/**
 * Audiobook Maker Pro v4.3 - Main Application
 * UPDATED: Lazy audio loading + Storage & Maintenance (VACUUM)
 */

// ============================================
// Global State
// ============================================

let currentProject = {
    id: null,
    name: 'My Audiobook',
    chapters: []
};

let voices = [];
let archiveModal = null;
let ttsEditModal = null;
let publishModal = null;
let dbMaintenanceModal = null;
let publishingProjectId = null;
let currentWorkflowStage = 'upload';
let allArchiveProjects = [];

// ============================================
// Initialization
// ============================================

document.addEventListener('DOMContentLoaded', function() {
    console.log('🎧 Audiobook Maker Pro v4.3 initializing...');
    
    archiveModal = new bootstrap.Modal(document.getElementById('archiveModal'));
    ttsEditModal = new bootstrap.Modal(document.getElementById('ttsEditModal'));
    
    loadVoices();
    initPdfHandler();
    initMarkdownEditor();
    setupEventListeners();
    
    initWelcomeOverlay();
    updateWorkflowProgress('upload');
    initFloatingGuidePanel();
    loadCurrentUser();
    
    if (typeof hideReaderUI === 'function') {
        hideReaderUI();
    }
    
    console.log('✅ Application initialized');
});

function setupEventListeners() {
    document.getElementById('projectName').addEventListener('change', function() {
        currentProject.name = this.value;
    });
    
    document.getElementById('reader-tab').addEventListener('shown.bs.tab', function() {
        renderInteractiveReader();
        if (typeof showReaderUI === 'function') {
            showReaderUI();
        }
        hideGuidePanelForReader();
    });
    
    document.getElementById('editor-tab').addEventListener('shown.bs.tab', function() {
        if (typeof hideReaderUI === 'function') {
            hideReaderUI();
        }
        restoreGuidePanelForEditor();
    });
}

// ============================================
// Welcome Overlay
// ============================================

function initWelcomeOverlay() {
    const dontShow = localStorage.getItem('audiobookMakerHideWelcome');
    if (dontShow === 'true') {
        document.getElementById('welcomeOverlay').style.display = 'none';
    } else {
        document.getElementById('welcomeOverlay').style.display = 'flex';
    }
}

function dismissWelcome() {
    const dontShowCheckbox = document.getElementById('welcomeDontShow');
    if (dontShowCheckbox && dontShowCheckbox.checked) {
        localStorage.setItem('audiobookMakerHideWelcome', 'true');
    }
    document.getElementById('welcomeOverlay').style.display = 'none';
}

function showWelcome() {
    document.getElementById('welcomeOverlay').style.display = 'flex';
}

// ============================================
// Dynamic Header Help Button
// ============================================

function handleHeaderHelp() {
    if (currentWorkflowStage === 'upload') {
        showWelcome();
    } else {
        showGuidePanel();
    }
}

function updateHeaderHelpButton(stage) {
    const label = document.getElementById('headerHelpLabel');
    const btn = document.getElementById('headerHelpBtn');
    
    if (!label || !btn) return;
    
    if (stage === 'upload') {
        label.textContent = 'Quick Start';
        btn.title = 'Show quick start guide';
    } else {
        label.textContent = 'Quick Guide';
        btn.title = 'Show editor quick guide';
    }
}

// ============================================
// Floating Guide Panel
// ============================================

let guidePanelDragState = {
    isDragging: false,
    startX: 0,
    startY: 0,
    offsetX: 0,
    offsetY: 0
};

function initFloatingGuidePanel() {
    const panel = document.getElementById('floatingGuidePanel');
    const header = document.getElementById('guidePanelHeader');
    const toggle = document.getElementById('floatingGuideToggle');
    
    if (!panel || !header) return;
    
    const hideGuide = localStorage.getItem('audiobookMakerHideGuide');
    if (hideGuide === 'true') {
        panel.classList.remove('visible');
        if (toggle) toggle.classList.add('visible');
        return;
    }
    
    const collapsed = localStorage.getItem('audiobookMakerGuideCollapsed');
    if (collapsed === 'true') {
        panel.classList.add('collapsed');
        const icon = document.getElementById('guideCollapseIcon');
        if (icon) {
            icon.classList.remove('bi-chevron-up');
            icon.classList.add('bi-chevron-down');
        }
    }
    
    const savedPos = localStorage.getItem('audiobookMakerGuidePos');
    if (savedPos) {
        try {
            const pos = JSON.parse(savedPos);
            const maxX = window.innerWidth - 100;
            const maxY = window.innerHeight - 50;
            if (pos.x >= 0 && pos.x <= maxX && pos.y >= 0 && pos.y <= maxY) {
                panel.style.right = 'auto';
                panel.style.left = pos.x + 'px';
                panel.style.top = pos.y + 'px';
            }
        } catch(e) { /* ignore */ }
    }
    
    header.addEventListener('mousedown', onGuideDragStart);
    document.addEventListener('mousemove', onGuideDragMove);
    document.addEventListener('mouseup', onGuideDragEnd);
    
    header.addEventListener('touchstart', onGuideTouchStart, { passive: false });
    document.addEventListener('touchmove', onGuideTouchMove, { passive: false });
    document.addEventListener('touchend', onGuideTouchEnd);
}

function showGuidePanelOnEditor() {
    const panel = document.getElementById('floatingGuidePanel');
    const toggle = document.getElementById('floatingGuideToggle');
    const hideGuide = localStorage.getItem('audiobookMakerHideGuide');
    
    if (hideGuide === 'true') {
        if (toggle) toggle.classList.add('visible');
        return;
    }
    
    if (panel) panel.classList.add('visible');
    if (toggle) toggle.classList.remove('visible');
}

function showGuidePanel() {
    const panel = document.getElementById('floatingGuidePanel');
    const toggle = document.getElementById('floatingGuideToggle');
    
    if (panel) panel.classList.add('visible');
    if (toggle) toggle.classList.remove('visible');
    
    localStorage.removeItem('audiobookMakerHideGuide');
}

function hideGuidePanel() {
    const panel = document.getElementById('floatingGuidePanel');
    const toggle = document.getElementById('floatingGuideToggle');
    
    if (panel) panel.classList.remove('visible');
    if (toggle) toggle.classList.add('visible');
}

function toggleGuideCollapse() {
    const panel = document.getElementById('floatingGuidePanel');
    const icon = document.getElementById('guideCollapseIcon');
    
    if (!panel) return;
    
    const isCollapsed = panel.classList.toggle('collapsed');
    
    if (icon) {
        if (isCollapsed) {
            icon.classList.remove('bi-chevron-up');
            icon.classList.add('bi-chevron-down');
        } else {
            icon.classList.remove('bi-chevron-down');
            icon.classList.add('bi-chevron-up');
        }
    }
    
    localStorage.setItem('audiobookMakerGuideCollapsed', isCollapsed ? 'true' : 'false');
}

function handleGuideDontShow() {
    const checkbox = document.getElementById('guidePanelDontShow');
    if (checkbox && checkbox.checked) {
        localStorage.setItem('audiobookMakerHideGuide', 'true');
        hideGuidePanel();
    } else {
        localStorage.removeItem('audiobookMakerHideGuide');
    }
}

let guidePanelHiddenByReader = false;

function hideGuidePanelForReader() {
    const panel = document.getElementById('floatingGuidePanel');
    const toggle = document.getElementById('floatingGuideToggle');
    
    if (panel && panel.classList.contains('visible')) {
        panel.classList.remove('visible');
        guidePanelHiddenByReader = true;
    } else {
        guidePanelHiddenByReader = false;
    }
    
    if (toggle) toggle.classList.add('visible');
}

function restoreGuidePanelForEditor() {
    if (guidePanelHiddenByReader) {
        const panel = document.getElementById('floatingGuidePanel');
        const toggle = document.getElementById('floatingGuideToggle');
        const hideGuide = localStorage.getItem('audiobookMakerHideGuide');
        
        if (hideGuide !== 'true' && panel) {
            panel.classList.add('visible');
            if (toggle) toggle.classList.remove('visible');
        }
        guidePanelHiddenByReader = false;
    }
}

function onGuideDragStart(e) {
    if (e.target.closest('.guide-panel-btn') || e.target.closest('button')) return;
    const panel = document.getElementById('floatingGuidePanel');
    if (!panel) return;
    guidePanelDragState.isDragging = true;
    const rect = panel.getBoundingClientRect();
    guidePanelDragState.offsetX = e.clientX - rect.left;
    guidePanelDragState.offsetY = e.clientY - rect.top;
    panel.style.transition = 'none';
    e.preventDefault();
}

function onGuideDragMove(e) {
    if (!guidePanelDragState.isDragging) return;
    const panel = document.getElementById('floatingGuidePanel');
    if (!panel) return;
    let newX = e.clientX - guidePanelDragState.offsetX;
    let newY = e.clientY - guidePanelDragState.offsetY;
    const pw = panel.offsetWidth, ph = panel.offsetHeight;
    newX = Math.max(0, Math.min(newX, window.innerWidth - pw));
    newY = Math.max(0, Math.min(newY, window.innerHeight - ph));
    panel.style.right = 'auto';
    panel.style.left = newX + 'px';
    panel.style.top = newY + 'px';
    e.preventDefault();
}

function onGuideDragEnd(e) {
    if (!guidePanelDragState.isDragging) return;
    guidePanelDragState.isDragging = false;
    const panel = document.getElementById('floatingGuidePanel');
    if (panel) {
        panel.style.transition = '';
        localStorage.setItem('audiobookMakerGuidePos', JSON.stringify({
            x: parseInt(panel.style.left) || 0,
            y: parseInt(panel.style.top) || 0
        }));
    }
}

function onGuideTouchStart(e) {
    if (e.target.closest('.guide-panel-btn') || e.target.closest('button')) return;
    const panel = document.getElementById('floatingGuidePanel');
    if (!panel) return;
    const touch = e.touches[0];
    guidePanelDragState.isDragging = true;
    const rect = panel.getBoundingClientRect();
    guidePanelDragState.offsetX = touch.clientX - rect.left;
    guidePanelDragState.offsetY = touch.clientY - rect.top;
    panel.style.transition = 'none';
    e.preventDefault();
}

function onGuideTouchMove(e) {
    if (!guidePanelDragState.isDragging) return;
    const panel = document.getElementById('floatingGuidePanel');
    if (!panel) return;
    const touch = e.touches[0];
    let newX = touch.clientX - guidePanelDragState.offsetX;
    let newY = touch.clientY - guidePanelDragState.offsetY;
    const pw = panel.offsetWidth, ph = panel.offsetHeight;
    newX = Math.max(0, Math.min(newX, window.innerWidth - pw));
    newY = Math.max(0, Math.min(newY, window.innerHeight - ph));
    panel.style.right = 'auto';
    panel.style.left = newX + 'px';
    panel.style.top = newY + 'px';
    e.preventDefault();
}

function onGuideTouchEnd(e) {
    if (!guidePanelDragState.isDragging) return;
    guidePanelDragState.isDragging = false;
    const panel = document.getElementById('floatingGuidePanel');
    if (panel) {
        panel.style.transition = '';
        localStorage.setItem('audiobookMakerGuidePos', JSON.stringify({
            x: parseInt(panel.style.left) || 0,
            y: parseInt(panel.style.top) || 0
        }));
    }
}

// ============================================
// Workflow Progress Bar
// ============================================

function updateWorkflowProgress(stage) {
    const step1 = document.getElementById('wpStep1');
    const step2 = document.getElementById('wpStep2');
    const step3 = document.getElementById('wpStep3');
    const conn1 = document.getElementById('wpConn1');
    const conn2 = document.getElementById('wpConn2');
    
    if (!step1) return;
    
    currentWorkflowStage = stage;
    updateHeaderHelpButton(stage);
    
    [step1, step2, step3].forEach(s => s.classList.remove('completed', 'active'));
    [conn1, conn2].forEach(c => c.classList.remove('active'));
    
    switch (stage) {
        case 'upload':
            step1.classList.add('active');
            break;
        case 'edit':
            step1.classList.add('completed');
            conn1.classList.add('active');
            step2.classList.add('active');
            showGuidePanelOnEditor();
            break;
        case 'audio-ready':
            step1.classList.add('completed');
            conn1.classList.add('active');
            step2.classList.add('completed');
            conn2.classList.add('active');
            step3.classList.add('active');
            const badge = document.getElementById('readerTabBadge');
            if (badge) badge.style.display = 'inline';
            break;
    }
}

// ============================================
// Helpers
// ============================================

function switchToEditorTab() {
    const editorTab = document.getElementById('editor-tab');
    if (editorTab) {
        const tab = new bootstrap.Tab(editorTab);
        tab.show();
    }
}

function startFromScratch() {
    document.getElementById('uploadSection').style.display = 'none';
    document.getElementById('editorSection').style.display = 'block';
    updateWorkflowProgress('edit');
    
    const panel = document.getElementById('audiobookMakerPanel');
    if (panel) panel.style.display = 'flex';
    
    const sidebar = document.getElementById('documentOutlineSidebar');
    if (sidebar) sidebar.style.display = 'block';
    
    const editor = document.getElementById('markdownEditor');
    if (editor && (typeof editorBlocks === 'undefined' || editorBlocks.length === 0)) {
        addBlock('paragraph', '');
        repairAllNewBlockLines();
        updatePanelUI();
    }
}

function showLoader(text = 'Processing...', subtext = 'Please wait') {
    const overlay = document.getElementById('loadingOverlay');
    if(overlay) {
        document.getElementById('loadingText').textContent = text;
        document.getElementById('loadingSubtext').textContent = subtext;
        overlay.classList.add('active');
    }
}

function hideLoader() {
    const overlay = document.getElementById('loadingOverlay');
    if(overlay) overlay.classList.remove('active');
}

// ============================================
// Voice Management
// ============================================

async function loadVoices() {
    try {
        const response = await fetch('/api/voices');
        const data = await response.json();
        voices = data.voices || [];
        console.log(`📢 Loaded ${voices.length} voices`);
        
        populatePanelVoiceSelect();
    } catch (error) {
        console.error('Failed to load voices:', error);
        voices = [
            { id: 'af_heart', name: 'Heart (US Female)' },
            { id: 'am_adam', name: 'Adam (US Male)' }
        ];
        populatePanelVoiceSelect();
    }
}

function populatePanelVoiceSelect() {
    const select = document.getElementById('ampVoiceSelect');
    if (!select) return;
    
    let currentVoice = 'af_heart';
    if (typeof panelState !== 'undefined' && panelState.voice) {
        currentVoice = panelState.voice;
    }
    
    select.innerHTML = voices.map(v => 
        `<option value="${v.id}" ${v.id === currentVoice ? 'selected' : ''}>${v.name}</option>`
    ).join('');
}

function getVoiceOptions(selectedVoice = 'af_heart') {
    return voices.map(v => 
        `<option value="${v.id}" ${v.id === selectedVoice ? 'selected' : ''}>${v.name}</option>`
    ).join('');
}

// ============================================
// Project Management
// ============================================

async function saveProject() {
    const projectNameInput = document.getElementById('projectName');
    if(!projectNameInput) return;
    const projectName = projectNameInput.value.trim();
    
    if (!projectName) {
        alert('Please enter a project name');
        return;
    }
    
    currentProject.name = projectName;
    const chapters = typeof collectEditorContent === 'function' ? collectEditorContent() : [];
    
    if (chapters.length === 0) {
        alert('No content to save. Add some blocks first.');
        return;
    }
    
    showLoader('Saving Project...', 'Please wait');
    
    try {
        let projectId = currentProject.id;
        
        if (!projectId) {
            const createResponse = await fetch('/api/projects', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({ name: projectName })
            });
            
            const createData = await createResponse.json();
            
            if (createData.error) {
                const listResponse = await fetch('/api/projects');
                const listData = await listResponse.json();
                const existing = listData.projects.find(p => p.name === projectName);
                
                if (existing) {
                    projectId = existing.id;
                } else {
                    throw new Error(createData.error);
                }
            } else {
                projectId = createData.project_id;
            }
            
            currentProject.id = projectId;
        }
        
        const saveResponse = await fetch(`/api/projects/${projectId}/save`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ chapters })
        });
        
        const saveData = await saveResponse.json();
        
        if (saveData.error) {
            throw new Error(saveData.error);
        }
        
        hideLoader();
        showNotification('Project saved successfully!', 'success');
        
    } catch (error) {
        hideLoader();
        console.error('Save error:', error);
        alert('Failed to save project: ' + error.message);
    }
}

async function exportProject() {
    if (!currentProject.id) {
        await saveProject();
        if (!currentProject.id) return;
    }
    
    showLoader('Exporting...', 'Creating ZIP file');
    
    try {
        window.location.href = `/api/export/${currentProject.id}`;
        setTimeout(() => { hideLoader(); }, 2000);
    } catch (error) {
        hideLoader();
        alert('Export failed: ' + error.message);
    }
}

async function openProjectArchive() {
    showLoader('Loading projects...');
    
    try {
        const response = await fetch('/api/projects');
        const data = await response.json();
        
        allArchiveProjects = data.projects || [];
        
        const container = document.getElementById('projectList');
        if(!container) return;
        
        if (allArchiveProjects.length === 0) {
            container.innerHTML = `
                <div class="text-center text-muted py-5">
                    <i class="bi bi-folder2-open" style="font-size: 3rem;"></i>
                    <p class="mt-3">No saved projects yet</p>
                </div>
            `;
        } else {
            container.innerHTML = allArchiveProjects.map(project => {
                const thumbHtml = project.thumbnail_data
                    ? `<img src="data:image/${project.thumbnail_format};base64,${project.thumbnail_data}" 
                            class="project-thumb-img" alt="thumbnail">`
                    : `<div class="project-thumb-placeholder"><i class="bi bi-book"></i></div>`;
                
                const publishBadge = project.is_published
                    ? `<span class="badge bg-success ms-2"><i class="bi bi-globe me-1"></i>Published</span>`
                    : '';
                
                const canPublish = project.audio_count > 0;
                
                return `
                <div class="project-item-v2" id="project-item-${project.id}">
                    <div class="project-thumb" onclick="document.getElementById('thumb-input-${project.id}').click()" 
                         title="Click to upload thumbnail">
                        ${thumbHtml}
                        <div class="project-thumb-overlay">
                            <i class="bi bi-camera"></i>
                            <span>Edit</span>
                        </div>
                        <input type="file" id="thumb-input-${project.id}" accept="image/*" hidden
                               onchange="uploadThumbnail(${project.id}, this)">
                    </div>
                    
                    <div class="project-info-v2" id="project-info-${project.id}">
                        <div class="d-flex align-items-center mb-1 flex-wrap">
                            <h6 class="mb-0" id="project-name-text-${project.id}">${escapeHtml(project.name)}</h6>
                            ${publishBadge}
                        </div>
                        <div class="project-meta">
                            <i class="bi bi-collection me-1"></i> ${project.chapter_count} sections •
                            <i class="bi bi-soundwave mx-1"></i> ${project.audio_count} audio blocks •
                            <i class="bi bi-eye mx-1"></i> ${project.view_count} views
                        </div>
                        ${project.author ? `<div class="project-meta-author"><i class="bi bi-person me-1"></i>${escapeHtml(project.author)}</div>` : ''}
                    </div>
                    
                    <div class="project-edit-form" id="project-edit-${project.id}" style="display:none; flex:1; min-width:200px;">
                        <input type="text" class="form-control form-control-sm project-name-edit-input" 
                               id="edit-input-${project.id}" value="${escapeHtml(project.name)}">
                    </div>
                    
                    <div class="project-actions-v2" id="project-actions-${project.id}">
                        ${project.is_published 
                            ? `<button class="btn btn-sm btn-outline-warning" onclick="unpublishProject(${project.id})" title="Unpublish from public library">
                                <i class="bi bi-eye-slash"></i> Unpublish
                            </button>`
                            : `<button class="btn btn-sm btn-success" onclick="openPublishDialog(${project.id})" 
                                  title="${canPublish ? 'Publish to public library' : 'Generate audio first to publish'}"
                                  ${!canPublish ? 'disabled' : ''}>
                                <i class="bi bi-globe"></i> Publish
                            </button>`
                        }
                        <button class="btn btn-sm btn-outline-secondary" onclick="startEditProjectName(${project.id})" title="Rename">
                            <i class="bi bi-pencil"></i>
                        </button>
                        <button class="btn btn-sm btn-primary" onclick="loadProject(${project.id})">
                            <i class="bi bi-folder2-open"></i> Load
                        </button>
                        <button class="btn btn-sm btn-outline-danger" onclick="deleteProject(${project.id})" title="Delete">
                            <i class="bi bi-trash"></i>
                        </button>
                    </div>
                    
                    <div class="project-actions-v2" id="project-edit-actions-${project.id}" style="display:none;">
                        <button class="btn btn-sm btn-success" onclick="saveProjectName(${project.id})" title="Save">
                            <i class="bi bi-check-lg"></i>
                        </button>
                        <button class="btn btn-sm btn-outline-secondary" onclick="cancelEditProjectName(${project.id})" title="Cancel">
                            <i class="bi bi-x-lg"></i>
                        </button>
                    </div>
                </div>
                `;
            }).join('');
        }
        
        hideLoader();
        if(archiveModal) archiveModal.show();
        
    } catch (error) {
        hideLoader();
        alert('Failed to load projects: ' + error.message);
    }
}

// ============================================
// Rename
// ============================================

function startEditProjectName(projectId) {
    document.getElementById(`project-info-${projectId}`).style.display = 'none';
    document.getElementById(`project-actions-${projectId}`).style.display = 'none';
    
    document.getElementById(`project-edit-${projectId}`).style.display = 'block';
    document.getElementById(`project-edit-actions-${projectId}`).style.display = 'flex';
    
    const input = document.getElementById(`edit-input-${projectId}`);
    input.focus();
    input.select();
    
    input.onkeydown = function(e) {
        if (e.key === 'Enter') {
            e.preventDefault();
            saveProjectName(projectId);
        } else if (e.key === 'Escape') {
            cancelEditProjectName(projectId);
        }
    };
}

function cancelEditProjectName(projectId) {
    document.getElementById(`project-info-${projectId}`).style.display = 'block';
    document.getElementById(`project-actions-${projectId}`).style.display = 'flex';
    
    document.getElementById(`project-edit-${projectId}`).style.display = 'none';
    document.getElementById(`project-edit-actions-${projectId}`).style.display = 'none';
    
    const textElement = document.getElementById(`project-name-text-${projectId}`);
    const input = document.getElementById(`edit-input-${projectId}`);
    if (textElement && input) {
        input.value = textElement.textContent;
    }
}

async function saveProjectName(projectId) {
    const input = document.getElementById(`edit-input-${projectId}`);
    const newName = input.value.trim();
    
    if (!newName) {
        showNotification('Project name cannot be empty', 'warning');
        return;
    }
    
    try {
        const response = await fetch(`/api/projects/${projectId}`, {
            method: 'PUT',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ name: newName })
        });
        
        const data = await response.json();
        
        if (data.error) {
            showNotification(data.error, 'error');
            return;
        }
        
        const textEl = document.getElementById(`project-name-text-${projectId}`);
        if (textEl) textEl.textContent = newName;
        
        const cached = allArchiveProjects.find(p => p.id === projectId);
        if (cached) cached.name = newName;
        
        cancelEditProjectName(projectId);
        showNotification('Project renamed successfully', 'success');
        
        if (currentProject.id === projectId) {
            currentProject.name = newName;
            const nameInput = document.getElementById('projectName');
            if (nameInput) nameInput.value = newName;
        }
        
    } catch (error) {
        console.error(error);
        showNotification('Failed to rename project', 'error');
    }
}

// ============================================
// Thumbnail Upload
// ============================================

async function uploadThumbnail(projectId, inputEl) {
    const file = inputEl.files[0];
    if (!file) return;
    
    if (file.size > 5 * 1024 * 1024) {
        showNotification('Image too large (max 5MB)', 'error');
        return;
    }
    
    const formData = new FormData();
    formData.append('file', file);
    
    showLoader('Uploading thumbnail...');
    
    try {
        const resp = await fetch(`/api/projects/${projectId}/thumbnail`, {
            method: 'POST',
            body: formData
        });
        const data = await resp.json();
        
        hideLoader();
        
        if (data.error) {
            showNotification(data.error, 'error');
            return;
        }
        
        showNotification('Thumbnail updated', 'success');
        openProjectArchive();
    } catch (e) {
        hideLoader();
        showNotification('Failed to upload thumbnail', 'error');
    }
}

// ============================================
// Publishing
// ============================================

function openPublishDialog(projectId) {
    publishingProjectId = projectId;
    
    const project = allArchiveProjects.find(p => p.id === projectId);
    
    if (!publishModal) {
        const modalHtml = `
        <div class="modal fade" id="publishModal" tabindex="-1">
            <div class="modal-dialog">
                <div class="modal-content">
                    <div class="modal-header">
                        <h5 class="modal-title"><i class="bi bi-globe me-2"></i>Publish to Public Library</h5>
                        <button type="button" class="btn-close" data-bs-dismiss="modal"></button>
                    </div>
                    <div class="modal-body">
                        <p class="text-muted small">Publishing makes your audiobook available to anyone visiting the public library at <code>/home</code>.</p>
                        
                        <div class="mb-3">
                            <label class="form-label">Project</label>
                            <input type="text" class="form-control" id="pub-name" readonly>
                        </div>
                        <div class="mb-3">
                            <label class="form-label">Author <span class="text-muted small">(optional)</span></label>
                            <input type="text" class="form-control" id="pub-author" placeholder="Author name">
                        </div>
                        <div class="mb-3">
                            <label class="form-label">Description <span class="text-muted small">(optional)</span></label>
                            <textarea class="form-control" id="pub-description" rows="3" placeholder="Short description of the audiobook"></textarea>
                        </div>
                        <div class="mb-3">
                            <label class="form-label">Category <span class="text-muted small">(optional)</span></label>
                            <input type="text" class="form-control" id="pub-category" placeholder="e.g., Fiction, Non-fiction, Self-help">
                        </div>
                    </div>
                    <div class="modal-footer">
                        <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">Cancel</button>
                        <button type="button" class="btn btn-success" onclick="confirmPublish()">
                            <i class="bi bi-globe me-1"></i>Publish Now
                        </button>
                    </div>
                </div>
            </div>
        </div>`;
        document.body.insertAdjacentHTML('beforeend', modalHtml);
        publishModal = new bootstrap.Modal(document.getElementById('publishModal'));
    }
    
    document.getElementById('pub-name').value = project ? project.name : '';
    document.getElementById('pub-author').value = project ? (project.author || '') : '';
    document.getElementById('pub-description').value = project ? (project.description || '') : '';
    document.getElementById('pub-category').value = project ? (project.category || '') : '';
    
    publishModal.show();
}

async function confirmPublish() {
    const author = document.getElementById('pub-author').value.trim();
    const description = document.getElementById('pub-description').value.trim();
    const category = document.getElementById('pub-category').value.trim();
    
    try {
        const resp = await fetch(`/api/projects/${publishingProjectId}/publish`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ author, description, category })
        });
        const data = await resp.json();
        
        if (data.error) {
            showNotification(data.error, 'error');
            return;
        }
        
        publishModal.hide();
        showNotification(data.message || 'Published!', 'success');
        openProjectArchive();
    } catch (e) {
        showNotification('Failed to publish', 'error');
    }
}

async function unpublishProject(projectId) {
    if (!confirm('Unpublish this audiobook? It will no longer appear on the public library.')) return;
    
    try {
        const resp = await fetch(`/api/projects/${projectId}/unpublish`, { method: 'POST' });
        const data = await resp.json();
        
        if (data.error) {
            showNotification(data.error, 'error');
            return;
        }
        
        showNotification('Unpublished', 'success');
        openProjectArchive();
    } catch (e) {
        showNotification('Failed to unpublish', 'error');
    }
}

// ============================================
// Project Load / Delete - LAZY AUDIO LOADING
// ============================================

async function loadProject(projectId) {
    showLoader('Loading project...', 'Fetching metadata');
    if(archiveModal) archiveModal.hide();
    
    try {
        // Step 1: Load lightweight metadata (no audio_data)
        const response = await fetch(`/api/projects/${projectId}`);
        const data = await response.json();
        
        if (data.error) throw new Error(data.error);
        
        currentProject = { id: data.id, name: data.name, chapters: data.chapters };
        document.getElementById('projectName').value = data.name;
        
        document.getElementById('uploadSection').style.display = 'none';
        document.getElementById('editorSection').style.display = 'block';
        
        const panel = document.getElementById('audiobookMakerPanel');
        if (panel) panel.style.display = 'flex';
        
        const sidebar = document.getElementById('documentOutlineSidebar');
        if (sidebar) sidebar.style.display = 'block';
        
        if (typeof renderProjectInEditor === 'function') {
            renderProjectInEditor(data);
        }
        
        // Step 2: Find blocks that need audio fetched
        const audioBlocks = [];
        for (const ch of data.chapters) {
            for (const bl of ch.blocks) {
                if (bl.has_audio && bl.block_type !== 'image') {
                    audioBlocks.push(bl.id);
                }
            }
        }
        
        updateWorkflowProgress(audioBlocks.length > 0 ? 'audio-ready' : 'edit');
        
        hideLoader();
        
        if (audioBlocks.length === 0) {
            showNotification('Project loaded successfully!', 'success');
            return;
        }
        
        // Step 3: Lazy-load audio in background, parallel batches
        showNotification(`Project loaded. Fetching ${audioBlocks.length} audio blocks in background...`, 'info');
        loadAudioBlocksInBackground(projectId, audioBlocks);
        
    } catch (error) {
        hideLoader();
        console.error('Load project error:', error);
        alert('Failed to load project: ' + error.message);
    }
}


async function loadAudioBlocksInBackground(projectId, blockIds) {
    const BATCH_SIZE = 5;
    let loaded = 0;
    let failed = 0;
    
    async function fetchOne(blockId) {
        try {
            const resp = await fetch(`/api/projects/${projectId}/audio/${blockId}`);
            
            // v4.3: এন্ডপয়েন্ট বাইনারি অডিও (audio/*) অথবা legacy base64 JSON দিতে পারে
            const contentType = resp.headers.get('content-type') || '';
            
            const blockData = editorBlocks.find(b => b.db_id === blockId);
            
            if (contentType.startsWith('audio/')) {
                // নতুন: ফাইল আছে — শুধু indicator আপডেট করি, base64 মেমরিতে রাখি না
                // (reader নিজেই lazy fetch করবে)
                if (blockData) {
                    blockData.has_audio = true;
                    const blockEl = document.getElementById(blockData.id);
                    if (blockEl) {
                        const indicator = blockEl.querySelector('.audio-indicator');
                        if (indicator) {
                            indicator.classList.remove('no-audio');
                            indicator.classList.add('has-audio');
                            indicator.title = 'Audio available';
                        }
                    }
                }
                loaded++;
                return;
            }
            
            // Legacy base64 JSON
            const data = await resp.json();
            
            if (data.error || !data.audio_data) {
                failed++;
                return;
            }
            
            if (blockData) {
                blockData.audio_data = data.audio_data;
                blockData.audio_format = data.audio_format;
                blockData.has_audio = true;
                
                const blockEl = document.getElementById(blockData.id);
                if (blockEl) {
                    const indicator = blockEl.querySelector('.audio-indicator');
                    if (indicator) {
                        indicator.classList.remove('no-audio');
                        indicator.classList.add('has-audio');
                        indicator.title = 'Audio loaded';
                    }
                }
            }
            
            loaded++;
        } catch (e) {
            failed++;
            console.warn(`Failed to load audio for block ${blockId}:`, e);
        }
    }
    
    for (let i = 0; i < blockIds.length; i += BATCH_SIZE) {
        const batch = blockIds.slice(i, i + BATCH_SIZE);
        await Promise.all(batch.map(fetchOne));
    }
    
    const msg = failed > 0 
        ? `Verified ${loaded}/${blockIds.length} audio blocks (${failed} failed)`
        : `All ${loaded} audio blocks verified ✓`;
    showNotification(msg, failed > 0 ? 'warning' : 'success');
    
    if (typeof updatePanelUI === 'function') {
        updatePanelUI();
    }
}


async function deleteProject(projectId) {
    if (!confirm('Are you sure you want to delete this project? This action cannot be undone.\n\nএই প্রজেক্টের অডিও ও ইমেজ ফাইলগুলোও মুছে যাবে।')) return;
    
    showLoader('Deleting...');
    
    try {
        const response = await fetch(`/api/projects/${projectId}`, { method: 'DELETE' });
        const data = await response.json();
        if (data.error) throw new Error(data.error);
        
        await openProjectArchive();
        showNotification('Project deleted', 'success');
        
    } catch (error) {
        hideLoader();
        alert('Failed to delete project: ' + error.message);
    }
}

// ============================================
// v4.3: Storage & Maintenance (VACUUM)
// ============================================

function openDbMaintenance() {
    if (!dbMaintenanceModal) {
        dbMaintenanceModal = new bootstrap.Modal(document.getElementById('dbMaintenanceModal'));
    }
    dbMaintenanceModal.show();
    loadDbStats();
}

async function loadDbStats() {
    const loadingEl = document.getElementById('dbStatsLoading');
    const contentEl = document.getElementById('dbStatsContent');
    if (loadingEl) loadingEl.style.display = 'block';
    if (contentEl) contentEl.style.display = 'none';
    
    try {
        const resp = await fetch('/api/maintenance/db-stats');
        const s = await resp.json();
        
        if (s.error) {
            showNotification(s.error, 'error');
            return;
        }
        
        document.getElementById('dbmFileSize').textContent = `${s.file_size_mb} MB`;
        document.getElementById('dbmMediaSize').textContent = `${s.media_size_mb} MB`;
        document.getElementById('dbmFreeText').textContent =
            `${s.free_mb} MB (${s.free_percent}%)`;
        
        const bar = document.getElementById('dbmFreeBar');
        const pct = Math.min(s.free_percent, 100);
        bar.style.width = pct + '%';
        bar.textContent = `${s.free_percent}%`;
        
        // রঙ: কম হলে সবুজ, বেশি হলে হলুদ/লাল
        bar.className = 'progress-bar';
        if (s.free_percent >= 30) {
            bar.classList.add('bg-danger');
        } else if (s.free_percent >= 15) {
            bar.classList.add('bg-warning');
        } else {
            bar.classList.add('bg-success');
        }
        
        const advice = document.getElementById('dbmAdvice');
        if (s.free_percent >= 15) {
            advice.className = 'alert alert-warning';
            advice.style.display = 'block';
            advice.innerHTML = `<i class="bi bi-exclamation-triangle me-1"></i>` +
                `ডেটাবেসে <strong>${s.free_percent}%</strong> ফাঁকা স্পেস জমেছে। ` +
                `<strong>Run VACUUM</strong> চালিয়ে এটি reclaim করতে পারেন।`;
        } else {
            advice.className = 'alert alert-success';
            advice.style.display = 'block';
            advice.innerHTML = `<i class="bi bi-check-circle me-1"></i>` +
                `ফাঁকা স্পেস কম (<strong>${s.free_percent}%</strong>) — এখন VACUUM চালানোর দরকার নেই।`;
        }
        
        if (loadingEl) loadingEl.style.display = 'none';
        if (contentEl) contentEl.style.display = 'block';
        
    } catch (e) {
        console.error(e);
        showNotification('Failed to load storage info', 'error');
    }
}

async function runDbVacuum() {
    const vacuumBtn = document.getElementById('dbmVacuumBtn');
    const refreshBtn = document.getElementById('dbmRefreshBtn');
    
    if (!confirm('VACUUM এখন চালাবেন? এটি ডেটাবেস ছোট করবে কিন্তু কিছু সময় (ডেটাবেস বড় হলে কয়েক মিনিট) নিতে পারে।')) {
        return;
    }
    
    if (vacuumBtn) {
        vacuumBtn.disabled = true;
        vacuumBtn.innerHTML = '<span class="spinner-border spinner-border-sm me-1"></span>Running...';
    }
    if (refreshBtn) refreshBtn.disabled = true;
    
    try {
        const resp = await fetch('/api/maintenance/vacuum', { method: 'POST' });
        const data = await resp.json();
        
        if (data.error) {
            showNotification(data.error, 'error');
        } else {
            showNotification(data.message || 'VACUUM complete', 'success');
            loadDbStats();
        }
    } catch (e) {
        showNotification('VACUUM failed', 'error');
    } finally {
        if (vacuumBtn) {
            vacuumBtn.disabled = false;
            vacuumBtn.innerHTML = '<i class="bi bi-stars me-1"></i>Run VACUUM';
        }
        if (refreshBtn) refreshBtn.disabled = false;
    }
}

// ============================================
// TTS Text Editing
// ============================================

function openTtsEditor(blockId, currentContent) {
    const plainText = stripMarkdown(currentContent);
    document.getElementById('ttsTextInput').value = plainText;
    document.getElementById('ttsBlockId').value = blockId;
    if(ttsEditModal) ttsEditModal.show();
}

function saveTtsText() {
    const blockId = document.getElementById('ttsBlockId').value;
    const ttsText = document.getElementById('ttsTextInput').value;
    
    const block = document.querySelector(`[data-block-id="${blockId}"]`);
    if (block) {
        block.dataset.ttsText = ttsText;
    }
    
    if(ttsEditModal) ttsEditModal.hide();
    showNotification('TTS text saved', 'success');
}

// ============================================
// Utility Functions
// ============================================

function escapeHtml(text) {
    if(!text) return '';
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
}

function formatDate(dateStr) {
    if (!dateStr) return '';
    const date = new Date(dateStr);
    return date.toLocaleDateString() + ' ' + date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
}

function stripMarkdown(text) {
    if (!text) return '';
    let result = text;
    result = result.replace(/^#{1,6}\s*/gm, '');
    result = result.replace(/\*\*(.+?)\*\*/g, '$1');
    result = result.replace(/\*(.+?)\*/g, '$1');
    result = result.replace(/__(.+?)__/g, '$1');
    result = result.replace(/_(.+?)_/g, '$1');
    result = result.replace(/\[([^\]]+)\]\([^)]+\)/g, '$1');
    result = result.replace(/!\[([^\]]*)\]\([^)]+\)/g, '');
    result = result.replace(/^>\s*/gm, '');
    result = result.replace(/^\s*[-*+]\s+/gm, '');
    result = result.replace(/^\s*\d+\.\s+/gm, '');
    return result.trim();
}

function showNotification(message, type = 'info') {
    const notification = document.createElement('div');
    notification.className = `alert alert-${type === 'success' ? 'success' : type === 'error' ? 'danger' : type === 'warning' ? 'warning' : 'info'} notification-toast`;
    notification.innerHTML = `
        <i class="bi bi-${type === 'success' ? 'check-circle' : type === 'error' ? 'exclamation-circle' : type === 'warning' ? 'exclamation-triangle' : 'info-circle'} me-2"></i>
        ${message}
    `;
    notification.style.cssText = `
        position: fixed; top: 20px; right: 20px; z-index: 9999;
        min-width: 250px; animation: slideIn 0.3s ease;
    `;
    
    document.body.appendChild(notification);
    
    setTimeout(() => {
        notification.style.animation = 'slideOut 0.3s ease';
        setTimeout(() => notification.remove(), 300);
    }, 3000);
}

// ============================================
// Authentication
// ============================================

let changePasswordModal = null;

async function loadCurrentUser() {
    try {
        const response = await fetch('/api/auth/me');
        const data = await response.json();
        
        if (data.user) {
            const usernameEl = document.getElementById('headerUsername');
            if (usernameEl) usernameEl.textContent = data.user.username;
            
            if (data.user.role === 'admin') {
                const adminItem = document.getElementById('adminMenuItem');
                const adminDivider = document.getElementById('adminDivider');
                if (adminItem) adminItem.style.display = 'block';
                if (adminDivider) adminDivider.style.display = 'block';
            }
        }
    } catch (error) {
        console.error('Failed to load user info:', error);
    }
}

async function handleLogout() {
    try {
        await fetch('/api/auth/logout', { method: 'POST' });
    } catch(e) { /* ignore */ }
    window.location.href = '/login';
}

function openChangePassword() {
    if (!changePasswordModal) {
        changePasswordModal = new bootstrap.Modal(document.getElementById('changePasswordModal'));
    }
    document.getElementById('currentPassword').value = '';
    document.getElementById('newPassword').value = '';
    document.getElementById('confirmPassword').value = '';
    document.getElementById('changePasswordError').style.display = 'none';
    changePasswordModal.show();
}

async function submitChangePassword() {
    const currentPassword = document.getElementById('currentPassword').value;
    const newPassword = document.getElementById('newPassword').value;
    const confirmPassword = document.getElementById('confirmPassword').value;
    const errorDiv = document.getElementById('changePasswordError');
    
    errorDiv.style.display = 'none';
    
    if (!currentPassword || !newPassword) {
        errorDiv.textContent = 'All fields are required';
        errorDiv.style.display = 'block';
        return;
    }
    
    if (newPassword !== confirmPassword) {
        errorDiv.textContent = 'New passwords do not match';
        errorDiv.style.display = 'block';
        return;
    }
    
    if (newPassword.length < 4) {
        errorDiv.textContent = 'New password must be at least 4 characters';
        errorDiv.style.display = 'block';
        return;
    }
    
    try {
        const response = await fetch('/api/auth/change-password', {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ current_password: currentPassword, new_password: newPassword })
        });
        
        const data = await response.json();
        
        if (data.error) {
            errorDiv.textContent = data.error;
            errorDiv.style.display = 'block';
            return;
        }
        
        changePasswordModal.hide();
        showNotification('Password changed successfully!', 'success');
    } catch(e) {
        errorDiv.textContent = 'Network error. Please try again.';
        errorDiv.style.display = 'block';
    }
}

const notifStyle = document.createElement('style');
notifStyle.textContent = `
    @keyframes slideIn { from { transform: translateX(100%); opacity: 0; } to { transform: translateX(0); opacity: 1; } }
    @keyframes slideOut { from { transform: translateX(0); opacity: 1; } to { transform: translateX(100%); opacity: 0; } }
`;
document.head.appendChild(notifStyle);