module Byebug::FrameFunctions

def adjust_frame(frame_pos, absolute, context=@state.context)
  @state.frame_pos = 0 if context != @state.context
  if absolute
    if frame_pos < 0
      abs_frame_pos = context.stack_size + frame_pos
    else
      abs_frame_pos = frame_pos
    end
  else
    abs_frame_pos = @state.frame_pos + frame_pos
  end
  if abs_frame_pos >= context.stack_size then
    errmsg "Adjusting would put us beyond the oldest (initial) frame.\n"
    return
  elsif abs_frame_pos < 0 then
    errmsg "Adjusting would put us beyond the newest (innermost) frame.\n"
    return
  end
  if @state.frame_pos != abs_frame_pos then
    @state.previous_line = nil
    @state.frame_pos = abs_frame_pos
  end
  @state.file = context.frame_file(@state.frame_pos)
  @state.line = context.frame_line(@state.frame_pos)
  print_frame(@state.frame_pos, false)
end

def get_frame_call(prefix, pos, context)
  id = context.frame_method(pos)
  return "<main>" unless id
  klass = context.frame_class(pos)
  if Command.settings[:callstyle] != :short && klass
    call_str = "#{klass}.#{id.id2name}"
  else
    call_str = "#{id.id2name}"
  end
  args = context.frame_args(pos)
  locals = context.frame_locals(pos)
  if args.any?
    call_str += "("
    args.each_with_index do |name, i|
      case Command.settings[:callstyle]
      when :short
        call_str += "#{name}, "
      when :last
        klass = locals[name].class
        if klass.inspect.size > 20 + 3
          klass = klass.inspect[0..20] + "..."
        end
        call_str += "#{name}##{klass}, "
      when :tracked
        arg_info = context.frame_args_info(pos)
        if arg_info && arg_info.size > i
          call_str += "#{name}: #{arg_info[i].inspect}, "
        else
          call_str += "#{name}, "
        end
      end
      if call_str.size > Command.settings[:width] - prefix.size
        # Strip off trailing ', ' if any but add stuff for later trunc
        call_str[-2..-1] = ",...XX"
        break
      end
    end
    call_str[-2..-1] = ")" # Strip off trailing ', ' if any
  end
  return call_str
end

def print_backtrace
  (0...@state.context.stack_size).each do |idx|
    print_frame(idx)
  end
end

def print_frame(pos, mark_current = true, context = @state.context)
  file = context.frame_file(pos)
  line = context.frame_line(pos)
  klass = context.frame_class(pos)
  unless Command.settings[:full_path]
    path_components = file.split(/[\\\/]/)
    if path_components.size > 3
      path_components[0...-3] = '...'
      file = path_components.join(File::ALT_SEPARATOR || File::SEPARATOR)
    end
  end
  if mark_current
    frame_str = (pos == @state.frame_pos) ? "--> " : "    "
  else
    frame_str = ""
  end
  frame_str += sprintf "#%-2d ", pos
  frame_str += get_frame_call(frame_str, pos, context)
  file_line = "at #{CommandProcessor.canonic_file(file)}:#{line}"
  if frame_str.size + file_line.size + 1 > Command.settings[:width]
    frame_str += "\n      #{file_line}\n"
  else
    frame_str += " #{file_line}\n"
  end
  print frame_str
end

def truncated_callstack?(context, sentinal=nil, cs=caller)
  recorded_size = context.stack_size
  to_find_fl = "#{context.frame_file(0)}:#{context.frame_line(0)}"
  top_discard = false
  cs.each_with_index do |fl, i|
    fl.gsub!(/in `.*'$/, '')
    fl.gsub!(/:$/, '')
    if fl == to_find_fl
      top_discard = i
      break
    end
  end
  if top_discard
    cs = cs[top_discard..-1]
    return false unless cs
    return cs unless sentinal
    if cs.size > recorded_size+2 && cs[recorded_size+2] != sentinal
      # caller seems to truncate recursive calls and we don't.
      # See if we can find sentinal in the first 0..recorded_size+1 entries
      return false if cs[0..recorded_size+1].any?{ |f| f==sentinal }
      return cs
    end
    return false
  end
  return nil
end