class Hbc::CLI::Doctor < Hbc::CLI::Base
  def self.run
    ohai "macOS Release:", render_with_none_as_error(MacOS.release)
    ohai "macOS Release with Patchlevel:", render_with_none_as_error(MacOS.release_with_patchlevel)
    ohai "Hardware Architecture:", render_with_none_as_error("#{Hardware::CPU.type}-#{Hardware::CPU.bits}")
    ohai "Ruby Version:", render_with_none_as_error("#{RUBY_VERSION}-p#{RUBY_PATCHLEVEL}")
    ohai "Ruby Path:", render_with_none_as_error(RbConfig.ruby)
    # TODO: consider removing most Homebrew constants from doctor output
    ohai "Homebrew Version:", render_with_none_as_error(homebrew_version)
    ohai "Homebrew Executable Path:", render_with_none_as_error(Hbc.homebrew_executable)
    ohai "Homebrew Cellar Path:", render_with_none_as_error(homebrew_cellar)
    ohai "Homebrew Repository Path:", render_with_none_as_error(homebrew_repository)
    ohai "Homebrew Origin:", render_with_none_as_error(homebrew_origin)
    ohai "Homebrew-cask Version:", render_with_none_as_error(Hbc.full_version)
    ohai "Homebrew-cask Install Location:", render_install_location
    ohai "Homebrew-cask Staging Location:", render_staging_location(Hbc.caskroom)
    ohai "Homebrew-cask Cached Downloads:", render_cached_downloads
    ohai "Homebrew-cask Default Tap Path:", render_tap_paths(fq_default_tap)
    ohai "Homebrew-cask Alternate Cask Taps:", render_tap_paths(alt_taps)
    ohai "Homebrew-cask Default Tap Cask Count:", render_with_none_as_error(default_cask_count)
    ohai "Contents of $LOAD_PATH:", render_load_path($LOAD_PATH)
    ohai "Contents of $RUBYLIB Environment Variable:", render_env_var("RUBYLIB")
    ohai "Contents of $RUBYOPT Environment Variable:", render_env_var("RUBYOPT")
    ohai "Contents of $RUBYPATH Environment Variable:", render_env_var("RUBYPATH")
    ohai "Contents of $RBENV_VERSION Environment Variable:", render_env_var("RBENV_VERSION")
    ohai "Contents of $CHRUBY_VERSION Environment Variable:", render_env_var("CHRUBY_VERSION")
    ohai "Contents of $GEM_HOME Environment Variable:", render_env_var("GEM_HOME")
    ohai "Contents of $GEM_PATH Environment Variable:", render_env_var("GEM_PATH")
    ohai "Contents of $BUNDLE_PATH Environment Variable:", render_env_var("BUNDLE_PATH")
    ohai "Contents of $PATH Environment Variable:", render_env_var("PATH")
    ohai "Contents of $SHELL Environment Variable:", render_env_var("SHELL")
    ohai "Contents of Locale Environment Variables:", render_with_none(locale_variables)
    ohai "Running As Privileged User:", render_with_none_as_error(privileged_uid)
  end

  def self.fq_default_tap
    return @fq_default_tap if @fq_default_tap
    @fq_default_tap = homebrew_repository.join "Library", "Taps", Hbc.default_tap
  rescue StandardError
    @fq_default_tap = notfound_string
  end

  def self.alt_taps
    alt_taps = Pathname.glob(homebrew_repository
                       .join("Library", "Taps", "*", "*", "Casks"))
                       .map(&:dirname) - [fq_default_tap]
    nil if alt_taps.empty?
  rescue StandardError
    notfound_string
  end

  def self.default_cask_count
    default_cask_count = notfound_string
    begin
      default_cask_count = homebrew_repository.join(fq_default_tap, "Casks").children.count(&:file?)
    rescue StandardError
      default_cask_count = "0 #{error_string "Error reading #{fq_default_tap}"}"
    end
    default_cask_count
  end

  def self.homebrew_origin
    homebrew_origin = notfound_string
    begin
      Dir.chdir(homebrew_repository) do
        homebrew_origin = Hbc::SystemCommand.run("/usr/bin/git",
                                                 args:         %w[config --get remote.origin.url],
                                                 print_stderr: false).stdout.strip
      end
      if homebrew_origin !~ %r{\S}
        homebrew_origin = "#{none_string} #{error_string}"
      elsif homebrew_origin !~ %r{(mxcl|Homebrew)/(home)?brew(\.git)?\Z}
        homebrew_origin.concat " #{error_string 'warning: nonstandard origin'}"
      end
    rescue StandardError
      homebrew_origin = error_string "Not Found - Error running git"
    end
    homebrew_origin
  end

  def self.homebrew_repository
    homebrew_constants("repository")
  end

  def self.homebrew_cellar
    homebrew_constants("cellar")
  end

  def self.homebrew_version
    homebrew_constants("version")
  end

  def self.homebrew_taps
    @homebrew_taps ||= if homebrew_repository.respond_to?(:join)
                         homebrew_repository.join("Library", "Taps")
                       end
  end

  def self.homebrew_constants(name)
    @homebrew_constants ||= {}
    return @homebrew_constants[name] if @homebrew_constants.key?(name)
    @homebrew_constants[name] = notfound_string
    begin
      @homebrew_constants[name] = Hbc::SystemCommand.run!(Hbc.homebrew_executable,
                                                          args:         ["--#{name}"],
                                                          print_stderr: false)
                                                    .stdout
                                                    .strip
      if @homebrew_constants[name] !~ %r{\S}
        @homebrew_constants[name] = "#{none_string} #{error_string}"
      end
      path = Pathname.new(@homebrew_constants[name])
      @homebrew_constants[name] = path if path.exist?
    rescue StandardError
      @homebrew_constants[name] = error_string "Not Found - Error running brew"
    end
    @homebrew_constants[name]
  end

  def self.locale_variables
    ENV.keys.grep(%r{^(?:LC_\S+|LANG|LANGUAGE)\Z}).collect { |v| %Q{#{v}="#{ENV[v]}"} }.sort.join("\n")
  end

  def self.privileged_uid
    Process.euid == 0 ? "Yes #{error_string 'warning: not recommended'}" : "No"
  rescue StandardError
    notfound_string
  end

  def self.none_string
    "<NONE>"
  end

  def self.legacy_tap_pattern
    %r{phinze}
  end

  def self.notfound_string
    "#{Hbc::Utils::Tty.red.underline}Not Found - Unknown Error#{Hbc::Utils::Tty.reset}"
  end

  def self.error_string(string = "Error")
    "#{Hbc::Utils::Tty.red.underline}(#{string})#{Hbc::Utils::Tty.reset}"
  end

  def self.render_with_none(string)
    return string if !string.nil? && string.respond_to?(:to_s) && !string.to_s.empty?
    none_string
  end

  def self.render_with_none_as_error(string)
    return string if !string.nil? && string.respond_to?(:to_s) && !string.to_s.empty?
    "#{none_string} #{error_string}"
  end

  def self.render_tap_paths(paths)
    paths = [paths] unless paths.respond_to?(:each)
    paths.collect do |dir|
      if dir.nil? || dir.to_s.empty?
        none_string
      elsif dir.to_s.match(legacy_tap_pattern)
        dir.to_s.concat(" #{error_string 'Warning: legacy tap path'}")
      else
        dir.to_s
      end
    end
  end

  def self.render_env_var(var)
    if ENV.key?(var)
      %Q{#{var}="#{ENV[var]}"}
    else
      none_string
    end
  end

  # This could be done by calling into Homebrew, but the situation
  # where "doctor" is needed is precisely the situation where such
  # things are less dependable.
  def self.render_install_location
    locations = Dir.glob(homebrew_cellar.join("brew-cask", "*")).reverse
    if locations.empty?
      none_string
    else
      locations.collect do |l|
        "#{l} #{error_string 'error: legacy install. Run "brew uninstall --force brew-cask".'}"
      end
    end
  end

  def self.render_staging_location(path)
    path = Pathname.new(path)
    if !path.exist?
      "#{path} #{error_string 'error: path does not exist'}}"
    elsif !path.writable?
      "#{path} #{error_string 'error: not writable by current user'}"
    else
      path
    end
  end

  def self.render_load_path(paths)
    return "#{none_string} #{error_string}" if paths.nil? || paths.empty?
    copy = Array.new(paths)
    unless Hbc::Utils.file_is_descendant(copy[0], homebrew_taps)
      copy[0] = "#{copy[0]} #{error_string 'error: should be descendant of Homebrew taps directory'}"
    end
    copy
  end

  def self.render_cached_downloads
    cleanup = Hbc::CLI::Cleanup.default
    files = cleanup.all_cache_files
    count = files.size
    size = cleanup.disk_cleanup_size
    size_msg = "#{number_readable(count)} files, #{disk_usage_readable(size)}"
    warn_msg = error_string('warning: run "brew cask cleanup"')
    size_msg << " #{warn_msg}" if count > 0
    [HOMEBREW_CACHE, HOMEBREW_CACHE_CASKS, size_msg]
  end

  def self.help
    "checks for configuration issues"
  end
end
