feat(transactions): add transaction detail page with live energy and cost estimation

feat(transactions): implement active transaction checks and idTag validation
feat(id-tag): enhance idTag card with disabled state for active transactions
fix(transactions): improve error handling and user feedback for transaction actions

apps/csms/src/ocpp/actions/authorize.ts

@@ -1,7 +1,7 @@
-import { eq } from "drizzle-orm";
+import { and, eq, isNull } from "drizzle-orm";
 import dayjs from "dayjs";
 import { useDrizzle } from "@/lib/db.js";
-import { idTag } from "@/db/schema.js";
+import { idTag, transaction } from "@/db/schema.js";
 import type {
   AuthorizeRequest,
   AuthorizeResponse,
@@ -19,6 +19,7 @@ import type {
 export async function resolveIdTagInfo(
   idTagValue: string,
   checkBalance = true,
+  checkConcurrent = true,
 ): Promise<IdTagInfo> {
   const db = useDrizzle();
   const [tag] = await db.select().from(idTag).where(eq(idTag.idTag, idTagValue)).limit(1);
@@ -31,6 +32,17 @@ export async function resolveIdTagInfo(
   if (tag.status !== "Accepted") {
     return { status: tag.status as IdTagInfo["status"] };
   }
+
+  // Enforce single active transaction per idTag.
+  if (checkConcurrent) {
+    const [activeTx] = await db
+      .select({ id: transaction.id })
+      .from(transaction)
+      .where(and(eq(transaction.idTag, idTagValue), isNull(transaction.stopTimestamp)))
+      .limit(1);
+    if (activeTx) return { status: "ConcurrentTx" };
+  }
+
   // Reject if balance is zero or negative
   if (checkBalance && tag.balance <= 0) {
     return { status: "Blocked" };

apps/csms/src/ocpp/actions/stop-transaction.ts

@@ -183,7 +183,9 @@ export async function handleStopTransaction(
   );
 
   // Resolve idTagInfo for the stop tag if provided (no balance check — charging already occurred)
-  const idTagInfo = payload.idTag ? await resolveIdTagInfo(payload.idTag, false) : undefined;
+  const idTagInfo = payload.idTag
+    ? await resolveIdTagInfo(payload.idTag, false, false)
+    : undefined;
 
   return { idTagInfo };
 }

apps/csms/src/routes/transactions.ts

@@ -2,11 +2,12 @@ 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, meterValue } from "@/db/schema.js";
+import { transaction, chargePoint, connector, idTag } 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";
+import { resolveIdTagInfo } from "@/ocpp/actions/authorize.js";
 import type { HonoEnv } from "@/types/hono.ts";
 
 const app = new Hono<HonoEnv>();
@@ -42,15 +43,33 @@ app.post("/remote-start", async (c) => {
     );
   }
 
-  // Non-admin: verify idTag belongs to current user and is Accepted
+  // Non-admin: verify idTag belongs to current user
   if (currentUser.role !== "admin") {
     const [tag] = await db
-      .select({ status: idTag.status })
+      .select({ idTag: idTag.idTag })
       .from(idTag)
       .where(and(eq(idTag.idTag, body.idTag.trim()), eq(idTag.userId, currentUser.id)))
       .limit(1);
     if (!tag) return c.json({ error: "idTag not found or not authorized" }, 403);
-    if (tag.status !== "Accepted") return c.json({ error: "idTag is not accepted" }, 400);
+  }
+
+  // Reuse the same authorization logic as Authorize/StartTransaction.
+  const tagInfo = await resolveIdTagInfo(body.idTag.trim());
+  if (tagInfo.status !== "Accepted") {
+    if (tagInfo.status === "ConcurrentTx") {
+      return c.json({ error: "ConcurrentTx: idTag already has an active transaction" }, 409);
+    }
+    return c.json({ error: `idTag rejected: ${tagInfo.status}` }, 400);
+  }
+
+  // One idTag can only have one active transaction at a time.
+  const [activeTx] = await db
+    .select({ id: transaction.id })
+    .from(transaction)
+    .where(and(eq(transaction.idTag, body.idTag.trim()), isNull(transaction.stopTimestamp)))
+    .limit(1);
+  if (activeTx) {
+    return c.json({ error: "ConcurrentTx: idTag already has an active transaction" }, 409);
   }
 
   // Verify charge point exists and is Accepted
@@ -224,21 +243,64 @@ app.get("/:id", async (c) => {
     .select({
       transaction,
       chargePointIdentifier: chargePoint.chargePointIdentifier,
+      connectorNumber: connector.connectorId,
+      feePerKwh: chargePoint.feePerKwh,
+      pricingMode: chargePoint.pricingMode,
     })
     .from(transaction)
     .leftJoin(chargePoint, eq(transaction.chargePointId, chargePoint.id))
+    .leftJoin(connector, eq(transaction.connectorId, connector.id))
     .where(eq(transaction.id, id))
     .limit(1);
 
   if (!row) return c.json({ error: "Not found" }, 404);
 
+  let liveEnergyWh: number | null = null;
+  let estimatedCost: number | null = null;
+
+  // For active transactions, return live estimated energy/cost like the list endpoint.
+  if (!row.transaction.stopTimestamp) {
+    const latestRows = await db.execute<{
+      sampled_values: SampledValue[];
+    }>(sql`
+      SELECT sampled_values
+      FROM meter_value
+      WHERE transaction_id = ${id}
+      ORDER BY timestamp DESC
+      LIMIT 1
+    `);
+
+    const latest = latestRows.rows[0];
+    if (latest) {
+      const svList = latest.sampled_values as SampledValue[];
+      const energySv = svList.find(
+        (sv) => (!sv.measurand || sv.measurand === "Energy.Active.Import.Register") && !sv.phase,
+      );
+
+      if (energySv != null) {
+        const raw = parseFloat(energySv.value);
+        if (!Number.isNaN(raw) && row.transaction.startMeterValue != null) {
+          const latestMeterWh = energySv.unit === "kWh" ? raw * 1000 : raw;
+          liveEnergyWh = latestMeterWh - row.transaction.startMeterValue;
+
+          if (liveEnergyWh > 0 && row.pricingMode === "fixed" && (row.feePerKwh ?? 0) > 0) {
+            estimatedCost = Math.ceil((liveEnergyWh * (row.feePerKwh ?? 0)) / 1000);
+          }
+        }
+      }
+    }
+  }
+
   return c.json({
     ...row.transaction,
     chargePointIdentifier: row.chargePointIdentifier,
+    connectorNumber: row.connectorNumber,
     energyWh:
       row.transaction.stopMeterValue != null
         ? row.transaction.stopMeterValue - row.transaction.startMeterValue
         : null,
+    liveEnergyWh,
+    estimatedCost,
   });
 });