refactor: create trend route handler

src/server/routes/mileage/trend.ts

@@ -0,0 +1,48 @@
+import { Hono } from 'hono';
+import pool from '../../db.js';
+import mileagePool from '../../mileage-db.js';
+
+const app = new Hono();
+
+app.get('/', async (c) => {
+  const targetId = c.req.query('targetId');
+  const days = Number(c.req.query('days')) || 7;
+
+  try {
+    let plates: string[] = [];
+    if (targetId) {
+      const [vehicleRows] = await pool.execute(
+        'SELECT plate_number FROM tab_mileage_assessment_vehicle WHERE target_id = ? AND is_deleted = 0',
+        [targetId]
+      ) as [{ plate_number: string }[], unknown];
+      plates = vehicleRows.map(r => r.plate_number);
+      if (plates.length === 0) return c.json([]);
+    }
+
+    let sql = `
+      SELECT DATE_FORMAT(stat_date, '%m-%d') as date, SUM(daily_km) as mileage
+      FROM v_vehicle_daily_stats
+      WHERE stat_date >= DATE_SUB(CURDATE(), INTERVAL ? DAY) AND stat_date < CURDATE()
+    `;
+    const params: (string | number)[] = [days];
+
+    if (plates.length > 0) {
+      sql += ` AND plate IN (${plates.map(() => '?').join(',')})`;
+      params.push(...plates);
+    }
+
+    sql += ' GROUP BY stat_date ORDER BY stat_date';
+
+    const [rows] = await mileagePool.execute(sql, params) as [any[], unknown];
+
+    return c.json(rows.map((r: any) => ({
+      date: r.date,
+      mileage: Math.round(Number(r.mileage) || 0),
+    })));
+  } catch (e: unknown) {
+    console.error('trend error:', e);
+    return c.json([], 500);
+  }
+});
+
+export default app;