#! /usr/bin/env python3

"""
This script should be called *manually* when we want to upgrade SSLError
`library` and `reason` mnemnonics to a more recent OpenSSL version.

It takes two arguments:
- the path to the OpenSSL include files' directory
  (e.g. openssl-1.0.1-beta3/include/openssl/)
- the path to the C file to be generated
  (probably Modules/_ssl_data.h)
"""

import datetime
import os
import re
import sys


def parse_error_codes(h_file, prefix):
    pat = re.compile(r"#define\W+(%s([\w]+))\W+(\d+)\b" % re.escape(prefix))
    codes = []
    with open(h_file, "r", encoding="latin1") as f:
        for line in f:
            match = pat.search(line)
            if match:
                code, name, num = match.groups()
                num = int(num)
                codes.append((code, name, num))
    return codes

if __name__ == "__main__":
    openssl_inc = sys.argv[1]
    outfile = sys.argv[2]
    use_stdout = outfile == '-'
    f = sys.stdout if use_stdout else open(outfile, "w")
    error_libraries = (
        # (library code, mnemonic, error prefix, header file)
        ('ERR_LIB_PEM', 'PEM', 'PEM_R_', 'pem.h'),
        ('ERR_LIB_SSL', 'SSL', 'SSL_R_', 'ssl.h'),
        ('ERR_LIB_X509', 'X509', 'X509_R_', 'x509.h'),
        )
    def w(l):
        f.write(l + "\n")
    w("/* File generated by Tools/ssl/make_ssl_data.py */")
    w("/* Generated on %s */" % datetime.datetime.now().isoformat())
    w("")

    w("static struct py_ssl_library_code library_codes[] = {")
    for libcode, mnemo, _, _ in error_libraries:
        w('    {"%s", %s},' % (mnemo, libcode))
    w('    { NULL }')
    w('};')
    w("")

    w("static struct py_ssl_error_code error_codes[] = {")
    for libcode, _, prefix, h_file in error_libraries:
        codes = parse_error_codes(os.path.join(openssl_inc, h_file), prefix)
        for code, name, num in sorted(codes):
            w('  #ifdef %s' % (code))
            w('    {"%s", %s, %s},' % (name, libcode, code))
            w('  #else')
            w('    {"%s", %s, %d},' % (name, libcode, num))
            w('  #endif')
    w('    { NULL }')
    w('};')
    if not use_stdout:
        f.close()