# Copyright (C) 2010, 2011 Rocky Bernstein <rockyb@rubyforge.net>
# For recording hook events in a buffer for review later. Make use of
# Trace::Buffer for this prupose.

require 'rubygems'; require 'require_relative'
require 'linecache'
require_relative '../app/eventbuffer'
require_relative 'virtual'

class Trepan::CmdProcessor < Trepan::VirtualCmdProcessor

  attr_reader :eventbuf
  attr_reader :event_tracefilter
  
  def eventbuf_initialize(size=100)
    @eventbuf = Trace::EventBuffer.new(size)
    # @event_tracefilter = Trace::Filter.new
  end
  
  # def event_processor(event, frame, arg=nil)
  #   @eventbuf.append(event, frame, arg)
  # end
  
  # Print event buffer entries from FROM up to TO try to stay within
  # WIDTH. We show source lines only the first time they are
  # encountered. Also we use separators to indicate points that the
  # debugger has stopped at.
  def eventbuf_print(from=nil, to=nil, width=80)
    sep = '-' * ((width - 7) / 2)
    last_container, last_location = nil, nil
    if from == nil || !@eventbuf.marks[-1] 
      mark_index = 0
    else
      mark_index = @eventbuf.marks.size-1
      translated_from = @eventbuf.zero_pos + from
      @eventbuf.marks.each_with_index do
        |m, i|
        if m > translated_from
          mark_index = [0, i-1].max
          break
        elsif m == translated_from
          mark_index = i
          break
        end
      end
    end
    
    nextmark = @eventbuf.marks[mark_index]
    @eventbuf.each_with_index(from, to) do |e, i| 
      if nextmark 
        if nextmark == i
          msg "#{sep} %5d #{sep}" % (mark_index - @eventbuf.marks.size)
          mark_index += 1 if mark_index < @eventbuf.marks.size - 1
          nextmark = @eventbuf.marks[mark_index]
        elsif nextmark < i
          mark_index += 1 if mark_index < @eventbuf.marks.size - 1
          nextmark = @eventbuf.marks[mark_index]
        end
      end
      last_container, last_location, mess = 
        format_eventbuf_entry(e, last_container, last_location) if e
      msg mess
    end
  end
  
  # Show event buffer entry. If the location is the same as the previous
  # location we don't show the duplicated location information.
  def format_eventbuf_entry(item, last_container, last_location)
    mess = format_location(item.event, item.frame, 0)
    return nil, nil, mess
  end
  
  # FIXME: multiple hook mechanism needs work. 
  # def start_capture
  #   @event_tracefilter.add_trace_func(method(:event_processor).to_proc,
  #                                     Trace::DEFAULT_EVENT_MASK)
  # end
  
  # def stop_capture
  #   @event_tracefilter.set_trace_func(nil)
  # end
  
end

if __FILE__ == $0
  # Demo it.
  cmdproc = Trepan::CmdProcessor.new([])
  cmdproc.eventbuf_initialize(5)

  def cmdproc.msg(mess)
    puts mess
  end
  # cmdproc.start_capture
  # z=5
  # z.times do |i|
  #   x = i
  #   y = x+2
  # end
  # cmdproc.stop_capture
  cmdproc.eventbuf_print
end