JQC_multi_tenant/app/billing/routes.py

"""
app/billing/routes.py
---------------------
MT-8 Stripe billing routes.

Routes:
  GET  /billing/subscribe   → create Stripe Checkout session → redirect
  GET  /billing/portal      → create Stripe Customer Portal session → redirect
  POST /billing/webhook     → verify Stripe signature → handle event
  GET  /billing/suspended   → suspension landing page (no auth required)
  GET  /billing/success     → post-checkout success landing
  GET  /billing/cancel      → post-checkout cancel (redirects to plan page)

All routes are CSRF-exempt (billing.bp is exempted in app/__init__.py).
The webhook route is the primary reason — Stripe cannot send CSRF tokens.
"""

import logging

from flask import (
    current_app, redirect, url_for, render_template,
    request, flash, g, abort,
)
from flask_login import login_required, current_user

from app.billing import bp
from app.utils.decorators import admin_required

logger = logging.getLogger(__name__)


def _billing_enabled():
    return current_app.config.get('BILLING_ENABLED', False)


def _mt_enabled():
    return current_app.config.get('MULTI_TENANT_ENABLED', False)


# ── Subscribe: initiate Stripe Checkout ───────────────────────────────────────

@bp.route('/subscribe')
@login_required
@admin_required
def subscribe():
    if not _billing_enabled():
        flash('Billing is not enabled on this deployment.', 'info')
        return redirect(url_for('tenant_settings.plan'))

    if not _mt_enabled():
        flash('Billing is only available in multi-tenant mode.', 'info')
        return redirect(url_for('tenant_settings.plan'))

    tenant = getattr(g, 'tenant', None)
    if tenant is None:
        abort(400)

    from control.base import control_session
    from control.models import Tenant as ControlTenant, Plan
    from app.billing.stripe_client import create_stripe_customer, create_checkout_session

    # Allow tenant to pick a plan via ?plan=<code> when on Free.
    requested_plan_code = request.args.get('plan')

    with control_session() as s:
        t = s.get(ControlTenant, tenant.id)
        if t is None:
            flash('Tenant not found.', 'danger')
            return redirect(url_for('tenant_settings.plan'))

        plan = t.plan

        # If a specific plan was requested (e.g. from the plan picker), use it.
        if requested_plan_code:
            chosen = s.query(Plan).filter_by(code=requested_plan_code).first()
            if chosen and chosen.stripe_price_id:
                plan = chosen

        # If still on Free (no price ID), show the plan picker instead.
        if plan is None or not plan.stripe_price_id:
            paid_plans = (s.query(Plan)
                          .filter(Plan.stripe_price_id.isnot(None))
                          .order_by(Plan.price_cents)
                          .all())
            return render_template('billing/plan_picker.html', plans=paid_plans)

        # Get or create Stripe customer. Write back immediately within the
        # control_session so the customer_id is persisted before the redirect.
        if not t.stripe_customer_id:
            try:
                customer = create_stripe_customer(
                    email=current_user.email,
                    name=current_user.display_name,
                    tenant_id=tenant.id,
                    slug=tenant.slug,
                )
                t.stripe_customer_id = customer['id']
                t.billing_email      = current_user.email
            except Exception as exc:
                logger.error('BILLING | create_customer_failed | tenant=%s err=%s', tenant.slug, exc)
                flash('Could not connect to Stripe. Please try again or contact support.', 'danger')
                return redirect(url_for('tenant_settings.plan'))

        stripe_customer_id = t.stripe_customer_id
        price_id           = plan.stripe_price_id

    # Create Checkout Session AFTER the control_session commits customer_id.
    base_url = (current_app.config.get('APP_BASE_URL') or request.host_url).rstrip('/')
    try:
        session = create_checkout_session(
            customer_id=stripe_customer_id,
            price_id=price_id,
            tenant_id=tenant.id,
            success_url=f'{base_url}/billing/success?session_id={{CHECKOUT_SESSION_ID}}',
            cancel_url=f'{base_url}/billing/cancel',
        )
    except Exception as exc:
        logger.error('BILLING | create_checkout_failed | tenant=%s err=%s', tenant.slug, exc)
        flash('Could not create a Stripe Checkout session. Please try again.', 'danger')
        return redirect(url_for('tenant_settings.plan'))

    return redirect(session['url'], 303)


# ── Portal: Stripe Customer Portal for managing subscriptions ─────────────────

@bp.route('/portal')
@login_required
@admin_required
def portal():
    if not _billing_enabled():
        flash('Billing is not enabled on this deployment.', 'info')
        return redirect(url_for('tenant_settings.plan'))

    tenant = getattr(g, 'tenant', None)
    if tenant is None:
        abort(400)

    from control.base import control_session
    from control.models import Tenant as ControlTenant
    from app.billing.stripe_client import create_portal_session

    with control_session() as s:
        t = s.get(ControlTenant, tenant.id)
        if t is None or not t.stripe_customer_id:
            flash('No active subscription found. Please subscribe first.', 'warning')
            return redirect(url_for('tenant_settings.plan'))
        stripe_customer_id = t.stripe_customer_id

    base_url   = (current_app.config.get('APP_BASE_URL') or request.host_url).rstrip('/')
    return_url = f'{base_url}/settings/plan'

    try:
        session = create_portal_session(
            customer_id=stripe_customer_id,
            return_url=return_url,
        )
    except Exception as exc:
        logger.error('BILLING | create_portal_failed | tenant=%s err=%s', tenant.slug, exc)
        flash('Could not open the billing portal. Please try again.', 'danger')
        return redirect(url_for('tenant_settings.plan'))

    return redirect(session['url'], 303)


# ── Webhook: receives all Stripe events ───────────────────────────────────────

@bp.route('/webhook', methods=['POST'])
def webhook():
    """Stripe webhook endpoint. Verifies signature then dispatches to webhooks.py."""
    webhook_secret = current_app.config.get('STRIPE_WEBHOOK_SECRET')
    if not webhook_secret:
        logger.error('BILLING WEBHOOK | STRIPE_WEBHOOK_SECRET not configured')
        return {'error': 'Webhook secret not configured'}, 500

    payload    = request.get_data()
    sig_header = request.headers.get('Stripe-Signature', '')

    try:
        import stripe
        stripe.api_key = current_app.config.get('STRIPE_SECRET_KEY', '')
        event = stripe.Webhook.construct_event(payload, sig_header, webhook_secret)
    except ValueError:
        logger.warning('BILLING WEBHOOK | invalid_payload')
        return {'error': 'Invalid payload'}, 400
    except stripe.error.SignatureVerificationError:
        logger.warning('BILLING WEBHOOK | invalid_signature')
        return {'error': 'Invalid signature'}, 400

    from app.billing.webhooks import handle_event
    handle_event(event)

    return {'ok': True}, 200


# ── Suspended: shown when subscription is cancelled ───────────────────────────

@bp.route('/suspended')
def suspended():
    """Billing-suspended landing page. No authentication required."""
    return render_template('billing/suspended.html')


# ── Post-checkout success / cancel ────────────────────────────────────────────

@bp.route('/success')
@login_required
def success():
    flash('Your subscription is now active. Welcome aboard!', 'success')
    return render_template('billing/success.html')


@bp.route('/cancel')
@login_required
def cancel():
    flash('Checkout was cancelled. Your subscription has not changed.', 'info')
    return redirect(url_for('tenant_settings.plan'))