import marshal
import bkfile


# Write a file containing frozen code for the modules in the dictionary.

header = """
#include "Python.h"

static struct _frozen _PyImport_FrozenModules[] = {
"""
trailer = """\
 {0, 0, 0} /* sentinel */
};
"""

# if __debug__ == 0 (i.e. -O option given), set Py_OptimizeFlag in frozen app.
default_entry_point = """
int
main(int argc, char **argv)
{
 extern int Py_FrozenMain(int, char **);
""" + ((not __debug__ and """
 Py_OptimizeFlag++;
""") or "") + """
 PyImport_FrozenModules = _PyImport_FrozenModules;
 return Py_FrozenMain(argc, argv);
}

"""

def makefreeze(base, dict, debug=0, entry_point=None, fail_import=()):
 if entry_point is None: entry_point = default_entry_point
 done = []
 files = []
 mods = sorted(dict.keys())
 for mod in mods:
 m = dict[mod]
 mangled = "__".join(mod.split("."))
 if m.__code__:
 file = 'M_' + mangled + '.c'
 with bkfile.open(base + file, 'w') as outfp:
 files.append(file)
 if debug:
 print("freezing", mod, "...")
 str = marshal.dumps(m.__code__)
 size = len(str)
 if m.__path__:
 # Indicate package by negative size
 size = -size
 done.append((mod, mangled, size))
 writecode(outfp, mangled, str)
 if debug:
 print("generating table of frozen modules")
 with bkfile.open(base + 'frozen.c', 'w') as outfp:
 for mod, mangled, size in done:
 outfp.write('extern unsigned char M_%s[];\n' % mangled)
 outfp.write(header)
 for mod, mangled, size in done:
 outfp.write('\t{"%s", M_%s, %d},\n' % (mod, mangled, size))
 outfp.write('\n')
 # The following modules have a NULL code pointer, indicating
 # that the frozen program should not search for them on the host
 # system. Importing them will *always* raise an ImportError.
 # The zero value size is never used.
 for mod in fail_import:
 outfp.write('\t{"%s", NULL, 0},\n' % (mod,))
 outfp.write(trailer)
 outfp.write(entry_point)
 return files



# Write a C initializer for a module containing the frozen python code.
# The array is called M_<mod>.

def writecode(outfp, mod, str):
 outfp.write('unsigned char M_%s[] = {' % mod)
 for i in range(0, len(str), 16):
 outfp.write('\n\t')
 for c in bytes(str[i:i+16]):
 outfp.write('%d,' % c)
 outfp.write('\n};\n')

## def writecode(outfp, mod, str):
## outfp.write('unsigned char M_%s[%d] = "%s";\n' % (mod, len(str),
## '\\"'.join(map(lambda s: repr(s)[1:-1], str.split('"')))))