# encoding: utf-8

module Mutant
  # Zombifier namespace
  class Zombifier
    include Adamantium::Flat, Concord.new(:namespace)

    # Excluded from zombification
    IGNORE = [
      # Unparser is not performant enough (does some backtracking!) for generated lexer.rb
      'parser',
      'parser/all',
      'parser/current',
      # Wierd constant definitions / guards.
      'diff/lcs',
      'diff/lcs/hunk',
      # Mix beteen constants defined in .so and .rb files
      # Cannot be deterministically namespaced from ruby
      # without dynamically recompiling openssl ;)
      'openssl',
      # Constant propagation errors
      'thread_safe',
      # Unparser errors!
      'time'
    ].to_set.freeze

    # Initialize object
    #
    # @param [Symbol] namespace
    #
    # @return [undefined]
    #
    # @api private
    #
    def initialize(namespace)
      @namespace = namespace
      @zombified = Set.new(IGNORE)
    end

    # Perform zombification of target library
    #
    # @param [String] logical_name
    # @param [Symbol] namespace
    #
    # @api private
    #
    def self.run(logical_name, namespace)
      new(namespace).run(logical_name)
    end

    # Run zombifier
    #
    # @param [String] logical_name
    #
    # @return [undefined]
    #
    # @api private
    #
    def run(logical_name)
      highjack = RequireHighjack.new(Kernel, method(:require))
      highjack.infect
      require(logical_name)
    end

    # Require file in zombie namespace
    #
    # @param [String] logical_name
    #
    # @return [self]
    #
    # @api private
    #
    def require(logical_name)
      return if @zombified.include?(logical_name)
      @zombified << logical_name
      file = File.find(logical_name)
      file.zombify(namespace) if file
      self
    end

  end # Zombifier
end # Mutant