#!/usr/bin/env python
#
# Create frozen modules structure for MicroPython.
#
# Usage:
#
# Have a directory with modules to be frozen (only modules, not packages
# supported so far):
#
# frozen/foo.py
# frozen/bar.py
#
# Run script, passing path to the directory above:
#
# ./make-frozen.py frozen > frozen.c
#
# Include frozen.c in your build, having defined MICROPY_MODULE_FROZEN_STR in
# config.
#
from __future__ import print_function
import sys
import os


def module_name(f):
 return f


modules = []

if len(sys.argv) > 1:
 root = sys.argv[1].rstrip("/")
 root_len = len(root)

 for dirpath, dirnames, filenames in os.walk(root):
 for f in filenames:
 fullpath = dirpath + "/" + f
 st = os.stat(fullpath)
 modules.append((fullpath[root_len + 1 :], st))

print("#include <stdint.h>")
print("const char mp_frozen_str_names[] = {")
for f, st in modules:
 m = module_name(f)
 print('"%s\\0"' % m)
print('"\\0"};')

print("const uint32_t mp_frozen_str_sizes[] = {")

for f, st in modules:
 print("%d," % st.st_size)

print("0};")

print("const char mp_frozen_str_content[] = {")
for f, st in modules:
 data = open(sys.argv[1] + "/" + f, "rb").read()

 # We need to properly escape the script data to create a C string.
 # When C parses hex characters of the form \x00 it keeps parsing the hex
 # data until it encounters a non-hex character. Thus one must create
 # strings of the form "data\x01" "abc" to properly encode this kind of
 # data. We could just encode all characters as hex digits but it's nice
 # to be able to read the resulting C code as ASCII when possible.

 data = bytearray(data) # so Python2 extracts each byte as an integer
 esc_dict = {ord("\n"): "\\n", ord("\r"): "\\r", ord('"'): '\\"', ord("\\"): "\\\\"}
 chrs = ['"']
 break_str = False
 for c in data:
 try:
 chrs.append(esc_dict[c])
 except KeyError:
 if 32 <= c <= 126:
 if break_str:
 chrs.append('" "')
 break_str = False
 chrs.append(chr(c))
 else:
 chrs.append("\\x%02x" % c)
 break_str = True
 chrs.append('\\0"')
 print("".join(chrs))

print('"\\0"};')