read(source_file))
        File.open(output_file, "w") {|f| f << erb.result(binding) }
      else
        raise ArgumentError, "the source file `#{source_file}` does not exist"
      end
    end

  end

end