Adding backend changes for alerts view

server/.chalice/config.json

@@ -1,6 +1,6 @@
 {
   "version": "2.0",
-  "app_name": "data-dashboard-v4",
+  "app_name": "data-dashboard",
   "api_gateway_endpoint_type": "REGIONAL",
   "minimum_compression_size": 1000,
   "lambda_timeout": 30,

server/.chalice/policy.json

@@ -2,36 +2,22 @@
   "Version": "2012-10-17",
   "Statement": [
     {
-      "Action": [
-        "logs:CreateLogGroup",
-        "logs:CreateLogStream",
-        "logs:PutLogEvents"
-      ],
+      "Action": ["logs:CreateLogGroup", "logs:CreateLogStream", "logs:PutLogEvents"],
       "Effect": "Allow",
       "Resource": "arn:*:logs:*:*:*"
     },
     {
-      "Action": [
-        "s3:ListBucket"
-      ],
+      "Action": ["s3:ListBucket"],
       "Effect": "Allow",
-      "Resource": [
-        "arn:aws:s3:::tm-mbta-performance"
-      ]
+      "Resource": ["arn:aws:s3:::tm-mbta-performance"]
     },
     {
-      "Action": [
-        "s3:GetObject"
-      ],
+      "Action": ["s3:GetObject"],
       "Effect": "Allow",
-      "Resource": [
-        "arn:aws:s3:::tm-mbta-performance/*"
-      ]
+      "Resource": ["arn:aws:s3:::tm-mbta-performance/*"]
     },
     {
-      "Action": [
-        "dynamodb:Query"
-      ],
+      "Action": ["dynamodb:Query"],
       "Effect": "Allow",
       "Resource": [
         "arn:aws:dynamodb:*:*:table/DeliveredTripMetrics",
@@ -41,8 +27,9 @@
         "arn:aws:dynamodb:*:*:table/ScheduledServiceDaily",
         "arn:aws:dynamodb:*:*:table/Ridership",
         "arn:aws:dynamodb:*:*:table/SpeedRestrictions",
-        "arn:aws:dynamodb:*:*:table/TimePredictions"
+        "arn:aws:dynamodb:*:*:table/TimePredictions",
+        "arn:aws:dynamodb:*:*:table/AlertDelaysWeekly"
       ]
     }
   ]
-}
+}

server/app.py

@@ -8,6 +8,7 @@
     aggregation,
     data_funcs,
     secrets,
+    delays,
     mbta_v3,
     speed,
     speed_restrictions,
@@ -164,6 +165,12 @@ def get_alerts():
     return json.dumps(response, indent=4, sort_keys=True, default=str)
 
 
+@app.route("/api/linedelays", cors=cors_config)
+def get_delays_by_line():
+    response = delays.delay_time_by_line(app.current_request.query_params)
+    return json.dumps(response, indent=4, sort_keys=True)
+
+
 @app.route("/api/tripmetrics", cors=cors_config)
 def get_trips_by_line():
     response = speed.trip_metrics_by_line(app.current_request.query_params)

server/chalicelib/constants.py

@@ -1,6 +1,8 @@
 EVENT_ARRIVAL = ["ARR", "PRA"]
 EVENT_DEPARTURE = ["DEP", "PRD"]
 
+DATE_FORMAT_BACKEND = "%Y-%m-%d"
+
 LINE_TO_ROUTE_MAP = {
     "line-red": ["line-red-a", "line-red-b"],
     "line-green": ["line-green-b", "line-green-c", "line-green-d", "line-green-e"],

server/chalicelib/delays.py

@@ -0,0 +1,46 @@
+from typing import TypedDict
+from chalice import BadRequestError, ForbiddenError
+from chalicelib import dynamo
+from datetime import date, datetime, timedelta
+from chalicelib.constants import DATE_FORMAT_BACKEND
+
+
+TABLE_NAME = "AlertDelaysWeekly"
+MAX_DELTA = 5000
+
+
+class AlertDelaysByLineParams(TypedDict):
+    start_date: str | date
+    end_date: str | date
+    line: str
+
+
+def is_invalid_range(start_date, end_date, max_delta):
+    """Check if number of requested entries is more than maximum for the table"""
+    start_datetime = datetime.strptime(start_date, DATE_FORMAT_BACKEND)
+    end_datetime = datetime.strptime(end_date, DATE_FORMAT_BACKEND)
+    return start_datetime + timedelta(days=max_delta) < end_datetime
+
+
+def delay_time_by_line(params: AlertDelaysByLineParams):
+    try:
+        start_date = params["start_date"]
+        end_date = params["end_date"]
+        line = params["line"]
+        if line not in [
+            "Red",
+            "Blue",
+            "Orange",
+            "Green-B",
+            "Green-C",
+            "Green-D",
+            "Green-E",
+        ]:
+            raise BadRequestError("Invalid Line key.")
+    except KeyError:
+        raise BadRequestError("Missing or invalid parameters.")
+    # Prevent queries of more than 5000 items.
+    if is_invalid_range(start_date, end_date, MAX_DELTA):
+        raise ForbiddenError("Date range too long. The maximum number of requested values is 150.")
+    # If querying for weekly/monthly data, can just return the query.
+    return dynamo.query_agg_trip_metrics(start_date, end_date, TABLE_NAME, line)

server/chalicelib/speed.py

@@ -4,6 +4,7 @@
 from datetime import date, datetime, timedelta
 import pandas as pd
 import numpy as np
+from chalicelib.constants import DATE_FORMAT_BACKEND
 
 
 class TripMetricsByLineParams(TypedDict):
@@ -20,8 +21,6 @@ class TripMetricsByLineParams(TypedDict):
     "monthly": {"table_name": "DeliveredTripMetricsMonthly", "delta": 30 * 150},
 }
 
-DATE_FORMAT_BACKEND = "%Y-%m-%d"
-
 
 def aggregate_actual_trips(actual_trips, agg, start_date):
     flat_data = [entry for sublist in actual_trips for entry in sublist]