require 'net/http'
require 'guard/jasmine/formatter'

module Guard
  class Jasmine

    # Provider of some shared utility methods.
    #
    module Util

      # Verifies if the Jasmine test runner is available.
      #
      # @param [String] url the location of the test runner
      # @return [Boolean] when the runner is available
      #
      def runner_available?(url)
        url = URI.parse(url)

        begin
          Net::HTTP.start(url.host, url.port) do |http|
            response = http.request(Net::HTTP::Head.new(url.path))

            if response.code.to_i == 200
              ::Guard::Jasmine::Formatter.info "Jasmine test runner is available at #{ url }"
            else
              ::Guard::Jasmine::Formatter.error "Jasmine test runner isn't available at #{ url } (#{ response.code })"
            end

            response.code.to_i == 200
          end

        rescue => e
          ::Guard::Jasmine::Formatter.error "Jasmine test runner isn't available at #{ url }: #{ e.message }"

          false
        end
      end

      # Verifies that the phantomjs bin is available and the
      # right version is installed.
      #
      # @param [String] bin the location of the phantomjs bin
      # @return [Boolean] when the runner is available
      #
      def phantomjs_bin_valid?(bin)
        if bin && !bin.empty?
          version = `#{ bin } --version`

          if version
            # Remove all but version, e.g. from '1.5 (development)'
            version = version.match(/(\d\.)*(\d)/)[0]

            if Gem::Version.new(version) < Gem::Version.new('1.3.0')
              ::Guard::Jasmine::Formatter.error "PhantomJS executable at #{ bin } must be at least version 1.3.0"
            else
              true
            end
          else
            ::Guard::Jasmine::Formatter.error "PhantomJS executable doesn't exist at #{ bin }"
          end
        else
          ::Guard::Jasmine::Formatter.error "PhantomJS executable couldn't be auto detected."
        end
      end

      # Cross-platform way of finding an executable in the $PATH.
      # http://stackoverflow.com/questions/2108727/which-in-ruby-checking-if-program-exists-in-path-from-ruby
      #
      # @example
      #   which('ruby') #=> /usr/bin/ruby
      #
      # @param cmd [String] the executable to find
      # @return [String, nil] the path to the executable
      #
      def which(cmd)
        exts = ENV['PATHEXT'] ? ENV['PATHEXT'].split(';') : ['']

        ENV['PATH'].split(File::PATH_SEPARATOR).each do |path|
          exts.each do |ext|
            exe = "#{ path }/#{ cmd }#{ ext }"
            return exe if File.executable?(exe)
          end
        end

        nil
      end

    end

  end
end