from __future__ import annotations

from datetime import UTC, datetime
import hashlib
import json

from govoplan_core.core.records import (
    RecordArchiveProviderState,
    RecordArchiveReceipt,
    RecordArchiveTransferRequest,
    RecordContractError,
)


SIMULATION_PROVIDER_ID = "simulation"
SIMULATION_PROFILE = "govoplan-simulation-v1"


class SimulatedRecordArchiveProvider:
    """Exercise the transfer boundary without claiming archival custody."""

    provider_id = SIMULATION_PROVIDER_ID

    def state(self) -> RecordArchiveProviderState:
        checked_at = datetime.now(UTC)
        return RecordArchiveProviderState(
            provider_id=self.provider_id,
            label="Records transfer simulation",
            profiles=(SIMULATION_PROFILE,),
            authority_modes=("linked_reference",),
            healthy=True,
            checked_at=checked_at,
            last_success_at=checked_at,
            freshness_seconds=0,
            limitations=(
                "Simulation validates package and receipt handling but does not transfer custody.",
                "It is not an xDOMEA or archival conformance profile.",
            ),
            simulated=True,
        )

    def dispatch(
        self,
        session: object,
        principal: object,
        *,
        request: RecordArchiveTransferRequest,
    ) -> RecordArchiveReceipt:
        del session, principal
        if request.package.profile != SIMULATION_PROFILE:
            raise RecordContractError(
                "The simulation provider only accepts its declared profile."
            )
        observed_at = datetime.now(UTC)
        receipt_payload = {
            "provider_id": self.provider_id,
            "package_id": request.package.package_id,
            "manifest_sha256": request.package.manifest_sha256,
            "profile": request.package.profile,
            "outcome": "accepted",
            "simulated": True,
        }
        receipt_sha256 = hashlib.sha256(
            json.dumps(
                receipt_payload,
                sort_keys=True,
                separators=(",", ":"),
            ).encode("utf-8")
        ).hexdigest()
        return RecordArchiveReceipt(
            provider_id=self.provider_id,
            package_id=request.package.package_id,
            outcome="accepted",
            observed_at=observed_at,
            receipt_sha256=receipt_sha256,
            external_reference=f"simulation:{request.package.package_id}",
            retry_safe=True,
            simulated=True,
            metadata={
                "manifest_sha256": request.package.manifest_sha256,
                "profile": request.package.profile,
                "custody_transferred": False,
            },
        )


__all__ = [
    "SIMULATION_PROFILE",
    "SIMULATION_PROVIDER_ID",
    "SimulatedRecordArchiveProvider",
]