"""The sample billing tools as LangChain tools (the same 9 as ../catalog.json), with canned results."""

import json

from langchain.tools import tool

CUSTOMERS = {"globex": {"customer_id": "cus_8812", "name": "Globex", "plan": "growth"},
             "initech": {"customer_id": "cus_1207", "name": "Initech", "plan": "starter"}}


@tool
def find_customer(query: str) -> str:
    """Find a customer by name, email or domain. Returns the customer id."""
    for key, customer in CUSTOMERS.items():
        if key in query.lower():
            return json.dumps(customer)
    return json.dumps({"error": "no customer matches " + query})


@tool
def get_customer_invoices(customer_id: str, status: str = "any") -> str:
    """List a customer's invoices, newest first. Returns invoice ids, amounts and statuses."""
    return json.dumps([{"invoice_id": "INV-1042", "amount": 490, "status": "paid", "customer_id": customer_id},
                       {"invoice_id": "INV-0977", "amount": 490, "status": "paid", "customer_id": customer_id}])


@tool
def refund_invoice(invoice_id: str, amount: float | None = None) -> str:
    """Refund a paid invoice fully or partially."""
    return json.dumps({"refund_id": "re_301", "invoice_id": invoice_id, "amount": amount or 490})


@tool
def create_invoice(customer_id: str, amount: float, description: str) -> str:
    """Create and send a one-off invoice to a customer."""
    return json.dumps({"invoice_id": "INV-1043", "customer_id": customer_id, "amount": amount})


@tool
def change_plan(customer_id: str, plan: str) -> str:
    """Move a customer's subscription to another plan (starter, growth, scale)."""
    return json.dumps({"customer_id": customer_id, "plan": plan, "effective": "now"})


@tool
def cancel_subscription(customer_id: str, at_period_end: bool = True) -> str:
    """Cancel a customer's subscription, now or at the end of the billing period."""
    return json.dumps({"customer_id": customer_id, "cancelled": True, "at_period_end": at_period_end})


@tool
def export_report(report: str, format: str = "csv") -> str:
    """Export a revenue, churn or invoices report as CSV or PDF."""
    return json.dumps({"url": f"https://example.com/reports/{report}.{format}"})


@tool
def update_tax_settings(country: str, vat_rate: float) -> str:
    """Change the account's tax settings, such as the VAT rate per country. Admins only."""
    return json.dumps({"country": country, "vat_rate": vat_rate})


@tool
def ask_user(question: str) -> str:
    """Ask the user a clarifying question when something needed is missing or ambiguous."""
    return "(the question is shown to the user)"


TOOLS = [find_customer, get_customer_invoices, refund_invoice, create_invoice, change_plan, cancel_subscription,
         export_report, update_tax_settings, ask_user]

# catalog fields LangChain tools do not carry: which ids a tool returns, roles, always-on helpers, user phrasings
EXTRAS = {
    "find_customer": {"produces": ["customer_id"]},
    "get_customer_invoices": {"produces": ["invoice_id"]},
    "refund_invoice": {"examples": ["give them their money back", "refund INV-1042"]},
    "update_tax_settings": {"requiredRoles": ["admin"]},
    "ask_user": {"core": True},
}