"""Core delegation lifecycle — GCAP-SPEC-LLM-PRINCIPAL-BROKER-0001 §3."""

import logging
import uuid
from datetime import datetime, timedelta

from llm_broker import chronicle, db
from llm_broker.db import DelegationDB
from llm_broker.gsap import GSAPClient
from llm_broker.models import (
    AgentPrincipal,
    DelegationRequest,
    DelegationResponse,
    DelegationScope,
)
from llm_broker.registrar_factory import create_registrar
from llm_broker.settings import Settings

logger = logging.getLogger(__name__)


class DelegationManager:
    def __init__(self, config: Settings):
        self.config = config
        self.registrar = create_registrar(config)
        self.gsap = GSAPClient(config.gsap_broker_url, config.gsap_bearer_token)

    async def create_delegation(
        self, request: DelegationRequest, delegator_did: str
    ) -> DelegationResponse:
        delegation_id = f"del-{uuid.uuid4().hex[:8]}"
        scope = request.scope or DelegationScope()
        now = datetime.utcnow()
        expires_at = now + timedelta(minutes=scope.max_ttl_minutes)

        agent_did = f"did:web:guildhouse.dev/agent/{request.agent_type}-{delegation_id}"
        delegator_short = delegator_did.rsplit("/", 1)[-1]
        agent_display = f"{request.agent_type} (delegated by {delegator_short})"

        # 1. Register agent identity via the configured registrar
        credentials = await self.registrar.register_agent(
            delegation_id=delegation_id,
            agent_type=request.agent_type,
            delegator_id=delegator_did,
            display_name=agent_display,
            expires_at=expires_at.isoformat(),
            metadata={"model": request.agent_model},
        )

        # 2. Request delegated AC from GSAP broker
        try:
            ac_result = await self.gsap.request_delegated_ac(
                delegator_ac_id=request.delegator_ac_id,
                agent_did=agent_did,
                delegation_id=delegation_id,
                corpus_entry_cid="sha256:dev-jumphost",
                capability_ceiling=scope.capability_ceiling,
                ttl_minutes=scope.max_ttl_minutes,
            )
        except Exception as e:
            await self.registrar.delete_agent(credentials.client_id)
            raise RuntimeError(f"Failed to request delegated AC: {e}")

        # 3. Record in Chronicle
        chronicle_cid = await chronicle.delegation_created(
            delegation_id=delegation_id,
            delegator_did=delegator_did,
            agent_did=agent_did,
            agent_type=request.agent_type,
            scope=scope.model_dump(),
        )

        # 4. Persist
        delegation = DelegationDB(
            delegation_id=delegation_id,
            status="active",
            agent_type=request.agent_type,
            agent_model=request.agent_model,
            agent_did=agent_did,
            agent_keycloak_client_id=credentials.client_id,
            delegator_did=delegator_did,
            delegator_ac_id=request.delegator_ac_id,
            delegated_ac_id=ac_result.get("context_id", ""),
            capability_ceiling=scope.capability_ceiling,
            ceremony_required_for=",".join(scope.ceremony_required_for),
            max_commands=scope.max_commands,
            created_at=now,
            expires_at=expires_at,
            chronicle_cid=chronicle_cid or None,
        )
        await db.create_delegation(delegation)

        logger.info(
            "Delegation created: %s (%s → %s) via %s",
            delegation_id, delegator_did, agent_did, credentials.idp_backend,
        )

        return DelegationResponse(
            delegation_id=delegation_id,
            agent_principal=AgentPrincipal(
                did=agent_did,
                keycloak_client_id=credentials.client_id,
                display_name=credentials.agent_display_name,
            ),
            delegated_ac=ac_result,
            agent_token=credentials.client_secret,
            expires_at=expires_at.isoformat(),
            max_commands=scope.max_commands,
            chronicle_cid=chronicle_cid,
        )

    async def revoke_delegation(self, delegation_id: str, reason: str) -> bool:
        delegation = await db.get_delegation(delegation_id)
        if not delegation or delegation.status != "active":
            return False

        if delegation.agent_keycloak_client_id:
            await self.registrar.delete_agent(delegation.agent_keycloak_client_id)

        await db.revoke_delegation(delegation_id, reason)
        await chronicle.delegation_revoked(delegation_id, reason)

        logger.info("Delegation revoked: %s (%s)", delegation_id, reason)
        return True

    async def cleanup_expired(self) -> int:
        """Expire stale delegations and clean up IdP registrations."""
        expired = await db.expire_stale()
        for d in expired:
            if d.agent_keycloak_client_id:
                await self.registrar.delete_agent(d.agent_keycloak_client_id)
            await chronicle.delegation_expired(d.delegation_id)
        if expired:
            logger.info("Expired %d stale delegations", len(expired))
        return len(expired)