module PryStackExplorer

def self.bindings_equal?(b1, b2)
  (b1.eval('self') == b2.eval('self')) &&
    (b1.eval('__method__') == b2.eval('__method__')) &&
    (b1.eval('local_variables').map { |v| b1.eval("#{v}") } ==
     b2.eval('local_variables').map { |v| b2.eval("#{v}") })
end

def self.clear_frame_managers(_pry_)
  init_frame_hash
  pop_frame_manager(_pry_) until frame_managers(_pry_).empty?
  frame_hash.delete(_pry_) # this line should be unnecessary!
end

def self.create_and_push_frame_manager(bindings, _pry_)
  init_frame_hash
  frame_hash[_pry_].push FrameManager.new(bindings, _pry_)
end

def self.frame_hash
  Thread.current[:__pry_frame_managers__]
end

def self.frame_manager(_pry_)
  init_frame_hash
  frame_hash[_pry_].last
end

def self.frame_managers(_pry_)
  init_frame_hash
  frame_hash[_pry_]
end

def self.init_frame_hash
  Thread.current[:__pry_frame_managers__] ||= Hash.new { |h, k| h[k] = [] }
end

def self.pop_frame_manager(_pry_)
  init_frame_hash
  popped = frame_managers(_pry_).pop
  frame_hash.delete(_pry_) if frame_managers(_pry_).empty?
  _pry_.backtrace = popped.prior_backtrace
  popped
end