require "ostruct"

require "guard/rspec"

module Guard
  class RSpec < Plugin
    class Dsl
      def initialize(dsl)
        @dsl = dsl
      end

      def watch_spec_files_for(expr)
        @dsl.send(:watch, expr) { |m| rspec.spec.call(m[1]) }
      end

      def self.detect_spec_file_for(rspec, file)
        # TODO: when spec not found ... run specs in topmost found path?
        # Or show warning?

        path = "#{rspec.spec_dir}/#{file}_spec.rb"
        return path unless file.start_with?("lib/")
        return path if Dir.exist?("#{rspec.spec_dir}/lib")

        without_lib = file.sub(%r{^lib/}, "")
        "#{rspec.spec_dir}/#{without_lib}_spec.rb"
      end

      def rspec
        @rspec ||= OpenStruct.new(to_s: "spec").tap do |rspec|
          rspec.spec_dir = "spec"
          rspec.spec = ->(m) { Dsl.detect_spec_file_for(rspec, m) }
          rspec.spec_helper = "#{rspec.spec_dir}/spec_helper.rb"
          rspec.spec_files = %r{^#{rspec.spec_dir}/.+_spec\.rb$}
          rspec.spec_support = %r{^#{rspec.spec_dir}/support/(.+)\.rb$}
        end
      end

      def ruby
        # Ruby apps
        @ruby ||= OpenStruct.new.tap do |ruby|
          ruby.lib_files = %r{^(lib/.+)\.rb$}
        end
      end

      def rails(options = {})
        # Rails example
        @rails ||= _build_rails_rules(_view_extensions(options) * "|")
      end

      private

      def _view_extensions(options)
        options.dup.delete(:view_extensions) || %w(erb haml slim)
      end

      def _build_rails_rules(exts)
        OpenStruct.new.tap do |rails|
          rails.app_files = %r{^app/(.+)\.rb$}

          rails.views = %r{^app/(views/.+/[^/]*\.(?:#{exts}))$}
          rails.view_dirs = %r{^app/views/(.+)/[^/]*\.(?:#{exts})$}
          rails.layouts = %r{^app/layouts/(.+)/[^/]*\.(?:#{exts})$}

          rails.controllers = %r{^app/controllers/(.+)_controller\.rb$}
          rails.routes = "config/routes.rb"
          rails.app_controller = "app/controllers/application_controller.rb"
          rails.spec_helper = "#{rspec.spec_dir}/rails_helper.rb"
        end
      end
    end
  end
end