App 2.43.5: update checks log what happens

Each check writes down the networks Android sees, the server's name lookup,
how a failure happened and how many reports wait, and on a failure whether
the internet answers at all, to tell a SIM without data from a server that is
down. The report goes to a USB stick and, once online, the server. No address
or token is written. Tried on the emulator. Not tried on the car.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

app/src/main/java/com/evsuite/abrp/LogOutbox.java

@@ -85,6 +85,12 @@ final class LogOutbox {
         return true;
     }
 
+    /** Removes what waits under names starting with [prefix]. */
+    static synchronized void dropWaiting(Context context, String prefix) {
+        File dir = new File(context.getFilesDir(), DIR);
+        for (String name : waiting(dir)) if (name.startsWith(prefix)) new File(dir, name).delete();
+    }
+
     /** Sends what waits, unless the last attempt failed less than {@link #RETRY_MS} ago. Blocking:
      *  call it off the main thread. */
     static void sendIfDue(Context context) {

app/src/main/java/com/evsuite/abrp/UpdateDiagnosis.java

@@ -0,0 +1,69 @@
+package com.evsuite.abrp;
+
+import java.io.IOException;
+import java.net.ConnectException;
+import java.net.NoRouteToHostException;
+import java.net.SocketException;
+import java.net.SocketTimeoutException;
+import java.net.UnknownHostException;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import javax.net.ssl.SSLException;
+
+/**
+ * Why an update check failed, in words for the update log, and what the car's networks look
+ * like. Built from an error's type and an HTTP status only, because an error's own text can carry
+ * the server's address: nothing here holds a URL or a credential. Android-free and unit-tested.
+ */
+final class UpdateDiagnosis {
+
+    private static final Pattern STATUS = Pattern.compile("^Release API returned (\\d{3})$");
+
+    private UpdateDiagnosis() {}
+
+    /** One line about a failed step. */
+    static String failure(Throwable t) {
+        if (t == null) return "unknown failure";
+        String type = " (" + t.getClass().getSimpleName() + ")";
+        if (t instanceof UnknownHostException) return "the name could not be looked up: no data connection, or no name service" + type;
+        if (t instanceof SocketTimeoutException) return "no answer in time: a very slow or blocked connection" + type;
+        if (t instanceof ConnectException || t instanceof NoRouteToHostException) return "no connection could be made" + type;
+        if (t instanceof SSLException) return "the secure connection failed: something in between may have answered, or the head unit's clock is wrong" + type;
+        if (t instanceof SocketException) return "the connection broke off" + type;
+        if (t instanceof IOException && t.getMessage() != null) {
+            Matcher status = STATUS.matcher(t.getMessage());
+            if (status.matches()) return status(Integer.parseInt(status.group(1)));
+            if (t.getMessage().equals("Invalid release response")) return "the answer was not a list of releases";
+        }
+        return "failed" + type;
+    }
+
+    /** What a status from the car server means here. */
+    static String status(int code) {
+        String what;
+        if (code >= 300 && code < 400) what = "something in between redirected it, as a SIM without data may";
+        else if (code == 401 || code == 403) what = "the server refuses the car's token";
+        else if (code == 404) what = "the server does not know this address";
+        else if (code >= 500) what = "the server or the forge behind it has a problem";
+        else what = "not what was expected";
+        return "the server answered HTTP " + code + ": " + what;
+    }
+
+    /** The outside-world test: a 204 is the internet working; anything else stands in between. */
+    static String internet(int code) {
+        if (code == 204) return "the internet works (HTTP 204)";
+        return "something in between answered HTTP " + code + " instead, as a SIM without data may";
+    }
+
+    /** One network as Android sees it. */
+    static String network(List<String> transports, boolean internet, boolean validated,
+                          boolean active, boolean roaming) {
+        return (transports.isEmpty() ? "unknown type" : String.join("+", transports))
+                + (active ? ", in use" : "")
+                + (internet ? ", offers internet" : ", no internet")
+                + (validated ? ", confirmed by Android" : ", not confirmed by Android")
+                + (roaming ? ", roaming" : "");
+    }
+}

app/src/main/java/com/evsuite/abrp/UpdateLog.java

@@ -21,7 +21,7 @@ import java.util.Locale;
  */
 final class UpdateLog {
 
-    static final int MAX_LINES = 10;
+    static final int MAX_LINES = 40;
     private static final String PREFS = "update_log";
     private static final String KEY = "lines";
     private static final String KEY_VERSION = "version";