import json

def simulate_normalize_signal(raw_json, approved_id):
    data = json.loads(raw_json)
    sender = data.get("source")
    text = data.get("message")
    
    if sender == approved_id:
        return {"type": "EVENT", "payload": {"sensor": "inbound-message", "channel": "signal", "text": text}}
    return None

if __name__ == "__main__":
    approved_id = "+1234567890"
    
    print("--- Test 1: Authorized Signal Message ---")
    valid_payload = json.dumps({"source": "+1234567890", "message": "Hello Agent"})
    res1 = simulate_normalize_signal(valid_payload, approved_id)
    print(f"Result: {res1}")
    status1 = "PASS" if res1 and res1["payload"]["text"] == "Hello Agent" else "FAIL"
    
    print("\n--- Test 2: Unauthorized Signal Message ---")
    malicious_payload = json.dumps({"source": "+9999999999", "message": "I am evil"})
    res2 = simulate_normalize_signal(malicious_payload, approved_id)
    print(f"Result: {res2}")
    status2 = "PASS" if res2 is None else "FAIL"
    
    print(f"\nFinal Status: {'PASS' if status1 == 'PASS' and status2 == 'PASS' else 'FAIL'}")