# File lib/fpm/package/cpan.rb, line 34
  def input(package)
    #if RUBY_VERSION =~ /^1\.8/
      #raise FPM::Package::InvalidArgument,
        #"Sorry, CPAN support requires ruby 1.9 or higher. You have "          #"#{RUBY_VERSION}. If this negatively impacts you, please let "          #"me know by filing an issue: "          #"https://github.com/jordansissel/fpm/issues"
    #end
    #require "ftw" # for http access
    require "net/http"
    require "json"

    if (attributes[:cpan_local_module?])
      moduledir = package
    else
      result = search(package)
      tarball = download(result, version)
      moduledir = unpack(tarball)
    end

    # Read package metadata (name, version, etc)
    if File.exist?(File.join(moduledir, "META.json"))
      metadata = JSON.parse(File.read(File.join(moduledir, ("META.json"))))
    elsif File.exist?(File.join(moduledir, ("META.yml")))
      require "yaml"
      metadata = YAML.load_file(File.join(moduledir, ("META.yml")))
    elsif File.exist?(File.join(moduledir, "MYMETA.json"))
      metadata = JSON.parse(File.read(File.join(moduledir, ("MYMETA.json"))))
    elsif File.exist?(File.join(moduledir, ("MYMETA.yml")))
      require "yaml"
      metadata = YAML.load_file(File.join(moduledir, ("MYMETA.yml")))
    else
      raise FPM::InvalidPackageConfiguration,
        "Could not find package metadata. Checked for META.json and META.yml"
    end
    self.version = metadata["version"]
    self.description = metadata["abstract"]

    self.license = case metadata["license"]
      when Array; metadata["license"].first
      when nil; "unknown"
      else; metadata["license"]
    end

    unless metadata["distribution"].nil?
      logger.info("Setting package name from 'distribution'",
                   :distribution => metadata["distribution"])
      self.name = fix_name(metadata["distribution"])
    else
      logger.info("Setting package name from 'name'",
                   :name => metadata["name"])
      self.name = fix_name(metadata["name"])
    end

    # author is not always set or it may be a string instead of an array
    self.vendor = case metadata["author"]
      when String; metadata["author"]
      when Array; metadata["author"].join(", ")
      else
        raise FPM::InvalidPackageConfiguration, "Unexpected CPAN 'author' field type: #{metadata["author"].class}. This is a bug."
    end if metadata.include?("author")

    self.url = metadata["resources"]["homepage"] rescue "unknown"

    # TODO(sissel): figure out if this perl module compiles anything
    # and set the architecture appropriately.
    self.architecture = "all"

    # Install any build/configure dependencies with cpanm.
    # We'll install to a temporary directory.
    logger.info("Installing any build or configure dependencies")

    if attributes[:cpan_sandbox_non_core?]
      cpanm_flags = ["-L", build_path("cpan"), moduledir]
    else
      cpanm_flags = ["-l", build_path("cpan"), moduledir]
    end

    # This flag causes cpanm to ONLY download dependencies, skipping the target
    # module itself.  This is fine, because the target module has already been
    # downloaded, and there's no need to download twice, test twice, etc.
    cpanm_flags += ["--installdeps"]
    cpanm_flags += ["-n"] if !attributes[:cpan_test?]
    cpanm_flags += ["--mirror", "#{attributes[:cpan_mirror]}"] if !attributes[:cpan_mirror].nil?
    cpanm_flags += ["--mirror-only"] if attributes[:cpan_mirror_only?] && !attributes[:cpan_mirror].nil?

    safesystem(attributes[:cpan_cpanm_bin], *cpanm_flags)

    if !attributes[:no_auto_depends?]
      unless metadata["requires"].nil?
        metadata["requires"].each do |dep_name, version|
          # Special case for representing perl core as a version.
          if dep_name == "perl"
            self.dependencies << "#{dep_name} >= #{version}"
            next
          end
          dep = search(dep_name)

          if dep.include?("distribution")
            name = fix_name(dep["distribution"])
          else
            name = fix_name(dep_name)
          end

          if version.to_s == "0"
            # Assume 'Foo = 0' means any version?
            self.dependencies << "#{name}"
          else
            # The 'version' string can be something complex like:
            #   ">= 0, != 1.0, != 1.2"
            if version.is_a?(String)
              version.split(/\s*,\s*/).each do |v|
                if v =~ /\s*[><=]/
                  self.dependencies << "#{name} #{v}"
                else
                  self.dependencies << "#{name} = #{v}"
                end
              end
            else
              self.dependencies << "#{name} >= #{version}"
            end
          end
        end
      end
    end #no_auto_depends

    ::Dir.chdir(moduledir) do
      # TODO(sissel): install build and config dependencies to resolve
      # build/configure requirements.
      # META.yml calls it 'configure_requires' and 'build_requires'
      # META.json calls it prereqs/build and prereqs/configure

      prefix = attributes[:prefix] || "/usr/local"
      # TODO(sissel): Set default INSTALL path?

      # Try Makefile.PL, Build.PL
      #
      if File.exist?("Build.PL")
        # Module::Build is in use here; different actions required.
        safesystem(attributes[:cpan_perl_bin],
                   "-Mlocal::lib=#{build_path("cpan")}",
                   "Build.PL")
        safesystem(attributes[:cpan_perl_bin],
                   "-Mlocal::lib=#{build_path("cpan")}",
                   "./Build")

        if attributes[:cpan_test?]
          safesystem(attributes[:cpan_perl_bin],
                   "-Mlocal::lib=#{build_path("cpan")}",
                   "./Build", "test")
        end
        if attributes[:cpan_perl_lib_path]
          perl_lib_path = attributes[:cpan_perl_lib_path]
          safesystem("./Build install --install_path lib=#{perl_lib_path} \
                     --destdir #{staging_path} --prefix #{prefix} --destdir #{staging_path}")
        else
           safesystem("./Build", "install",
                     "--prefix", prefix, "--destdir", staging_path,
                     # Empty install_base to avoid local::lib being used.
                     "--install_base", "")
        end
      elsif File.exist?("Makefile.PL")
        if attributes[:cpan_perl_lib_path]
          perl_lib_path = attributes[:cpan_perl_lib_path]
          safesystem(attributes[:cpan_perl_bin],
                     "-Mlocal::lib=#{build_path("cpan")}",
                     "Makefile.PL", "PREFIX=#{prefix}", "LIB=#{perl_lib_path}",
                     # Empty install_base to avoid local::lib being used.
                     "INSTALL_BASE=")
        else
          safesystem(attributes[:cpan_perl_bin],
                     "-Mlocal::lib=#{build_path("cpan")}",
                     "Makefile.PL", "PREFIX=#{prefix}",
                     # Empty install_base to avoid local::lib being used.
                     "INSTALL_BASE=")
        end
        if attributes[:cpan_test?]
          make = [ "env", "PERL5LIB=#{build_path("cpan/lib/perl5")}", "make" ]
        else
          make = [ "make" ]
        end
        safesystem(*make)
        safesystem(*(make + ["test"])) if attributes[:cpan_test?]
        safesystem(*(make + ["DESTDIR=#{staging_path}", "install"]))


      else
        raise FPM::InvalidPackageConfiguration,
          "I don't know how to build #{name}. No Makefile.PL nor " \
          "Build.PL found"
      end

      # Fix any files likely to cause conflicts that are duplicated
      # across packages.
      # https://github.com/jordansissel/fpm/issues/443
      # https://github.com/jordansissel/fpm/issues/510
      glob_prefix = attributes[:cpan_perl_lib_path] || prefix
      ::Dir.glob(File.join(staging_path, glob_prefix, "**/perllocal.pod")).each do |path|
        logger.debug("Removing useless file.",
                      :path => path.gsub(staging_path, ""))
        File.unlink(path)
      end
    end


    # TODO(sissel): figure out if this perl module compiles anything
    # and set the architecture appropriately.
    self.architecture = "all"

    # Find any shared objects in the staging directory to set architecture as
    # native if found; otherwise keep the 'all' default.
    Find.find(staging_path) do |path|
      if path =~ /\.so$/
        logger.info("Found shared library, setting architecture=native",
                     :path => path)
        self.architecture = "native"
      end
    end
  end