module VimGolf

  GOLFDEBUG    = ENV['GOLFDEBUG'].to_sym rescue false
  GOLFHOST     = ENV['GOLFHOST']     || "http://www.vimgolf.com"
  GOLFDIFF     = ENV['GOLFDIFF']     || 'diff'
  GOLFSHOWDIFF = ENV['GOLFSHOWDIFF'] || 'vim -d -n'
  GOLFVIM      = ENV['GOLFVIM']      || 'vim'
  PROXY        = ENV['http_proxy']   || ''

  class Error
  end

  class RetryException < Exception; end

  class UI
    def debug(*); end
  end

  class << self
    attr_accessor :ui

    def ui
      @ui ||= UI.new
    end
  end

  class CLI < Thor
    include Thor::Actions

    def self.start(*)
      Thor::Base.shell = VimGolf::CLI::UI
      VimGolf.ui = VimGolf::CLI::UI.new
      super
    end

    desc "setup", "configure your VimGolf credentials"
    long_desc <<-DESC
    To participate in the challenge please go to vimgolf.com and register an
    account. Once signed in, you will get your API key, which you need to
    setup the command client.

      If you have the key, simply run the setup and paste in your key.
      DESC

    def setup
      key = VimGolf.ui.ask "Please specify your VimGolf API key (register on vimgolf.com to get it):"

      if key =~ /[\w\d]{32}/
        FileUtils.mkdir_p Config.path
        FileUtils.mkdir_p Config.put_path
        Config.save({'key' => key})

        VimGolf.ui.info "Saved. Happy golfing!"
      else
        VimGolf.ui.error "Invalid key, please double check your key on vimgolf.com"
      end
    end

    desc "put [ID]", "launch Vim session"
    long_desc <<-DESC
    Launch a VimGolf session for the specified challenge ID. To find a currently
    active challenge ID, please visit vimgolf.com!
    DESC

    def put(id = nil)
      VimGolf.ui.warn "Downloading Vimgolf challenge: #{id}"
      VimGolf::Challenge.path(Config.put_path)
      challenge = Challenge.new(id)
      challenge.download

      begin
        VimGolf.ui.warn "Launching VimGolf session for challenge: #{id}"
        # - n - no swap file, memory only editing
        # - +0 - always start on line 0
        # - --noplugin - don't load any plugins, lets be fair!
        # -i NONE - don't load .viminfo (for saved macros and the like)
        # - u - load vimgolf .vimrc to level the playing field
        vimcmd = "#{GOLFVIM} -Z -n --noplugin -i NONE +0 -u \"#{challenge.vimrc_path}\" -W \"#{challenge.log_path}\" \"#{challenge.work_path}\""
        debug(vimcmd)
        system(vimcmd)

        if $?.exitstatus.zero?
          diff_files = "\"#{challenge.work_path}\" \"#{challenge.output_path}\""
          diff = `#{GOLFDIFF} #{diff_files}`
          log = Keylog.new(IO.read(challenge.log_path))

          # Handle incorrect solutions
          if diff.size > 0
            VimGolf.ui.error "\nUh oh, looks like your entry does not match the desired output."
            VimGolf.ui.error "Your score for this failed attempt was: #{log.score}"

            loop do
              VimGolf.ui.warn "[d] Show diff"
              VimGolf.ui.warn "[r] Retry the current challenge"
              VimGolf.ui.warn "[q] Quit vimgolf"

              case VimGolf.ui.ask_question "Choice> ",
                                  :type      => :warn,
                                  :choices   => [:diff, :retry, :quit]
              when :diff
                VimGolf.ui.warn "Showing vimdiff of your attempt (left) and correct output (right)"
                system("#{GOLFSHOWDIFF} #{diff_files}")
              when :retry
                VimGolf.ui.warn "Retrying current challenge..."
                challenge.start
                raise RetryException
              when :quit
                raise Interrupt
              end
            end
          end

          # Handle correct solutions
          VimGolf.ui.info "\nSuccess! Your output matches. Your score: #{log.score}"

          loop do
            VimGolf.ui.warn "[w] Upload result and retry the challenge"
            VimGolf.ui.warn "[x] Upload result and quit"
            VimGolf.ui.warn "[r] Do not upload result and retry the challenge"
            VimGolf.ui.warn "[q] Do not upload result and quit"

            case VimGolf.ui.ask_question "Choice> ",
                                :type    => :warn,
                                :choices => [:w, :x, :retry, :quit]
            when :w
              next unless upload?(challenge)
              challenge.start
              raise RetryException
            when :x
              next unless upload?(challenge)
              raise Interrupt
            when :retry
              challenge.start
              raise RetryException
            when :quit
              raise Interrupt
            end
          end

        else
          error = <<-MSG
	  Uh oh, Vim did not exit properly. 
	  Please ensure you can execute 'Vim' from the commandline.
	  If the problem persists, please report the error on github.com/igrigorik/vimgolf
          MSG

          VimGolf.ui.error error
        end

      rescue RetryException => e
        retry
      end

    rescue Interrupt
      VimGolf.ui.info "\nThanks for playing!"
    rescue RuntimeError, Exception => e
      VimGolf.ui.error "Uh oh, something went wrong! Error: #{e}"
      VimGolf.ui.error "If the error persists, please report it to github.com/igrigorik/vimgolf"
    end

    private

    def upload?(challenge)
      VimGolf.ui.warn "Uploading to VimGolf..."

      if challenge.upload == :ok
        VimGolf.ui.warn "Uploaded entry."
        VimGolf.ui.warn "View the leaderboard: #{GOLFHOST}/challenges/#{challenge.id}"
      else
        VimGolf.ui.error "Uh oh, upload failed. You're not cheating are you? :-)"
        nil
      end
    end

    def debug(msg)
      p [caller.first, msg] if GOLFDEBUG
    end
  end

end