# -*- coding: utf-8 -*-
# Copyright (C) 2010 Rocky Bernstein <rockyb@rubyforge.net>
require_relative 'base/cmd'
class Trepan::Command::BacktraceCommand < Trepan::Command

  unless defined?(HELP)
    NAME          = File.basename(__FILE__, '.rb')
    HELP = <<-HELP
#{NAME} [count]

Print a stack trace, with the most recent frame at the top.  With a
positive number, print at most many entries.  With a negative number
print the top entries minus that number.

An arrow indicates the 'current frame'. The current frame determines
the context used for many debugger commands such as expression
evaluation or source-line listing.

Examples:
   #{NAME}    # Print a full stack trace
   #{NAME} 2  # Print only the top two entries
   #{NAME} -1 # Print a stack trace except the initial (least recent) call."
      HELP

    ALIASES       = %w(bt where)
    CATEGORY      = 'stack'
    MAX_ARGS      = 1  # Need at most this many
    NEED_STACK    = true
    SHORT_HELP    = 'Print backtrace of stack frames'
  end

  require_relative '../../app/frame'
  include Trepan::Frame

  def complete(prefix)
    @proc.frame_complete(prefix, nil)
  end
  
  # This method runs the command
  def run(args)
    unless @proc.frame
      errmsg 'No frame.'
      return false
    end
    hide_level  = 
      if (!settings[:hidelevel] || settings[:hidelevel] < 0) && 
          @proc.hidelevels[Thread.current] 
        @proc.hidelevels[Thread.current] 
      else settings[:hidelevel]
      end
    stack_size = @proc.top_frame.stack_size - hide_level
    opts = {
      :basename    => settings[:basename],
      :current_pos => @proc.frame_index,
      :maxstack    => settings[:maxstack],
      :maxwidth    => settings[:maxwidth],
      :show_pc     => settings[:show_pc]
    }
    opts[:count] = 
      if args.size > 1
        opts[:maxstack] = @proc.get_int(args[1], 
                                       :cmdname   => self.name,
                                       :max_value => stack_size)
      else
        stack_size
      end
    return false unless opts[:count]
    # FIXME: Fix Ruby so we don't need this workaround? 
    # See also location.rb
    opts[:class] = @proc.core.hook_arg  if 
      'CFUNC' == @proc.frame.type && 
      @proc.core.hook_arg && @proc.event != 'raise'
    print_stack_trace(@proc.top_frame, opts)
  end
end

if __FILE__ == $0
  # Demo it.
  require 'thread_frame'
  require_relative '../mock'
  dbgr, cmd = MockDebugger::setup

  def run_cmd(cmd, args)
    cmd.run(args)
    puts '=' * 40
  end

  run_cmd(cmd, [cmd.name])

  %w(1 100).each {|count| run_cmd(cmd, [cmd.name, count])}
  cmd.settings[:basename] = true
  def foo(cmd, name)
    cmd.proc.frame_setup(RubyVM::ThreadFrame::current)
    run_cmd(cmd, [cmd.name])
  end
  foo(cmd, cmd.name)
  cmd.settings[:show_pc] = true
  1.times {run_cmd(cmd, [cmd.name])}
end