class Bundler::SpecSet

def <<(spec)
  @specs << spec
end

def [](key)
  key = key.name if key.respond_to?(:name)
  lookup[key].reverse
end

def []=(key, value)
  @specs << value
  @lookup = nil
  @sorted = nil
end

def each(&b)
  sorted.each(&b)
end

def empty?
  @specs.empty?
end

def extract_circular_gems(error)
  error.message.scan(/@name="(.*?)"/).flatten
end

def find_by_name_and_platform(name, platform)
  @specs.detect {|spec| spec.name == name && spec.match_platform(platform) }
end

def for(dependencies, check = false, match_current_platform = false)
  handled = []
  deps = dependencies.dup
  specs = []
  loop do
    break unless dep = deps.shift
    next if handled.any?{|d| d.name == dep.name && (match_current_platform || d.__platform == dep.__platform) } || dep.name == "bundler"
    handled << dep
    specs_for_dep = spec_for_dependency(dep, match_current_platform)
    if specs_for_dep.any?
      match_current_platform ? specs += specs_for_dep : specs |= specs_for_dep
      specs_for_dep.first.dependencies.each do |d|
        next if d.type == :development
        d = DepProxy.get_proxy(d, dep.__platform) unless match_current_platform
        deps << d
      end
    elsif check
      return false
    end
  end
  if spec = lookup["bundler"].first
    specs << spec
  end
  check ? true : specs
end

def initialize(specs)
  @specs = specs
end

def length
  @specs.length
end

def lookup
  @lookup ||= begin
    lookup = Hash.new {|h, k| h[k] = [] }
    Index.sort_specs(@specs).reverse_each do |s|
      lookup[s.name] << s
    end
    lookup
  end
end

def materialize(deps)
  materialized = self.for(deps, false, true)
  materialized.map! do |s|
    next s unless s.is_a?(LazySpecification)
    s.source.local!
    s.__materialize__ || s
  end
  SpecSet.new(materialized)
end

def materialized_for_all_platforms
  @specs.map do |s|
    next s unless s.is_a?(LazySpecification)
    s.source.local!
    s.source.remote!
    spec = s.__materialize__
    raise GemNotFound, "Could not find #{s.full_name} in any of the sources" unless spec
    spec
  end
end

def merge(set)
  arr = sorted.dup
  set.each do |set_spec|
    full_name = set_spec.full_name
    next if arr.any? {|spec| spec.full_name == full_name }
    arr << set_spec
  end
  SpecSet.new(arr)
end

def missing_specs
  @specs.select {|s| s.is_a?(LazySpecification) }
end

def size
  @specs.size
end

def sort!
  self
end

def sorted
  rake = @specs.find {|s| s.name == "rake" }
  begin
    @sorted ||= ([rake] + tsort).compact.uniq
  rescue TSort::Cyclic => error
    cgems = extract_circular_gems(error)
    raise CyclicDependencyError, "Your bundle requires gems that depend" \
      " on each other, creating an infinite loop. Please remove either" \
      " gem '#{cgems[1]}' or gem '#{cgems[0]}' and try again."
  end
end

def spec_for_dependency(dep, match_current_platform)
  specs_for_platforms = lookup[dep.name]
  if match_current_platform
    GemHelpers.select_best_platform_match(specs_for_platforms.select{|s| Gem::Platform.match_spec?(s) }, Bundler.local_platform)
  else
    GemHelpers.select_best_platform_match(specs_for_platforms, dep.__platform)
  end
end

def to_a
  sorted.dup
end

def to_hash
  lookup.dup
end

def tsort_each_child(s)
  s.dependencies.sort_by(&:name).each do |d|
    next if d.type == :development
    lookup[d.name].each {|s2| yield s2 }
  end
end

def tsort_each_node
  # MUST sort by name for backwards compatibility
  @specs.sort_by(&:name).each {|s| yield s }
end

def what_required(spec)
  unless req = find {|s| s.dependencies.any? {|d| d.type == :runtime && d.name == spec.name } }
    return [spec]
  end
  what_required(req) << spec
end