module Homebrew
  module Diagnostic
    class Checks
      undef supported_configuration_checks, development_tools_checks,
            fatal_development_tools_checks, build_error_checks

      def supported_configuration_checks
        %w[
          check_build_from_source
          check_homebrew_prefix
          check_for_unsupported_macos
        ].freeze
      end

      def development_tools_checks
        %w[
          check_for_installed_developer_tools
          check_xcode_license_approved
          check_xcode_up_to_date
          check_clt_up_to_date
        ].freeze
      end

      def fatal_development_tools_checks
        %w[
          check_xcode_minimum_version
          check_clt_minimum_version
          check_if_xcode_needs_clt_installed
        ].freeze
      end

      def build_error_checks
        (development_tools_checks + %w[
          check_for_unsupported_macos
        ]).freeze
      end

      def check_for_non_prefixed_findutils
        findutils = Formula["findutils"]
        return unless findutils.any_version_installed?

        gnubin = %W[#{findutils.opt_libexec}/gnubin #{findutils.libexec}/gnubin]
        default_names = Tab.for_name("findutils").with? "default-names"
        return if !default_names && (paths & gnubin).empty?

        <<~EOS
          Putting non-prefixed findutils in your path can cause python builds to fail.
        EOS
      rescue FormulaUnavailableError
        nil
      end

      def check_for_unsupported_macos
        return if ARGV.homebrew_developer?

        who = "We"
        if OS::Mac.prerelease?
          what = "pre-release version"
        elsif OS::Mac.outdated_release?
          who << " (and Apple)"
          what = "old version"
        else
          return
        end

        <<~EOS
          You are using macOS #{MacOS.version}.
          #{who} do not provide support for this #{what}.
          #{please_create_pull_requests(what)}
        EOS
      end

      def check_xcode_up_to_date
        return unless MacOS::Xcode.outdated?

        # CI images are going to end up outdated so don't complain when
        # `brew test-bot` runs `brew doctor` in the CI for the Homebrew/brew
        # repository. This only needs to support whatever CI providers
        # Homebrew/brew is currently using.
        return if ENV["HOMEBREW_AZURE_PIPELINES"]

        message = <<~EOS
          Your Xcode (#{MacOS::Xcode.version}) is outdated.
          Please update to Xcode #{MacOS::Xcode.latest_version} (or delete it).
          #{MacOS::Xcode.update_instructions}
        EOS

        if OS::Mac.prerelease?
          current_path = Utils.popen_read("/usr/bin/xcode-select", "-p")
          message += <<~EOS
            If #{MacOS::Xcode.latest_version} is installed, you may need to:
              sudo xcode-select --switch /Applications/Xcode.app
            Current developer directory is:
              #{current_path}
          EOS
        end
        message
      end

      def check_clt_up_to_date
        return unless MacOS::CLT.outdated?

        # CI images are going to end up outdated so don't complain when
        # `brew test-bot` runs `brew doctor` in the CI for the Homebrew/brew
        # repository. This only needs to support whatever CI providers
        # Homebrew/brew is currently using.
        return if ENV["HOMEBREW_AZURE_PIPELINES"]

        <<~EOS
          A newer Command Line Tools release is available.
          #{MacOS::CLT.update_instructions}
        EOS
      end

      def check_xcode_minimum_version
        return unless MacOS::Xcode.below_minimum_version?
        xcode = MacOS::Xcode.version.to_s
        xcode += " => #{MacOS::Xcode.prefix}" unless MacOS::Xcode.default_prefix?

        <<~EOS
          Your Xcode (#{xcode}) is too outdated.
          Please update to Xcode #{MacOS::Xcode.latest_version} (or delete it).
          #{MacOS::Xcode.update_instructions}
        EOS
      end

      def check_clt_minimum_version
        return unless MacOS::CLT.below_minimum_version?

        <<~EOS
          Your Command Line Tools are too outdated.
          #{MacOS::CLT.update_instructions}
        EOS
      end

      def check_if_xcode_needs_clt_installed
        return unless MacOS::Xcode.needs_clt_installed?

        <<~EOS
          Xcode alone is not sufficient on #{MacOS.version.pretty_name}.
          #{DevelopmentTools.installation_instructions}
        EOS
      end

      def check_ruby_version
        ruby_version = "2.3.7"
        return if RUBY_VERSION == ruby_version
        return if ARGV.homebrew_developer? && OS::Mac.prerelease?

        <<~EOS
          Ruby version #{RUBY_VERSION} is unsupported on #{MacOS.version}. Homebrew
          is developed and tested on Ruby #{ruby_version}, and may not work correctly
          on other Rubies. Patches are accepted as long as they don't cause breakage
          on supported Rubies.
        EOS
      end

      def check_xcode_prefix
        prefix = MacOS::Xcode.prefix
        return if prefix.nil?
        return unless prefix.to_s.include?(" ")

        <<~EOS
          Xcode is installed to a directory with a space in the name.
          This will cause some formulae to fail to build.
        EOS
      end

      def check_xcode_prefix_exists
        prefix = MacOS::Xcode.prefix
        return if prefix.nil? || prefix.exist?

        <<~EOS
          The directory Xcode is reportedly installed to doesn't exist:
            #{prefix}
          You may need to `xcode-select` the proper path if you have moved Xcode.
        EOS
      end

      def check_xcode_select_path
        return if MacOS::CLT.installed?
        return unless MacOS::Xcode.installed?
        return if File.file?("#{MacOS.active_developer_dir}/usr/bin/xcodebuild")

        path = MacOS::Xcode.bundle_path
        path = "/Developer" if path.nil? || !path.directory?
        <<~EOS
          Your Xcode is configured with an invalid path.
          You should change it to the correct path:
            sudo xcode-select -switch #{path}
        EOS
      end

      def check_xcode_license_approved
        # If the user installs Xcode-only, they have to approve the
        # license or no "xc*" tool will work.
        return unless `/usr/bin/xcrun clang 2>&1` =~ /license/ && !$CHILD_STATUS.success?

        <<~EOS
          You have not agreed to the Xcode license.
          Builds will fail! Agree to the license by opening Xcode.app or running:
            sudo xcodebuild -license
        EOS
      end

      def check_xquartz_up_to_date
        return unless MacOS::XQuartz.outdated?

        <<~EOS
          Your XQuartz (#{MacOS::XQuartz.version}) is outdated.
          Please install XQuartz #{MacOS::XQuartz.latest_version} (or delete the current version).
          XQuartz can be updated using Homebrew Cask by running
            brew cask reinstall xquartz
        EOS
      end

      def check_filesystem_case_sensitive
        dirs_to_check = [
          HOMEBREW_PREFIX,
          HOMEBREW_REPOSITORY,
          HOMEBREW_CELLAR,
          HOMEBREW_TEMP,
        ]
        case_sensitive_dirs = dirs_to_check.select do |dir|
          # We select the dir as being case-sensitive if either the UPCASED or the
          # downcased variant is missing.
          # Of course, on a case-insensitive fs, both exist because the os reports so.
          # In the rare situation when the user has indeed a downcased and an upcased
          # dir (e.g. /TMP and /tmp) this check falsely thinks it is case-insensitive
          # but we don't care because: 1. there is more than one dir checked, 2. the
          # check is not vital and 3. we would have to touch files otherwise.
          upcased = Pathname.new(dir.to_s.upcase)
          downcased = Pathname.new(dir.to_s.downcase)
          dir.exist? && !(upcased.exist? && downcased.exist?)
        end
        return if case_sensitive_dirs.empty?

        volumes = Volumes.new
        case_sensitive_vols = case_sensitive_dirs.map do |case_sensitive_dir|
          volumes.get_mounts(case_sensitive_dir)
        end
        case_sensitive_vols.uniq!

        <<~EOS
          The filesystem on #{case_sensitive_vols.join(",")} appears to be case-sensitive.
          The default macOS filesystem is case-insensitive. Please report any apparent problems.
        EOS
      end

      def check_for_gettext
        find_relative_paths("lib/libgettextlib.dylib",
                            "lib/libintl.dylib",
                            "include/libintl.h")
        return if @found.empty?

        # Our gettext formula will be caught by check_linked_keg_only_brews
        gettext = begin
          Formulary.factory("gettext")
        rescue
          nil
        end

        if gettext&.linked_keg&.directory?
          homebrew_owned = @found.all? do |path|
            Pathname.new(path).realpath.to_s.start_with? "#{HOMEBREW_CELLAR}/gettext"
          end
          return if homebrew_owned
        end

        inject_file_list @found, <<~EOS
          gettext files detected at a system prefix.
          These files can cause compilation and link failures, especially if they
          are compiled with improper architectures. Consider removing these files:
        EOS
      end

      def check_for_iconv
        find_relative_paths("lib/libiconv.dylib", "include/iconv.h")
        return if @found.empty?

        libiconv = begin
          Formulary.factory("libiconv")
        rescue
          nil
        end
        if libiconv&.linked_keg&.directory?
          unless libiconv.keg_only?
            <<~EOS
              A libiconv formula is installed and linked.
              This will break stuff. For serious. Unlink it.
            EOS
          end
        else
          inject_file_list @found, <<~EOS
            libiconv files detected at a system prefix other than /usr.
            Homebrew doesn't provide a libiconv formula, and expects to link against
            the system version in /usr. libiconv in other prefixes can cause
            compile or link failure, especially if compiled with improper
            architectures. macOS itself never installs anything to /usr/local so
            it was either installed by a user or some other third party software.

            tl;dr: delete these files:
          EOS
        end
      end

      def check_for_multiple_volumes
        return unless HOMEBREW_CELLAR.exist?

        volumes = Volumes.new

        # Find the volumes for the TMP folder & HOMEBREW_CELLAR
        real_cellar = HOMEBREW_CELLAR.realpath
        where_cellar = volumes.which real_cellar

        begin
          tmp = Pathname.new(Dir.mktmpdir("doctor", HOMEBREW_TEMP))
          begin
            real_tmp = tmp.realpath.parent
            where_tmp = volumes.which real_tmp
          ensure
            Dir.delete tmp
          end
        rescue
          return
        end

        return if where_cellar == where_tmp

        <<~EOS
          Your Cellar and TEMP directories are on different volumes.
          macOS won't move relative symlinks across volumes unless the target file already
          exists. Brews known to be affected by this are Git and Narwhal.

          You should set the "HOMEBREW_TEMP" environmental variable to a suitable
          directory on the same volume as your Cellar.
        EOS
      end
    end
  end
end