"""ZeroTier reconciliation service — polling loop to sync state with the controller."""

import logging
from datetime import datetime, timezone

from gatehouse_app.extensions import db
from gatehouse_app.models import (
    Device,
    DeviceNetworkMembership,
    ActivationSession,
    ZeroTierMembership,
    PortalNetwork,
    UserNetworkApproval,
)
from gatehouse_app.services import zerotier_api_service as zt
from gatehouse_app.utils.constants import (
    ActivationEndReason,
    MembershipState,
    ApprovalState,
)

logger = logging.getLogger(__name__)


def reconcile_expired_activations() -> int:
    """Find expired activation sessions and deactivate their memberships.

    Returns the number of sessions expired.
    """
    now = datetime.now(timezone.utc)
    expired = ActivationSession.query.filter(
        ActivationSession.expires_at < now,
        ActivationSession.ended_at.is_(None),
        ActivationSession.deleted_at.is_(None),
    ).all()

    count = 0
    for session in expired:
        try:
            _expire_session(session)
            count += 1
        except Exception as exc:
            logger.error(f"[Reconciliation] Failed to expire session {session.id}: {exc}")

    if count > 0:
        logger.info(f"[Reconciliation] Expired {count} activation sessions.")

    return count


def reconcile_network(portal_network_id: str) -> dict:
    """Full reconciliation for one portal network.

    Returns a dict with counts of actions taken.
    """
    network = PortalNetwork.query.get(portal_network_id)
    if not network or not network.is_active:
        return {"skipped": True, "reason": "network_inactive_or_deleted"}

    zerotier_network_id = network.zerotier_network_id
    actions = {
        "zt_members_checked": 0,
        "zt_members_added": 0,
        "authorized": 0,
        "deauthorized": 0,
        "join_seen_updated": 0,
        "unknown_members": [],
    }

    # Get current ZT members
    try:
        zt_members = {m.node_id: m for m in zt.list_members(zerotier_network_id)}
    except Exception as exc:
        logger.error(f"[Reconciliation] Failed to list ZT members for {zerotier_network_id}: {exc}")
        actions["error"] = str(exc)
        return actions

    actions["zt_members_checked"] = len(zt_members)

    # Get our portal memberships for this network
    our_memberships = {
        m.device.node_id: m
        for m in DeviceNetworkMembership.query.filter(
            DeviceNetworkMembership.portal_network_id == portal_network_id,
            DeviceNetworkMembership.deleted_at.is_(None),
        ).all()
        if m.device and m.device.deleted_at is None
    }

    # Reconcile each portal membership
    for node_id, membership in our_memberships.items():
        zt_member = zt_members.pop(node_id, None)
        device = membership.device

        if not zt_member:
            # Member not seen in ZT yet
            continue

        actions["join_seen_updated"] += 1

        # Update observed ZT membership
        _sync_zt_membership(membership, zt_member)

        # Sync authorization state
        if membership.state == MembershipState.ACTIVE_AUTHORIZED:
            if not zt_member.is_authorized:
                # We think it's active but ZT says it's not — re-authorize
                try:
                    zt.authorize_member(zerotier_network_id, node_id)
                    actions["authorized"] += 1
                except Exception as exc:
                    logger.warning(f"[Reconciliation] Re-authorize failed for {node_id}: {exc}")
        else:
            if zt_member.is_authorized:
                # We think it's not authorized but ZT says it is — deauthorize
                # (could be manual override in ZT console)
                try:
                    zt.deauthorize_member(zerotier_network_id, node_id)
                    actions["deauthorized"] += 1
                except Exception as exc:
                    logger.warning(f"[Reconciliation] Deauthorize failed for {node_id}: {exc}")

    # Unknown ZT members not in our portal
    actions["unknown_members"] = list(zt_members.keys())

    logger.info(
        f"[Reconciliation] Network {zerotier_network_id}: "
        f"checked={actions['zt_members_checked']} "
        f"authorized={actions['authorized']} "
        f"deauthorized={actions['deauthorized']} "
        f"unknown={len(actions['unknown_members'])}"
    )

    return actions


def reconcile_all() -> dict:
    """Run reconciliation on all active portal networks.

    Returns a summary dict.
    """
    networks = PortalNetwork.query.filter(
        PortalNetwork.is_active.is_(True),
        PortalNetwork.deleted_at.is_(None),
    ).all()

    results = {"networks_processed": 0, "errors": 0}
    for network in networks:
        try:
            result = reconcile_network(network.id)
            if "error" in result:
                results["errors"] += 1
            else:
                results["networks_processed"] += 1
        except Exception as exc:
            logger.error(f"[Reconciliation] Failed to reconcile network {network.id}: {exc}")
            results["errors"] += 1

    deleted_result = reconcile_deleted_memberships()
    results["deleted_memberships"] = deleted_result.get("deleted", 0)
    results["delete_errors"] = deleted_result.get("errors", 0)

    logger.info(
        f"[Reconciliation] Complete: {results['networks_processed']} networks processed, "
        f"{results['errors']} errors, {results.get('deleted_memberships', 0)} memberships purged."
    )

    return results


def reconcile_deleted_memberships() -> dict:
    """Find soft-deleted memberships and hard-delete them after ZeroTier cleanup.

    Only processes memberships whose ZeroTier members are already de-authorized
    (the de-authorize step happened in revoke_membership_soft). This function
    removes the member from ZeroTier entirely and then hard-deletes the DB record.
    """
    deleted = DeviceNetworkMembership.query.filter(
        DeviceNetworkMembership.deleted_at.isnot(None),
    ).all()

    if not deleted:
        return {"deleted": 0, "errors": 0}

    results = {"deleted": 0, "errors": 0}
    for membership in deleted:
        try:
            device = Device.query.get(membership.device_id)
            network = PortalNetwork.query.get(membership.portal_network_id)

            if not device or not network:
                db.session.delete(membership)
                db.session.commit()
                results["deleted"] += 1
                continue

            try:
                zt.delete_network_member(network.zerotier_network_id, device.node_id)
                logger.info(f"[Reconciliation] Deleted {device.node_id} from ZT network {network.zerotier_network_id}")
            except Exception as zt_exc:
                logger.warning(
                    f"[Reconciliation] ZT delete failed for {device.node_id} "
                    f"on {network.zerotier_network_id}: {zt_exc}"
                )

            db.session.delete(membership)
            db.session.commit()
            results["deleted"] += 1

        except Exception as exc:
            logger.error(f"[Reconciliation] Failed to hard-delete membership {membership.id}: {exc}")
            results["errors"] += 1

    if results["deleted"] > 0:
        logger.info(f"[Reconciliation] Purged {results['deleted']} memberships.")

    return results


def _sync_zt_membership(membership: DeviceNetworkMembership, zt_member) -> None:
    """Update the ZeroTierMembership cache record from a ZT API response."""
    device = membership.device
    network = membership.portal_network

    zt_membership = ZeroTierMembership.query.filter(
        ZeroTierMembership.zerotier_network_id == network.zerotier_network_id,
        ZeroTierMembership.node_id == device.node_id,
        ZeroTierMembership.deleted_at.is_(None),
    ).first()

    if not zt_membership:
        zt_membership = ZeroTierMembership(
            organization_id=membership.organization_id,
            device_network_membership_id=membership.id,
            zerotier_network_id=network.zerotier_network_id,
            node_id=device.node_id,
        )

    zt_membership.member_seen = True
    zt_membership.authorized = zt_member.is_authorized
    zt_membership.last_synced_at = datetime.now(timezone.utc)
    zt_membership.raw_controller_payload = zt_member.raw

    if zt_member.last_seen and zt_member.last_seen > 0:
        zt_membership.join_seen_at = datetime.fromtimestamp(
            zt_member.last_seen / 1000, tz=timezone.utc
        )

    zt_membership.save()

    # Update membership join_seen flag
    if not membership.join_seen:
        membership.join_seen = True
        membership.state = MembershipState.JOINED_DEAUTHORIZED
        membership.save()


def _expire_session(session: ActivationSession) -> None:
    """Expire an activation session and deauthorize the membership in ZT."""
    session.ended_at = datetime.now(timezone.utc)
    session.end_reason = ActivationEndReason.EXPIRED
    session.save()

    membership = DeviceNetworkMembership.query.get(session.device_network_membership_id)
    if membership:
        membership.state = MembershipState.ACTIVATION_EXPIRED
        membership.currently_authorized = False
        membership.save()

        device = Device.query.get(membership.device_id)
        network = PortalNetwork.query.get(membership.portal_network_id)
        if device and network:
            try:
                zt.deauthorize_member(network.zerotier_network_id, device.node_id)

                # Update ZT membership cache
                zt_membership = ZeroTierMembership.query.filter(
                    ZeroTierMembership.zerotier_network_id == network.zerotier_network_id,
                    ZeroTierMembership.node_id == device.node_id,
                    ZeroTierMembership.deleted_at.is_(None),
                ).first()
                if zt_membership:
                    zt_membership.authorized = False
                    zt_membership.last_synced_at = datetime.now(timezone.utc)
                    zt_membership.save()

            except Exception as exc:
                logger.warning(
                    f"[_expire_session] Failed to deauthorize {device.node_id} "
                    f"on {network.zerotier_network_id}: {exc}"
                )

    from gatehouse_app.services.audit_service import AuditService
    AuditService.log_action(
        action="zt.activation.expired",
        user_id=session.user_id,
        organization_id=session.organization_id,
        resource_type="activation_session",
        resource_id=session.id,
        metadata={"membership_id": session.device_network_membership_id},
        description="Activation session expired",
        success=True,
    )