Improve error handling and ordering flows

backend/routes/resources.js

@@ -1,12 +1,76 @@
 const express = require("express");
 const router = express.Router();
+const db = require("../db");
 const controller = require("../controllers/resourceController");
 
+const isMissingPositionColumn = (error) =>
+  error && error.code === "ER_BAD_FIELD_ERROR" && String(error.sqlMessage || "").includes("position");
+
 router.get("/active", controller.getActive);
 router.get("/cancelled", controller.getCancelled);
 
+router.post("/:id/move", async (req, res) => {
+
+  const { direction } = req.body
+
+  if (direction !== "up" && direction !== "down") {
+    return res.status(400).json({ error: "Ungueltige Richtung" })
+  }
+
+  try {
+
+    let rows
+
+    try {
+      await db.query(
+        "UPDATE resources SET position = id WHERE position IS NULL"
+      )
+
+      ;[rows] = await db.query(
+        "SELECT id FROM resources WHERE status != 'gekündigt' ORDER BY position, id"
+      )
+    } catch (e) {
+      if (isMissingPositionColumn(e)) {
+        return res.status(400).json({ error: "Position-Spalte in resources fehlt noch" })
+      }
+      throw e
+    }
+
+    const index = rows.findIndex(r => r.id == req.params.id)
+
+    if (index === -1) {
+      return res.status(404).json({ error: "Ressource nicht gefunden" })
+    }
+
+    const swapIndex = direction === "up" ? index - 1 : index + 1
+
+    if (swapIndex < 0 || swapIndex >= rows.length) {
+      return res.json({ success: true })
+    }
+
+    const moved = rows.splice(index, 1)[0]
+    rows.splice(swapIndex, 0, moved)
+
+    for(let i = 0; i < rows.length; i++){
+      await db.query(
+        "UPDATE resources SET position=? WHERE id=?",
+        [i + 1, rows[i].id]
+      )
+    }
+
+    res.json({ success: true })
+
+  } catch (e) {
+    console.error("MOVE resource error:", e)
+    res.status(500).json({ error: "Reihenfolge konnte nicht geaendert werden" })
+  }
+
+})
+
 router.post("/", controller.create);
 router.put("/:id", controller.update);
 router.delete("/:id", controller.remove);
 
+
+
 module.exports = router;