"""
This script reads in the given CMSIS device include file (eg stm32f405xx.h),
extracts relevant peripheral constants, and creates qstrs, mpz's and constants
for the stm module.
"""

from __future__ import print_function

import argparse
import re

# Python 2/3 compatibility
import platform
if platform.python_version_tuple()[0] == '2':
    def convert_bytes_to_str(b):
        return b
elif platform.python_version_tuple()[0] == '3':
    def convert_bytes_to_str(b):
        try:
            return str(b, 'utf8')
        except ValueError:
            # some files have invalid utf8 bytes, so filter them out
            return ''.join(chr(l) for l in b if l <= 126)
# end compatibility code

# given a list of (name,regex) pairs, find the first one that matches the given line
def re_match_first(regexs, line):
    for name, regex in regexs:
        match = re.match(regex, line)
        if match:
            return name, match
    return None, None

class LexerError(Exception):
    def __init__(self, line):
        self.line = line

class Lexer:
    re_io_reg = r'__IO uint(?P<bits>8|16|32)_t +(?P<reg>[A-Z0-9]+)'
    re_comment = r'(?P<comment>[A-Za-z0-9 \-/_()&]+)'
    re_addr_offset = r'Address offset: (?P<offset>0x[0-9A-Z]{2,3})'
    regexs = (
        ('#define hex', re.compile(r'#define +(?P<id>[A-Z0-9_]+) +(?:\(\(uint32_t\))?(?P<hex>0x[0-9A-F]+)U?(?:\))?($| +/\*)')),
        ('#define X', re.compile(r'#define +(?P<id>[A-Z0-9_]+) +(?P<id2>[A-Z0-9_]+)($| +/\*)')),
        ('#define X+hex', re.compile(r'#define +(?P<id>[A-Za-z0-9_]+) +\((?P<id2>[A-Z0-9_]+) \+ (?P<hex>0x[0-9A-F]+)U?\)($| +/\*)')),
        ('#define typedef', re.compile(r'#define +(?P<id>[A-Z0-9_]+(ext)?) +\(\([A-Za-z0-9_]+_TypeDef \*\) (?P<id2>[A-Za-z0-9_]+)\)($| +/\*)')),
        ('typedef struct', re.compile(r'typedef struct$')),
        ('{', re.compile(r'{$')),
        ('}', re.compile(r'}$')),
        ('} TypeDef', re.compile(r'} *(?P<id>[A-Z][A-Za-z0-9_]+)_(?P<global>([A-Za-z0-9_]+)?)TypeDef;$')),
        ('IO reg', re.compile(re_io_reg + r'; +/\*!< ' + re_comment + r', +' + re_addr_offset + r' *\*/')),
        ('IO reg array', re.compile(re_io_reg + r'\[(?P<array>[2-8])\]; +/\*!< ' + re_comment + r', +' + re_addr_offset + r'-(0x[0-9A-Z]{2,3}) *\*/')),
    )

    def __init__(self, filename):
        self.file = open(filename, 'rb')
        self.line_number = 0

    def next_match(self, strictly_next=False):
        while True:
            line = self.file.readline()
            line = convert_bytes_to_str(line)
            self.line_number += 1
            if len(line) == 0:
                return ('EOF', None)
            match = re_match_first(Lexer.regexs, line.strip())
            if strictly_next or match[0] is not None:
                return match

    def must_match(self, kind):
        match = self.next_match(strictly_next=True)
        if match[0] != kind:
            raise LexerError(self.line_number)
        return match

def parse_file(filename):
    lexer = Lexer(filename)

    reg_defs = {}
    consts = {}
    periphs = []
    while True:
        m = lexer.next_match()
        if m[0] == 'EOF':
            break
        elif m[0] == '#define hex':
            d = m[1].groupdict()
            consts[d['id']] = int(d['hex'], base=16)
        elif m[0] == '#define X':
            d = m[1].groupdict()
            if d['id2'] in consts:
                consts[d['id']] = consts[d['id2']]
        elif m[0] == '#define X+hex':
            d = m[1].groupdict()
            if d['id2'] in consts:
                consts[d['id']] = consts[d['id2']] + int(d['hex'], base=16)
        elif m[0] == '#define typedef':
            d = m[1].groupdict()
            if d['id2'] in consts:
                periphs.append((d['id'], consts[d['id2']]))
        elif m[0] == 'typedef struct':
            lexer.must_match('{')
            m = lexer.next_match()
            regs = []
            while m[0] in ('IO reg', 'IO reg array'):
                d = m[1].groupdict()
                reg = d['reg']
                offset = int(d['offset'], base=16)
                bits = int(d['bits'])
                comment = d['comment']
                if m[0] == 'IO reg':
                    regs.append((reg, offset, bits, comment))
                else:
                    for i in range(int(d['array'])):
                        regs.append((reg + str(i), offset + i * bits // 8, bits, comment))
                m = lexer.next_match()
            if m[0] == '}':
                pass
            elif m[0] == '} TypeDef':
                reg_defs[m[1].groupdict()['id']] = regs
            else:
                raise LexerError(lexer.line_number)

    return periphs, reg_defs

def print_int_obj(val, needed_mpzs):
    if -0x40000000 <= val < 0x40000000:
        print('MP_ROM_INT(%#x)' % val, end='')
    else:
        print('MP_ROM_PTR(&mpz_%08x)' % val, end='')
        needed_mpzs.add(val)

def print_periph(periph_name, periph_val, needed_qstrs, needed_mpzs):
    qstr = periph_name.upper()
    print('{ MP_ROM_QSTR(MP_QSTR_%s), ' % qstr, end='')
    print_int_obj(periph_val, needed_mpzs)
    print(' },')
    needed_qstrs.add(qstr)

def print_regs(reg_name, reg_defs, needed_qstrs, needed_mpzs):
    reg_name = reg_name.upper()
    for r in reg_defs:
        qstr = reg_name + '_' + r[0]
        print('{ MP_ROM_QSTR(MP_QSTR_%s), ' % qstr, end='')
        print_int_obj(r[1], needed_mpzs)
        print(' }, // %s-bits, %s' % (r[2], r[3]))
        needed_qstrs.add(qstr)

# This version of print regs groups registers together into submodules (eg GPIO submodule).
# This makes the qstrs shorter, and makes the list of constants more manageable (since
# they are not all in one big module) but it is then harder to compile the constants, and
# is more cumbersome to access.
# As such, we don't use this version.
# And for the number of constants we have, this function seems to use about the same amount
# of ROM as print_regs.
def print_regs_as_submodules(reg_name, reg_defs, modules, needed_qstrs):
    mod_name_lower = reg_name.lower() + '_'
    mod_name_upper = mod_name_lower.upper()
    modules.append((mod_name_lower, mod_name_upper))

    print("""
STATIC const mp_rom_map_elem_t stm_%s_globals_table[] = {
    { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_%s) },
""" % (mod_name_lower, mod_name_upper))
    needed_qstrs.add(mod_name_upper)

    for r in reg_defs:
        print('    { MP_ROM_QSTR(MP_QSTR_%s), MP_ROM_INT(%#x) }, // %s-bits, %s' % (r[0], r[1], r[2], r[3]))
        needed_qstrs.add(r[0])

    print("""};

STATIC MP_DEFINE_CONST_DICT(stm_%s_globals, stm_%s_globals_table);

const mp_obj_module_t stm_%s_obj = {
    .base = { &mp_type_module },
    .name = MP_QSTR_%s,
    .globals = (mp_obj_dict_t*)&stm_%s_globals,
};
""" % (mod_name_lower, mod_name_lower, mod_name_lower, mod_name_upper, mod_name_lower))

def main():
    cmd_parser = argparse.ArgumentParser(description='Extract ST constants from a C header file.')
    cmd_parser.add_argument('file', nargs=1, help='input file')
    cmd_parser.add_argument('-q', '--qstr', dest='qstr_filename', default='build/stmconst_qstr.h',
                            help='Specified the name of the generated qstr header file')
    cmd_parser.add_argument('--mpz', dest='mpz_filename', default='build/stmconst_mpz.h',
                            help='the destination file of the generated mpz header')
    args = cmd_parser.parse_args()

    periphs, reg_defs = parse_file(args.file[0])

    # add legacy GPIO constants that were removed when upgrading CMSIS
    if 'GPIO' in reg_defs and 'stm32f4' in args.file[0]:
        reg_defs['GPIO'].append(['BSRRL', 0x18, 16, 'legacy register'])
        reg_defs['GPIO'].append(['BSRRH', 0x1a, 16, 'legacy register'])

    modules = []
    needed_qstrs = set()
    needed_mpzs = set()

    print("// Automatically generated from %s by make-stmconst.py" % args.file[0])
    print("")

    for periph_name, periph_val in periphs:
        print_periph(periph_name, periph_val, needed_qstrs, needed_mpzs)

    for reg in (
        'ADC',
        #'ADC_Common',
        #'CAN_TxMailBox',
        #'CAN_FIFOMailBox',
        #'CAN_FilterRegister',
        #'CAN',
        'CRC',
        'DAC',
        'DBGMCU',
        'DMA_Stream',
        'DMA',
        'EXTI',
        'FLASH',
        'GPIO',
        'SYSCFG',
        'I2C',
        'IWDG',
        'PWR',
        'RCC',
        'RTC',
        #'SDIO',
        'SPI',
        'TIM',
        'USART',
        'WWDG',
        'RNG',
        ):
        if reg in reg_defs:
            print_regs(reg, reg_defs[reg], needed_qstrs, needed_mpzs)
        #print_regs_as_submodules(reg, reg_defs[reg], modules, needed_qstrs)

    #print("#define MOD_STM_CONST_MODULES \\")
    #for mod_lower, mod_upper in modules:
    #    print("    { MP_ROM_QSTR(MP_QSTR_%s), MP_ROM_PTR(&stm_%s_obj) }, \\" % (mod_upper, mod_lower))

    print("")

    with open(args.qstr_filename, 'wt') as qstr_file:
        for qstr in sorted(needed_qstrs):
            print('Q({})'.format(qstr), file=qstr_file)

    with open(args.mpz_filename, 'wt') as mpz_file:
        for mpz in sorted(needed_mpzs):
            assert 0 <= mpz <= 0xffffffff
            print('STATIC const mp_obj_int_t mpz_%08x = {{&mp_type_int}, '
                '{.neg=0, .fixed_dig=1, .alloc=2, .len=2, ' '.dig=(uint16_t*)(const uint16_t[]){%#x, %#x}}};'
                % (mpz, mpz & 0xffff, (mpz >> 16) & 0xffff), file=mpz_file)

if __name__ == "__main__":
    main()
