document.addEventListener('DOMContentLoaded', function() {
    const searchInput = document.getElementById('mainSearch');
    if (searchInput) {
        searchInput.addEventListener('keypress', function(e) {
            if (e.key === 'Enter') {
                e.preventDefault();
                if (searchInput.value.trim().toLowerCase() === 'deep1') {
                    window.location.href = 'premium.php';
                } else {
                    alert('Searching for: ' + searchInput.value);
                }
            }
        });
    }

    // --- AUTHENTICATION ---
    const authButtons = document.getElementById('auth-buttons');
    const userGreeting = document.getElementById('user-greeting');
    const loginForm = document.getElementById('login-form');
    const signupForm = document.getElementById('signup-form');
    const loginModal = new bootstrap.Modal(document.getElementById('loginModal'));
    const signupModal = new bootstrap.Modal(document.getElementById('signupModal'));
    const loginError = document.getElementById('login-error');
    const signupError = document.getElementById('signup-error');
    let isLoggedIn = false;

    async function checkAuth() {
        try {
            const response = await fetch('auth.php', { 
                method: 'POST', 
                headers: {'Content-Type': 'application/x-www-form-urlencoded'}, 
                body: 'action=check_auth' 
            });
            const result = await response.json();
            isLoggedIn = result.loggedIn;
            if (isLoggedIn) {
                authButtons.classList.add('d-none');
                userGreeting.innerHTML = `Welcome, ${escapeHTML(result.email)} <button id="logout-button" class="btn btn-sm btn-outline-secondary ms-2">Logout</button>`;
                userGreeting.classList.remove('d-none');
            } else {
                authButtons.classList.remove('d-none');
                userGreeting.classList.add('d-none');
            }
        } catch (error) {
            console.error('Auth check failed', error);
        }
        await renderPlaylists();
    }

    if(loginForm) {
        loginForm.addEventListener('submit', async (e) => {
            e.preventDefault();
            loginError.textContent = '';
            const response = await fetch('auth.php', { 
                method: 'POST', 
                body: new URLSearchParams({action: 'login', email: document.getElementById('login-email').value, password: document.getElementById('login-password').value})
            });
            const result = await response.json();
            if (result.success) {
                loginModal.hide();
                await checkAuth();
            } else {
                loginError.textContent = result.message;
            }
        });
    }

    if(signupForm) {
        signupForm.addEventListener('submit', async (e) => {
            e.preventDefault();
            signupError.textContent = '';
            const response = await fetch('auth.php', { 
                method: 'POST', 
                body: new URLSearchParams({action: 'register', email: document.getElementById('signup-email').value, password: document.getElementById('signup-password').value})
            });
            const result = await response.json();
            if (result.success) {
                signupModal.hide();
                await checkAuth();
            } else {
                signupError.textContent = result.message;
            }
        });
    }

    userGreeting.addEventListener('click', async (e) => {
        if (e.target.id === 'logout-button') {
            await fetch('auth.php', { method: 'POST', headers: {'Content-Type': 'application/x-www-form-urlencoded'}, body: 'action=logout' });
            isLoggedIn = false;
            checkAuth();
        }
    });
    
    // --- END AUTHENTICATION ---

    const navLinks = {
        home: document.getElementById('nav-home'),
        playlists: document.getElementById('nav-playlists'),
        settings: document.getElementById('nav-settings'),
        help: document.getElementById('nav-help'),
    };

    const sections = {
        home: document.getElementById('home-section'),
        playlists: document.getElementById('playlists-section'),
    };

    function navigateTo(sectionName) {
        Object.values(sections).forEach(section => {
            if (section) section.style.display = 'none';
        });
        if (sections[sectionName]) {
            sections[sectionName].style.display = 'block';
        }
        Object.values(navLinks).forEach(link => {
            if(link) link.classList.remove('active');
        });
        if (navLinks[sectionName]) {
            navLinks[sectionName].classList.add('active');
        }
    }

    if(navLinks.home) navLinks.home.addEventListener('click', (e) => { e.preventDefault(); navigateTo('home'); });
    if(navLinks.playlists) navLinks.playlists.addEventListener('click', (e) => { e.preventDefault(); navigateTo('playlists'); });
    if(navLinks.settings) navLinks.settings.addEventListener('click', (e) => { e.preventDefault(); alert('Settings page is not yet implemented.'); });
    if(navLinks.help) navLinks.help.addEventListener('click', (e) => { e.preventDefault(); alert('Help page is not yet implemented.'); });

    // --- PLAYLISTS ---
    const playlistForm = document.getElementById('add-playlist-form');
    const playlistsList = document.getElementById('playlists-list');

    // Local Storage Functions
    const getLocalPlaylists = () => JSON.parse(localStorage.getItem('user_playlists')) || [];
    const saveLocalPlaylists = (playlists) => localStorage.setItem('user_playlists', JSON.stringify(playlists));

    async function renderPlaylists() {
        playlistsList.innerHTML = '<p class="text-white-50">Loading...</p>';
        let playlists = [];
        if (isLoggedIn) {
            const response = await fetch('playlist_manager.php?action=get');
            playlists = await response.json();
        } else {
            playlists = getLocalPlaylists();
        }

        playlistsList.innerHTML = '';
        if (playlists.length === 0) {
            playlistsList.innerHTML = '<p class="text-white-50">Your added playlists will appear here.</p>';
            if (!isLoggedIn) {
                 playlistsList.innerHTML += '<p class="text-white-50">Sign up to save your playlists to your account.</p>';
            }
            return;
        }

        playlists.forEach((playlist, index) => {
            const playlistEl = document.createElement('div');
            playlistEl.className = 'card playlist-card mb-3';
            const playlistId = isLoggedIn ? playlist.id : index;
            playlistEl.innerHTML = `
                <div class="card-body d-flex justify-content-between align-items-center">
                    <div>
                        <h5 class="card-title mb-1">${escapeHTML(playlist.name)}</h5>
                        <p class="card-text text-white-50 text-truncate" style="max-width: 200px;">${escapeHTML(playlist.url)}</p>
                    </div>
                    <div>
                        <button class="btn btn-sm btn-primary play-playlist" data-url="${escapeHTML(playlist.url)}"><i class="bi bi-play-fill"></i></button>
                        <button class="btn btn-sm btn-outline-danger delete-playlist" data-id="${playlistId}"><i class="bi bi-trash-fill"></i></button>
                    </div>
                </div>
            `;
            playlistsList.appendChild(playlistEl);
        });
    }

    if (playlistForm) {
        playlistForm.addEventListener('submit', async function(e) {
            e.preventDefault();
            const name = document.getElementById('playlist-name').value;
            const url = document.getElementById('playlist-url').value;
            
            if (isLoggedIn) {
                await fetch('playlist_manager.php', { 
                    method: 'POST', 
                    body: new URLSearchParams({action: 'add', name, url})
                });
            } else {
                const playlists = getLocalPlaylists();
                playlists.push({ name, url });
                saveLocalPlaylists(playlists);
            }
            
            renderPlaylists();
            playlistForm.reset();
        });
    }

    playlistsList.addEventListener('click', async function(e) {
        const playButton = e.target.closest('.play-playlist');
        const deleteButton = e.target.closest('.delete-playlist');

        if (playButton) {
            window.location.href = `player.php?url=${encodeURIComponent(playButton.dataset.url)}`;
        }

        if (deleteButton) {
            const id = deleteButton.dataset.id;
            if (isLoggedIn) {
                await fetch('playlist_manager.php', { 
                    method: 'POST', 
                    body: new URLSearchParams({action: 'delete', id})
                });
            } else {
                let playlists = getLocalPlaylists();
                playlists.splice(id, 1);
                saveLocalPlaylists(playlists);
            }
            renderPlaylists();
        }
    });

    checkAuth();
});

function escapeHTML(str) {
    var p = document.createElement("p");
    p.appendChild(document.createTextNode(str));
    return p.innerHTML;
}