Fix unreadable text on light terminals

bin/sonic.js

@@ -18,6 +18,7 @@ import {
   verifyLogin
 } from '../lib/spotify.js';
 import { UI } from '../lib/ui.js';
+import { queryTerminalBackground } from '../lib/themes.js';
 import {
   CHANNELS, ACTIVITIES,
   getSuggestedChannel, getSuggestedActivity,
@@ -811,7 +812,11 @@ function promptSearch(notice = '') {
   });
 }
 
-process.stdin.on('data', async (key) => {
+process.stdin.on('data', async (input) => {
+  const key = String(input);
+  // A late reply to the background-color query is not a keypress.
+  if (key.startsWith('\x1b]')) return;
+
   if (key === '\x03') {
     cleanup(0);
     return;
@@ -1144,6 +1149,9 @@ async function main() {
     process.exit(1);
   }
 
+  // Learn light vs dark before the first frame, so text never lands white on white.
+  if (store.config.colorMode === 'auto') await queryTerminalBackground();
+
   ui.hideCursor();
 
   if (connectMode) {

lib/themes.js

@@ -242,6 +242,37 @@ export function cycleTheme(themeId, direction = 1) {
 
 let _detectedMode = null;
 
+// Ask the terminal for its background color (OSC 11). Most terminals answer
+// within a few ms; Terminal.app sets no COLORFGBG, so this is the reliable path.
+export function queryTerminalBackground(timeoutMs = 250) {
+  return new Promise((resolve) => {
+    if (!process.stdin.isTTY || !process.stdout.isTTY) return resolve(null);
+    const wasRaw = process.stdin.isRaw;
+    let buffer = '';
+    const finish = (mode) => {
+      clearTimeout(timer);
+      process.stdin.off('data', onData);
+      if (!wasRaw) process.stdin.setRawMode(false);
+      process.stdin.pause();
+      if (mode) _detectedMode = mode;
+      resolve(mode);
+    };
+    const onData = (chunk) => {
+      buffer += chunk.toString();
+      const match = buffer.match(/rgb:([0-9a-f]+)\/([0-9a-f]+)\/([0-9a-f]+)/i);
+      if (!match) return;
+      const [r, g, b] = match.slice(1).map((hex) => parseInt(hex, 16) / (16 ** hex.length - 1));
+      const luminance = 0.2126 * r + 0.7152 * g + 0.0722 * b;
+      finish(luminance > 0.5 ? 'light' : 'dark');
+    };
+    const timer = setTimeout(() => finish(null), timeoutMs);
+    process.stdin.setRawMode(true);
+    process.stdin.resume();
+    process.stdin.on('data', onData);
+    process.stdout.write('\x1b]11;?\x07');
+  });
+}
+
 export function detectColorMode() {
   if (_detectedMode) return _detectedMode;
   const colorfgbg = process.env.COLORFGBG;