// static/js/design.js

// ── Marked.js config ──────────────────────────────────────────────────────────
marked.setOptions({
  breaks: true,
  gfm: true,
  highlight: (code, lang) => {
    if (lang && hljs.getLanguage(lang)) {
      return hljs.highlight(code, { language: lang }).value;
    }
    return hljs.highlightAuto(code).value;
  }
});

// ── DOM refs ──────────────────────────────────────────────────────────────────
const chatWindow   = document.getElementById("chatWindow");
const queryInput   = document.getElementById("queryInput");
const sendBtn      = document.getElementById("sendBtn");
const topicInput   = document.getElementById("topicInput");
const clearBtn     = document.getElementById("clearBtn");
const menuBtn      = document.getElementById("menuBtn");
const sidebar      = document.getElementById("sidebar");
const overlay      = document.getElementById("overlay");
const sidebarClose = document.getElementById("sidebarClose");
const quickBtns    = document.querySelectorAll(".quick-btn");

// ── Conversation history ──────────────────────────────────────────────────────
let history = [];

// ── Sidebar toggle ────────────────────────────────────────────────────────────
function openSidebar() {
  sidebar.classList.add("open");
  overlay.classList.add("show");
}

function closeSidebar() {
  sidebar.classList.remove("open");
  overlay.classList.remove("show");
}

menuBtn.addEventListener("click", openSidebar);
sidebarClose.addEventListener("click", closeSidebar);
overlay.addEventListener("click", closeSidebar);

// ── Auto-resize textarea ──────────────────────────────────────────────────────
function autoResize() {
  queryInput.style.height = "auto";
  queryInput.style.height = Math.min(queryInput.scrollHeight, 200) + "px";
}

queryInput.addEventListener("input", autoResize);

// ── Quick prompt buttons ──────────────────────────────────────────────────────
quickBtns.forEach(btn => {
  btn.addEventListener("click", () => {
    queryInput.value = btn.dataset.prompt;
    autoResize();
    queryInput.focus();
    closeSidebar();
  });
});

// ── Clear chat ────────────────────────────────────────────────────────────────
clearBtn.addEventListener("click", () => {
  history = [];
  const welcome = document.getElementById("welcomeMsg");
  chatWindow.innerHTML = "";
  if (welcome) chatWindow.appendChild(welcome);
});

// ── Scroll to bottom ──────────────────────────────────────────────────────────
function scrollToBottom() {
  chatWindow.scrollTo({ top: chatWindow.scrollHeight, behavior: "smooth" });
}

// ── Add message bubble ────────────────────────────────────────────────────────
function addMessage(role, content) {
  const msg     = document.createElement("div");
  msg.className = `message ${role}`;

  const avatar     = document.createElement("div");
  avatar.className = "avatar";
  avatar.textContent = role === "user" ? "YOU" : "SS";

  const bubble     = document.createElement("div");
  bubble.className = "bubble";

  if (role === "assistant") {
    bubble.innerHTML = marked.parse(content);
    bubble.querySelectorAll("pre code").forEach(el => hljs.highlightElement(el));
  } else {
    // user bubble: preserve newlines and show code syntax as plain text
    bubble.style.whiteSpace = "pre-wrap";
    bubble.textContent = content;
  }

  msg.appendChild(avatar);
  msg.appendChild(bubble);
  chatWindow.appendChild(msg);
  scrollToBottom();
}

// ── Typing indicator ──────────────────────────────────────────────────────────
function showTyping() {
  const msg     = document.createElement("div");
  msg.className = "message assistant";
  msg.id        = "typingIndicator";

  const avatar     = document.createElement("div");
  avatar.className = "avatar";
  avatar.textContent = "SS";

  const bubble     = document.createElement("div");
  bubble.className = "bubble";
  bubble.innerHTML = `
    <div class="typing-indicator">
      <span></span><span></span><span></span>
    </div>`;

  msg.appendChild(avatar);
  msg.appendChild(bubble);
  chatWindow.appendChild(msg);
  scrollToBottom();
}

function hideTyping() {
  const indicator = document.getElementById("typingIndicator");
  if (indicator) indicator.remove();
}

// ── Send message ──────────────────────────────────────────────────────────────
async function sendMessage() {
  const query = queryInput.value.trim();
  if (!query) return;

  const topic = topicInput.value.trim() || null;

  addMessage("user", query);
  history.push({ role: "user", content: query });

  // reset input
  queryInput.value = "";
  queryInput.style.height = "auto";
  sendBtn.disabled = true;

  showTyping();

  try {
    const res = await fetch("/chat", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ query, topic, history })
    });

    const data = await res.json();
    hideTyping();

    if (data.error) {
      addMessage("assistant", `⚠️ **Error:** ${data.error}`);
    } else {
      addMessage("assistant", data.response);
      history.push({ role: "assistant", content: data.response });
    }

  } catch (err) {
    hideTyping();
    addMessage("assistant", "⚠️ **Network error.** Flask server se connect nahi ho saka.");
  } finally {
    sendBtn.disabled = false;
    queryInput.focus();
  }
}

// ── Keyboard handling ─────────────────────────────────────────────────────────
queryInput.addEventListener("keydown", (e) => {
  if (e.key === "Enter") {
    if (e.shiftKey) {
      // Shift+Enter — insert a real newline and resize
      // let the browser insert \n naturally, then resize
      setTimeout(autoResize, 0);
      return;                       // do NOT send
    }
    // plain Enter — send
    e.preventDefault();
    sendMessage();
  }
});

// ── Send button ───────────────────────────────────────────────────────────────
sendBtn.addEventListener("click", sendMessage);