feat(CG4): add recommendations & anomaly engine

agents/core-logic/app.py

@@ -5,7 +5,7 @@ import os
 import logging
 from contextlib import asynccontextmanager
 
-from fastapi import FastAPI, HTTPException
+from fastapi import FastAPI, HTTPException, Request
 from fastapi.responses import JSONResponse
 from pydantic import BaseModel
 
@@ -17,6 +17,7 @@ try:
     from google.adk.sessions import InMemorySessionService
     from google.genai.types import Content, Part
     from agent import root_agent
+    from agents.recommendations_engine import get_recommendations
 except ImportError as e:
     logger.error(f"Failed to import ADK dependencies: {e}")
     raise
@@ -165,3 +166,16 @@ async def billing_tokens_summary():
     except Exception as e:
         logger.error(f"[/billing/tokens/summary] Failed: {e}", exc_info=True)
         raise HTTPException(status_code=500, detail=str(e))
+
+@app.get("/billing/recommendations")
+async def billing_recommendations(budget: float = 500.0):
+    """
+    CG4 — Kjører anbefalings- og anomali-motoren.
+    Returnerer en liste med anbefalinger og estimert besparelse.
+    """
+    try:
+        recommendations = get_recommendations(budget)
+        return JSONResponse(recommendations)
+    except Exception as e:
+        logger.error(f"[/billing/recommendations] Failed: {e}", exc_info=True)
+        raise HTTPException(status_code=500, detail=str(e))

agents/recommendations_engine.py

@@ -0,0 +1,86 @@
+from google.cloud import bigquery
+from datetime import datetime, timezone
+
+PROJECT_ID = "propane-will-491900-m5"
+DATASET = "costguard_dataset"
+BILLING_TABLE = f"{PROJECT_ID}.{DATASET}.gcp_billing_export"
+
+def get_recommendations(budget_nok: float = 500.0) -> dict:
+    client = bigquery.Client(project=PROJECT_ID)
+    recommendations = []
+
+    # 1. Anomali: tjenester der siste 3d-snitt >= 2x 30d-snitt
+    anomaly_query = f"""
+    WITH base AS (
+      SELECT service.description AS service,
+        AVG(cost) AS avg_30d
+      FROM `{BILLING_TABLE}`
+      WHERE DATE(usage_start_time) >= DATE_SUB(CURRENT_DATE(), INTERVAL 30 DAY)
+      GROUP BY service
+    ),
+    recent AS (
+      SELECT service.description AS service,
+        AVG(cost) AS avg_3d
+      FROM `{BILLING_TABLE}`
+      WHERE DATE(usage_start_time) >= DATE_SUB(CURRENT_DATE(), INTERVAL 3 DAY)
+      GROUP BY service
+    )
+    SELECT r.service, r.avg_3d, b.avg_30d,
+      SAFE_DIVIDE(r.avg_3d, b.avg_30d) AS ratio
+    FROM recent r JOIN base b ON r.service = b.service
+    WHERE SAFE_DIVIDE(r.avg_3d, b.avg_30d) >= 2.0
+      AND b.avg_30d > 0.001
+    ORDER BY ratio DESC
+    """
+
+    # 2. Sløsing: tjenester med kostnad men 0 aktivitet siste 7d
+    waste_query = f"""
+    WITH active AS (
+      SELECT DISTINCT service.description AS service
+      FROM `{BILLING_TABLE}`
+      WHERE DATE(usage_start_time) >= DATE_SUB(CURRENT_DATE(), INTERVAL 7 DAY)
+        AND cost > 0
+    ),
+    all_svc AS (
+      SELECT DISTINCT service.description AS service
+      FROM `{BILLING_TABLE}`
+      WHERE DATE(usage_start_time) >= DATE_SUB(CURRENT_DATE(), INTERVAL 30 DAY)
+        AND cost > 0
+    )
+    SELECT a.service FROM all_svc a
+    LEFT JOIN active b ON a.service = b.service
+    WHERE b.service IS NULL
+    """
+
+    try:
+        # Anomalier
+        for row in client.query(anomaly_query).result():
+            ratio = row.ratio or 0
+            severity = "high" if ratio >= 3 else "medium"
+            savings = round(float(row.avg_3d - row.avg_30d) * 30 * 10, 2)  # rough NOK
+            recommendations.append({
+                "type": "anomaly",
+                "severity": severity,
+                "service": row.service,
+                "message": f"Unormal kostnadsøkning på {row.service} — {ratio:.1f}x over normalt",
+                "estimated_savings_nok": max(savings, 0)
+            })
+
+        # Sløsing
+        for row in client.query(waste_query).result():
+            recommendations.append({
+                "type": "waste",
+                "severity": "low",
+                "service": row.service,
+                "message": f"{row.service} har hatt kostnad men ingen aktivitet siste 7 dager — vurder å skru av",
+                "estimated_savings_nok": 0
+            })
+
+    except Exception as e:
+        return {"recommendations": [], "total_estimated_savings_nok": 0, "error": str(e)}
+
+    total_savings = sum(r["estimated_savings_nok"] for r in recommendations)
+    return {
+        "recommendations": recommendations,
+        "total_estimated_savings_nok": round(total_savings, 2)
+    }

static/billing-dashboard.html

@@ -835,6 +835,36 @@ if ('serviceWorker' in navigator) {
     });
   });
 }
+// CG4: hent anbefalinger
+(function(){
+  const ICONS = {high:'🔴', medium:'🟡', low:'🟢', anomaly:'⚡', waste:'♻️', budget:'💸'};
+  fetch('/billing/recommendations')
+    .then(r=>r.ok?r.json():Promise.reject(r.status))
+    .then(data=>{
+      const body=document.getElementById('recommendations-body');
+      const sub=document.getElementById('rec-savings');
+      if(!data.recommendations||!data.recommendations.length){
+        body.innerHTML='<div class="empty-state"><span class="material-symbols-outlined">check_circle</span>Ingen anbefalinger — forbruket ser normalt ut</div>';
+        sub.textContent='Alt OK';
+        return;
+      }
+      sub.textContent=`Estimert besparelse: ${(data.total_estimated_savings_nok||0).toLocaleString('no-NO',{minimumFractionDigits:2})} kr/mnd`;
+      body.innerHTML=data.recommendations.map(r=>`
+        <div class="svc-row">
+          <span style="font-size:16px">${ICONS[r.severity]||'💡'}</span>
+          <span class="svc-name">${r.message}</span>
+          <span style="font-size:11px;color:var(--muted);background:var(--surface-3);padding:2px 8px;border-radius:99px;flex-shrink:0">${r.service}</span>
+          ${r.estimated_savings_nok>0?`<span class="svc-cost">-${r.estimated_savings_nok.toLocaleString('no-NO',{minimumFractionDigits:2})} kr</span>`: ''}
+        </div>
+      `).join('');
+    })
+    .catch(()=>{
+      document.getElementById('recommendations-body').innerHTML=
+        '<div class="empty-state"><span class="material-symbols-outlined">check_circle</span>Ingen anbefalinger tilgjengelig</div>';
+      document.getElementById('rec-savings').textContent='';
+    });
+})();
+
 // CG3e: hent tokenbruk
 (function(){
   fetch('/billing/tokens/summary')