Add on-device logger

2026-05-31 14:44:48 +02:00
parent b4c5578e8c
commit 2ebb4a6f01
4 changed files with 152 additions and 16 deletions
@@ -0,0 +1,82 @@
+import * as FileSystem from 'expo-file-system';
+
+const logFileUri = FileSystem.documentDirectory + 'app_logs.txt';
+
+export const logger = {
+  log: async (message: string) => {
+    try {
+      const timestamp = new Date().toISOString();
+      const logLine = `[INFO] ${timestamp}: ${message}\n`;
+      console.log(logLine.trim());
+      
+      const fileInfo = await FileSystem.getInfoAsync(logFileUri);
+      if (!fileInfo.exists) {
+        await FileSystem.writeAsStringAsync(logFileUri, logLine, { encoding: FileSystem.EncodingType.UTF8 });
+      } else {
+        // Read existing and append (simplistic approach for small logs)
+        // expo-file-system doesn't have an append method out of the box in older versions, 
+        // but wait, we can just read, then write. To avoid OOM we should truncate if too big.
+        const current = await FileSystem.readAsStringAsync(logFileUri, { encoding: FileSystem.EncodingType.UTF8 });
+        // Keep last 100000 chars
+        let newContent = current + logLine;
+        if (newContent.length > 100000) {
+            newContent = newContent.slice(-100000);
+        }
+        await FileSystem.writeAsStringAsync(logFileUri, newContent, { encoding: FileSystem.EncodingType.UTF8 });
+      }
+    } catch (e) {
+      console.log('Failed to write log:', e);
+    }
+  },
+  
+  error: async (message: string, error?: any) => {
+    try {
+      const timestamp = new Date().toISOString();
+      let errorString = '';
+      if (error) {
+        if (error instanceof Error) {
+          errorString = `\n  Name: ${error.name}\n  Message: ${error.message}\n  Stack: ${error.stack}`;
+        } else if (typeof error === 'object') {
+          errorString = `\n  Object: ${JSON.stringify(error)}`;
+        } else {
+          errorString = `\n  Value: ${String(error)}`;
+        }
+      }
+      
+      const logLine = `[ERROR] ${timestamp}: ${message}${errorString}\n`;
+      console.error(logLine.trim());
+      
+      const fileInfo = await FileSystem.getInfoAsync(logFileUri);
+      if (!fileInfo.exists) {
+        await FileSystem.writeAsStringAsync(logFileUri, logLine, { encoding: FileSystem.EncodingType.UTF8 });
+      } else {
+        const current = await FileSystem.readAsStringAsync(logFileUri, { encoding: FileSystem.EncodingType.UTF8 });
+        let newContent = current + logLine;
+        if (newContent.length > 100000) {
+            newContent = newContent.slice(-100000);
+        }
+        await FileSystem.writeAsStringAsync(logFileUri, newContent, { encoding: FileSystem.EncodingType.UTF8 });
+      }
+    } catch (e) {
+      console.log('Failed to write error log:', e);
+    }
+  },
+
+  readLogs: async (): Promise<string> => {
+    try {
+      const fileInfo = await FileSystem.getInfoAsync(logFileUri);
+      if (!fileInfo.exists) return 'Keine Logs vorhanden.';
+      return await FileSystem.readAsStringAsync(logFileUri, { encoding: FileSystem.EncodingType.UTF8 });
+    } catch (e) {
+      return `Fehler beim Lesen der Logs: ${e}`;
+    }
+  },
+
+  clearLogs: async () => {
+    try {
+      await FileSystem.deleteAsync(logFileUri, { idempotent: true });
+    } catch (e) {
+      console.log('Failed to clear logs:', e);
+    }
+  }
+};