#!/usr/bin/env python
# -*- coding: utf-8 -*-
# vim: ts=4
#
# Copyright (c) 2007 Benjamin Schweizer. All rights reserved.
#
# Abstract
# ~~~~~~~~
# an interactive editor for pickle encoded data structures
#
# Authors
# ~~~~~~~
# Benjamin Schweizer <code at benjamin-schweizer dot de>
#
# Changes
# ~~~~~~~
# 2007-06-05, schweizer: reworked indent
# 2007-06-04, schweizer: initial release
#
# Todo
# ~~~~~
# - testing, especially indent()
# - error handling
#

import sys
import tempfile
import subprocess
import os
import pickle
import types

def usage():
	print """Copyright (c) 2007 Benjamin Schweizer. All rights reserved.

pedit - an interactive editor for pickle encoded data structures

usage:

	pedit [--dump] FILENAME

	--dump	simple dump, don't load editor
"""

def indent(data, level=0, bol=True):
	"""poor man's indent"""
	def escape(str):
		"""string escape"""

		newstr = ''
		for c in str:
			if ord(c) in range(128):
				newstr += c
			else:
				newstr += '\\x%2x' % ord(c)
		str = newstr
		
		if '\r' in str or '\n' in str:
			return '"""%s"""' % str
		else:
			return '"%s"' % str.replace('"', '\\"')

	result = ''
	if bol:
		result += '  ' * level

	if type(data) == types.ListType:
		if not len(data):
			result += '[]'
		else:
			result += '[\n'
			for e in data:
				result += indent(e, level+1)
			result += '  ' * level + ']'
	elif type(data) == types.DictType:
		if not len(data):
			result += '{}'
		else:
			result += '{\n'
			for k in data:
				v = data[k]
				result += '  ' * (level+1) + '%s: ' % escape(k)
				result += indent(v, level+1, bol=False)
			result += '  ' * level + '}'
	elif type(data) == types.TupleType:
		if not len(data):
			result += '()'
		else:
			result += '(\n'
			for e in data:
				result += indent(e, level+1)
			result += '  ' * level + ')'
	elif type(data) == types.IntType:
		result += '%d' % data
	elif type(data) == types.LongType:
		result += '%dL' % data
	elif type(data) == types.FloatType:
		result += '%f' % data
	elif type(data) == types.BooleanType:
		result += '%s' % data
	elif type(data) == types.StringType:
		result += '%s' % escape(data)
	elif type(data) == types.UnicodeType:
		result += 'u%s' % escape(data)
	else:
		raise Exception('unhandeled data type, %s' % type(data))

	if level:
		result += ','
	result += '\n'

	return result


if __name__ == '__main__':
	picklefilename = False
	for e in sys.argv:
		if e[0] != '-':
			picklefilename = e

	if not picklefilename:
		usage()
		sys.exit(1)

	# load pickle data
	try:
		fh = open(picklefilename, 'rb')
		data = pickle.load(fh)
		fh.close()
	except IOError, error:
		if not error.errno == 2:
			raise
		# else: file not found
		data = False

	# dump
	if '--dump' in sys.argv:
		print "%s" % indent(data)
		sys.exit(0)
	#else: fire up editor

	# export pretty printed data
	fd, tempfilename = tempfile.mkstemp()
	fh = os.fdopen(fd, "w+b")
	fh.write('# %s - pedit\n\n' % picklefilename)
	fh.write(indent(data))
	fh.write('\n# eof.')
	fh.close()

	# edit tempfile
	editor = os.environ['EDITOR'] or 'vi'
	process = subprocess.Popen([editor, tempfilename])
	process.communicate()
#	process.wait()

	# import tempfile
	fh = open(tempfilename, "rb")
	data_new = eval(fh.read())
	fh.close()
	os.unlink(tempfilename)

	# updata source
	if data_new != data:
		fh = open(picklefilename, 'wb')
		pickle.dump(data_new, fh)
		fh.close()
	# else: do nothing

# eof.