Printing Debug

src/printer.js

@@ -336,24 +336,26 @@ export async function printBadge(visit, site) {
   const port = Number(site.printer_port) || 9100;
   const target = `tcp://${site.printer_host}:${port}`;
 
+  const args = [
+    '--backend', 'network',
+    '--model', site.printer_model || 'QL-820NWB',
+    '--printer', target,
+    'print',
+    '--label', labelFor(site),
+    file,
+  ];
+
   try {
-    await runBrotherQl(
-      [
-        '--backend', 'network',
-        '--model', site.printer_model || 'QL-820NWB',
-        '--printer', target,
-        'print',
-        '--label', labelFor(site),
-        file,
-      ],
-      config.printing.timeoutMs
-    );
+    await runBrotherQl(args, config.printing.timeoutMs);
     note(site.id, true, `Printed to ${site.printer_host}`);
     return { ok: true, target };
   } catch (err) {
     const friendly = explainPrintError(err.message, site.printer_host);
     note(site.id, false, friendly);
-    throw new Error(friendly);
+    const wrapped = new Error(friendly);
+    wrapped.raw = err.message;
+    wrapped.command = `${config.printing.command} ${args.join(' ')}`;
+    throw wrapped;
   } finally {
     fs.rm(file, { force: true }, () => {});
   }

src/routes/admin.js

@@ -510,10 +510,40 @@ router.post('/sites/:id/test-print', async (req, res) => {
     const result = await printer.printBadge(printer.sampleVisit(site), site);
     res.json({ ok: true, ...result });
   } catch (err) {
-    res.status(400).json({ error: err.message });
+    // The raw output and the exact command matter when the friendly message is
+    // not enough — a printer refusing a job says why in its own words.
+    res.status(400).json({ error: err.message, raw: err.raw || null, command: err.command || null });
   }
 });
 
+/** Everything about how this site would print, for working out why it will not. */
+router.get('/sites/:id/printer-diagnostics', (req, res) => {
+  const site = db.prepare('SELECT * FROM sites WHERE id = ?').get(req.params.id);
+  if (!site) return res.status(404).json({ error: 'Not found.' });
+  res.json({
+    site: site.name,
+    printing: {
+      enabled: Boolean(site.printer_enabled),
+      host: site.printer_host,
+      port: site.printer_port,
+      model: site.printer_model,
+      rotate: site.printer_rotate,
+    },
+    rollSetting: site.printer_label,
+    labelSentToPrinter: printer.labelFor(site),
+    redRequested: Boolean(site.badge_accent),
+    redWillPrint: printer.accentWillPrintRed(site),
+    badgeMm: { width: site.badge_width_mm, height: site.badge_height_mm },
+    lastResult: printer.printerStatus(site.id),
+    command: [
+      'brother_ql --backend network',
+      `--model ${site.printer_model || 'QL-820NWB'}`,
+      `--printer tcp://${site.printer_host}:${site.printer_port || 9100}`,
+      `print --label ${printer.labelFor(site)} badge.png`,
+    ].join(' '),
+  });
+});
+
 /** Reprints a real visitor's badge on the server's printer. */
 router.post('/visits/:id/print', async (req, res) => {
   const visit = db.prepare('SELECT * FROM visits WHERE id = ?').get(req.params.id);