BE-14: Implement Import and Export JSON functionality

beat-editor/backend/app.js

@@ -3,8 +3,12 @@ const cors = require("cors");
 const fs = require("fs");
 const path = require("path");
 const bodyParser = require("body-parser");
+const multer = require("multer");
+const upload = multer({ dest: "temp/" });
 const app = express();
 
+const validateEditsJson = require("./helper/validateEditsJson");
+
 // Middleware to parse JSON bodies
 app.use(bodyParser.json());
 
@@ -18,13 +22,13 @@ app.get("/fetch-file", async (req, res) => {
   try {
     const dataFiles = await fs.promises.readdir(dataDir);
     const fileDirJsonFiles = dataFiles.filter((file) =>
-      file.endsWith("_edit.json")
+      file.endsWith("_edit.json"),
     );
 
     // Extract the name of the _edit.json file
     const jsonFileName = fileDirJsonFiles[0].substring(
       0,
-      fileDirJsonFiles[0].length - 10
+      fileDirJsonFiles[0].length - 10,
     );
 
     // Skip the /saved folder if it doesn't exist
@@ -33,9 +37,7 @@ app.get("/fetch-file", async (req, res) => {
       : [];
     // Grab the _edited.json file that matches the _edit.json file
     const savedDirJsonFiles = fs.existsSync(savedDir)
-      ? savedFiles.filter((file) =>
-          file.endsWith(`${jsonFileName}_edited.json`)
-        )
+      ? savedFiles.filter((file) => file.endsWith(`_edited.json`))
       : [];
 
     if (dataFiles.length === 0) {
@@ -50,7 +52,7 @@ app.get("/fetch-file", async (req, res) => {
           fileName: file.replace("_edit.json", ""),
           data: JSON.parse(fileContent),
         };
-      })
+      }),
     );
 
     // If there's a '_edited.json' file, take the data in there too to replot
@@ -64,16 +66,16 @@ app.get("/fetch-file", async (req, res) => {
                 fileName: file,
                 data: JSON.parse(fileContent),
               };
-            })
+            }),
           )
         : null;
 
     // Extract unique segment options
     const segmentOptions = [
       ...new Set(
         allFileData.flatMap((file) =>
-          file.data.map((o) => o.Segment.toString())
-        )
+          file.data.map((o) => o.Segment.toString()),
+        ),
       ),
     ];
 
@@ -97,7 +99,7 @@ app.post("/saved", async (req, res) => {
     __dirname,
     "..",
     "saved",
-    `${fileName}_edited.json`
+    `${fileName}_edited.json`,
   );
 
   try {
@@ -141,6 +143,46 @@ app.post("/saved", async (req, res) => {
   }
 });
 
+app.post("/import-edits", upload.single("file"), async (req, res) => {
+  try {
+    const savedDir = path.join(__dirname, "..", "saved");
+
+    if (!fs.existsSync(savedDir)) {
+      fs.mkdirSync(savedDir);
+    }
+
+    const tempPath = req.file.path;
+    const rawData = await fs.promises.readFile(tempPath, "utf-8");
+    let parsedData;
+
+    try {
+      parsedData = JSON.parse(rawData);
+    } catch {
+      await fs.promises.unlink(tempPath);
+      return res.status(400).json({ message: "Invalid JSON file." });
+    }
+
+    const validationResult = validateEditsJson(parsedData);
+    if (!validationResult.ok) {
+      await fs.promises.unlink(tempPath);
+      return res.status(400).json({
+        message: "Invalid JSON structure.",
+        error: validationResult.error,
+      });
+    }
+
+    const targetPath = path.join(savedDir, req.file.originalname);
+
+    await fs.promises.rename(tempPath, targetPath);
+
+    res.status(200).json({ message: "File imported successfully." });
+  } catch (err) {
+    res
+      .status(500)
+      .json({ message: "Error importing file.", error: err.message });
+  }
+});
+
 // Start the server
 const port = process.env.PORT || 3001;
 app.listen(port, () => {

beat-editor/backend/helper/validateEditsJson.js

@@ -0,0 +1,48 @@
+const EDIT_TYPES = ["ADD", "DELETE", "UNUSABLE"];
+
+/**
+ *  validateEditsJson
+ *
+ *  Validates the structure of the imported _edits.json file.
+ *
+ *  @param {Array} data - The parsed JSON data to validate.
+ *  @returns {Object} An object with 'ok' boolean and 'error' message if not valid.
+ */
+
+function validateEditsJson(data) {
+  if (!Array.isArray(data)) {
+    return { ok: false, error: "Expected an array" };
+  }
+
+  for (const [key, value] of data.entries()) {
+    if (!value || typeof value !== "object") {
+      return { ok: false, error: `Item ${key} is not an object` };
+    }
+
+    const { editType, segment, x, y } = value;
+
+    if (!EDIT_TYPES.includes(editType))
+      return { ok: false, error: `Item ${key} has an invalid editType` };
+    if (typeof segment !== "string")
+      return { ok: false, error: `Item ${key} has an invalid segment` };
+    if (typeof x !== "number" || typeof y !== "number")
+      return { ok: false, error: `Item ${key} has invalid x or y` };
+
+    if (editType === "UNUSABLE") {
+      if (
+        !Number.isFinite(value.from) ||
+        !Number.isFinite(value.to) ||
+        typeof value.color !== "string"
+      ) {
+        return {
+          ok: false,
+          error: `Item ${key} has invalid from or to for UNUSABLE editType`,
+        };
+      }
+    }
+  }
+
+  return { ok: true };
+}
+
+module.exports = validateEditsJson;

beat-editor/backend/package.json

@@ -12,6 +12,7 @@
   "license": "ISC",
   "dependencies": {
     "cors": "^2.8.5",
-    "express": "^4.19.2"
+    "express": "^4.19.2",
+    "multer": "^2.0.2"
   }
 }