orders = [
    {"order_id": 1, "customer_id": 101, "amount": 59.99,  "status": "completed"},
    {"order_id": 2, "customer_id": 102, "amount": 120.00, "status": "completed"},
    {"order_id": 3, "customer_id": 101, "amount": 34.50,  "status": "refunded"},
    {"order_id": 4, "customer_id": 103, "amount": 89.00,  "status": "completed"},
    {"order_id": 5, "customer_id": 102, "amount": 45.00,  "status": "completed"},
]

@timer
def transform_orders(orders: list[dict]) -> list[dict]:
    # Compute lifetime value per customer
    ltv = {}
    for o in orders:
        if o["status"] == "completed":
            ltv[o["customer_id"]] = ltv.get(o["customer_id"], 0) + o["amount"]

    # Enrich each order with LTV and spend tier
    def spend_tier(value):
        if value >= 200: return "high"
        if value >= 100: return "mid"
        return "low"

    return [
        {**o, "customer_ltv": ltv.get(o["customer_id"], 0),
              "spend_tier": spend_tier(ltv.get(o["customer_id"], 0))}
        for o in orders
    ]


result = transform_orders(orders)

for row in result:
    print(row)