"""BillingProcessor — governed billing drain function per §5."""
from __future__ import annotations

from typing import Any

from gsap_broker.functions.base import FunctionContext, FunctionPlugin, FunctionResult


RATE_CARD: dict[str, float] = {
    "connector_invocation": 0.002,
    "function_invocation": 0.001,
    "chronicle_event": 0.0005,
    "gsap_ac_issued": 0.003,
    "gsap_cr_completed": 0.005,
}


class BillingProcessor(FunctionPlugin):
    function_id = "billing-processor"
    corpus_entry_cid = "sha256:" + "b" * 64
    capability_mask = 3  # MUTATE
    trigger_events = ["GSAP_CR_RECEIVED"]
    accord_template = ""
    gsap_required = False
    chronicle_enabled = True
    max_duration_seconds = 10
    display_name = "Billing Processor"
    description = "Governed billing drain — only bills completed outcomes with Chronicle CID reference."
    version = "0.1.0"

    async def handle(self, event: dict[str, Any], context: FunctionContext) -> FunctionResult:
        outcome = event.get("outcome", "")
        if outcome != "completed":
            return FunctionResult(
                success=True,
                data={"billed": False, "reason": f"Outcome '{outcome}' is not billable"},
                metadata={"function_id": self.function_id},
            )

        event_type = event.get("event_type", "gsap_cr_completed")
        rate = RATE_CARD.get(event_type, RATE_CARD["gsap_cr_completed"])
        quantity = event.get("quantity", 1)
        amount = rate * quantity

        billing_record = {
            "billed": True,
            "event_type": event_type,
            "rate": rate,
            "quantity": quantity,
            "amount": amount,
            "chronicle_cid": context.trigger_event_cid or event.get("chronicle_cid", ""),
            "invocation_id": context.invocation_id,
        }

        return FunctionResult(
            success=True,
            data=billing_record,
            metadata={"function_id": self.function_id},
        )

    def health_check(self) -> bool:
        return True