/*
 * This wrapper program executes a python executable hidden inside an
 * application bundle inside the Python framework. This is needed to run
 * GUI code: some GUI API's don't work unless the program is inside an
 * application bundle.
 *
 * This program uses posix_spawn rather than plain execv because we need
 * slightly more control over how the "real" interpreter is executed.
 */
#include <unistd.h>
#include <spawn.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <err.h>

extern char** environ;

/*
 * FIXME: dynamicly determine PYTHONWEXECUTABLE path by linking to
 * Python.framework and looking for Py_Initialize. This would make
 * it a lot easier to have pythonw functinality in virtualenv
 */
static char Python[] = "/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python"; /*PYTHONWEXECUTABLE;*/

int 
main(int argc, char **argv) {
	posix_spawnattr_t spawnattr = NULL;
	size_t ocount;
	size_t count;
	cpu_type_t cpu_types[1];
	short flags = 0;

	if ((errno = posix_spawnattr_init(&spawnattr)) != 0) {
		err(2, "posix_spawnattr_int");
		/* NOTREACHTED */
	}

	count = 1;

	/* Run the real python executable using the same architure as this executable,
	 * this allows users to controle the architecture using "arch -ppc python"
	 */

#if defined(__ppc64__)
	cpu_types[0] = CPU_TYPE_POWERPC64;

#elif defined(__x86_64__)
	cpu_types[0] = CPU_TYPE_X86_64;

#elif defined(__ppc__)
	cpu_types[0] = CPU_TYPE_POWERPC;
#elif defined(__i386__)
	cpu_types[0] = CPU_TYPE_X86;
#else
#	error "Unknown CPU"
#endif

#ifdef __LP64__
	/* We're running in 64-bit mode. 
	 *
	 * There are some APIs, both in the system and in 3th-party python
	 * extensions, that don't work in 64-bit mode. Therefore allow the
	 * user to select 32-bit mode using a -X flag as well.
	 */
	{
		int c;
		/* FIXME: the string of options needs to be synchronized with Py_Main,
		 * and preferably without copying the getopt string as I've done below.
		 */
		while ((c = getopt(argc, argv, "3bBc:dEhiJm:OQ:sStuUvVW:xX:?")) != EOF) {
		 	switch (c) {
			case 'X':
				if (strcmp(optarg, "32bit") == 0) {
					printf("force 32bit mode\n");
#ifdef __ppc64__
					cpu_types[0] = CPU_TYPE_POWERPC;
#else /* !__ppc64__ */
					cpu_types[0] = CPU_TYPE_X86;
#endif /* !__ppc64__ */
				}
				break;
			}
		}
	}
#endif /* __LP64__ */


	if (posix_spawnattr_setbinpref_np(&spawnattr, count, cpu_types, &ocount) == -1) {
		err(1, "posix_spawnattr_setbinpref");
		/* NOTREACHTED */
	}
	if (count != ocount) {
		fprintf(stderr, "posix_spawnattr_setbinpref failed to copy %ld != %ld\n", (long)count, (long)ocount);
		return 1;
		/* NOTREACHTED */
	}


	/* 
	 * Set flag that causes posix_spawn to behave like execv
	 */
	flags |= POSIX_SPAWN_SETEXEC;
	if ((errno = posix_spawnattr_setflags(&spawnattr, flags)) != 0) {
		err(1, "posix_spawnattr_setflags");
		/* NOTREACHTED */
	}

	argv[0] = Python;

	posix_spawn(NULL, argv[0], NULL,
		&spawnattr, argv, environ);
	err(1, "posix_spawn: %s", Python);
	/* NOTREACHED */
}