feat(mysql): 接入只读电池数据源

src/server/battery/mysql.ts

@@ -0,0 +1,75 @@
+import mysql, { type Pool, type RowDataPacket } from 'mysql2/promise'
+
+import { type BatteryInfo, type BatteryInfoSourceRow, toBatteryInfo } from '@/domain/battery'
+import { env } from '@/env'
+
+const historyLimit = 500
+
+type BatteryInfoMysqlRow = RowDataPacket & BatteryInfoSourceRow
+
+let pool: Pool | undefined
+
+function getBatteryPool() {
+  pool ??= mysql.createPool({
+    uri: env.DATABASE_URL,
+    waitForConnections: true,
+    connectionLimit: 5,
+    namedPlaceholders: true,
+  })
+
+  return pool
+}
+
+export async function closeBatteryPool() {
+  if (!pool) return
+
+  await pool.end()
+  pool = undefined
+}
+
+const sourceColumns = `
+  id,
+  user_id AS userId,
+  mac,
+  dev_model AS devModel,
+  dev_name AS devName,
+  is_low_power AS isLowPower,
+  power_status AS powerStatus,
+  power,
+  create_time AS createTime,
+  remark
+`
+
+export async function getBatteryHistory(mac: string): Promise<BatteryInfo[]> {
+  const [rows] = await getBatteryPool().query<BatteryInfoMysqlRow[]>(
+    `
+      SELECT ${sourceColumns}
+      FROM ls_battery_info
+      WHERE mac = :mac
+      ORDER BY create_time DESC, id DESC
+      LIMIT :limit
+    `,
+    { mac, limit: historyLimit },
+  )
+
+  return rows.map(toBatteryInfo)
+}
+
+export async function getLatestBatteryPerDevice(): Promise<BatteryInfo[]> {
+  const [rows] = await getBatteryPool().query<BatteryInfoMysqlRow[]>(`
+    SELECT ${sourceColumns}
+    FROM ls_battery_info AS current_record
+    WHERE NOT EXISTS (
+      SELECT 1
+      FROM ls_battery_info AS newer_record
+      WHERE newer_record.mac = current_record.mac
+        AND (
+          newer_record.create_time > current_record.create_time
+          OR (newer_record.create_time = current_record.create_time AND newer_record.id > current_record.id)
+        )
+    )
+    ORDER BY current_record.create_time DESC, current_record.id DESC
+  `)
+
+  return rows.map(toBatteryInfo)
+}