require 'set'

# Data plus utilities surrounding platforms that the automation in this repo
# explicitly supports
module Pkg
  module Platforms

    module_function

    DEBIAN_SOURCE_FORMATS = ['debian.tar.gz', 'orig.tar.gz', 'dsc', 'changes']

    # Each element in this hash
    PLATFORM_INFO = {
      'aix' => {
        '6.1' => {
          architectures: ['power'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          repo: false,
        },
        '7.1' => {
          architectures: ['power'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          repo: false,
        },
      },

      'cisco-wrlinux' => {
        '5' => {
          architectures: ['x86_64'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        },
        '7' => {
          architectures: ['x86_64'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        },
      },

      'debian' => {
        '8' => {
          codename: 'jessie',
          architectures: ['amd64', 'i386', 'powerpc'],
          source_architecture: 'source',
          package_format: 'deb',
          source_package_formats: DEBIAN_SOURCE_FORMATS,
          repo: true,
        },
        '9' => {
          codename: 'stretch',
          architectures: ['amd64', 'i386'],
          source_architecture: 'source',
          package_format: 'deb',
          source_package_formats: DEBIAN_SOURCE_FORMATS,
          repo: true,
        },
        '10' => {
          codename: 'buster',
          architectures: ['amd64', 'i386'],
          source_architecture: 'source',
          package_format: 'deb',
          source_package_formats: DEBIAN_SOURCE_FORMATS,
          repo: true,
        },
      },

      'el' => {
        '5' => {
          architectures: ['x86_64', 'i386'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v3',
          repo: true,
        },
        '6' => {
          architectures: ['x86_64', 'i386'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        },
        '7' => {
          architectures: ['x86_64', 'ppc64le', 'aarch64'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        },
        '8' => {
          architectures: ['x86_64'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        }
      },

      'eos' => {
        '4' => {
          architectures: ['i386'],
          package_format: 'swix',
          repo: false,
        },
      },

      'fedora' => {
        '30' => {
          architectures: ['x86_64'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        },
        '31' => {
          architectures: ['x86_64'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        },
        '32' => {
          architectures: ['x86_64'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        },
      },

      'osx' => {
        '10.13' => {
          architectures: ['x86_64'],
          package_format: 'dmg',
          repo: false,
        },
        '10.14' => {
          architectures: ['x86_64'],
          package_format: 'dmg',
          repo: false,
        },
        '10.15' => {
          architectures: ['x86_64'],
          package_format: 'dmg',
          repo: false,
        },
      },

      'redhatfips' => {
        '7' => {
          architectures: ['x86_64'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v3',
          repo: true,
        }
      },

      'sles' => {
        '11' => {
          architectures: ['x86_64', 'i386'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v3',
          repo: true,
        },
        '12' => {
          architectures: ['x86_64', 'ppc64le'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        },
        '15' => {
          architectures: ['x86_64', 'ppc64le'],
          source_architecture: 'SRPMS',
          package_format: 'rpm',
          source_package_formats: ['src.rpm'],
          signature_format: 'v4',
          repo: true,
        },
      },

      'solaris' => {
        '10' => {
          architectures: ['i386', 'sparc'],
          package_format: 'svr4',
          repo: false,
        },
        '11' => {
          architectures: ['i386', 'sparc'],
          package_format: 'ips',
          repo: false,
        },
      },

      'ubuntu' => {
        '14.04' => {
          codename: 'trusty',
          architectures: ['amd64', 'i386'],
          source_architecture: 'source',
          package_format: 'deb',
          source_package_formats: DEBIAN_SOURCE_FORMATS,
          repo: true,
        },
        '16.04' => {
          codename: 'xenial',
          architectures: ['amd64', 'i386', 'ppc64el'],
          source_architecture: 'source',
          package_format: 'deb',
          source_package_formats: DEBIAN_SOURCE_FORMATS,
          repo: true,
        },
        '18.04' => {
          codename: 'bionic',
          architectures: ['amd64', 'ppc64el'],
          source_architecture: 'source',
          package_format: 'deb',
          source_package_formats: DEBIAN_SOURCE_FORMATS,
          repo: true,
        },
        '18.10' => {
          codename: 'cosmic',
          architectures: ['amd64', 'ppc64el'],
          source_architecture: 'source',
          package_format: 'deb',
          source_package_formats: DEBIAN_SOURCE_FORMATS,
          repo: true,
        },
        '20.04' => {
          codename: 'focal',
          architectures: ['amd64'],
          source_architecture: 'source',
          package_format: 'deb',
          source_package_formats: DEBIAN_SOURCE_FORMATS,
          repo: true,
        },
      },

      'windows' => {
        '2012' => {
          architectures: ['x86', 'x64'],
          package_format: 'msi',
          repo: false,
        }
      },
      'windowsfips' => {
        '2012' => {
          architectures: ['x64'],
          package_format: 'msi',
          repo: false,
        }
      },
    }.freeze

    # @return [Array] An array of Strings, containing all of the supported
    #   platforms as defined in PLATFORM_INFO
    def supported_platforms
      PLATFORM_INFO.keys
    end

    # @return [Array] An Array of Strings, containing all the supported
    #   versions for the given platform
    def versions_for_platform(platform)
      PLATFORM_INFO[platform].keys
    rescue
      raise "No information found for '#{platform}'"
    end

    # @param platform_tag [String] May be either the two or three unit string
    #   that corresponds to a platform in the form of platform-version or
    #   platform-version-arch.
    # @return [Array] An array of three elements: the platform name, the platform
    #   version, and the architecture. If the architecture was not included in
    #   the original platform tag, then nil is returned in place of the
    #   architecture
    def parse_platform_tag(platform_tag)
      platform_elements = platform_tag.split('-')

      # Look for platform. This is probably the only place where we have to look
      # for a combination of elements rather than a single element
      platform = (platform_elements & supported_platforms).first
      codename = (platform_elements & codenames).first

      # This is probably a bad assumption, but I'm assuming if we find a codename,
      # that's more reliable as it's less likely to give us a false match
      if codename
        platform, version = codename_to_platform_version(codename)
      end

      # There's a possibility that the platform name has a dash in it, in which
      # case, our assumption that it's an element of the above array is false,
      # since it would be a combination of elements in that array
      platform ||= supported_platforms.find { |p| platform_tag =~ /#{p}-/ }

      version ||= (platform_elements & versions_for_platform(platform)).first


      # For platform names with a dash in them, because everything is special
      supported_arches = arches_for_platform_version(platform, version, true)
      architecture = platform_tag.sub(/^(#{platform}-#{version}|#{codename})-?/, '')

      fail unless supported_arches.include?(architecture) || architecture.empty?

      # AIX uses 'ppc' as its architecture in paths and file names
      architecture = 'ppc' if platform == 'aix'
      return [platform, version, architecture]
    rescue
      raise "Could not verify that '#{platform_tag}' is a valid tag"
    end

    # @param platform_tag [String] May be either the two or three unit string
    #   that corresponds to a platform in the form of platform-version or
    #   platform-version-arch
    # @return [Hash] The hash of data associated with the given platform version
    def platform_lookup(platform_tag)
      platform, version, _ = parse_platform_tag(platform_tag)
      PLATFORM_INFO[platform][version]
    end

    # @param platform_tag [String] May be either the two or three unit string
    #   that corresponds to a platform in the form of platform-version or
    #   platform-version-arch
    # @param attribute_name [String, Symbol] The name of the requested attribute
    # @return [String, Array] the contents of the requested attribute
    def get_attribute(platform_tag, attribute_name)
      info = platform_lookup(platform_tag)
      raise "#{platform_tag} doesn't have information about #{attribute_name} available" unless info.key?(attribute_name)
      info[attribute_name]
    end

    def get_attribute_for_platform_version(platform, version, attribute_name)
      info = PLATFORM_INFO[platform][version]
      raise "#{platform_tag} doesn't have information about #{attribute_name} available" unless info.key?(attribute_name)
      info[attribute_name]
    end

    # @private List platforms that use a given package format
    # @param format [String] The name of the packaging format to filter on
    # @return [Array] An Array of Strings, containing all platforms that
    #   use <format> for their packages
    def by_package_format(format)
      PLATFORM_INFO.keys.select do |key|
        formats = PLATFORM_INFO[key].values.collect { |v| v[:package_format] }
        formats.include? format
      end
    end

    # @return [Array] An Array of Strings, containing all of the package
    #   formats defined in Pkg::Platforms
    def formats
      fmts = PLATFORM_INFO.flat_map do |_, p|
        p.collect do |_, r|
          r[:package_format]
        end
      end
      fmts.to_set.sort
    end

    # @return [Array] An Array of Strings, containing all the package formats
    #   and source package formats defined in Pkg::Platforms
    def all_supported_package_formats
      fmts = formats
      source_fmts = PLATFORM_INFO.flat_map do |_, p|
        p.collect do |_, r|
          r[:source_package_formats]
        end
      end

      (fmts + source_fmts).flatten.compact.uniq.to_set.sort
    end

    # @param platform [String] Optional, the platform to list all codenames for.
    #   Defaults to 'deb'
    # @return [Array] An Array of Strings, containing all of the codenames
    #   defined for a given Platform
    def codenames(platform = 'deb')
      releases = by_package_format(platform).flat_map do |p|
        PLATFORM_INFO[p].values.collect { |r| r[:codename] }
      end
      releases.sort
    end

    # Given a debian codename, return the platform and version it corresponds to
    def codename_to_platform_version(codename)
      PLATFORM_INFO.each do |platform, platform_versions|
        platform_versions.each do |version, info|
          return [platform, version] if info[:codename] && codename == info[:codename]
        end
      end
      raise "Unable to find a platform and version for '#{codename}'"
    end

    # Given a debian platform and version, return the codename that corresponds to
    # the set
    def codename_for_platform_version(platform, version)
      get_attribute_for_platform_version(platform, version, :codename)
    end

    # Given a debian codename, return the arches that we build for that codename
    def arches_for_codename(codename, include_source = false)
      platform, version = codename_to_platform_version(codename)
      arches_for_platform_version(platform, version, include_source)
    end

    # Given a codename, return an array of associated tags
    def codename_to_tags(codename)
      platform_tags = []
      platform, version = codename_to_platform_version(codename)
      arches_for_codename(codename).each do |arch|
        platform_tags << "#{platform}-#{version}-#{arch}"
      end
      platform_tags
    end

    # Given a platform and version, return the arches that we build for that
    # platform
    def arches_for_platform_version(platform, version, include_source = false)
      platform_architectures = get_attribute_for_platform_version(platform, version, :architectures)
      # get_attribute_for_platform_version will raise an exception if the attribute
      # isn't found. We don't want this to be a fatal error, we just want to append
      # the source architecture if it's found
      source_architecture = []
      if include_source
        begin
          source_architecture = Array(get_attribute_for_platform_version(platform, version, :source_architecture))
        rescue
        end
      end
      return (platform_architectures + source_architecture).flatten
    end

    # Returns an array of all currently valid platform tags
    def platform_tags
      tags = []
      PLATFORM_INFO.each do |platform, platform_versions|
        platform_versions.each do |version, info|
          info[:architectures].each do |arch|
            tags << "#{platform}-#{version}-#{arch}"
          end
        end
      end
      tags
    end

    def package_format_for_tag(platform_tag)
      get_attribute(platform_tag, :package_format)
    end

    def signature_format_for_tag(platform_tag)
      get_attribute(platform_tag, :signature_format)
    end

    def signature_format_for_platform_version(platform, version)
      get_attribute_for_platform_version(platform, version, :signature_format)
    end

    def source_architecture_for_platform_tag(platform_tag)
      get_attribute(platform_tag, :source_architecture)
    end

    def source_package_formats_for_platform_tag(platform_tag)
      get_attribute(platform_tag, :source_package_formats)
    end

    # Return an array of platform tags associated with a given package format
    def platform_tags_for_package_format(format)
      platform_tags = []
      PLATFORM_INFO.each do |platform, platform_versions|
        platform_versions.each do |version, info|
          info[:architectures].each do |architecture|
            if info[:package_format] == format
              platform_tags << "#{platform}-#{version}-#{architecture}"
            end
          end
        end
      end
      platform_tags
    end

    # Return a supported platform tag for the given platform, not caring about
    # version or architecture
    def generic_platform_tag(platform)
      version = versions_for_platform(platform).first
      arch = arches_for_platform_version(platform, version).first
      return "#{platform}-#{version}-#{arch}"
    end

    # @method by_deb
    # @return [Array] An Array of Strings, containing all platforms
    #   that use .deb packages
    # Helper meta-method to return all platforms that use .deb packages
    # @scope class
    def by_deb
      by_package_format('deb')
    end

    # @method by_rpm
    # @return [Array] An Array of Strings, containing all platforms
    #   that use .rpm packages
    # Helper meta-method to return all platforms that use .rpm packages
    # @scope class
    def by_rpm
      by_package_format('rpm')
    end

    private :by_package_format
  end
end