import sys
from generate import renderer
import string

with open(sys.argv[1], 'r') as f:
    buf = f.read()

def split_line(line):
    register_name = line[0:21]
    addr = line[21:44]
    bits = line[44:53]
    description = line[53:]
    return (
        register_name.strip(),
        addr.strip(),
        bits.strip(),
        description.strip()
    )

def parse_addr(addr):
    base10, base16 = addr.split()
    base16 = base16.removeprefix('(').removesuffix(')')
    assert int(base10, 10) == int(base16, 16)
    return int(base16, 16)

def parse_bits(bits):
    high, low = bits.split(":")
    return int(high, 10), int(low, 10)

def parse_lines(buf):
    it = map(split_line, buf.strip().split('\n'))
    header = next(it)
    assert header == ('Register Name', 'Addr', 'Bits', 'Description')
    for register_name, addr, bits, description in it:
        if register_name.lower() == "reserved":
            continue
        addr = parse_addr(addr)
        bits = parse_bits(bits)
        yield register_name, addr, bits, description

def bits_length(bits):
    high, low = bits
    assert (high + 1) % 8 == 0 and low == 0
    length = (high + 1) // 8
    return length

def reg_type(length):
    if length == 1:
        return "reg8"
    if length == 2:
        return "reg16"
    if length == 3:
        return "reg8"
    if length == 4:
        return "reg32"
    assert False, length


def format_name(s):
    def do():
        prev_lower = False
        for i, c in enumerate(s):
            if prev_lower and i > 0 and c in string.ascii_uppercase:
                yield "_"
            prev_lower = c in string.ascii_lowercase
            yield c.upper()

    return "".join(do())

def render_struct(buf):
    next_address = 0
    reserved_ix = 0
    yield "struct voodoo2_config {"
    lines = list(parse_lines(buf))
    for register_name, addr, bits, description in lines:
        if addr != next_address:
            yield f"reg8 _reserved{reserved_ix}[{addr - next_address}];"
            reserved_ix += 1
        length = bits_length(bits)
        arr = "" if length != 3 else "[3]"
        yield f"{reg_type(length)} {format_name(register_name)}{arr};"
        next_address = addr + length
    yield "};"
    yield ""
    for register_name, addr, bits, description in lines:
        length = bits_length(bits)
        arr = "" if length != 3 else "[0]"
        yield f"static_assert((offsetof (struct voodoo2_config, {format_name(register_name)}{arr})) == 0x{addr:02x});"

def render_macros(buf):
    lines = list(parse_lines(buf))
    for register_name, addr, bits, description in lines:
        yield f"#define PCI__CONFIG__{format_name(register_name)} (0x{addr:02x})"

def render_all(buf):
    yield "#pragma once"
    yield ""
    yield "#include <stddef.h>"
    yield "#include <stdint.h>"
    yield ""
    yield '#include "reg.h"'
    yield ""
    yield from render_macros(buf)
    yield ""
    yield "typedef struct voodoo2_config voodoo2_config;"

with open(sys.argv[1], 'r') as f:
    buf = f.read()
lines = buf.split('\n')
render, out = renderer()
render(render_all(buf))
sys.stdout.write(out.getvalue())