#!/usr/bin/env ruby
# vim: set sw=4 sts=4 et tw=80 :
#
['Paludis','find','getoptlong'].each {|x| require x}

include Paludis

Log.instance.log_level = LogLevel::Warning
Log.instance.program_name = $0

unsafe = false

def get_contents(repo)
  in_contents = { }
  repo.category_names do |cat|
    repo.package_names(cat) do |pkg|
      versions = repo.version_specs(pkg)
      if versions.length > 1
        in_contents[pkg.to_s()] = versions.reverse
      end
    end
  end
  return in_contents
end

def each_atom(atom)
  yield atom if atom.kind_of? PackageDepAtom
  atom.each { |sub| each_atom(sub) { |sub2| yield sub2 } } if atom.kind_of? CompositeDepAtom
end
def format_versions(key, value)
  return key + " (" + value.join(", ") + ")"
end

def check_deps(repo, versions)
  needed = []
  
  repo.category_names do |cat|
    repo.package_names(cat) do |pkg|
      repo.version_specs(pkg) do |ver|
        meta = repo.version_metadata(pkg, ver)
        meta.run_depend().each do |dep|
          each_atom(dep) { |atom| 
            if versions.has_key? atom.package.to_s
              print "not removing ", format_versions(atom.package.to_s, versions[atom.package.to_s]), " (dep: ", pkg, "-", ver, ")\n"
              versions.delete atom.package.to_s
            end
          }
        end
      end
    end
  end
  
  return needed
end

opts = GetoptLong.new(
  [ '--help',          '-h',  GetoptLong::NO_ARGUMENT ],
  [ '--version',       '-V',  GetoptLong::NO_ARGUMENT ],
  [ '--log-level',            GetoptLong::REQUIRED_ARGUMENT ],
  [ '--config-suffix', '-c',  GetoptLong::REQUIRED_ARGUMENT ],
  [ '--unsafe', '-u', GetoptLong::NO_ARGUMENT ]
)

config_suffix = ""
opts.each do | opt, arg |
  case opt
  when '--help'
    puts "Usage: " + $0 + " [options]"
    puts
    puts "Options:"
    puts "  --help                  Display a help message"
    puts "  --version               Display program version"
    puts
    puts "  --log-level level       Set log level (debug, qa, warning, silent)"
    puts "  --config-suffix suffix  Set configuration suffix)"
    puts "  --unsafe                Do nasty stuff"
    exit 0
    
  when '--version'
    puts $0.to_s.split(/\//).last + " " + Paludis::Version
    exit 0
    
  when '--log-level'
    case arg
    when 'debug'
      Paludis::Log.instance.log_level = Paludis::LogLevel::Debug
    when 'qa'
      Paludis::Log.instance.log_level = Paludis::LogLevel::Qa
    when 'warning'
      Paludis::Log.instance.log_level = Paludis::LogLevel::Warning
    when 'silent'
      Paludis::Log.instance.log_level = Paludis::LogLevel::Silent
    else
      puts "Bad --log-level value " + arg
      exit 1
    end
    
  when '--config-suffix'
    config_suffix = arg
    
  end
end

Paludis::DefaultConfig::config_suffix = config_suffix
db = DefaultEnvironment.instance.package_database

multi_versions = {}
db.repositories do |repo|
  next unless repo.format == 'vdb'
  multi_versions.update get_contents(repo)
end

necessary = []
db.repositories do |repo|
  next unless repo.format == 'vdb'
  necessary += check_deps(repo, multi_versions)
end

print "Keep:\n"
multi_versions.each { |key, val| print format_versions(key.to_s, val[0,1]), "\n" }

print "Could remove:\n"
multi_versions.each { |key, val| print format_versions(key.to_s, val[1..-1]), "\n" }

print "Command:\n"
print "paludis -u "

multi_versions.each { |key, val| val[1..-1].each { |ver| print "=" + key + "-" + ver.to_s + " " };  }
print "\n"