import os
import stripe
from fastapi import APIRouter, Request, HTTPException, Depends
from pydantic import BaseModel
from typing import Optional
from core.subscription.middleware import verify_token
from core.subscription.db import SessionLocal
from core.subscription.models import User
from clerk_backend_api import Clerk

stripe_router = APIRouter()

stripe.api_key = os.getenv("STRIPE_SECRET_KEY")
endpoint_secret = os.getenv("STRIPE_WEBHOOK_SECRET")

clerk_secret = os.getenv("CLERK_SECRET_KEY")
clerk = Clerk(bearer_auth=clerk_secret) if clerk_secret else None

FRONTEND_URL = os.getenv("FRONTEND_URL", "https://grantforge-frontend.onrender.com")


# ─── Checkout session ───────────────────────────────────────────────────────


class CheckoutRequest(BaseModel):
    plan: Optional[str] = "pro"  # "pro" | "business"


@stripe_router.post("/subscription/checkout")
async def create_checkout_session(
    payload: CheckoutRequest,
    token_data: dict = Depends(verify_token),
):
    """Tworzy sesję Stripe Checkout i zwraca URL do płatności."""
    user_id = token_data.get("sub")
    if not user_id:
        raise HTTPException(status_code=401, detail="Brak autoryzacji")

    price_id = os.getenv("STRIPE_PRICE_ID_PRO")
    if not price_id:
        raise HTTPException(
            status_code=503, detail="Stripe price ID nie skonfigurowany."
        )

    if not stripe.api_key:
        raise HTTPException(
            status_code=503,
            detail="Stripe nie jest skonfigurowany. Skontaktuj się z supportem.",
        )

    success_url = f"{FRONTEND_URL}/projects?upgraded=1&tier={payload.plan}&session_id={{CHECKOUT_SESSION_ID}}"
    cancel_url = f"{FRONTEND_URL}/cennik?cancelled=1"

    try:
        session = stripe.checkout.Session.create(
            mode="subscription",
            payment_method_types=["card"],
            line_items=[{"price": price_id, "quantity": 1}],
            success_url=success_url,
            cancel_url=cancel_url,
            client_reference_id=user_id,
            metadata={"tier": payload.plan or "pro"},
            locale="pl",
            billing_address_collection="auto",
            tax_id_collection={"enabled": True},
            invoice_creation={"enabled": True},
        )
        return {"checkout_url": session.url, "session_id": session.id}
    except stripe.error.InvalidRequestError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Błąd Stripe: {str(e)}")


# ─── Stripe Webhook ───────────────────────────────────────────────────────


@stripe_router.post("/webhook/stripe")
async def stripe_webhook_endpoint(request: Request):
    payload = await request.body()
    sig_header = request.headers.get("stripe-signature")

    if not endpoint_secret:
        return {"status": "ignored", "reason": "No webhook secret configured"}

    try:
        event = stripe.Webhook.construct_event(payload, sig_header, endpoint_secret)
    except ValueError:
        raise HTTPException(status_code=400, detail="Invalid payload")
    except stripe.error.SignatureVerificationError:
        raise HTTPException(status_code=400, detail="Invalid signature")

    if event["type"] == "checkout.session.completed":
        session = event["data"]["object"]
        user_id = session.get("client_reference_id")
        customer_id = session.get("customer")
        subscription_id = session.get("subscription")
        tier = session.get("metadata", {}).get("tier", "pro").lower()

        if user_id:
            # 1. Aktualizacja Clerk public_metadata
            if clerk:
                try:
                    clerk.users.update_user(
                        user_id=user_id, public_metadata={"stripe_subscription": tier}
                    )
                except Exception as e:
                    print(f"[Webhook] Błąd Clerk update {user_id}: {e}")

            # 2. Aktualizacja user.tier w PostgreSQL
            db = SessionLocal()
            try:
                user = db.query(User).filter(User.clerk_id == user_id).first()
                if not user:
                    user = User(clerk_id=user_id)
                    db.add(user)
                user.tier = tier
                user.stripe_customer_id = customer_id
                user.stripe_subscription_id = subscription_id
                db.commit()
                print(f"[Webhook] ✅ User {user_id} upgrade -> {tier}")
            except Exception as e:
                db.rollback()
                print(f"[Webhook] ❌ DB error {user_id}: {e}")
            finally:
                db.close()

    elif event["type"] == "customer.subscription.deleted":
        subscription = event["data"]["object"]
        sub_id = subscription.get("id")
        db = SessionLocal()
        try:
            user = db.query(User).filter(User.stripe_subscription_id == sub_id).first()
            if user:
                user.tier = "free"
                if clerk:
                    try:
                        clerk.users.update_user(
                            user_id=user.clerk_id,
                            public_metadata={"stripe_subscription": "free"},
                        )
                    except Exception:
                        pass
                db.commit()
                print(f"[Webhook] Downgrade user {user.clerk_id} -> free")
        except Exception:
            db.rollback()
        finally:
            db.close()

    return {"status": "success"}