Improve deployment safety and chat reliability
Deploy FluentGerman.ai / deploy (push) Successful in 1m25s

This commit is contained in:
2026-08-29 17:28:50 +02:00
parent e9f12bc2ba
commit d974aaedc8
15 changed files with 746 additions and 153 deletions
+191 -65
View File
@@ -58,6 +58,15 @@ document.addEventListener('DOMContentLoaded', async () => {
let history = [];
let voiceModeOn = false;
let sending = false;
let abortController = null;
// Bumped by "New chat" — a send started before the bump must not write
// its late results into the conversation that replaced it.
let chatGeneration = 0;
// Conversations survive a reload but not a closed tab, and are scoped to
// the logged-in user so a shared device never shows someone else's lesson.
const CHAT_KEY = `fg_chat_${user?.id ?? 'anon'}`;
// ── Personalised welcome ──────────────────────────────────────────
const greetingEl = document.getElementById('welcome-greeting');
@@ -156,14 +165,123 @@ document.addEventListener('DOMContentLoaded', async () => {
return div;
}
/**
* Read an SSE stream to completion, calling onToken for every token.
*
* Buffers across reads: a chunk boundary can fall anywhere, splitting a
* multi-byte character (ä, ö, ü, ß) or a whole event across two reads.
*/
function saveHistory() {
try {
sessionStorage.setItem(CHAT_KEY, JSON.stringify(history.slice(-40)));
} catch (e) {
console.warn('[Chat] Could not save conversation:', e);
}
}
function restoreHistory() {
let saved = [];
try {
saved = JSON.parse(sessionStorage.getItem(CHAT_KEY) || '[]');
} catch (e) {
return;
}
if (!Array.isArray(saved) || saved.length === 0) return;
history = saved;
for (const msg of saved) {
if (msg?.role && typeof msg.content === 'string') {
appendMessage(msg.role, msg.content);
}
}
}
function startNewChat() {
chatGeneration++;
abortController?.abort();
voice.stopPlayback();
abortController = null;
setSending(false);
history = [];
try {
sessionStorage.removeItem(CHAT_KEY);
} catch (e) {
/* storage may be blocked */
}
messagesEl.querySelectorAll('.message').forEach(el => el.remove());
inputEl.focus();
}
/** Toggle the composer between "Send" and "Stop". */
function setSending(on) {
sending = on;
sendBtn.textContent = on ? 'Stop' : 'Send';
sendBtn.classList.toggle('btn-danger', on);
sendBtn.classList.toggle('btn-primary', !on);
}
async function readSSE(response, onToken) {
const reader = response.body.getReader();
const decoder = new TextDecoder();
let buffer = '';
let finished = false;
const handleEvent = (event) => {
for (const line of event.split('\n')) {
if (!line.startsWith('data: ')) continue;
const data = line.slice(6).trim();
if (data === '[DONE]') {
finished = true;
return;
}
try {
const parsed = JSON.parse(data);
if (parsed.token) onToken(parsed.token);
if (parsed.error) showToast(parsed.error, 'error');
} catch (err) {
console.warn('[Chat] Unparseable SSE data:', data);
}
}
};
while (!finished) {
const { done, value } = await reader.read();
if (done) {
buffer += decoder.decode(); // flush any pending bytes
if (buffer.trim()) handleEvent(buffer);
break;
}
buffer += decoder.decode(value, { stream: true });
// Events are separated by a blank line — keep the trailing fragment.
const events = buffer.split('\n\n');
buffer = events.pop();
for (const event of events) {
handleEvent(event);
if (finished) break;
}
}
try { await reader.cancel(); } catch (err) { /* already closed */ }
}
async function sendMessage() {
if (sending) return;
const text = inputEl.value.trim();
if (!text) return;
setSending(true);
const controller = new AbortController();
abortController = controller;
const generation = chatGeneration;
const isCurrent = () => generation === chatGeneration;
voice.lastInputWasVoice = false;
inputEl.value = '';
sendBtn.disabled = true;
appendMessage('user', text);
history.push({ role: 'user', content: text });
@@ -175,6 +293,7 @@ document.addEventListener('DOMContentLoaded', async () => {
const response = await api('/chat/', {
method: 'POST',
body: JSON.stringify({ message: text, history: history.slice(-20) }),
signal: controller.signal,
});
if (!response?.ok) {
@@ -182,94 +301,96 @@ document.addEventListener('DOMContentLoaded', async () => {
throw new Error(errData.detail || `Chat failed (${response?.status})`);
}
const reader = response.body.getReader();
const decoder = new TextDecoder();
// Special handling for Voice Mode: Buffer text, wait for TTS, then show & play
if (voiceModeOn) {
// "Thinking..." is already shown from appendMessage above
// Buffer the whole reply, fetch its audio, then reveal text and
// player together — "Thinking..." stays up until audio is ready.
await readSSE(response, (token) => {
fullResponse += token;
});
while (true) {
const { done, value } = await reader.read();
if (done) break;
const chunk = decoder.decode(value);
const lines = chunk.split('\n');
for (const line of lines) {
if (line.startsWith('data: ')) {
const data = line.slice(6).trim();
if (data === '[DONE]') break;
try {
const parsed = JSON.parse(data);
if (parsed.token) fullResponse += parsed.token;
if (parsed.error) showToast(parsed.error, 'error');
} catch (e) { }
}
}
}
if (!isCurrent()) return;
assistantEl.classList.remove('message-thinking');
// Text complete. Now fetch audio.
if (fullResponse) {
history.push({ role: 'assistant', content: fullResponse });
saveHistory();
// Keep "Thinking..." until audio is ready or failed
const audioUrl = await voice.fetchAudio(fullResponse);
// Same signal as the chat request, so Stop cancels TTS too
const audioUrl = await voice.fetchAudio(fullResponse, controller.signal);
if (!isCurrent()) return;
// Visual update: Remove thinking, show text
assistantEl.classList.remove('message-thinking');
// The reply itself is complete — show it even when Stop
// cancelled the audio
assistantEl.innerHTML = renderMarkdown(fullResponse);
messagesEl.scrollTop = messagesEl.scrollHeight;
if (audioUrl) {
if (audioUrl && !controller.signal.aborted) {
// Re-enable sending before playback: playAudio() only
// settles on ended/error, so a paused player would
// otherwise keep chat locked until a reload.
setSending(false);
await voice.playAudio(audioUrl, assistantEl);
}
} else {
assistantEl.textContent = 'No response received. Please try again.';
}
} else {
// Normal Text Mode: Stream directly to UI
while (true) {
const { done, value } = await reader.read();
if (done) break;
// Text mode: stream straight into the bubble
await readSSE(response, (token) => {
fullResponse += token;
assistantEl.innerHTML = renderMarkdown(fullResponse);
messagesEl.scrollTop = messagesEl.scrollHeight;
});
const chunk = decoder.decode(value);
const lines = chunk.split('\n');
for (const line of lines) {
if (line.startsWith('data: ')) {
const data = line.slice(6).trim();
if (data === '[DONE]') break;
try {
const parsed = JSON.parse(data);
if (parsed.token) {
fullResponse += parsed.token;
assistantEl.innerHTML = renderMarkdown(fullResponse);
messagesEl.scrollTop = messagesEl.scrollHeight;
}
if (parsed.error) {
showToast(parsed.error, 'error');
}
} catch (e) {
// skip unparseable chunks
}
}
}
}
if (!isCurrent()) return;
if (fullResponse) {
history.push({ role: 'assistant', content: fullResponse });
saveHistory();
} else {
assistantEl.textContent = 'No response received. Please try again.';
}
}
} catch (e) {
assistantEl.textContent = 'Sorry, something went wrong. Please try again.';
showToast(e.message, 'error');
console.error('[Chat] Error:', e);
if (e.name === 'AbortError') {
// Aborted by "New chat": that conversation is gone, discard this
if (!isCurrent()) {
assistantEl.remove();
return;
}
// User pressed Stop — keep the partial reply, drop an empty one
assistantEl.classList.remove('message-thinking');
if (fullResponse) {
assistantEl.innerHTML = renderMarkdown(fullResponse);
history.push({ role: 'assistant', content: fullResponse });
saveHistory();
} else {
assistantEl.remove();
}
} else {
assistantEl.textContent = 'Sorry, something went wrong. Please try again.';
showToast(e.message, 'error');
console.error('[Chat] Error:', e);
}
} finally {
// In voice mode this runs after playback, by which time a newer
// send may already own the composer — don't clobber its state.
if (abortController === controller) {
abortController = null;
setSending(false);
}
if (isCurrent()) saveHistory();
inputEl.focus();
}
sendBtn.disabled = false;
inputEl.focus();
}
sendBtn.addEventListener('click', sendMessage);
sendBtn.addEventListener('click', () => {
if (sending) {
abortController?.abort();
return;
}
sendMessage();
});
inputEl.addEventListener('keydown', (e) => {
if (e.key === 'Enter' && !e.shiftKey) {
e.preventDefault();
@@ -277,6 +398,11 @@ document.addEventListener('DOMContentLoaded', async () => {
}
});
document.getElementById('new-chat-btn')?.addEventListener('click', startNewChat);
// Logout
document.getElementById('logout-btn').addEventListener('click', logout);
// Bring back this session's conversation, if there is one
restoreHistory();
});