Show the rail network on a Rail tab in the staff panel

backend/src/api/admin_routes.py

@@ -17,6 +17,7 @@
 from src.api.auth_routes import _config, _no_store, current_user, require_same_origin, session_cookie
 from src.auth import admin, audit, players, roles, users
 from src.coreprotect.reader import CoreProtectConfig
+from src.rail import network as rail
 
 admin_router = APIRouter(prefix="/admin", tags=["admin"])
 
@@ -166,6 +167,19 @@ def get_movement(request: Request, response: Response,
                     "view_player_movement")
 
 
+@admin_router.get("/rail")
+def get_rail(request: Request, response: Response, map: str = Query("main", max_length=32)):
+    _capable(request, "view_rail")
+    _no_store(response)
+    try:
+        return rail.load_network(rail.RailConfig.from_env(), map)
+    except ValueError:
+        raise HTTPException(400, detail="bad_map") from None
+    except rail.RailUnavailable as exc:
+        return {"status": exc.code, "world": rail.RailConfig.from_env().world, "updated_at": None,
+                "unreadable_files": 0, "lines": [], "tracks": [], "junctions": [], "stops": []}
+
+
 @admin_router.post("/accounts/{user_id}/role")
 def post_role(user_id: int, body: RoleBody, request: Request, response: Response):
     _no_store(response)

backend/src/auth/roles.py

@@ -12,6 +12,8 @@
     "view_player_messages": "admin",
     # Where players went, minute by minute; every view is audited.
     "view_player_movement": "admin",
+    # The rail network as VehicleFramework saved it.
+    "view_rail": "admin",
     "revoke_sessions": "mod",
     "change_role": "admin",
     # In-game LuckPerms ranks: everyone on staff sees them; what an admin may

backend/src/rail/README.md

@@ -0,0 +1,40 @@
+# Rail network
+
+The staff panel's Rail tab draws the Minecraft server's rail network on the
+live map: every VehicleFramework track, its junctions and ends, broken or
+damaged stretches, and the stops along it. `GET /admin/rail?map=<id>` serves
+it to admins and the owner (`view_rail`). Track positions are not personal
+data, so views are not audited.
+
+VehicleFramework saves one JSON file per track in
+`plugins/VehicleFramework/data/tracks/<world>/`, with switches in
+`junctions/` beside them. A track holds a sample about every block and one
+segment per pair of samples; a segment can be broken or damaged. The backend
+reads the files on request and keeps the result until any file, the map's
+`map_markers.json` or its `province_id_runs.bin.gz` changes. A file caught
+mid-save is skipped and counted, so the page can say so.
+
+- **Stops** are the settlements whose provinces a track crosses. Each sits
+  where the track comes closest to the settlement inside its provinces.
+- **Lines** are tracks joined by junctions. A line is named after its first and
+  last stop along its longest track; one with no stops is an "Unnamed line".
+- Tracks are simplified (Douglas-Peucker, 0.35 blocks) before they are sent.
+
+## Settings
+
+| Variable | Meaning |
+| --- | --- |
+| `RAIL_TRACKS_DIR` | VehicleFramework's `data/tracks` folder inside the backend container. Unset: the tab says the site is not set up to read the network. |
+| `RAIL_WORLD` | The world folder to read: the server's `level-name`. Defaults to `COREPROTECT_MAP_WORLD`, then `TFMC_Map`. |
+
+Mount the folder read-only in the host's `docker-compose.override.yml`, like
+CoreProtect's:
+
+```yaml
+services:
+  backend:
+    volumes:
+      - /home/amp/.ampdata/instances/TFMCMain01/Minecraft/plugins/VehicleFramework/data/tracks:/vehicleframework-tracks:ro
+    environment:
+      - RAIL_TRACKS_DIR=/vehicleframework-tracks
+```

backend/src/rail/conftest.py

@@ -0,0 +1,18 @@
+import sys
+from pathlib import Path
+import pytest
+
+BACKEND = Path(__file__).resolve().parents[2]
+if str(BACKEND) not in sys.path:
+    sys.path.insert(0, str(BACKEND))
+
+
+@pytest.fixture
+def database(tmp_path, monkeypatch):
+    from src.skins import db
+    monkeypatch.setattr(db, "DB_PATH", tmp_path / "province.db")
+    monkeypatch.setattr(db, "DATA_DIR", tmp_path)
+    for name in ("SKINS_DIR", "WARDROBE_DIR", "DRINKS_DIR"):
+        monkeypatch.setattr(db, name, tmp_path / name.lower())
+    db.migrate()
+    return db