class Bundler::SpecSet

def -(other)
  SpecSet.new(to_a - other.to_a)
end

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 delete(spec)
  @specs.delete(spec)
  @lookup = nil
  @sorted = nil
end

def delete_by_name_and_version(name, version)
  @specs.reject! {|spec| spec.name == name && spec.version == version }
  @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, platforms = [nil])
  handled = ["bundler"].product(platforms).map {|k| [k, true] }.to_h
  deps = dependencies.product(platforms)
  specs = []
  loop do
    break unless dep = deps.shift
    name = dep[0].name
    platform = dep[1]
    key = [name, platform]
    next if handled.key?(key)
    handled[key] = true
    specs_for_dep = specs_for_dependency(*dep)
    if specs_for_dep.any?
      specs.concat(specs_for_dep)
      specs_for_dep.first.dependencies.each do |d|
        next if d.type == :development
        deps << [d, dep[1]]
      end
    elsif check
      @incomplete_specs += lookup[name]
    end
  end
  specs
end

def incomplete_ruby_specs?(deps)
  self.for(deps, true, [Gem::Platform::RUBY])
  @incomplete_specs.any?
end

def initialize(specs, incomplete_specs = [])
  @specs = specs
  @incomplete_specs = incomplete_specs
end

def length
  @specs.length
end

def lookup
  @lookup ||= begin
    lookup = Hash.new {|h, k| h[k] = [] }
    @specs.each do |s|
      lookup[s.name] << s
    end
    lookup
  end
end

def materialize(deps)
  materialized = self.for(deps, true)
  SpecSet.new(materialized, incomplete_specs)
end

def materialized_for_all_platforms
  @specs.map do |s|
    next s unless s.is_a?(LazySpecification)
    s.source.remote!
    spec = s.materialize_for_installation
    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 specs_for_dependency(dep, platform)
  specs_for_name = lookup[dep.name]
  if platform.nil?
    matching_specs = specs_for_name.map {|s| s.materialize_for_installation if Gem::Platform.match_spec?(s) }.compact
    GemHelpers.sort_best_platform_match(matching_specs, Bundler.local_platform)
  else
    GemHelpers.select_best_platform_match(specs_for_name, dep.force_ruby_platform ? Gem::Platform::RUBY : 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