// Firebase configuration
const firebaseConfig = {
  apiKey: "AIzaSyDN6tU7Ln3JgeFP7jTprAjSgXDfzunDGQI",
  authDomain: "gay-db7b1.firebaseapp.com",
  databaseURL: "https://gay-db7b1-default-rtdb.firebaseio.com",
  projectId: "gay-db7b1",
  storageBucket: "gay-db7b1.appspot.com",
  messagingSenderId: "959507085021",
  appId: "1:959507085021:web:755901093c2c81d0fb4d34",
  measurementId: "G-1900F4D48J"
};

// Initialize Firebase
firebase.initializeApp(firebaseConfig);
const auth = firebase.auth();
const db = firebase.database();

// Global variables
let currentRoomId = "general";
let currentUser = null;

// DOM elements
const loginForm = document.getElementById("login-form");
const registerForm = document.getElementById("register-form");
const toggleAuth = document.getElementById("toggle-auth");
const authTitle = document.getElementById("auth-title");

// Toggle between login and register forms
toggleAuth.addEventListener("click", () => {
  loginForm.classList.toggle("hidden");
  registerForm.classList.toggle("hidden");
  authTitle.textContent = loginForm.classList.contains("hidden") ? "Đăng ký" : "Đăng nhập";
  toggleAuth.textContent = loginForm.classList.contains("hidden") ? "Đã có tài khoản? Đăng nhập" : "Chưa có tài khoản? Đăng ký";
});

// Register form handler
registerForm.addEventListener("submit", (e) => {
  e.preventDefault();
  const username = document.getElementById("register-username").value;
  const email = document.getElementById("register-email").value;
  const password = document.getElementById("register-password").value;
  
  auth.createUserWithEmailAndPassword(email, password).then(userCredential => {
    return userCredential.user.updateProfile({ displayName: username });
  }).then(() => {
    document.getElementById("display-name").textContent = auth.currentUser.displayName;
    showChat();
  }).catch(error => alert(error.message));
});

// Login form handler
loginForm.addEventListener("submit", (e) => {
  e.preventDefault();
  const email = document.getElementById("login-email").value;
  const password = document.getElementById("login-password").value;
  
  auth.signInWithEmailAndPassword(email, password).then(() => {
    document.getElementById("display-name").textContent = auth.currentUser.displayName || auth.currentUser.email;
    showChat();
  }).catch(error => alert(error.message));
});

// Google login handler
document.getElementById("google-login").addEventListener("click", () => {
  const provider = new firebase.auth.GoogleAuthProvider();
  auth.signInWithPopup(provider).then(() => {
    document.getElementById("display-name").textContent = auth.currentUser.displayName;
    showChat();
  }).catch(error => alert(error.message));
});

// Show chat section
function showChat() {
  document.getElementById("auth-section").classList.add("hidden");
  document.getElementById("chat-section").classList.remove("hidden");
  currentUser = auth.currentUser;
  
  // Initialize room functionality
  initializeRooms();
  loadUserRooms();
  setupRoomListeners();
}

// Send message function
function sendMessage() {
  const input = document.getElementById("chat-input");
  const imageInput = document.getElementById("imageInput");
  const videoInput = document.getElementById("videoInput");
  const text = input.value.trim();
  const images = imageInput.files;
  const videos = videoInput.files;
  
  if (!text && images.length === 0 && videos.length === 0) return;

  // Send text message if exists
  if (text) {
    db.ref(`rooms/${currentRoomId}/messages`).push({
      name: auth.currentUser.displayName || auth.currentUser.email,
      text: text,
      uid: auth.currentUser.uid,
      timestamp: Date.now()
    });
    
    // Update room last message
    updateRoomLastMessage(currentRoomId, text);
  }

  // Send images
  if (images.length > 0) {
    sendImages(images);
  }

  // Send videos
  if (videos.length > 0) {
    sendVideos(videos);
  }

  // Clear inputs
  input.value = "";
  imageInput.value = "";
  videoInput.value = "";
  document.getElementById("mediaPreview").innerHTML = "";
}

// Send images function
async function sendImages(files) {
  for (const file of files) {
    try {
      const base64 = await toBase64(file);
      const imageUrl = await uploadToImgbb(base64);
      if (imageUrl) {
        db.ref(`rooms/${currentRoomId}/messages`).push({
          name: auth.currentUser.displayName || auth.currentUser.email,
          text: "",
          image: imageUrl,
          uid: auth.currentUser.uid,
          timestamp: Date.now()
        });
        
        // Update room last message
        updateRoomLastMessage(currentRoomId, "📷 Hình ảnh");
      }
    } catch (error) {
      console.error("Error uploading image:", error);
      alert("Lỗi upload ảnh!");
    }
  }
}

// Send videos function
async function sendVideos(files) {
  for (const file of files) {
    try {
      showUploadProgress("Đang upload video...");
      const videoUrl = await uploadVideo(file);
      hideUploadProgress();
      if (videoUrl) {
        db.ref(`rooms/${currentRoomId}/messages`).push({
          name: auth.currentUser.displayName || auth.currentUser.email,
          text: "",
          video: videoUrl,
          uid: auth.currentUser.uid,
          timestamp: Date.now()
        });
        
        // Update room last message
        updateRoomLastMessage(currentRoomId, "🎥 Video");
      }
    } catch (error) {
      hideUploadProgress();
      console.error("Error uploading video:", error);
      alert("Lỗi upload video!");
    }
  }
}

// Convert file to base64
function toBase64(file) {
  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.onloadend = () => resolve(reader.result.split(',')[1]);
    reader.onerror = reject;
    reader.readAsDataURL(file);
  });
}

// Upload image to imgbb
async function uploadToImgbb(base64) {
  const apiKey = "eb64cc8f94a115e3a412694f2a0f10b3";
  const formData = new FormData();
  formData.append("key", apiKey);
  formData.append("image", base64);

  try {
    const response = await fetch("https://api.imgbb.com/1/upload", {
      method: "POST",
      body: formData
    });
    const result = await response.json();
    return result.data.url;
  } catch (error) {
    console.error("Error uploading to imgbb:", error);
    return null;
  }
}

// Upload video to server
async function uploadVideo(file) {
  const formData = new FormData();
  formData.append("file", file);

  try {
    const response = await fetch("http://192.168.2.47:5000/upload", {
      method: "POST",
      body: formData,
    });
    
    const result = await response.json();
    
    // Check if upload was successful
    if (result.status === "success" && result.data && result.data.url) {
      return result.data.url;
    } else {
      console.error("Upload failed:", result);
      return null;
    }
  } catch (error) {
    console.error("Error uploading video:", error);
    return null;
  }
}

// Show upload progress
function showUploadProgress(message) {
  const preview = document.getElementById("mediaPreview");
  preview.innerHTML = `
    <div class="upload-progress">
      <div class="upload-progress-bar" style="width: 100%">${message}</div>
    </div>
  `;
}

// Hide upload progress
function hideUploadProgress() {
  document.getElementById("mediaPreview").innerHTML = "";
}

// Preview selected images
document.getElementById("imageInput").addEventListener("change", function() {
  const files = this.files;
  const preview = document.getElementById("mediaPreview");
  preview.innerHTML = "";
  
  for (const file of files) {
    const reader = new FileReader();
    reader.onload = () => {
      const img = document.createElement("img");
      img.src = reader.result;
      img.title = file.name;
      preview.appendChild(img);
    };
    reader.readAsDataURL(file);
  }
});

// Preview selected videos
document.getElementById("videoInput").addEventListener("change", function() {
  const files = this.files;
  const preview = document.getElementById("mediaPreview");
  preview.innerHTML = "";
  
  for (const file of files) {
    const reader = new FileReader();
    reader.onload = () => {
      const video = document.createElement("video");
      video.src = reader.result;
      video.title = file.name;
      video.controls = true;
      video.muted = true;
      preview.appendChild(video);
    };
    reader.readAsDataURL(file);
  }
});

// Allow Enter key to send message
document.getElementById("chat-input").addEventListener("keydown", function(event) {
  if (event.key === "Enter") {
    event.preventDefault();
    sendMessage();
  }
});

// Listen for new messages
const chatBox = document.getElementById("chat-box");
let messagesListener = null;

function listenToMessages() {
  // Remove previous listener
  if (messagesListener) {
    messagesListener.off();
  }
  
  // Clear chat box
  chatBox.innerHTML = "";
  
  // Listen to current room messages
  messagesListener = db.ref(`rooms/${currentRoomId}/messages`);
  messagesListener.on("child_added", snapshot => {
    const msg = snapshot.val();
    const div = document.createElement("div");
    div.className = "message " + (msg.uid === auth.currentUser?.uid ? "mine" : "other");
    
    let content = `<strong>${msg.name}:</strong><br>`;
    
    // Add text if exists
    if (msg.text) {
      content += `<span>${msg.text}</span>`;
    }
    
    // Add image if exists
    if (msg.image) {
      content += `<br><a href="${msg.image}" target="_blank">
        <img src="${msg.image}" alt="Image" />
      </a>`;
    }
    
    // Add video if exists
    if (msg.video) {
      content += `<br><video controls>
        <source src="${msg.video}" type="video/mp4">
        <source src="${msg.video}" type="video/webm">
        Your browser does not support the video tag.
      </video>`;
    }
    
    div.innerHTML = content;
    chatBox.appendChild(div);
    chatBox.scrollTop = chatBox.scrollHeight;
  });
}

// Room management functions
function initializeRooms() {
  // Create general room if not exists
  db.ref('rooms/general').once('value', snapshot => {
    if (!snapshot.exists()) {
      db.ref('rooms/general').set({
        name: "Room chung",
        description: "Phòng chat chung cho tất cả mọi người",
        createdBy: auth.currentUser.uid,
        createdAt: Date.now(),
        members: {
          [auth.currentUser.uid]: {
            name: auth.currentUser.displayName || auth.currentUser.email,
            joinedAt: Date.now()
          }
        }
      });
    } else {
      // Add current user to general room if not already member
      db.ref(`rooms/general/members/${auth.currentUser.uid}`).set({
        name: auth.currentUser.displayName || auth.currentUser.email,
        joinedAt: Date.now()
      });
    }
  });
  
  // Switch to general room
  switchToRoom("general", "Room chung");
}

function loadUserRooms() {
  const roomList = document.getElementById("room-list");
  
  // Listen for rooms where user is a member
  db.ref('rooms').on('value', snapshot => {
    roomList.innerHTML = "";
    const rooms = snapshot.val();
    
    if (rooms) {
      Object.keys(rooms).forEach(roomId => {
        const room = rooms[roomId];
        if (room.members && room.members[auth.currentUser.uid]) {
          createRoomListItem(roomId, room);
        }
      });
    }
  });
}

function createRoomListItem(roomId, room) {
  const roomList = document.getElementById("room-list");
  const roomItem = document.createElement("div");
  roomItem.className = `room-item ${roomId === currentRoomId ? 'active' : ''}`;
  roomItem.dataset.roomId = roomId;
  roomItem.onclick = () => switchToRoom(roomId, room.name);
  
  roomItem.innerHTML = `
    <div class="room-info">
      <div class="room-name">${room.name}</div>
      <div class="room-last-message">${room.lastMessage || "Chưa có tin nhắn"}</div>
    </div>
  `;
  
  roomList.appendChild(roomItem);
}

function switchToRoom(roomId, roomName) {
  currentRoomId = roomId;
  document.getElementById("current-room-name").textContent = roomName;
  
  // Update active room in UI
  document.querySelectorAll(".room-item").forEach(item => {
    item.classList.remove("active");
  });
  
  // Find and activate current room by checking data attribute
  document.querySelectorAll(".room-item").forEach(item => {
    if (item.dataset.roomId === roomId) {
      item.classList.add("active");
    }
  });
  
  // Load messages for this room
  listenToMessages();
}

function updateRoomLastMessage(roomId, message) {
  db.ref(`rooms/${roomId}/lastMessage`).set(message);
  db.ref(`rooms/${roomId}/lastMessageTime`).set(Date.now());
}

function createRoom() {
  const roomName = prompt("Nhập tên phòng chat:");
  if (!roomName || !roomName.trim()) return;
  
  const roomDescription = prompt("Nhập mô tả phòng (tùy chọn):") || `Phòng chat ${roomName.trim()}`;
  
  const roomId = 'room_' + Date.now();
  db.ref(`rooms/${roomId}`).set({
    name: roomName.trim(),
    description: roomDescription.trim(),
    createdBy: auth.currentUser.uid,
    createdAt: Date.now(),
    members: {
      [auth.currentUser.uid]: {
        name: auth.currentUser.displayName || auth.currentUser.email,
        joinedAt: Date.now()
      }
    }
  }).then(() => {
    switchToRoom(roomId, roomName.trim());
    alert(`Đã tạo phòng "${roomName.trim()}" thành công!`);
  });
}

function setupRoomListeners() {
  // Room list toggle
  document.getElementById("roomListToggle").addEventListener("click", () => {
    const sidebar = document.getElementById("room-sidebar");
    sidebar.classList.toggle("show");
  });
  
  // Create room button
  document.getElementById("createRoomBtn").addEventListener("click", createRoom);
  
  // Join room button
  document.getElementById("joinRoomBtn").addEventListener("click", showJoinRoomDialog);
  
  // Room search functionality
  const searchInput = document.getElementById("roomSearchInput");
  searchInput.addEventListener("input", handleRoomSearch);
  searchInput.addEventListener("focus", () => {
    if (searchInput.value.trim()) {
      document.getElementById("search-results").classList.remove("hidden");
    }
  });
  
  // Hide search results when clicking outside
  document.addEventListener("click", (event) => {
    const sidebar = document.getElementById("room-sidebar");
    const searchResults = document.getElementById("search-results");
    
    if (!sidebar.contains(event.target)) {
      searchResults.classList.add("hidden");
    }
  });
}

// Room search functionality
function handleRoomSearch() {
  const searchTerm = document.getElementById("roomSearchInput").value.trim().toLowerCase();
  const searchResults = document.getElementById("search-results");
  const searchRoomList = document.getElementById("search-room-list");
  
  if (!searchTerm) {
    searchResults.classList.add("hidden");
    return;
  }
  
  searchResults.classList.remove("hidden");
  searchRoomList.innerHTML = "";
  
  // Search all rooms in database
  db.ref('rooms').once('value', snapshot => {
    const rooms = snapshot.val();
    let foundRooms = [];
    
    if (rooms) {
      Object.keys(rooms).forEach(roomId => {
        const room = rooms[roomId];
        if (room.name && room.name.toLowerCase().includes(searchTerm)) {
          foundRooms.push({ id: roomId, ...room });
        }
      });
    }
    
    if (foundRooms.length === 0) {
      searchRoomList.innerHTML = '<div class="no-results">Không tìm thấy phòng nào</div>';
    } else {
      foundRooms.forEach(room => {
        createSearchResultItem(room.id, room);
      });
    }
  });
}

function createSearchResultItem(roomId, room) {
  const searchRoomList = document.getElementById("search-room-list");
  const roomItem = document.createElement("div");
  const isMember = room.members && room.members[auth.currentUser.uid];
  
  roomItem.className = `room-item search-result`;
  roomItem.dataset.roomId = roomId;
  
  // Count members
  const memberCount = room.members ? Object.keys(room.members).length : 0;
  
  roomItem.innerHTML = `
    <div class="room-info">
      <div class="room-name">${room.name}</div>
      <div class="room-last-message">${room.description || "Không có mô tả"}</div>
      <div class="room-member-count">${memberCount} thành viên</div>
    </div>
    ${isMember ? 
      `<button class="room-join-btn" onclick="switchToRoom('${roomId}', '${room.name}'); hideSearchResults();">Vào phòng</button>` :
      `<button class="room-join-btn" onclick="joinRoom('${roomId}', '${room.name}')">Tham gia</button>`
    }
  `;
  
  searchRoomList.appendChild(roomItem);
}

function joinRoom(roomId, roomName) {
  // Add user to room members
  db.ref(`rooms/${roomId}/members/${auth.currentUser.uid}`).set({
    name: auth.currentUser.displayName || auth.currentUser.email,
    joinedAt: Date.now()
  }).then(() => {
    // Switch to the joined room
    switchToRoom(roomId, roomName);
    hideSearchResults();
    alert(`Đã tham gia phòng "${roomName}" thành công!`);
  }).catch(error => {
    console.error("Error joining room:", error);
    alert("Lỗi khi tham gia phòng!");
  });
}

function hideSearchResults() {
  document.getElementById("search-results").classList.add("hidden");
  document.getElementById("roomSearchInput").value = "";
}

function showJoinRoomDialog() {
  const roomId = prompt("Nhập ID phòng muốn tham gia:");
  if (!roomId || !roomId.trim()) return;
  
  // Check if room exists
  db.ref(`rooms/${roomId}`).once('value', snapshot => {
    if (snapshot.exists()) {
      const room = snapshot.val();
      joinRoom(roomId, room.name);
    } else {
      alert("Không tìm thấy phòng với ID này!");
    }
  });
}