"""BTCPay webhook router — advances orders through the money flow.

POST /api/webhooks/btcpay  (signed by BTCPay)

InvoiceSettled  -> order paid -> place supplier order -> status supplier_order
InvoiceExpired  -> order cancelled (no payment)
InvoiceInvalid  -> order cancelled (payment failed)
"""
from fastapi import APIRouter, Depends, Header, HTTPException, Request
from sqlalchemy.orm import Session

from app.database import get_db
from app.engines.payments import btcpay
from app.engines.suppliers.base import build_adapter
from app.models import AuditLog, Order, Supplier

router = APIRouter()


def _get_order_by_invoice(db: Session, invoice_id: str):
    return db.query(Order).filter(Order.btcpay_invoice_id == invoice_id).first()


def _place_supplier_order(db: Session, order: Order):
    """Call the supplier's real create_order and store the reference."""
    if order.supplier_id is None:
        order.status = "supplier_order"
        db.add(AuditLog(actor="webhook", action="no_supplier", entity="order",
                        entity_id=order.order_number))
        return
    supplier = db.query(Supplier).filter(Supplier.id == order.supplier_id).first()
    if supplier is None:
        order.status = "supplier_order"
        return
    try:
        adapter = build_adapter(supplier)
        items = [
            {"supplier_sku": it.get("sku"), "qty": it.get("qty", 1)}
            for it in (order.items or [])
        ]
        result = adapter.create_order(items)
        order.supplier_order_ref = str(result.get("ref", ""))
        order.status = "supplier_order"
        db.add(AuditLog(actor="webhook", action="supplier_order_placed", entity="order",
                        entity_id=order.order_number,
                        detail={"supplier": supplier.name, "ref": order.supplier_order_ref}))
    except Exception as e:
        order.status = "paid"  # paid but supplier order failed -> needs manual retry
        db.add(AuditLog(actor="webhook", action="supplier_order_failed", entity="order",
                        entity_id=order.order_number, detail={"error": str(e)}))


@router.post("/btcpay")
async def btcpay_webhook(request: Request, db: Session = Depends(get_db)):
    raw = await request.body()
    sig = request.headers.get("btcpay-sig", "")
    if not btcpay.verify_webhook(raw, sig):
        raise HTTPException(status_code=401, detail="invalid signature")

    payload = await request.json()
    event_type = payload.get("type")
    invoice_id = payload.get("invoiceId") or payload.get("id")
    order = _get_order_by_invoice(db, invoice_id) if invoice_id else None
    if order is None:
        return {"ok": True, "matched": False}

    if event_type == "InvoiceSettled":
        order.status = "paid"
        _place_supplier_order(db, order)
    elif event_type in ("InvoiceExpired", "InvoiceInvalid"):
        order.status = "cancelled"
    db.commit()

    db.add(AuditLog(actor="btcpay", action=event_type, entity="order",
                    entity_id=order.order_number, detail={"invoice_id": invoice_id}))
    db.commit()
    return {"ok": True, "order": order.order_number, "status": order.status}