document.addEventListener("DOMContentLoaded", () => {
  const chatBox = document.getElementById("chatBox");
  const input = document.getElementById("userInput");
  const micBtn = document.getElementById("micBtn");

  // Append a message to the chat box
  function appendMessage(text, sender = "bot") {
    const msg = document.createElement("div");
    msg.className = sender === "bot" ? "bot-message" : "user-message";
    msg.innerText = text;
    chatBox.appendChild(msg);
    chatBox.scrollTop = chatBox.scrollHeight;
  }

  // Send message to backend
  async function sendMessage() {
    const message = input.value.trim();
    if (!message) return;

    appendMessage(message, "user");
    input.value = "";

    const loadingMsg = document.createElement("div");
    loadingMsg.className = "bot-message";
    loadingMsg.innerText = "Loading...";
    chatBox.appendChild(loadingMsg);
    chatBox.scrollTop = chatBox.scrollHeight;

    try {
      const res = await fetch("/api", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ question: message })
      });

      const data = await res.json();
      loadingMsg.remove();

      appendMessage(data.answer || "❌ No response from AI.", "bot");
    } catch (err) {
      loadingMsg.remove();
      appendMessage("❌ Failed to get response: " + err.message, "bot");
    }
  }

  // Make sendMessage available globally for <form onsubmit>
  window.sendMessage = sendMessage;

  // Submit on Enter key (in case form fallback fails)
  input.addEventListener("keydown", (e) => {
    if (e.key === "Enter") {
      e.preventDefault();
      sendMessage();
    }
  });

  // Voice input (mic) support
  if ("webkitSpeechRecognition" in window || "SpeechRecognition" in window) {
    const recognition = new (window.SpeechRecognition || window.webkitSpeechRecognition)();
    recognition.lang = "en-IN";

    recognition.onstart = () => appendMessage("🎙️ Listening...", "bot");

    recognition.onresult = (e) => {
      const transcript = e.results[0][0].transcript;
      input.value = transcript;
      sendMessage();
    };

    recognition.onerror = (e) => {
      appendMessage("⚠️ Mic error: " + e.error, "bot");
    };

    micBtn.onclick = () => recognition.start();
  } else {
    micBtn.disabled = true;
    micBtn.title = "🎤 Voice input not supported in this browser.";
  }
});