# 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 ServicesInspector < Inspector
  def inspect(system, description, options = {})
    if system.has_command?("systemctl")
      result = ServicesScope.new(
        init_system: "systemd",
        services: inspect_systemd_services(system)
      )
    else
      result = ServicesScope.new(
        init_system: "sysvinit",
        services: inspect_sysvinit_services(system)
      )
    end

    description.services = result
    @summary
  end

  private

  def inspect_systemd_services(system)
    output = system.run_command(
      "systemctl",
      "list-unit-files",
      "--type=service,socket",
      :stdout => :capture
    )

    # The first line contains a table header. The last two lines contain a
    # separator and a summary (e.g. "197 unit files listed"). We also filter
    # templates.
    lines = output.lines[1..-3].reject { |l| l =~ /@/ }
    services = lines.map do |line|
      name, state = line.split(/\s+/)

      Service.new(name: name, state: state)
    end

    @summary = "Found #{services.size} services."
    ServiceList.new(services.sort_by(&:name))
  end

  def inspect_sysvinit_services(system)
    # Red Hat's chkconfig behaves differently than SUSE's: It takes different
    # command line arguments and has a different output format. We determine
    # if it's Red Hat by calling 'chkconfig --version'. On SUSE it exits with
    # an error, on Red Hat it doesn't.
    #
    begin
      system.run_command("chkconfig", "--version")
      services = parse_redhat_chkconfig(system)
    rescue
      services = parse_suse_chkconfig(system)
    end

    @summary = "Found #{services.size} services."
    ServiceList.new(services.sort_by(&:name))
  end

  def parse_suse_chkconfig(system)
    system.check_requirement("chkconfig", "--help")
    output = system.run_command(
      "chkconfig",
      "--allservices",
      :stdout => :capture
    )

    services = output.lines.map do |line|
      name, state = line.split(/\s+/)
      Service.new(name: name, state: state)
    end
  end

  def parse_redhat_chkconfig(system)
    system.check_requirement("chkconfig", "--version")
    system.check_requirement("runlevel")
    _, runlevel = system.run_command(
      "runlevel",
      stdout: :capture
    ).split(" ")

    output = system.run_command(
      "chkconfig", "--list",
      stdout: :capture
    )

    services = output.lines.map do |line|
      state = []
      name, state[0], state[1], state[2], state[3], state[4], state[5], state[6] = line.split(/\s+/)
      Service.new(name: name, state: state[runlevel.to_i].split(":")[1])
    end
    services
  end
end