# Copyright (c) 2013-2016 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

module Machinery
  class PackagesInspector < Machinery::Inspector
    has_priority 20
    def initialize(system, description)
      @system = system
      @description = description
    end

    def inspect(_filter, _options = {})
      @system.check_requirement(["rpm", "dpkg"], "--version")

      if @system.has_command?("rpm")
        inspect_rpm
      elsif @system.has_command?("dpkg")
        @system.check_requirement("apt-cache", "--version")
        inspect_dpkg
      end

      @description
    end

    def summary
      "Found #{Machinery.pluralize(@description.packages.length, "%d package")}."
    end

    private

    def inspect_rpm
      packages = Machinery::Array.new
      rpm_data = @system.run_command(
        "rpm",
        "-qa",
        "--qf",
        "%{NAME}|%{VERSION}|%{RELEASE}|%{ARCH}|%{VENDOR}|%{SIGMD5}$",
        stdout: :capture
      )
      # gpg-pubkeys are no real packages but listed by rpm in the regular
      # package list
      rpm_data.scan(/(.*?)\|(.*?)\|(.*?)\|(.*?)\|(.*?)\|(.*?)\$/).reject do |name, *_attrs|
        name =~ /^gpg-pubkey$/
      end.each do |name, version, release, arch, vendor, checksum|
        packages << RpmPackage.new(
          name:     name,
          version:  version,
          release:  release,
          arch:     arch,
          vendor:   vendor,
          checksum: checksum
        )
      end

      @description.packages = PackagesScope.new(
        packages.sort_by(&:name),
        package_system: "rpm"
      )
    end

    def inspect_dpkg
      dpkg_data = @system.run_command(
        "dpkg", "-l", stdout: :capture
      )

      lines = dpkg_data.lines.reject { |line| !line.start_with?("ii ") }

      packages = lines.map do |line|
        name, version, arch = line.split[1..3]
        version_segments = version.split("-")
        release = version_segments.pop if version_segments.length > 1
        version = version_segments.join("-")

        Machinery::DpkgPackage.new(
          name: name,
          version: version,
          release: release,
          arch: arch
        )
      end
      packages.each_slice(100) do |packages_slice|
        apt_cache_output = run_apt_cache(packages_slice)

        apt_cache_elements = Hash[
          *apt_cache_output.split("\n\n").flat_map do |element|
            name = element[/Package: (.+)$/, 1]
            [name, element]
          end
        ]

        packages_slice.each do |package|
          name = package.name.sub(/:[^:]+$/, "")
          apt_cache_element = apt_cache_elements[name]
          if apt_cache_element
            package.arch = apt_cache_element[/Architecture: (\w+)\n/, 1]
            checksum = apt_cache_element[/MD5[Ss]um: (\w+)\n/, 1]
            vendor = apt_cache_element[/Origin: (\w+)\n/, 1]
          end
          package.checksum = checksum || ""
          package.vendor = vendor || ""
          package.release ||= ""
        end

        @description.packages = Machinery::PackagesScope.new(
          packages.sort_by(&:name),
          package_system: "dpkg"
        )
      end
    end

    def run_apt_cache(packages_slice)
      @system.run_command(
        "apt-cache",
        "show",
        *packages_slice.map { |p| "#{p.name}=#{[p.version, p.release].compact.join("-")}" },
        stdout: :capture
      )
    rescue Cheetah::ExecutionFailed => e
      # Older Debian systems do not support the version parameter for `apt-cache show`
      raise unless e.stderr.include?("E: No packages found")
      @system.run_command("apt-cache", "show", *packages_slice.map(&:name), stdout: :capture)
    end
  end
end