From fc2c7947870f2761652b10b3170fd3b0fc89c88a Mon Sep 17 00:00:00 2001
From: Peter Stone <thepeterstone@gmail.com>
Date: Sun, 15 Mar 2026 08:36:44 +0000
Subject: feat: add file-based crash logger for offline diagnostics

NavApplication installs an UncaughtExceptionHandler that writes
crash stack traces to crash_latest.txt (and timestamped copies) in
the app's external files dir. Readable without root or ADB.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 .../main/kotlin/org/terst/nav/NavApplication.kt    | 52 ++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 android-app/app/src/main/kotlin/org/terst/nav/NavApplication.kt

(limited to 'android-app/app/src/main/kotlin/org/terst')

diff --git a/android-app/app/src/main/kotlin/org/terst/nav/NavApplication.kt b/android-app/app/src/main/kotlin/org/terst/nav/NavApplication.kt
new file mode 100644
index 0000000..1075930
--- /dev/null
+++ b/android-app/app/src/main/kotlin/org/terst/nav/NavApplication.kt
@@ -0,0 +1,52 @@
+package org.terst.nav
+
+import android.app.Application
+import android.os.Environment
+import java.io.File
+import java.io.PrintWriter
+import java.io.StringWriter
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+
+class NavApplication : Application() {
+
+    override fun onCreate() {
+        super.onCreate()
+        installCrashLogger()
+    }
+
+    private fun installCrashLogger() {
+        val default = Thread.getDefaultUncaughtExceptionHandler()
+        Thread.setDefaultUncaughtExceptionHandler { thread, throwable ->
+            try {
+                writeCrashLog(thread, throwable)
+            } catch (_: Exception) {
+                // never suppress the original crash
+            }
+            default?.uncaughtException(thread, throwable)
+        }
+    }
+
+    private fun writeCrashLog(thread: Thread, throwable: Throwable) {
+        val sw = StringWriter()
+        throwable.printStackTrace(PrintWriter(sw))
+        val timestamp = SimpleDateFormat("yyyyMMdd_HHmmss", Locale.US).format(Date())
+        val body = buildString {
+            appendLine("=== Nav Crash Log ===")
+            appendLine("Time   : $timestamp")
+            appendLine("Thread : ${thread.name}")
+            appendLine("Device : ${android.os.Build.MODEL} (API ${android.os.Build.VERSION.SDK_INT})")
+            appendLine()
+            append(sw)
+        }
+
+        // Try external storage first (readable without root)
+        val dir = getExternalFilesDir(null) ?: filesDir
+        val file = File(dir, "crash_${timestamp}.txt")
+        file.writeText(body)
+
+        // Also overwrite a fixed-name "latest" file for easy access
+        File(dir, "crash_latest.txt").writeText(body)
+    }
+}
-- 
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