start frontend

static/js/chat.js

@@ -0,0 +1,123 @@
+const statusEl = document.getElementById("status");
+const messagesEl = document.getElementById("messages");
+const formEl = document.getElementById("chat-form");
+const inputEl = document.getElementById("chat-input");
+const settingsToggle = document.getElementById("settings-toggle");
+const settingsDrawer = document.getElementById("settings-drawer");
+const settingsClose = document.getElementById("settings-close");
+const rangeInputs = settingsDrawer
+    ? Array.from(settingsDrawer.querySelectorAll("input[type='range']"))
+    : [];
+
+const scheme = window.location.protocol === "https:" ? "wss" : "ws";
+const socketUrl = `${scheme}://${window.location.host}/ws`;
+let socket;
+let streamingBubble = null;
+
+const addMessage = (text, direction) => {
+    const bubble = document.createElement("div");
+    bubble.className = `message message--${direction}`;
+    bubble.textContent = text;
+    messagesEl.appendChild(bubble);
+    messagesEl.scrollTop = messagesEl.scrollHeight;
+};
+
+const connect = () => {
+    socket = new WebSocket(socketUrl);
+
+    socket.addEventListener("open", () => {
+        statusEl.textContent = "Connected";
+    });
+
+    socket.addEventListener("message", (event) => {
+        let payload;
+        try {
+            payload = JSON.parse(event.data);
+        } catch (error) {
+            addMessage(event.data, "in");
+            return;
+        }
+
+        if (payload.type === "start") {
+            streamingBubble = document.createElement("div");
+            streamingBubble.className = "message message--in";
+            streamingBubble.textContent = "";
+            messagesEl.appendChild(streamingBubble);
+            messagesEl.scrollTop = messagesEl.scrollHeight;
+            return;
+        }
+
+        if (payload.type === "chunk") {
+            if (!streamingBubble) {
+                streamingBubble = document.createElement("div");
+                streamingBubble.className = "message message--in";
+                messagesEl.appendChild(streamingBubble);
+            }
+            streamingBubble.textContent += payload.data ?? "";
+            messagesEl.scrollTop = messagesEl.scrollHeight;
+            return;
+        }
+
+        if (payload.type === "end") {
+            streamingBubble = null;
+            return;
+        }
+    });
+
+    socket.addEventListener("close", () => {
+        statusEl.textContent = "Disconnected";
+    });
+
+    socket.addEventListener("error", () => {
+        statusEl.textContent = "Connection error";
+    });
+};
+
+const updateDrawerValue = (input) => {
+    const output = input.parentElement?.querySelector(".drawer__value");
+    if (!output) return;
+    output.textContent = input.value;
+};
+
+rangeInputs.forEach((input) => {
+    updateDrawerValue(input);
+    input.addEventListener("input", () => updateDrawerValue(input));
+});
+
+const closeDrawer = () => {
+    settingsDrawer?.classList.remove("drawer--open");
+    if (settingsDrawer) settingsDrawer.setAttribute("aria-hidden", "true");
+    if (settingsToggle) settingsToggle.setAttribute("aria-expanded", "false");
+};
+
+const openDrawer = () => {
+    settingsDrawer?.classList.add("drawer--open");
+    if (settingsDrawer) settingsDrawer.setAttribute("aria-hidden", "false");
+    if (settingsToggle) settingsToggle.setAttribute("aria-expanded", "true");
+};
+
+settingsToggle?.addEventListener("click", () => {
+    if (settingsDrawer?.classList.contains("drawer--open")) {
+        closeDrawer();
+    } else {
+        openDrawer();
+    }
+});
+
+settingsClose?.addEventListener("click", closeDrawer);
+
+formEl.addEventListener("submit", (event) => {
+    event.preventDefault();
+    const text = inputEl.value.trim();
+    if (!text) return;
+    if (!socket || socket.readyState !== WebSocket.OPEN) {
+        addMessage("Not connected.", "in");
+        return;
+    }
+    addMessage(text, "out");
+    socket.send(text);
+    inputEl.value = "";
+    inputEl.focus();
+});
+
+connect();