module Bones::App
class Plugins < Command

  def self.initialize_plugins
    synopsis 'bones plugins [options]'

    summary 'list available Mr Bones plugins'

    description <<-__
Parse the installed gems and then search for Mr Bones plugins related to
those gems. Passing in the 'all' flag will show plugins even if the related
gems are not installed.
    __

    option('-a', '--all', 'Show all plugins.', lambda { config[:all] = true })
  end

  def run
    stdout.write 'Looking up avaialble Mr Bones plugins ... '
    stdout.flush
    plugins = find_bones_plugins
    stdout.puts 'done!'
    stdout.puts

    if all?
      plugins.each { |name, version| show_plugin(name, version) }
    else
      plugins.each { |name, version|
        gemspecs.each { |gem_name, gem_version|
          next unless name.downcase == gem_name.downcase
          next if version && version != gem_version
          show_plugin(name, version)
        }
      }
    end

    stdout.puts
  end

  def all?
    config[:all]
  end

  def show_plugin( name, version )
    name = "bones-#{name}"
    name << "-#{version}" if version

    stdout.puts("  [%s]  %s" % [installed?(name) ? 'installed' : 'available', name])
  end

private

  def gemspecs
    specs = Gem.source_index.map { |_, spec| spec }

    specs.map! { |s| [s.name, s.version.segments.first] }

    specs.sort! { |a, b|
      names = a.first <=> b.first
      next names if names.nonzero?
      b.last <=> a.last
    }

    specs.uniq!
    return specs
  end

  def find_bones_plugins
    dep = Gem::Dependency.new(%r/^bones/i, Gem::Requirement.default)

    fetcher = Gem::SpecFetcher.fetcher
    specs = fetcher.find_matching dep

    specs.map! { |(name, version, _), _|
      next unless name =~ %r/^bones-(.*?)(?:-(\d+))?$/i
      $2 ? [$1, $2.to_i] : $1
    }

    specs.compact!
    specs.uniq!
    return specs
  end

  def installed?( name, version = Gem::Requirement.default )
    dep = Gem::Dependency.new name, version
    !Gem.source_index.search(dep).empty?
  end

end  # class Plugins
end  # module Bones::App