module WithRefinements

# File lib/with_refinements.rb, line 9
def context(refinements)
  @context_cache[refinements] ||= clean_binding.tap do |b|
    b.local_variable_set(:__refinements__, refinements)
    b.eval('__refinements__.each {|r| using r }')
  end
end

# File lib/with_refinements.rb, line 16
    def refined_proc(c, block)
      @refined_proc_cache[c][block.source_location] ||= (
        lvars = block.binding.local_variables
        c.eval(<<~RUBY)
          proc do |__binding__|
            proc { |#{lvars.join(",")}|
              ret = __binding__.receiver.instance_exec #{code_from_block(block)}
              #{lvars.map {|v| "__binding__.local_variable_set(:#{v}, #{v})" }.join("\n")}
              ret
            }.call(*__binding__.local_variables.map {|v| __binding__.local_variable_get(v) })
          end
        RUBY
      )
    end

# File lib/with_refinements.rb, line 31
    def refined_proc_light(c, block)
      @refined_proc_light_cache[c][block.source_location] ||= (
        c.eval(<<~RUBY)
          proc { |__receiver__, __args__| __receiver__.instance_exec(*__args__) #{code_from_block(block)} }
        RUBY
      )
    end

# File lib/with_refinements.rb, line 69
def with_refinements(*refinements, &block)
  c = WithRefinements.context(refinements)
  p = WithRefinements.refined_proc(c, block)
  p.call(block.binding)
end

# File lib/with_refinements.rb, line 75
def with_refinements_light(*refinements, args: [], &block)
  c = WithRefinements.context(refinements)
  p = WithRefinements.refined_proc_light(c, block)
  p.call(block.binding.receiver, args)
end

# File lib/with_refinements.rb, line 41
def block_source_location(block)
  iseq = RubyVM::InstructionSequence.of(block).to_a
  loc = iseq[4].yield_self {|h| h[:code_range] || h[:code_location] }
  path = iseq[7]
  return path, loc
end

# File lib/with_refinements.rb, line 48
def clean_binding
  TOPLEVEL_BINDING.eval('Module.new { break binding }')
end

# File lib/with_refinements.rb, line 52
def code_from_block(block)
  path, loc = block_source_location(block)
  File.readlines(path)[loc[0]-1..loc[2]-1].tap {|ls|
    if loc[0] == loc[2]
      ls[0] = ls[0][loc[1]...loc[3]]
    else
      ls[0], ls[-1] = ls[0][loc[1]..-1], ls[-1][0..loc[3]]
    end

    # remove -> from -> {}
    if ls[0].start_with?('->')
      ls[0] = ls[0][2..-1]
    end
  }.join
end

# File lib/with_refinements.rb, line 69
def with_refinements(*refinements, &block)
  c = WithRefinements.context(refinements)
  p = WithRefinements.refined_proc(c, block)
  p.call(block.binding)
end

# File lib/with_refinements.rb, line 75
def with_refinements_light(*refinements, args: [], &block)
  c = WithRefinements.context(refinements)
  p = WithRefinements.refined_proc_light(c, block)
  p.call(block.binding.receiver, args)
end