"""Billing routes: Stripe checkout, webhook, subscription management.

Business logic lives in ``app.billing.stripe_service.StripeService``.
The route layer handles HTTP concerns (request parsing, response shaping)
and delegates everything else to the service singleton.
"""

from __future__ import annotations

from typing import Any

from fastapi import APIRouter, Depends, Header, Request, status
from pydantic import BaseModel
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.deps import get_current_user
from app.billing.stripe_service import stripe_service
from app.db import get_session
from app.schemas import BillingTier, UserProfile

router = APIRouter(prefix="/billing", tags=["billing"])


# ── Request bodies ─────────────────────────────────────────────────────

class _CheckoutRequest(BaseModel):
    tier: BillingTier


# ── Routes ─────────────────────────────────────────────────────────────

@router.post("/checkout", response_model=dict)
async def create_checkout(
    body: _CheckoutRequest,
    current_user: UserProfile = Depends(get_current_user),
) -> dict[str, str]:
    """Create a Stripe checkout session for a tier upgrade.

    Returns a stub URL when ``STRIPE_SECRET_KEY`` is not configured.
    """
    url = stripe_service.create_checkout_session(current_user.id, body.tier)
    return {"checkout_url": url}


@router.post("/webhook", response_model=dict)
async def stripe_webhook(
    request: Request,
    stripe_signature: str = Header(default="", alias="Stripe-Signature"),
    db: AsyncSession = Depends(get_session),
) -> dict[str, bool]:
    """Handle Stripe webhook events.

    No JWT auth — authenticated via Stripe signature verification instead.
    Returns 200 immediately when Stripe is not configured (local dev).
    """
    payload = await request.body()
    await stripe_service.handle_webhook(payload, stripe_signature, db)
    return {"ok": True}


@router.get("/subscription", response_model=dict)
async def get_subscription(
    current_user: UserProfile = Depends(get_current_user),
    db: AsyncSession = Depends(get_session),
) -> dict[str, Any]:
    """Return the current subscription info for the authenticated user."""
    sub = await stripe_service.get_subscription(current_user.id, db)
    if sub is None:
        return {
            "tier": current_user.tier,
            "status": "free",
            "stripe_subscription_id": None,
            "current_period_end": None,
        }
    return sub


@router.delete("/subscription", response_model=dict, status_code=status.HTTP_200_OK)
async def cancel_subscription(
    current_user: UserProfile = Depends(get_current_user),
    db: AsyncSession = Depends(get_session),
) -> dict[str, bool]:
    """Cancel the active subscription."""
    await stripe_service.cancel_subscription(current_user.id, db)
    return {"ok": True}