fix: atomic config writes to prevent data loss on update/crash

- All config writes now go through _atomicWrite() (write to .tmp, backup
  to .bak, rename .tmp to main config)
- load() falls back to .bak if main config is empty or corrupt
- Prevents 0KB config files caused by process termination during write

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/config-store.js

@@ -82,10 +82,24 @@ class ConfigStore {
     } catch {}
   }
 
+  _readAndParse(filePath) {
+    const raw = fs.readFileSync(filePath, 'utf-8');
+    if (!raw || raw.trim().length < 2) return null;
+    return JSON.parse(raw);
+  }
+
   load() {
     try {
-      const raw = fs.readFileSync(this.filePath, 'utf-8');
-      const data = JSON.parse(raw);
+      let data = null;
+      // Try main config
+      try { data = this._readAndParse(this.filePath); } catch {}
+      // Fallback to backup if main is empty/corrupt
+      if (!data) {
+        const backupPath = this.filePath + '.bak';
+        try { data = this._readAndParse(backupPath); } catch {}
+      }
+      if (!data) return JSON.parse(JSON.stringify(DEFAULTS));
+
       // Merge with defaults so new hosters are always present
       const hosters = { ...DEFAULTS.hosters };
       for (const [name, val] of Object.entries(data.hosters || {})) {
@@ -116,12 +130,7 @@ class ConfigStore {
     if (config.hosters) current.hosters = config.hosters;
     if (config.hosterSettings) current.hosterSettings = config.hosterSettings;
     if (config.globalSettings) current.globalSettings = config.globalSettings;
-    const data = JSON.stringify(current, null, 2);
-    return new Promise((resolve, reject) => {
-      fs.writeFile(this.filePath, data, 'utf-8', (err) => {
-        if (err) reject(err); else resolve();
-      });
-    });
+    return this._atomicWrite(JSON.stringify(current, null, 2));
   }
 
   loadHistory() {
@@ -129,29 +138,39 @@ class ConfigStore {
     return config.history || [];
   }
 
+  _atomicWrite(data) {
+    return new Promise((resolve, reject) => {
+      const tmpPath = this.filePath + '.tmp';
+      const backupPath = this.filePath + '.bak';
+      fs.writeFile(tmpPath, data, 'utf-8', (err) => {
+        if (err) return reject(err);
+        try {
+          if (fs.existsSync(this.filePath)) {
+            const existing = fs.readFileSync(this.filePath, 'utf-8');
+            if (existing && existing.trim().length > 2) {
+              fs.writeFileSync(backupPath, existing, 'utf-8');
+            }
+          }
+          fs.renameSync(tmpPath, this.filePath);
+        } catch (e) { return reject(e); }
+        resolve();
+      });
+    });
+  }
+
   appendHistory(entry) {
     const config = this.load();
     config.history.push(entry);
     if (config.history.length > MAX_HISTORY) {
       config.history = config.history.slice(-MAX_HISTORY);
     }
-    const data = JSON.stringify(config, null, 2);
-    return new Promise((resolve, reject) => {
-      fs.writeFile(this.filePath, data, 'utf-8', (err) => {
-        if (err) reject(err); else resolve();
-      });
-    });
+    return this._atomicWrite(JSON.stringify(config, null, 2));
   }
 
   clearHistory() {
     const config = this.load();
     config.history = [];
-    const data = JSON.stringify(config, null, 2);
-    return new Promise((resolve, reject) => {
-      fs.writeFile(this.filePath, data, 'utf-8', (err) => {
-        if (err) reject(err); else resolve();
-      });
-    });
+    return this._atomicWrite(JSON.stringify(config, null, 2));
   }
 }
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "multi-hoster-uploader",
-  "version": "1.6.7",
+  "version": "1.6.8",
   "description": "Upload files to doodstream, voe, vidmoly, byse simultaneously",
   "main": "main.js",
   "scripts": {