feat(transactions): add live energy and estimated cost to transaction data

apps/csms/src/routes/transactions.ts

@@ -2,7 +2,8 @@ import { Hono } from "hono";
 import { and, desc, eq, isNull, isNotNull, sql } from "drizzle-orm";
 import dayjs from "dayjs";
 import { useDrizzle } from "@/lib/db.js";
-import { transaction, chargePoint, connector, idTag } from "@/db/schema.js";
+import { transaction, chargePoint, connector, idTag, meterValue } from "@/db/schema.js";
+import type { SampledValue } from "@/db/schema.js";
 import { user } from "@/db/auth-schema.js";
 import { ocppConnections } from "@/ocpp/handler.js";
 import { OCPP_MESSAGE_TYPE } from "@/ocpp/types.js";
@@ -20,11 +21,13 @@ app.post("/remote-start", async (c) => {
   if (!currentUser) return c.json({ error: "Unauthorized" }, 401);
 
   const db = useDrizzle();
-  const body = await c.req.json<{
-    chargePointIdentifier: string;
-    connectorId: number;
-    idTag: string;
-  }>().catch(() => null);
+  const body = await c.req
+    .json<{
+      chargePointIdentifier: string;
+      connectorId: number;
+      idTag: string;
+    }>()
+    .catch(() => null);
 
   if (
     !body ||
@@ -122,6 +125,8 @@ app.get("/", async (c) => {
     .select({
       transaction,
       chargePointIdentifier: chargePoint.chargePointIdentifier,
+      feePerKwh: chargePoint.feePerKwh,
+      pricingMode: chargePoint.pricingMode,
       connectorNumber: connector.connectorId,
       idTagUserId: idTag.userId,
       idTagUserName: user.name,
@@ -136,18 +141,74 @@ app.get("/", async (c) => {
     .limit(limit)
     .offset(offset);
 
+  // For active transactions, fetch the latest meter reading to show live energy
+  const activeTxIds = rows.filter((r) => !r.transaction.stopTimestamp).map((r) => r.transaction.id);
+
+  // Map: transactionId -> latest cumulative Wh from meterValue
+  const latestMeterMap = new Map<number, number>();
+  if (activeTxIds.length > 0) {
+    // DISTINCT ON picks the most recent row per transaction_id
+    const latestRows = await db.execute<{
+      transaction_id: number;
+      sampled_values: SampledValue[];
+    }>(sql`
+      SELECT DISTINCT ON (transaction_id) transaction_id, sampled_values
+      FROM meter_value
+      WHERE transaction_id IN (${sql.join(
+        activeTxIds.map((id) => sql`${id}`),
+        sql`, `,
+      )})
+      ORDER BY transaction_id, timestamp DESC
+    `);
+    for (const row of latestRows.rows) {
+      const svList = row.sampled_values as SampledValue[];
+      const energySv = svList.find(
+        (sv) => (!sv.measurand || sv.measurand === "Energy.Active.Import.Register") && !sv.phase,
+      );
+      if (energySv != null) {
+        // Unit defaults to Wh; kWh is also common
+        const raw = parseFloat(energySv.value);
+        if (!Number.isNaN(raw)) {
+          const wh = energySv.unit === "kWh" ? raw * 1000 : raw;
+          latestMeterMap.set(Number(row.transaction_id), wh);
+        }
+      }
+    }
+  }
+
   return c.json({
-    data: rows.map((r) => ({
-      ...r.transaction,
-      chargePointIdentifier: r.chargePointIdentifier,
-      connectorNumber: r.connectorNumber,
-      idTagUserId: r.idTagUserId,
-      idTagUserName: r.idTagUserName,
-      energyWh:
-        r.transaction.stopMeterValue != null
-          ? r.transaction.stopMeterValue - r.transaction.startMeterValue
-          : null,
-    })),
+    data: rows.map((r) => {
+      const isActive = !r.transaction.stopTimestamp;
+      const latestMeterWh = isActive ? (latestMeterMap.get(r.transaction.id) ?? null) : null;
+      const liveEnergyWh =
+        latestMeterWh != null ? latestMeterWh - r.transaction.startMeterValue : null;
+
+      // Estimated cost: only for fixed pricing (TOU requires full interval analysis)
+      let estimatedCost: number | null = null;
+      if (
+        isActive &&
+        liveEnergyWh != null &&
+        liveEnergyWh > 0 &&
+        r.pricingMode === "fixed" &&
+        (r.feePerKwh ?? 0) > 0
+      ) {
+        estimatedCost = Math.ceil((liveEnergyWh * (r.feePerKwh ?? 0)) / 1000);
+      }
+
+      return {
+        ...r.transaction,
+        chargePointIdentifier: r.chargePointIdentifier,
+        connectorNumber: r.connectorNumber,
+        idTagUserId: r.idTagUserId,
+        idTagUserName: r.idTagUserName,
+        energyWh:
+          r.transaction.stopMeterValue != null
+            ? r.transaction.stopMeterValue - r.transaction.startMeterValue
+            : null,
+        liveEnergyWh,
+        estimatedCost,
+      };
+    }),
     total,
     page,
     totalPages: Math.max(1, Math.ceil(total / limit)),