"""
Parse ISO 9660 from a MODE1/2352 raw BIN file.
Each sector = 2352 bytes; user data starts at byte 16 (after sync+header).
"""
import struct, sys, os

BIN = sys.argv[1] if len(sys.argv) > 1 else r"Z:\Development\devl\Havoc\tmp_cd\Havoc (USA) (Game Disk).bin"
SECTOR = 2352
DATA_OFF = 16   # within each sector: sync(12) + header(4)
DATA_LEN = 2048

def read_sector(f, lba):
    f.seek(lba * SECTOR + DATA_OFF)
    return f.read(DATA_LEN)

def read_u16_le(b, off): return struct.unpack_from('<H', b, off)[0]
def read_u32_le(b, off): return struct.unpack_from('<I', b, off)[0]
def read_u32_both(b, off): return struct.unpack_from('<I', b, off)[0]  # LE half

def parse_dir(f, lba, size, indent=0, entries=None):
    if entries is None:
        entries = []
    data = b''
    remaining = size
    cur_lba = lba
    while remaining > 0:
        chunk = read_sector(f, cur_lba)
        data += chunk[:min(DATA_LEN, remaining)]
        remaining -= DATA_LEN
        cur_lba += 1

    off = 0
    while off < len(data):
        reclen = data[off]
        if reclen == 0:
            off = (off + 1 + 1) & ~1  # skip padding; advance
            if off >= len(data): break
            continue
        flags   = data[off + 25]
        name_len = data[off + 32]
        name_raw = data[off+33:off+33+name_len]
        # Strip version suffix ;1
        name = name_raw.decode('ascii', errors='replace').split(';')[0].rstrip('\x00')
        file_lba  = read_u32_both(data, off + 2)
        file_size = read_u32_both(data, off + 10)
        is_dir = bool(flags & 0x02)
        if name not in ('', '\x01'):
            entries.append({'name': name, 'lba': file_lba, 'size': file_size,
                            'is_dir': is_dir, 'indent': indent})
            if is_dir:
                parse_dir(f, file_lba, file_size, indent+1, entries)
        off += reclen
    return entries

with open(BIN, 'rb') as f:
    # Check for ISO 9660 PVD at sector 16
    pvd = read_sector(f, 16)
    if pvd[1:6] != b'CD001':
        print(f"No ISO 9660 PVD at sector 16. Got: {pvd[0:8].hex(' ')}")
        # Try sector 16 with different offset (some TOAST BINs have ISO 9660 elsewhere)
        # Check volume descriptor sequence starting at 16
        for lba in [16, 17, 18, 32, 64]:
            s = read_sector(f, lba)
            print(f"  Sector {lba}: type={s[0]} sig={s[1:6]} system_id={s[8:40].rstrip()}")
        sys.exit(1)

    vol_type   = pvd[0]  # 1 = PVD
    system_id  = pvd[8:40].decode('ascii', errors='replace').strip()
    vol_id     = pvd[40:72].decode('ascii', errors='replace').strip()
    vol_space  = read_u32_both(pvd, 80)
    print(f"ISO 9660 PVD found:")
    print(f"  System ID:  {system_id!r}")
    print(f"  Volume ID:  {vol_id!r}")
    print(f"  Vol sectors:{vol_space}")

    root_dir_lba  = read_u32_both(pvd, 156 + 2)
    root_dir_size = read_u32_both(pvd, 156 + 10)
    print(f"  Root dir LBA={root_dir_lba} size={root_dir_size}")
    print()

    entries = parse_dir(f, root_dir_lba, root_dir_size)

    print(f"Files ({len(entries)} entries):")
    for e in entries:
        prefix = '  ' * e['indent']
        tag = '[DIR]' if e['is_dir'] else f"{e['size']:>10}"
        print(f"  {prefix}{e['name']:<30} {tag}")

    print()
    # Look for specific files we need
    targets = ['HAVOCDAT.DAT', 'KEYSET.DAT', 'BIGFILE.DAT', 'GAMIMAGE.DAT']
    print("Target file search:")
    for e in entries:
        if e['name'].upper() in targets:
            print(f"  FOUND: {e['name']} at LBA {e['lba']} size {e['size']}")