class IRB::SourceFinder

# File lib/irb/source_finder.rb, line 66
def initialize(irb_context)
  @irb_context = irb_context
end

# File lib/irb/source_finder.rb, line 70
def find_source(signature, super_level = 0)
  case signature
  when /\A(::)?[A-Z]\w*(::[A-Z]\w*)*\z/ # ConstName, ::ConstName, ConstPath::ConstName
    eval_receiver_or_owner(signature) # trigger autoload
    *parts, name = signature.split('::', -1)
    base =
      if parts.empty? # ConstName
        find_const_owner(name)
      elsif parts == [''] # ::ConstName
        Object
      else # ConstPath::ConstName
        eval_receiver_or_owner(parts.join('::'))
      end
    file, line = base.const_source_location(name)
  when /\A(?<owner>[A-Z]\w*(::[A-Z]\w*)*)#(?<method>[^ :.]+)\z/ # Class#method
    owner = eval_receiver_or_owner(Regexp.last_match[:owner])
    method = Regexp.last_match[:method]
    return unless owner.respond_to?(:instance_method)
    method = method_target(owner, super_level, method, "owner")
    file, line = method&.source_location
  when /\A((?<receiver>.+)(\.|::))?(?<method>[^ :.]+)\z/ # method, receiver.method, receiver::method
    receiver = eval_receiver_or_owner(Regexp.last_match[:receiver] || 'self')
    method = Regexp.last_match[:method]
    return unless receiver.respond_to?(method, true)
    method = method_target(receiver, super_level, method, "receiver")
    file, line = method&.source_location
  end
  return unless file && line

  if File.exist?(file)
    Source.new(file, line)
  elsif method
    # Method defined with eval, probably in IRB session
    source = RubyVM::InstructionSequence.of(method)&.script_lines&.join rescue nil
    Source.new(file, line, source)
  end
rescue EvaluationError
  nil
end

# File lib/irb/source_finder.rb, line 127
def eval_receiver_or_owner(code)
  context_binding = @irb_context.workspace.binding
  eval(code, context_binding)
rescue NameError
  raise EvaluationError
end

# File lib/irb/source_finder.rb, line 134
def find_const_owner(name)
  module_nesting = @irb_context.workspace.binding.eval('::Module.nesting')
  module_nesting.find { |mod| mod.const_defined?(name, false) } || module_nesting.find { |mod| mod.const_defined?(name) } || Object
end

# File lib/irb/source_finder.rb, line 112
def method_target(owner_receiver, super_level, method, type)
  case type
  when "owner"
    target_method = owner_receiver.instance_method(method)
  when "receiver"
    target_method = owner_receiver.method(method)
  end
  super_level.times do |s|
    target_method = target_method.super_method if target_method
  end
  target_method
rescue NameError
  nil
end