// State
let currentUser = null;
let mfaTypes = [];
let base64Image = '';
let currentPage = 1;
let adminCurrentPage = 1;

// DOM Elements
const pages = {
    login: document.getElementById('login-page'),
    mfa: document.getElementById('mfa-page'),
    main: document.getElementById('main-page'),
};

const sections = {
    generate: document.getElementById('generate-section'),
    gallery: document.getElementById('gallery-section'),
    admin: document.getElementById('admin-section'),
};

// API Helper
async function api(path, options = {}) {
    const response = await fetch(`/api${path}`, {
        ...options,
        headers: {
            'Content-Type': 'application/json',
            ...options.headers,
        },
    });

    const data = await response.json();

    if (!response.ok) {
        throw new Error(data.error || 'Request failed');
    }

    return data;
}

// Page Navigation
function showPage(pageName) {
    Object.values(pages).forEach(p => p.classList.add('hidden'));
    pages[pageName]?.classList.remove('hidden');
}

function showSection(sectionName) {
    Object.values(sections).forEach(s => s.classList.add('hidden'));
    sections[sectionName]?.classList.remove('hidden');

    document.querySelectorAll('.nav-link').forEach(link => {
        link.classList.toggle('active', link.dataset.page === sectionName);
    });

    if (sectionName === 'gallery') loadGallery();
    if (sectionName === 'admin') loadUsers();
}

// Auth
async function checkAuth() {
    try {
        const data = await api('/auth/me');
        currentUser = data.user;
        showMainApp();
    } catch {
        showPage('login');
    }
}

function showMainApp() {
    showPage('main');
    document.getElementById('current-user').textContent = currentUser.username;

    if (currentUser.isAdmin) {
        document.querySelectorAll('.admin-only').forEach(el => el.classList.remove('hidden'));
    }

    showSection('generate');
    checkPendingJobs();
}

// Pending Jobs
async function checkPendingJobs() {
    try {
        const data = await api('/generate/pending');
        if (data.jobs && data.jobs.length > 0) {
            showPendingJobsNotification(data.jobs);
        }
    } catch (error) {
        console.error('Failed to check pending jobs:', error);
    }
}

function showPendingJobsNotification(jobs) {
    // Remove existing banner if any
    const existingBanner = document.querySelector('.pending-jobs-banner');
    if (existingBanner) existingBanner.remove();

    const banner = document.createElement('div');
    banner.className = 'pending-jobs-banner';
    banner.innerHTML = `
        <span>You have ${jobs.length} video${jobs.length > 1 ? 's' : ''} generating in the background</span>
        <div class="pending-jobs-actions">
            <button class="btn btn-sm view-progress-btn" data-content-id="${jobs[0].id}" data-job-id="${jobs[0].runpod_job_id}">View Progress</button>
            <button class="btn btn-sm dismiss-btn">Dismiss</button>
        </div>
    `;

    // Attach event listeners properly instead of inline onclick
    banner.querySelector('.view-progress-btn').addEventListener('click', function() {
        const contentId = parseInt(this.dataset.contentId, 10);
        const jobId = this.dataset.jobId;
        resumeLatestJob(contentId, jobId);
    });

    banner.querySelector('.dismiss-btn').addEventListener('click', function() {
        banner.remove();
    });

    document.querySelector('.main-content').prepend(banner);
}

async function resumeLatestJob(contentId, jobId) {
    const statusEl = document.getElementById('generation-status');
    const videoEl = document.getElementById('output-video');
    const btn = document.getElementById('generate-btn');

    try {
        // Switch to generate tab and show progress
        showSection('generate');

        btn.disabled = true;
        btn.textContent = 'Generating...';
        statusEl.className = 'status-message info';
        statusEl.textContent = 'Resuming job...';
        statusEl.classList.remove('hidden');
        videoEl.classList.add('hidden');

        // Remove the banner
        const banner = document.querySelector('.pending-jobs-banner');
        if (banner) banner.remove();

        // Poll for completion
        await pollJob(jobId, contentId, statusEl, videoEl);
    } catch (error) {
        console.error('Error resuming job:', error);
        statusEl.className = 'status-message error';
        statusEl.textContent = error.message || 'Failed to resume job';
        statusEl.classList.remove('hidden');
    } finally {
        btn.disabled = false;
        btn.textContent = 'Generate Video';
    }
}

// Login
document.getElementById('login-form').addEventListener('submit', async (e) => {
    e.preventDefault();
    const errorEl = document.getElementById('login-error');
    errorEl.textContent = '';

    const username = document.getElementById('username').value;
    const password = document.getElementById('password').value;

    try {
        const data = await api('/auth/login', {
            method: 'POST',
            body: JSON.stringify({ username, password }),
        });

        if (data.requiresMfa) {
            mfaTypes = data.mfaTypes;
            showMfaPage();
        } else {
            currentUser = data.user;
            showMainApp();
        }
    } catch (error) {
        errorEl.textContent = error.message;
    }
});

function showMfaPage() {
    showPage('mfa');

    const totpSection = document.getElementById('totp-section');
    const webauthnSection = document.getElementById('webauthn-section');

    totpSection.classList.toggle('hidden', !mfaTypes.includes('totp'));
    webauthnSection.classList.toggle('hidden', !mfaTypes.includes('webauthn'));
}

// TOTP Verification
document.getElementById('totp-form').addEventListener('submit', async (e) => {
    e.preventDefault();
    const errorEl = document.getElementById('mfa-error');
    errorEl.textContent = '';

    const code = document.getElementById('totp-code').value;

    try {
        const data = await api('/auth/mfa/totp', {
            method: 'POST',
            body: JSON.stringify({ code }),
        });

        currentUser = data.user;
        showMainApp();
    } catch (error) {
        errorEl.textContent = error.message;
    }
});

// WebAuthn
document.getElementById('webauthn-btn').addEventListener('click', async () => {
    const errorEl = document.getElementById('mfa-error');
    errorEl.textContent = '';

    try {
        const options = await api('/auth/mfa/webauthn/challenge', { method: 'POST' });

        const credential = await navigator.credentials.get({
            publicKey: {
                ...options,
                challenge: base64UrlToBuffer(options.challenge),
                allowCredentials: options.allowCredentials?.map(c => ({
                    ...c,
                    id: base64UrlToBuffer(c.id),
                })),
            },
        });

        const response = {
            id: credential.id,
            rawId: bufferToBase64Url(credential.rawId),
            type: credential.type,
            response: {
                clientDataJSON: bufferToBase64Url(credential.response.clientDataJSON),
                authenticatorData: bufferToBase64Url(credential.response.authenticatorData),
                signature: bufferToBase64Url(credential.response.signature),
            },
        };

        const data = await api('/auth/mfa/webauthn/verify', {
            method: 'POST',
            body: JSON.stringify(response),
        });

        currentUser = data.user;
        showMainApp();
    } catch (error) {
        errorEl.textContent = error.message || 'WebAuthn verification failed';
    }
});

// Back to login from MFA
document.getElementById('mfa-back').addEventListener('click', async () => {
    await api('/auth/logout', { method: 'POST' });
    showPage('login');
});

// Logout
document.getElementById('logout-btn').addEventListener('click', async () => {
    await api('/auth/logout', { method: 'POST' });
    currentUser = null;
    showPage('login');
});

// Navigation
document.querySelectorAll('.nav-link').forEach(link => {
    link.addEventListener('click', (e) => {
        e.preventDefault();
        showSection(link.dataset.page);
    });
});

// Image Upload
const imageInput = document.getElementById('image-input');
const imageUploadArea = document.getElementById('image-upload-area');
const previewImage = document.getElementById('preview-image');

imageInput.addEventListener('change', (e) => {
    const file = e.target.files[0];
    if (file) {
        const reader = new FileReader();
        reader.onload = (event) => {
            previewImage.src = event.target.result;
            previewImage.classList.remove('hidden');
            imageUploadArea.classList.add('has-file');
            base64Image = event.target.result.split(',')[1];
        };
        reader.readAsDataURL(file);
    }
});

// Generation
document.getElementById('generate-form').addEventListener('submit', async (e) => {
    e.preventDefault();

    if (!base64Image) {
        showStatus('Please upload an image first', 'error');
        return;
    }

    const btn = document.getElementById('generate-btn');
    btn.disabled = true;
    btn.textContent = 'Generating...';

    const statusEl = document.getElementById('generation-status');
    const videoEl = document.getElementById('output-video');

    statusEl.className = 'status-message info';
    statusEl.textContent = 'Submitting job...';
    statusEl.classList.remove('hidden');
    videoEl.classList.add('hidden');

    try {
        const formData = {
            image: base64Image,
            prompt: document.getElementById('prompt').value,
            negativePrompt: document.getElementById('negative-prompt').value,
            resolution: parseInt(document.getElementById('resolution').value),
            steps: parseInt(document.getElementById('steps').value),
        };

        const submitData = await api('/generate', {
            method: 'POST',
            body: JSON.stringify(formData),
        });

        const { jobId, contentId } = submitData;
        statusEl.textContent = `Job submitted. ID: ${jobId}. Waiting for completion...`;

        // Poll for completion
        await pollJob(jobId, contentId, statusEl, videoEl);

    } catch (error) {
        showStatus(error.message, 'error');
    } finally {
        btn.disabled = false;
        btn.textContent = 'Generate Video';
    }
});

async function pollJob(jobId, contentId, statusEl, videoEl) {
    const startTime = Date.now();
    const maxTime = 25 * 60 * 1000; // 25 minutes

    while (Date.now() - startTime < maxTime) {
        const elapsed = Math.floor((Date.now() - startTime) / 1000);
        statusEl.textContent = `Generating... (${elapsed}s elapsed)`;

        try {
            const status = await api(`/generate/${jobId}/status`);

            if (status.status === 'COMPLETED') {
                statusEl.className = 'status-message success';
                statusEl.textContent = 'Generation complete!';

                // Load video
                videoEl.src = `/api/content/${contentId}/stream`;
                videoEl.classList.remove('hidden');
                videoEl.play();
                return;
            }

            if (status.status === 'FAILED') {
                throw new Error(status.error || 'Generation failed');
            }

            await new Promise(r => setTimeout(r, 5000));
        } catch (error) {
            showStatus(error.message, 'error');
            return;
        }
    }

    showStatus('Generation timed out', 'error');
}

function showStatus(message, type) {
    const statusEl = document.getElementById('generation-status');
    statusEl.className = `status-message ${type}`;
    statusEl.textContent = message;
    statusEl.classList.remove('hidden');
}

// Gallery
async function loadGallery(page = 1) {
    currentPage = page;
    const grid = document.getElementById('gallery-grid');
    const pagination = document.getElementById('gallery-pagination');
    const status = document.getElementById('status-filter').value;

    grid.innerHTML = '<div class="spinner"></div>';

    try {
        const params = new URLSearchParams({ page, limit: 12 });
        if (status) params.append('status', status);

        const data = await api(`/content?${params}`);
        renderGallery(grid, data.content);
        renderPagination(pagination, data.pagination, loadGallery);
    } catch (error) {
        grid.innerHTML = `<p class="error-message">${error.message}</p>`;
    }
}

document.getElementById('status-filter').addEventListener('change', () => loadGallery(1));

function renderGallery(container, items) {
    if (items.length === 0) {
        container.innerHTML = '<p style="text-align:center;color:var(--gray-500);grid-column:1/-1;">No content found</p>';
        return;
    }

    container.innerHTML = items.map(item => `
        <div class="gallery-item">
            <div class="gallery-item-media">
                ${item.status === 'completed'
                    ? `<video src="/api/content/${item.id}/stream" muted loop onmouseenter="this.play()" onmouseleave="this.pause()"></video>`
                    : '<div style="display:flex;align-items:center;justify-content:center;height:100%;color:var(--gray-500)">' + item.status + '</div>'
                }
                <span class="gallery-item-status ${item.status}">${item.status}</span>
            </div>
            <div class="gallery-item-info">
                <p class="gallery-item-prompt">${escapeHtml(item.prompt || 'No prompt')}</p>
                <div class="gallery-item-meta">
                    <span>${formatDate(item.createdAt)}</span>
                    <div class="gallery-item-actions">
                        ${item.status === 'completed' ? `<a href="/api/content/${item.id}/download" class="btn btn-sm btn-secondary">Download</a>` : ''}
                        <button class="btn btn-sm btn-danger" onclick="deleteContent(${item.id})">Delete</button>
                    </div>
                </div>
            </div>
        </div>
    `).join('');
}

async function deleteContent(id) {
    if (!confirm('Are you sure you want to delete this content?')) return;

    try {
        await api(`/content/${id}`, { method: 'DELETE' });
        loadGallery(currentPage);
    } catch (error) {
        alert(error.message);
    }
}

// Admin
document.querySelectorAll('.tab-btn').forEach(btn => {
    btn.addEventListener('click', () => {
        document.querySelectorAll('.tab-btn').forEach(b => b.classList.remove('active'));
        document.querySelectorAll('.admin-tab').forEach(t => t.classList.add('hidden'));

        btn.classList.add('active');
        document.getElementById(`${btn.dataset.tab}-tab`).classList.remove('hidden');

        if (btn.dataset.tab === 'all-content') loadAdminGallery();
    });
});

async function loadUsers() {
    const container = document.getElementById('users-list');
    container.innerHTML = '<div class="spinner"></div>';

    try {
        const data = await api('/users');
        container.innerHTML = data.users.map(user => `
            <div class="user-item">
                <div class="user-info">
                    <h4>${escapeHtml(user.username)}</h4>
                    <p>${escapeHtml(user.email || 'No email')}</p>
                    <div class="user-badges">
                        ${user.isAdmin ? '<span class="badge badge-admin">Admin</span>' : ''}
                        ${!user.isActive ? '<span class="badge badge-inactive">Inactive</span>' : ''}
                    </div>
                </div>
                <div class="user-actions">
                    <button class="btn btn-sm btn-secondary" onclick="editUser(${user.id})">Edit</button>
                    ${user.id !== currentUser.id ? `<button class="btn btn-sm btn-danger" onclick="deleteUser(${user.id})">Delete</button>` : ''}
                </div>
            </div>
        `).join('');
    } catch (error) {
        container.innerHTML = `<p class="error-message">${error.message}</p>`;
    }
}

document.getElementById('add-user-btn').addEventListener('click', () => {
    showModal(`
        <div class="modal-header">
            <h3>Add User</h3>
            <button class="modal-close" onclick="hideModal()">&times;</button>
        </div>
        <form id="add-user-form">
            <div class="form-group">
                <label>Username</label>
                <input type="text" name="username" required minlength="3">
            </div>
            <div class="form-group">
                <label>Password</label>
                <input type="password" name="password" required minlength="12">
            </div>
            <div class="form-group">
                <label>Email (optional)</label>
                <input type="email" name="email">
            </div>
            <div class="form-group">
                <label><input type="checkbox" name="isAdmin"> Admin</label>
            </div>
            <div class="modal-footer">
                <button type="button" class="btn btn-secondary" onclick="hideModal()">Cancel</button>
                <button type="submit" class="btn btn-primary">Create</button>
            </div>
        </form>
    `);

    document.getElementById('add-user-form').addEventListener('submit', async (e) => {
        e.preventDefault();
        const form = e.target;

        try {
            await api('/users', {
                method: 'POST',
                body: JSON.stringify({
                    username: form.username.value,
                    password: form.password.value,
                    email: form.email.value || null,
                    isAdmin: form.isAdmin.checked,
                }),
            });
            hideModal();
            loadUsers();
        } catch (error) {
            alert(error.message);
        }
    });
});

async function editUser(id) {
    try {
        const data = await api(`/users/${id}`);
        const user = data.user;

        showModal(`
            <div class="modal-header">
                <h3>Edit User: ${escapeHtml(user.username)}</h3>
                <button class="modal-close" onclick="hideModal()">&times;</button>
            </div>
            <form id="edit-user-form">
                <div class="form-group">
                    <label>Username</label>
                    <input type="text" name="username" value="${escapeHtml(user.username)}" required>
                </div>
                <div class="form-group">
                    <label>Email</label>
                    <input type="email" name="email" value="${escapeHtml(user.email || '')}">
                </div>
                <div class="form-group">
                    <label><input type="checkbox" name="isAdmin" ${user.isAdmin ? 'checked' : ''}> Admin</label>
                </div>
                <div class="form-group">
                    <label><input type="checkbox" name="isActive" ${user.isActive ? 'checked' : ''}> Active</label>
                </div>
                <hr>
                <div class="form-group">
                    <label>Reset Password (leave blank to keep)</label>
                    <input type="password" name="newPassword" minlength="12" placeholder="New password">
                </div>
                <div class="modal-footer">
                    <button type="button" class="btn btn-secondary" onclick="hideModal()">Cancel</button>
                    <button type="submit" class="btn btn-primary">Save</button>
                </div>
            </form>
        `);

        document.getElementById('edit-user-form').addEventListener('submit', async (e) => {
            e.preventDefault();
            const form = e.target;

            try {
                await api(`/users/${id}`, {
                    method: 'PUT',
                    body: JSON.stringify({
                        username: form.username.value,
                        email: form.email.value || null,
                        isAdmin: form.isAdmin.checked,
                        isActive: form.isActive.checked,
                    }),
                });

                if (form.newPassword.value) {
                    await api(`/users/${id}/reset-password`, {
                        method: 'POST',
                        body: JSON.stringify({ newPassword: form.newPassword.value }),
                    });
                }

                hideModal();
                loadUsers();
            } catch (error) {
                alert(error.message);
            }
        });
    } catch (error) {
        alert(error.message);
    }
}

async function deleteUser(id) {
    if (!confirm('Are you sure you want to delete this user?')) return;

    try {
        await api(`/users/${id}`, { method: 'DELETE' });
        loadUsers();
    } catch (error) {
        alert(error.message);
    }
}

async function loadAdminGallery(page = 1) {
    adminCurrentPage = page;
    const grid = document.getElementById('admin-gallery-grid');
    const pagination = document.getElementById('admin-gallery-pagination');

    grid.innerHTML = '<div class="spinner"></div>';

    try {
        const data = await api(`/content?page=${page}&limit=12`);
        renderGallery(grid, data.content);
        renderPagination(pagination, data.pagination, loadAdminGallery);
    } catch (error) {
        grid.innerHTML = `<p class="error-message">${error.message}</p>`;
    }
}

// Modal
function showModal(content) {
    document.getElementById('modal-content').innerHTML = content;
    document.getElementById('modal-overlay').classList.remove('hidden');
}

function hideModal() {
    document.getElementById('modal-overlay').classList.add('hidden');
}

document.getElementById('modal-overlay').addEventListener('click', (e) => {
    if (e.target === e.currentTarget) hideModal();
});

// Pagination
function renderPagination(container, pagination, loadFn) {
    const { page, totalPages } = pagination;
    if (totalPages <= 1) {
        container.innerHTML = '';
        return;
    }

    let html = '';
    html += `<button ${page === 1 ? 'disabled' : ''} onclick="(${loadFn.name})(${page - 1})">Prev</button>`;

    for (let i = 1; i <= totalPages; i++) {
        if (i === 1 || i === totalPages || (i >= page - 1 && i <= page + 1)) {
            html += `<button class="${i === page ? 'active' : ''}" onclick="(${loadFn.name})(${i})">${i}</button>`;
        } else if (i === page - 2 || i === page + 2) {
            html += '<span>...</span>';
        }
    }

    html += `<button ${page === totalPages ? 'disabled' : ''} onclick="(${loadFn.name})(${page + 1})">Next</button>`;
    container.innerHTML = html;
}

// Utilities
function escapeHtml(str) {
    if (!str) return '';
    return str.replace(/[&<>"']/g, c => ({
        '&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;', "'": '&#39;'
    }[c]));
}

function formatDate(dateStr) {
    return new Date(dateStr).toLocaleDateString('en-US', {
        month: 'short', day: 'numeric', hour: '2-digit', minute: '2-digit'
    });
}

function base64UrlToBuffer(base64url) {
    const base64 = base64url.replace(/-/g, '+').replace(/_/g, '/');
    const padding = '='.repeat((4 - base64.length % 4) % 4);
    const binary = atob(base64 + padding);
    return Uint8Array.from(binary, c => c.charCodeAt(0)).buffer;
}

function bufferToBase64Url(buffer) {
    const bytes = new Uint8Array(buffer);
    let binary = '';
    for (const byte of bytes) binary += String.fromCharCode(byte);
    return btoa(binary).replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');
}

// Init
checkAuth();