"""
Run INSIDE the NetBox Django shell to export the field-switch topology
(switches + every patch panel / splice module they physically pass through)
as JSON, for generate_drawio.py to render.

Usage (from the NetBox host, e.g. /opt/netbox):

    docker exec netbox-netbox-1 python3 /opt/netbox/netbox/manage.py shell \
        -c "$(cat topology/export_topology.py)" 2>/dev/null > topology/topo_full.json

The script only reads data -- it never modifies NetBox. If a switch's
connected_endpoints comes back empty when it clearly shouldn't, that is a
NetBox cable-path bug, not a bug in this script -- see the "gotchas" section
of the repo README before assuming the physical link doesn't exist.
"""
from dcim.models import Device, Interface
import json

switch_ids = set(
    Device.objects.filter(
        role__slug__in=["core-switch", "dist-switch", "field-switch"]
    ).values_list("id", flat=True)
)

ifaces = Interface.objects.filter(
    device_id__in=switch_ids, cable__isnull=False
).select_related("device")

touched_devices = set(switch_ids)
edges = set()  # (device_id_a, device_id_b), deduplicated, any two adjacent devices on a physical chain

for i in ifaces:
    path = i._path
    if not path or not path.is_active:
        continue
    chain = []
    for hop in i.trace():
        for item in hop:
            for t in item:
                dev = getattr(t, "device", None)
                if dev:
                    if not chain or chain[-1] != dev.id:
                        chain.append(dev.id)
                    touched_devices.add(dev.id)
    for a, b in zip(chain, chain[1:]):
        if a != b:
            edges.add(tuple(sorted((a, b))))

devs = Device.objects.filter(id__in=touched_devices).select_related(
    "site", "role", "device_type"
)

out = {
    "devices": [
        {
            "id": d.id,
            "name": d.name,
            "role": d.role.slug,
            "role_name": d.role.name,
            "site": d.site.name if d.site else "",
            "status": str(d.status),
            "device_type": d.device_type.model,
        }
        for d in devs
    ],
    "edges": [[a, b] for a, b in sorted(edges)],
}
print(json.dumps(out))