##############################################################################
#
# Copyright (c) 2004 Zope Corporation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Python Page

$Id$
"""

__docformat__ = 'restructuredtext'

import new
import re
from cStringIO import StringIO
from persistent import Persistent
from zope.proxy import removeAllProxies
from zope.security.untrustedpython.builtins import SafeBuiltins
from zope.security.untrustedpython.rcompile import compile
from zope.traversing.api import getParent, getPath
from zope.app.container.contained import Contained
#from zope.app.interpreter.interfaces import IInterpreter
from zope.interface import implements
from zope.app.i18n import ZopeMessageFactory as _

from cybertools.pyscript.interfaces import IPythonScript, IScriptContainer


class PythonScript(Contained, Persistent):
    """Persistent Python Page - Content Type
    """

    implements(IPythonScript)

    _v_compiled = None

    def __init__(self, source=u'', contentType=u'text/plain'):
        """Initialize the object."""
        super(PythonScript, self).__init__()
        self.source = source
        self.contentType = contentType

    def __filename(self):
        if self.__parent__ is None:
            filename = 'N/A'
        else:
            filename = getPath(self)
        return filename

    def setSource(self, source):
        """Set the source of the page and compile it.

        This method can raise a syntax error, if the source is not valid.
        """
        self.__source = source
        self.__prepared_source = self.prepareSource(source)
        # Compile objects cannot be pickled
        self._v_compiled = Function(self.__prepared_source, self.__filename())

    _tripleQuotedString = re.compile(
        r"^([ \t]*)[uU]?([rR]?)(('''|\"\"\")(.*)\4)", re.MULTILINE | re.DOTALL)

    def prepareSource(self, source):
        """Prepare source."""
        # compile() don't accept '\r' altogether
        source = source.replace("\r\n", "\n")
        source = source.replace("\r", "\n")
        if isinstance(source, unicode):
            # Use special conversion function to work around
            # compiler-module failure to handle unicode in literals
            try:
                source = source.encode('ascii')
            except UnicodeEncodeError:
                return self._tripleQuotedString.sub(_print_usrc, source)
        return self._tripleQuotedString.sub(r"\1print \2\3", source)


    def getSource(self):
        """Get the original source code."""
        return self.__source

    source = property(getSource, setSource)

    def __call__(self, request, **kw):
        output = StringIO()
        if self._v_compiled is None:
            self._v_compiled = Function(self.__prepared_source,
                                               self.__filename())
        parent = getParent(self)
        kw['request'] = request
        kw['script'] = self
        kw['untrusted_output'] = kw['printed'] = output
        kw['context'] = parent
        kw['script_result'] = None
        if IScriptContainer.providedBy(parent):
            parent.updateGlobals(kw)
        self._v_compiled(kw)
        result = kw['script_result']
        if result == output:
            result = result.getvalue().decode('unicode-escape')
        return result


class Function(object):
    """A compiled function.
    """

    def __init__(self, source, filename='<string>'):
        lines = []
        lines.insert(0, 'def dummy(): \n    pass')
        for line in source.splitlines():
            lines.append('    ' + line)
        lines.append('script_result = dummy()')
        source = '\n'.join(lines)
        #print source
        self.code = compile(source, filename, 'exec')

    def __call__(self, globals):
        globals['__builtins__'] = SafeBuiltins
        exec self.code in globals, None


def _print_usrc(match):
    string = match.group(3)
    raw = match.group(2)
    if raw:
        return match.group(1)+'print '+`string`
    return match.group(1)+'print '+match.group(3).encode('unicode-escape')