#!/usr/bin/env python3
"""Prueft, ob Java- und Bedrock-Endpunkt eines Crossplay-Servers antworten.

    python scripts/check-crossplay.py                      # localhost
    python scripts/check-crossplay.py minecraft.djnizz.at  # Live-Server

Der Java-Test spricht das Server-List-Ping-Protokoll, der Bedrock-Test einen
RakNet Unconnected Ping - also genau das, was die echten Clients tun.
"""
import json
import os
import socket
import struct
import sys
import time

HOST = sys.argv[1] if len(sys.argv) > 1 else "127.0.0.1"
JAVA_PORT = int(sys.argv[2]) if len(sys.argv) > 2 else 25565
BEDROCK_PORT = int(sys.argv[3]) if len(sys.argv) > 3 else 19132
TIMEOUT = 10


def _varint(n):
    out = b""
    while True:
        b = n & 0x7F
        n >>= 7
        out += bytes([b | (0x80 if n else 0)])
        if not n:
            return out


def _read_varint(sock):
    n = 0
    for i in range(5):
        b = sock.recv(1)
        if not b:
            raise EOFError("Verbindung vorzeitig geschlossen")
        n |= (b[0] & 0x7F) << (7 * i)
        if not b[0] & 0x80:
            return n
    raise ValueError("VarInt zu lang")


def java_ping(host, port):
    s = socket.create_connection((host, port), timeout=TIMEOUT)
    try:
        host_b = host.encode()
        # Handshake: Protokollversion ist beim Status-Ping beliebig
        payload = (b"\x00" + _varint(772) + _varint(len(host_b)) + host_b
                   + struct.pack(">H", port) + _varint(1))
        s.sendall(_varint(len(payload)) + payload)
        s.sendall(_varint(1) + b"\x00")  # Status Request
        _read_varint(s)                  # Paketlaenge
        _read_varint(s)                  # Paket-ID
        n = _read_varint(s)              # JSON-Laenge
        data = b""
        while len(data) < n:
            chunk = s.recv(n - len(data))
            if not chunk:
                break
            data += chunk
        return json.loads(data.decode("utf-8"))
    finally:
        s.close()


RAKNET_MAGIC = bytes([0x00, 0xFF, 0xFF, 0x00, 0xFE, 0xFE, 0xFE, 0xFE,
                      0xFD, 0xFD, 0xFD, 0xFD, 0x12, 0x34, 0x56, 0x78])


def bedrock_ping(host, port):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    s.settimeout(TIMEOUT)
    try:
        pkt = (b"\x01" + struct.pack(">Q", int(time.time() * 1000))
               + RAKNET_MAGIC + os.urandom(8))
        s.sendto(pkt, (host, port))
        data, _ = s.recvfrom(4096)
        if data[0] != 0x1C:
            raise ValueError(f"unerwartete Antwort-ID 0x{data[0]:02x}")
        strlen = struct.unpack(">H", data[33:35])[0]
        return data[35:35 + strlen].decode("utf-8", "replace")
    finally:
        s.close()


def main():
    print(f"Ziel: {HOST}  (Java {JAVA_PORT}/TCP, Bedrock {BEDROCK_PORT}/UDP)\n")
    failed = False

    print("=== Java Edition (TCP) ===")
    try:
        j = java_ping(HOST, JAVA_PORT)
        version = j.get("version", {})
        desc = j.get("description")
        if isinstance(desc, dict):
            desc = desc.get("text", "") or "".join(
                e.get("text", "") for e in desc.get("extra", []))
        players = j.get("players", {})
        print(f"  OK   {version.get('name')} (Protokoll {version.get('protocol')})")
        print(f"       MOTD    {desc!r}")
        print(f"       Spieler {players.get('online')}/{players.get('max')}")
    except Exception as e:
        failed = True
        print(f"  FEHLER  {type(e).__name__}: {e}")
        print("          -> Security List (TCP 25565), Instanz-Firewall, Container laeuft?")

    print("\n=== Bedrock Edition (UDP, RakNet) ===")
    try:
        fields = bedrock_ping(HOST, BEDROCK_PORT).split(";")
        labels = ["Edition", "MOTD Zeile 1", "Protokoll", "Version", "Spieler",
                  "Max. Spieler", "Server-GUID", "MOTD Zeile 2", "Gamemode"]
        print("  OK")
        for label, value in zip(labels, fields):
            print(f"       {label:<13} {value}")
    except Exception as e:
        failed = True
        print(f"  FEHLER  {type(e).__name__}: {e}")
        print("          -> Security List (UDP 19132!), Geyser gestartet?")

    print()
    if failed:
        print("Mindestens ein Endpunkt antwortet nicht.")
        sys.exit(1)
    print("Beide Editionen erreichbar.")


if __name__ == "__main__":
    main()