class Berkshelf::Lockfile::Graph

def add(name, version)
  @graph[name.to_s] = GraphItem.new(name, version)
end

def dependency?(dependency, options = {})
  name   = Dependency.name(dependency)
  ignore = Hash[*Array(options[:ignore]).map { |i| [i, true] }.flatten]
  @graph.values.each do |item|
    next if ignore[item.name]
    if item.dependencies.key?(name)
      return true
    end
  end
  false
end

def each(&block)
  @graph.values.each(&block)
end

def find(dependency)
  @graph[Dependency.name(dependency)]
end

def initialize(lockfile)
  @lockfile  = lockfile
  @berksfile = lockfile.berksfile
  @graph     = {}
end

def lock?(dependency)
  !find(dependency).nil?
end

def locks
  @graph.sort.inject({}) do |hash, (name, item)|
    dependency = @lockfile.find(name) ||
      @berksfile && @berksfile.find(name) ||
      Dependency.new(@berksfile, name)
    # We need to make a copy of the dependency, or else we could be
    # modifying an existing object that other processes depend on!
    dependency = dependency.dup
    dependency.locked_version = item.version unless dependency.locked_version
    hash[item.name] = dependency
    hash
  end
end

def remove(dependency, options = {})
  name = Dependency.name(dependency)
  if @lockfile.dependency?(name)
    return
  end
  if dependency?(name, options)
    return
  end
  # Grab the nested dependencies for this particular entry so we can
  # recurse and try to remove them from the graph.
  locked = @graph[name]
  nested_dependencies = locked && locked.dependencies.keys || []
  # Now delete the entry
  @graph.delete(name)
  # Recursively try to delete the remaining dependencies for this item
  nested_dependencies.each(&method(:remove))
end

def to_lock
  out = "#{Lockfile::GRAPH}\n"
  @graph.sort.each do |name, item|
    out << "  #{name} (#{item.version})\n"
    unless item.dependencies.empty?
      item.dependencies.sort.each do |dep_name, constraint|
        out << "    #{dep_name} (#{constraint})\n"
      end
    end
  end
  out
end

def update(cookbooks)
  @graph = {}
  cookbooks.each do |cookbook|
    @graph[cookbook.cookbook_name.to_s] = GraphItem.new(
      cookbook.cookbook_name,
      cookbook.version,
      cookbook.dependencies
    )
  end
end