import struct

def decode_scanline(data, width, max_rows=100000):
    i = 0
    n = len(data)
    rows = 0
    row_len = 0
    while i < n:
        if row_len >= width:
            rows += 1
            row_len = 0
            if rows > max_rows:
                return rows, i, False
            continue
        b = data[i]
        if (b & 0xC0) == 0xC0:
            count = b & 0x3F
            i += 1
            if i >= n:
                return rows, i, False
            i += 1
            need = width - row_len
            take = min(count, need)
            row_len += take
        else:
            row_len += 1
            i += 1
    if row_len == 0:
        return rows, i, True
    else:
        rows += 1  # partial
        return rows, i, False

base = "/home/aria/kellogg_remake/extracted_pre/"
files = ["B.BOB","E.BOB","N.BOB","O.BOB","A.BOB","J.BOB","K.BOB","D.BOB"]

for fn in files:
    data = open(base+fn, "rb").read()
    n = len(data)
    print(f"=== {fn} size={n} ===")
    found_any = False
    for headerlen in range(0, 17, 1):
        if headerlen % 2 != 0:
            continue
        header = data[:headerlen]
        body = data[headerlen:]
        num_u16 = headerlen // 2
        u16s = struct.unpack(f"<{num_u16}H", header) if headerlen else ()
        # try every pair (w_idx, h_idx) among header u16 fields as (width,height) candidates
        for wi in range(num_u16):
            w = u16s[wi]
            if w < 2 or w > 400:
                continue
            rows, consumed, ok = decode_scanline(body, w)
            if ok:
                # check if any header u16 equals rows (=height)
                match_h = [hi for hi,val in enumerate(u16s) if val == rows]
                print(f"  headerlen={headerlen} width_idx={wi} width={w} -> rows={rows} clean=True header_u16={u16s} height_field_match_idx={match_h}")
                found_any = True
    if not found_any:
        print("  (no clean header+width combo found in range)")