From 3ef6dcf5d91a69e662a150a382dd6b0d30d03eed Mon Sep 17 00:00:00 2001
From: Paul Bienkowski <pb@opatut.de>
Date: Fri, 18 Feb 2022 13:42:32 +0100
Subject: [PATCH] Add lean mode (overpass source and no map view in frontend)

---
 api/config.dev.py              |  1 +
 api/config.py.example          |  5 +++++
 api/obs/api/process.py         | 23 +++++++++++++++++------
 api/obs/api/routes/frontend.py | 29 +++++++++++++++++------------
 frontend/src/App.tsx           |  8 +++++---
 5 files changed, 45 insertions(+), 21 deletions(-)

diff --git a/api/config.dev.py b/api/config.dev.py
index fae82f7..e0bc632 100644
--- a/api/config.dev.py
+++ b/api/config.dev.py
@@ -4,6 +4,7 @@ DEBUG = True
 VERBOSE = False
 AUTO_RESTART = True
 SECRET = "!!!!!!!!!!!!CHANGE ME!!!!!!!!!!!!"
+LEAN_MODE = True
 POSTGRES_URL = "postgresql+asyncpg://obs:obs@postgres/obs"
 POSTGRES_POOL_SIZE = 20
 POSTGRES_MAX_OVERFLOW = 2 * POSTGRES_POOL_SIZE
diff --git a/api/config.py.example b/api/config.py.example
index 94f7280..1aac6e2 100644
--- a/api/config.py.example
+++ b/api/config.py.example
@@ -7,6 +7,11 @@ DEBUG = False
 VERBOSE = DEBUG
 AUTO_RESTART = DEBUG
 
+# Turn on lean mode to simplify the setup. Lots of features will be
+# unavailable, but you will not need to manage OpenStreetMap data. Please make
+# sure to configure the OBS_FACE_CACHE_DIR correctly for lean mode.
+LEAN_MODE = False
+
 # Required to encrypt or sign sessions, cookies, tokens, etc.
 SECRET = "!!!<<<CHANGEME>>>!!!"
 
diff --git a/api/obs/api/process.py b/api/obs/api/process.py
index b05bca7..0f3a1bf 100644
--- a/api/obs/api/process.py
+++ b/api/obs/api/process.py
@@ -25,7 +25,7 @@ from obs.face.filter import (
     RequiredFieldsFilter,
 )
 
-from obs.face.osm import DataSource, DatabaseTileSource
+from obs.face.osm import DataSource, DatabaseTileSource, OverpassTileSource
 
 from obs.api.db import OvertakingEvent, Track, make_session
 from obs.api.app import app
@@ -33,6 +33,20 @@ from obs.api.app import app
 log = logging.getLogger(__name__)
 
 
+def get_data_source():
+    """
+    Creates a data source based on the configuration of the portal. In *lean*
+    mode, the OverpassTileSource is used to fetch data on demand. In normal
+    mode, the roads database is used.
+    """
+    if app.config.LEAN_MODE:
+        tile_source = OverpassTileSource(cache_dir=app.config.OBS_FACE_CACHE_DIR)
+    else:
+        tile_source = DatabaseTileSource()
+
+    return DataSource(tile_source)
+
+
 async def process_tracks_loop(delay):
     while True:
         try:
@@ -50,9 +64,7 @@ async def process_tracks_loop(delay):
                     await asyncio.sleep(delay)
                     continue
 
-                tile_source = DatabaseTileSource()
-                data_source = DataSource(tile_source)
-
+                data_source = get_data_source()
                 await process_track(session, track, data_source)
         except BaseException:
             log.exception("Failed to process track. Will continue.")
@@ -66,8 +78,7 @@ async def process_tracks(tracks):
 
     :param tracks: A list of strings which
     """
-    tile_source = DatabaseTileSource()
-    data_source = DataSource(tile_source)
+    data_source = get_data_source()
 
     async with make_session() as session:
         for track_id_or_slug in tracks:
diff --git a/api/obs/api/routes/frontend.py b/api/obs/api/routes/frontend.py
index c5547c0..2334e34 100644
--- a/api/obs/api/routes/frontend.py
+++ b/api/obs/api/routes/frontend.py
@@ -6,6 +6,7 @@ from sanic.exceptions import NotFound
 from obs.api.app import app
 
 if app.config.FRONTEND_CONFIG:
+
     @app.get("/config.json")
     def get_frontend_config(req):
         result = {
@@ -13,18 +14,22 @@ if app.config.FRONTEND_CONFIG:
             **req.app.config.FRONTEND_CONFIG,
             "apiUrl": f"{req.ctx.api_url}/api",
             "loginUrl": f"{req.ctx.api_url}/login",
-            "obsMapSource": {
-                "type": "vector",
-                "tiles": [
-                    req.ctx.api_url
-                    + req.app.url_for("tiles", zoom="000", x="111", y="222.pbf")
-                    .replace("000", "{z}")
-                    .replace("111", "{x}")
-                    .replace("222", "{y}")
-                ],
-                "minzoom": 12,
-                "maxzoom": 14,
-            },
+            "obsMapSource": (
+                None
+                if app.config.LEAN_MODE
+                else {
+                    "type": "vector",
+                    "tiles": [
+                        req.ctx.api_url
+                        + req.app.url_for("tiles", zoom="000", x="111", y="222.pbf")
+                        .replace("000", "{z}")
+                        .replace("111", "{x}")
+                        .replace("222", "{y}")
+                    ],
+                    "minzoom": 12,
+                    "maxzoom": 14,
+                }
+            ),
         }
 
         return response.json(result)
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index 4feb1de..ab116fa 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -59,6 +59,8 @@ const App = connect((state) => ({login: state.login}))(function App({login}) {
   const config = useConfig()
   const apiVersion = useObservable(() => from(api.get('/info')).pipe(pluck('version')))
 
+  const hasMap = Boolean(config?.obsMapSource)
+
   React.useEffect(() => {
     api.loadUser()
   }, [])
@@ -72,7 +74,7 @@ const App = connect((state) => ({login: state.login}))(function App({login}) {
             OpenBikeSensor
           </Link>
 
-          {config?.obsMapSource && (
+          {hasMap && (
             <Link component={MenuItemForLink} to="/map" as="a">
               Map
             </Link>
@@ -110,9 +112,9 @@ const App = connect((state) => ({login: state.login}))(function App({login}) {
         <Route path="/" exact>
           <HomePage />
         </Route>
-        <Route path="/map" exact>
+        {hasMap && <Route path="/map" exact>
           <MapPage />
-        </Route>
+        </Route>}
         <Route path="/tracks" exact>
           <TracksPage />
         </Route>