#!/usr/bin/env python
#------------------------------------------------------------
# IDAPython - Python plugin for Interactive Disassembler Pro
#
# Copyright (c) 2004-2008 Gergely Erdelyi <dyce@d-dome.net> 
#
# All rights reserved.
#
# For detailed copyright information see the file COPYING in
# the root of the distribution archive.
#------------------------------------------------------------
# init.py - Essential init routines
#------------------------------------------------------------
import os
import sys
import time
import traceback
import warnings

import _idaapi

# FIXME: Should fix the offending constant instead
warnings.filterwarnings('ignore', category=FutureWarning)


def addscriptpath(script):
    """
    Add the path part of the scriptfile to the system path to
    allow modules to be loaded from the same place.

    Each path is added only once.
    """
    pathfound = 0

    scriptpath = os.path.dirname(script)

    for pathitem in sys.path:
        if pathitem == scriptpath:
            pathfound = 1
            break
    
    if pathfound == 0:
        sys.path.append(scriptpath)

    # Add the script to ScriptBox if it's not there yet
    if not script in ScriptBox_instance.list:
        ScriptBox_instance.list.insert(0, script)


def runscript(script):
    """
    Run the specified script after adding its directory path to
    system path.

    This function is used by the low-level plugin code.
    """
    addscriptpath(script)
    watchdog.reset()
    argv = sys.argv
    sys.argv = [ script ]
    execfile(script, globals())
    sys.argv = argv

def print_banner():
    version1 = "IDAPython version %d.%d.%d %s (serial %d) initialized" % IDAPYTHON_VERSION
    version2 = "Python interpreter version %d.%d.%d %s (serial %d)" % sys.version_info
    linelen  = max(len(version1), len(version2))

    print '-' * linelen
    print version1
    print version2
    print '-' * linelen


#-----------------------------------------------------------
# Take over the standard text outputs
#-----------------------------------------------------------
class MyStdOut:
    """
    Dummy file-like class that receives stout and stderr
    """
    def write(self, text):
        _idaapi.msg(text.replace("%", "%%"))

    def flush(self):
        pass

    def isatty(self):
        return False

# Redirect stderr and stdout to the IDA message window
sys.stdout = sys.stderr = MyStdOut()

# Assign a default sys.argv
sys.argv = [ "" ]

# Have to make sure Python finds our modules
sys.path.append(_idaapi.idadir("python"))

print_banner()

#-----------------------------------------------------------
# Import all the required modules
#-----------------------------------------------------------
from idaapi import Choose, get_user_idadir, cvar
from idc import *
from idautils import *


#-----------------------------------------------------------
# Build up the ScriptBox tool
#-----------------------------------------------------------
class ScriptBox(Choose):
    def __init__(self, list=[]):
        Choose.__init__(self, list, "ScriptBox", 1)
        self.width = 50

    def run(self):
        if len(self.list) == 0:
            Warning("ScriptBox history is empty.\nRun some script with Alt-9 and try again.")
            return None

        n = self.choose()
    
        if n > 0:
            return self.list[n-1]
        else:
            return None

    def addscript(self, scriptpath):
            self.list.append(scriptpath)

ScriptBox_instance = ScriptBox([])

#-------------------------------------------------------------
# Watchdog to catch runaway scripts after a specified timeout
#
# Usage:
#        watchdog.install()
#        watchdog.activate(10) # Use 10-second timeout
#
# Note: The watchdog only works for code running inside
#       functions, not in global/module namespace.         
#-------------------------------------------------------------
class WatchDog():
    """
    Python tracer-based watchdog class
    """
    def __init__(self, timeout=10):
        self.timeout = timeout
        self.installed = False
        self.active = False

    def install(self):
        """ Install the tracer function, required for the watchdog """
        if not self.installed:
            sys.settrace(self.tracer)
            self.installed = True

    def activate(self, timeout=None):
        """ Activate the watchdog, with optional timeout change """
        assert self.installed, "WatchDog must be installed before activating"
        if timeout:
            self.timeout = timeout
        self.reset()
        self.active = True

    def deactivate(self):
        """ Deactivate the watchdog """
        self.active = True

    def reset(self):
        """ Reset the timer, useful for long-running scripts """
        self.timestamp = time.clock()

    def tracer(self, frame, event, arg):
        """ Tracer function that receives the tracing events """
        if not self.active:
            return None
        if event == 'line':
            if time.clock() - self.timestamp > self.timeout:
                if AskYN(0, "The script has not finished in %d seconds\nWould you like to stop it now?" % self.timeout) == 1:
                    raise KeyboardInterrupt
                else:
                    self.timestamp = time.clock()
        return self.tracer

watchdog = WatchDog(10)

# Load the users personal init file
userrc = get_user_idadir() + os.sep + "idapythonrc.py"

if os.path.exists(userrc):
    runscript(userrc)
    # Remove the user script from the history
    del ScriptBox_instance.list[0]


# All done, ready to rock.