import argparse, os, struct, csv, hashlib, sys


def read_index(path):
    data = open(path, "rb").read()
    count = struct.unpack_from("<I", data, 0)[0]
    p = 4
    entries = []
    for i in range(count):
        ln = struct.unpack_from("<I", data, p)[0]
        p += 4
        name = data[p:p + ln].decode("latin1")
        p += ln
        off, size = struct.unpack_from("<II", data, p)
        p += 8
        entries.append((name, off, size))
    return data, entries, p


def safe_rel(name):
    rel = name.replace("\\", os.sep).replace("/", os.sep)
    parts = [x for x in rel.split(os.sep) if x not in ("", ".", "..")]
    return os.path.join(*parts) if parts else "_unnamed"


def main():
    ap = argparse.ArgumentParser(description="Extract the Dragon .res archive (index + raw blobs).")
    ap.add_argument("res")
    ap.add_argument("out")
    ap.add_argument("--csv", default=None)
    args = ap.parse_args()

    data, entries, header_end = read_index(args.res)
    os.makedirs(args.out, exist_ok=True)
    rows = []
    used = set()
    for name, off, size in entries:
        rel = safe_rel(name)
        dst = os.path.join(args.out, rel)
        base, ext = os.path.splitext(dst)
        n = 1
        while dst.lower() in used:
            dst = "%s__%d%s" % (base, n, ext)
            n += 1
        used.add(dst.lower())
        os.makedirs(os.path.dirname(dst), exist_ok=True)
        blob = data[off:off + size]
        with open(dst, "wb") as f:
            f.write(blob)
        rows.append({
            "name": name,
            "offset": off,
            "size": size,
            "file": os.path.relpath(dst, args.out),
            "sha1": hashlib.sha1(blob).hexdigest(),
        })
        print("[%4d/%d] %s (%d bytes)" % (len(rows), len(entries), name, size))

    if args.csv:
        with open(args.csv, "w", newline="", encoding="utf-8") as f:
            w = csv.DictWriter(f, fieldnames=["name", "offset", "size", "file", "sha1"])
            w.writeheader()
            w.writerows(rows)
    print("done: %d files -> %s" % (len(rows), args.out))


if __name__ == "__main__":
    main()