Your Bot Now Collects Payments —
From UPI to Stripe, Globally

# Customer button callbacks — advance the active workflow
pay_service:{id}          → stores selected service, auto-advances to region step
pay_region:{label}        → stores region codes, auto-advances to payment methods
pay_method:{account_id}   → stores provider, auto-generates payment link
pay_confirm:{reference}   → jumps to collect_utr step, asks for UTR
pay_other:{reference}     → rewinds to payment methods (different method)
pay_cancel:{reference}    → marks payment cancelled, completes workflow

# Owner button callbacks — received by the owner's Telegram
owner_pay_confirm:{ref}:{customer_id}  → confirms payment, notifies customer
owner_pay_reject:{ref}:{customer_id}   → rejects payment, notifies customer

# UPI — generates a deep link that opens any UPI app directly
def build_payment_link(provider_key, config, amount, currency, ref, service_name):
    upi_id    = config.get("upi_id", "")
    payee     = config.get("payee_name", "BizNode")
    inr_amt   = get_local_amount(amount, "IN")  # convert USD → INR

    return (
        f"upi://pay?pa={upi_id}&pn={payee}"
        f"&am={inr_amt}&cu=INR&tn={ref}"
    )

# Stripe — uses your pre-created Payment Link URL
# PayPal  — paypal.me/{username}/{amount}
# Crypto  — generates wallet address with amount
# Bank    — IBAN / account details formatted as text

GET    /api/payment-providers-catalog   # 22 built-in providers
GET    /api/services                    # list your service catalog
POST   /api/services                    # add a service
PUT    /api/services/{id}               # update a service
DELETE /api/services/{id}               # remove a service
GET    /api/payment-accounts            # list configured providers
POST   /api/payment-accounts            # add a payment account
PUT    /api/payment-accounts/{id}       # update credentials
DELETE /api/payment-accounts/{id}       # remove provider
GET    /api/payment-requests            # all payment requests (filterable)
POST   /api/payment-requests/{ref}/owner-action  # confirm / reject