# Copyright (c) 2013-2015 SUSE LLC
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of version 3 of the GNU General Public License as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.   See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, contact SUSE LLC.
#
# To contact SUSE about this file by physical or electronic mail,
# you may find current contact information at www.suse.com

class LocalSystem < System
  @@os = nil

  class << self
    def os
      if !@@os
        description = SystemDescription.new("localhost", SystemDescriptionMemoryStore.new)
        inspector = OsInspector.new(System.for("localhost"), description)
        inspector.inspect(nil)
        @@os = description.os
      end
      @@os
    end

    def validate_existence_of_package(package)
      validate_existence_of_packages([package])
    end

    def validate_existence_of_packages(packages)
      missing_packages = []
      needed_modules = []

      packages.each do |package|
        begin
          Cheetah.run("rpm", "-q", package)
        rescue Cheetah::ExecutionFailed
          missing_packages << package
          needed_module = os.module_required_by_package(package)
          if needed_module
            needed_modules << package
            if needed_module
              output = <<-EOF
You need the package '#{package}' from module '#{needed_module}'. You can install it as follows:
If you haven't selected the module '#{needed_module}' before, run `yast2 scc` and choose 'Select Extensions' and activate '#{needed_module}'.
Run `zypper install #{package}` to install the package.
              EOF
              raise(Machinery::Errors::MissingRequirement.new(output))
            end
          end
        end
      end

      if !missing_packages.empty?
        count = missing_packages.count
        error_string = <<-EOF
You need the #{Machinery::pluralize(count, "package")} '#{missing_packages.join("\',\'")}'.
You can install it by running `zypper install #{missing_packages.join(" ")}`.
        EOF
        raise(Machinery::Errors::MissingRequirement.new(error_string))
      end
    end

    def validate_machinery_compatibility
      return if !Machinery::Config.new.perform_support_check || os.can_run_machinery?

      supported_oses = Os.supported_host_systems.map { |o| o.canonical_name }.sort.join(", ")
      message = <<EOF
You are running Machinery on a platform we do not explicitly support and test.
It still could work very well. If you run into issues or would like to provide us feedback, you are welcome to file an issue at https://github.com/SUSE/machinery/issues/new or write an email to machinery@lists.suse.com.
Oficially supported operating systems are: '#{supported_oses}'

To disable this message in the machinery configuration use 'machinery config perform-support-check=false'
EOF

      Machinery::Ui.warn message
    end

    def validate_build_compatibility(system_description)
      if !os.can_build?(system_description.os)
        message = "Building '#{system_description.os.display_name}' is " \
          "not supported on this distribution.\n" \
          "Check the 'BUILD SUPPORT MATRIX' by running `#{$0} build --help` for " \
          "further information which build targets are supported."

        raise(Machinery::Errors::BuildFailed.new(message))
      end
    end

    def validate_architecture(arch)
      if os.architecture != arch
        raise(Machinery::Errors::UnsupportedArchitecture.new(
          "This operation is not supported on architecture '#{os.architecture}'."
        ))
      end
    end
  end

  def requires_root?
    true
  end

  def run_command(*args)
    if args.last.is_a?(Hash) && args.last[:disable_logging]
      cheetah_class = Cheetah
    else
      cheetah_class = LoggedCheetah
    end
    with_c_locale do
      cheetah_class.run(*args)
    end
  end

  # Retrieves files specified in filelist from the local system and raises an
  # Machinery::Errors::RsyncFailed exception when it's not successful. Destination is
  # the directory where to put the files.
  def retrieve_files(filelist, destination)
    begin
      LoggedCheetah.run(
        "rsync",
        "--chmod=go-rwx",
        "--files-from=-",
        "/",
        destination,
        stdout: :capture,
        stdin: filelist.join("\n")
        )
    rescue Cheetah::ExecutionFailed => e
      raise Machinery::Errors::RsyncFailed.new(
      "Could not rsync files from localhost. \n" \
      "Error: #{e}\n" \
      "If you lack read permissions on some files you may want to retry as user root or specify\n" \
      "the fully qualified host name instead of localhost in order to connect as root via ssh."
    )
    end
  end

  # Reads a file from the System. Returns nil if it does not exist.
  def read_file(file)
    File.read(file)
  rescue Errno::ENOENT
    # File not found, return nil
    return
  end
end