# Copyright 2005-2007 Nanorex, Inc.  See LICENSE file for details.
"""
extensions.py

Note: for now, this is intentionally not imported (even indirectly or
conditionally) by main.py; see comment below for why. But it should
remain in this directory. [bruce 071005].

Someday: handle all our custom extension modules.

For now:
Python interface to experimental Pyrex code -- mainly just needs to fail gracefully
if its compiled form (a Python extension) is not there, or doesn't work in a drastic way.
In future, might also make sure it's up-to-date, tell you how to remake it if not,
and handle all extensions instead of just one or just Pyrex extensions.

$Id$

This can't be called pyrex_test.py since then "import pyrex_test" would be ambiguous.
We want that to import the extension module... and this file might as well evolve
to try to handle all the extensions at once, so it gets a different more general name.

This fits the idea that this module contains only rarely-edited glue code,
with the real development action in the Pyrex source code (.pyx file).

For plans and status related to our use of Pyrex, see:

  http://www.nanoengineer-1.net/mediawiki/index.php?title=Integrating_Pyrex_into_the_Build_System

See README-Pyrex for the list of related files and their roles.

How to build:

% make pyx

(see also the wiki page listed above)

How to test:

[updated, bruce 071005, and retested on my Mac]

optional: in this source file, change debug_pyrex_test to True below.
But don't commit that change.

In NE1's run py code debug menu item, type "import extensions";
review the console prints for whether this succeeded;
then type "extensions.initialize()" and again review the console prints;
then use debug menu -> other -> count bonds.
If it failed, follow build instructions in README-Pyrex and/or pyrex_text.pyx.
(I don't know how similar your python environment needs to be to NE1's for that to work.)

Possible errors when you run "import extensions" or "extensions.initialize()":

ImportError: No module named pyrex_test -- you need to build it, e.g. "make pyx" in cad/src.

Fatal Python error: Interpreter not initialized (version mismatch?) -- this is
a Mac-specific problem related to the old bug 1724, caused by an interaction
between an Apple bug, a link error on our part, and having another Python
installed on your Mac -- typically in /Library/Frameworks. When this happens to
me, I can fix it by running the shell commands:

% cd /Library/Frameworks/Python.framework/Versions
% sudo mv 2.3 2.3-DISABLED

and rerunning NE1.

(That problem may occur, and the above fix works for me, whether I run NE1
directly as a developer or use the (Mac-specific) ALTERNATE_CAD_SRC_PATH
feature.)
"""
__author__ = 'bruce'

have_pyrex_test = False

debug_pyrex_test = False ## was debug_flags.atom_debug, changed to 0 for A7 release by bruce 060419

import foundation.env as env
from utilities.debug import register_debug_menu_command, call_func_with_timing_histmsg, print_compact_traceback

# I think it's safe for the following pyrex_test import to be attempted even by
# source analysis tools which import single files. Either they'll have
# pyrex_test.so (or the Windows equivalent) and succeed, or not have it and fail,
# but that failure won't print anything if the debug flags above have not been
# modified, or cause other harm. So I'm leaving this attemped import at toplevel.
#
# If this causes trouble, this import can be moved inside initialize()
# if nbonds and have_pyrex_test are declared as module globals.
#
# Note that it's NOT safe to add "import extensions" to main.py, even inside
# a conditional and/or to be run only on user request, until the build
# process compiles and includes pyrex_test.so (or the Windows equivalent);
# otherwise py2app or py2exe might get confused about that dynamic library
# being required but not present.
#
# [bruce 071005]

try:
    from pyrex_test import nbonds
    #e verify it's up-to-date? (could ask it for version and compare to a hardcoded version number in this file...)
    #e run a self-test and/or run our own test on it?
    have_pyrex_test = True
except:
    if debug_pyrex_test: ### this condition will become "if 1" when developers are required to have Pyrex installed
        print_compact_traceback("debug_pyrex_test: exception importing pyrex_test or something inside it: ")
        print "debug_pyrex_test: Can't import pyrex_test; we'll define stub functions for its functions,"
        print "but trying to use them will raise an exception; see README-Pyrex for how to fix this."

    def nbonds(mols): # stub function; in some cases it might be useful to define a correct but slow stub instead of a NIM stub
        "stub function for nbonds"
        assert 0, "nbonds NIM, since we couldn't import pyrex_test extension module; see README-Pyrex"
        pass
    pass

# whether we now have the real nbonds or a stub function, make it available for testing in a menu.

def count_bonds_cmd( target):
    win = target.topLevelWidget()
    assy = win.assy
    part = assy.tree.part
    mols = part.molecules
    env.history.message( "count bonds (twice each) in %d mols:" % len(mols) )
    def doit():
        return nbonds(mols)
    nb = call_func_with_timing_histmsg( doit)
    env.history.message("count was %d, half that is %d" % (nb, nb/2) )
    return

def initialize(): #bruce 071005 added this wrapping function
    if have_pyrex_test:
        register_debug_menu_command("count bonds (pyrex_test)", count_bonds_cmd)
    else:
        register_debug_menu_command("count bonds (stub)", count_bonds_cmd)
    return

# end