import json
import time
from flask import request

# In-memory корзина (живёт пока жив под poolmgr)
_CARTS: dict = {}


def _get_cart(user_id: str) -> dict:
    if user_id not in _CARTS:
        _CARTS[user_id] = {"user_id": user_id, "items": [], "created_at": int(time.time())}
    return _CARTS[user_id]


def _cart_total(cart: dict) -> float:
    return round(sum(i["price"] * i["qty"] for i in cart["items"]), 2)


def main():
    method = request.method.upper()
    user_id = request.headers.get("x-user-id", "user-1")
    body = {}
    if request.data:
        try:
            body = json.loads(request.data)
        except Exception:
            pass

    cart = _get_cart(user_id)

    if method == "GET":
        return json.dumps({
            "status": "ok",
            "cart": cart,
            "total": _cart_total(cart),
            "item_count": len(cart["items"]),
        })

    if method == "POST":
        # Добавить товар: {"product_id": "p-001", "name": "...", "price": 29.99, "qty": 2}
        required = ["product_id", "name", "price", "qty"]
        if not all(k in body for k in required):
            return {"status": 400,
                    "body": json.dumps({"error": "missing fields", "required": required}),
                    "headers": {"Content-Type": "application/json"}}

        # Если товар уже в корзине — увеличиваем qty
        for item in cart["items"]:
            if item["product_id"] == body["product_id"]:
                item["qty"] += int(body["qty"])
                return json.dumps({"status": "ok", "action": "updated", "cart": cart,
                                   "total": _cart_total(cart)})

        cart["items"].append({
            "product_id": body["product_id"],
            "name": body["name"],
            "price": float(body["price"]),
            "qty": int(body["qty"]),
        })
        return json.dumps({"status": "ok", "action": "added", "cart": cart,
                           "total": _cart_total(cart)})

    if method == "DELETE":
        product_id = body.get("product_id", "")
        cart["items"] = [i for i in cart["items"] if i["product_id"] != product_id]
        return json.dumps({"status": "ok", "action": "removed", "cart": cart,
                           "total": _cart_total(cart)})

    return {"status": 405, "body": json.dumps({"error": "method not allowed"}),
            "headers": {"Content-Type": "application/json"}}