New main page way of browsing the courses

offlineu_core.py

@@ -46,6 +46,7 @@ DEFAULT_SETTINGS = {
     'density': 'comfortable',     # 'comfortable' | 'compact'
     'card_style': 'flat',         # 'flat' | 'elevated' | 'bordered'
     'corner_radius': 'rounded',   # 'sharp' | 'rounded' | 'pill'
+    'library_path': '',           # '' = use COURSES_LIBRARY_PATH/--library-path default
 }
 
 # Allowed values for every setting except accent_color (validated separately
@@ -86,6 +87,10 @@ def load_settings() -> Dict[str, Any]:
             for key, value in saved.items():
                 if key == 'accent_color' and isinstance(value, str) and HEX_COLOR_RE.match(value):
                     settings[key] = value
+                elif key == 'library_path' and isinstance(value, str):
+                    # Lenient on load (directory may be transiently
+                    # unavailable at startup) - only validated on save.
+                    settings[key] = value
                 elif key in SETTINGS_CHOICES and value in SETTINGS_CHOICES[key]:
                     settings[key] = value
     except (json.JSONDecodeError, OSError) as e:
@@ -99,6 +104,11 @@ def save_settings(new_settings: Dict[str, Any]) -> Dict[str, Any]:
     for key, value in new_settings.items():
         if key == 'accent_color' and isinstance(value, str) and HEX_COLOR_RE.match(value):
             current[key] = value
+        elif key == 'library_path' and isinstance(value, str):
+            value = value.strip()
+            if value and not os.path.isdir(value):
+                raise ValueError(f"Directory not found: {value}")
+            current[key] = value
         elif key in SETTINGS_CHOICES and value in SETTINGS_CHOICES[key]:
             current[key] = value
     os.makedirs(DATA_DIR, exist_ok=True)
@@ -364,69 +374,69 @@ def _looks_like_course(directory: Path) -> bool:
     return len(children_with_media) >= 2
 
 
-def scan_course_library(library_path: str, max_depth: int = 5) -> Dict[str, Any]:
+def list_library_directory(dir_path: str) -> Dict[str, Any]:
     """
-    Scan a base 'library' directory for course folders and group them by the
+    List only the immediate children of dir_path for the lazy-loading
-    parent directory they live in, so the UI can show something like:
+    Library browser: subdirectories to drill into, and course folders to
+    load directly - without recursively scanning the whole tree. This is
+    what lets the UI start collapsed at the top level and expand on demand
+    instead of rendering hundreds of courses at once.
 
-        Udemy/
+    Directories that don't lead to any course anywhere inside them are
-            Python Bootcamp
+    left out entirely, so drilling down never dead-ends on an empty folder.
-            Web Dev Masterclass
-        Pluralsight/
-            Docker Deep Dive
-        (Library Root)
-            Standalone Course
-
-    Recursion stops as soon as a directory looks like a course (see
-    _looks_like_course), so nested "Section" folders inside a course aren't
-    mistaken for more courses.
     """
-    library_root = Path(library_path)
+    directory = Path(dir_path)
-    groups: Dict[str, List[Dict[str, Any]]] = {}
+    items: List[Dict[str, Any]] = []
-    errors: List[str] = []
 
-    if not library_root.exists() or not library_root.is_dir():
+    if not directory.exists() or not directory.is_dir():
-        return {'groups': groups, 'errors': [f"Library path not found: {library_path}"]}
+        return {'items': items, 'errors': [f"Directory not found: {dir_path}"]}
 
-    def walk(current: Path, depth: int):
+    try:
-        if depth > max_depth:
+        entries = sorted(
-            return
+            (p for p in directory.iterdir() if p.is_dir() and not p.name.startswith('.')),
-        try:
+            key=lambda p: p.name.lower()
-            entries = sorted(
+        )
-                (p for p in current.iterdir() if p.is_dir() and not p.name.startswith('.')),
+    except (PermissionError, OSError) as e:
-                key=lambda p: p.name.lower()
+        return {'items': items, 'errors': [f"Could not read {dir_path}: {e}"]}
+
+    for entry in entries:
+        if _looks_like_course(entry):
+            media_count = len([
+                f for f in entry.rglob('*')
+                if f.is_file() and f.suffix.lower() in VIDEO_EXTENSIONS | AUDIO_EXTENSIONS
+            ])
+            items.append({
+                'type': 'course',
+                'name': entry.name,
+                'path': str(entry),
+                'media_files': media_count
+            })
+        else:
+            has_course_inside = any(
+                f.is_file() and f.suffix.lower() in VIDEO_EXTENSIONS | AUDIO_EXTENSIONS
+                for f in entry.rglob('*')
             )
-        except (PermissionError, OSError) as e:
+            if has_course_inside:
-            errors.append(f"Could not read {current}: {e}")
+                items.append({
-            return
+                    'type': 'directory',
-
-        for entry in entries:
-            if _looks_like_course(entry):
-                try:
-                    rel_parent = entry.parent.relative_to(library_root)
-                except ValueError:
-                    rel_parent = Path('.')
-                group_label = str(rel_parent).replace('\\', '/') if str(rel_parent) != '.' else '(Library Root)'
-
-                media_count = len([
-                    f for f in entry.rglob('*')
-                    if f.is_file() and f.suffix.lower() in VIDEO_EXTENSIONS | AUDIO_EXTENSIONS
-                ])
-
-                groups.setdefault(group_label, []).append({
                     'name': entry.name,
                     'path': str(entry),
-                    'media_files': media_count
                 })
-            else:
-                walk(entry, depth + 1)
 
-    walk(library_root, 0)
+    return {'items': items, 'errors': []}
 
-    for courses in groups.values():
-        courses.sort(key=lambda c: c['name'].lower())
 
-    return {'groups': groups, 'errors': errors}
+def get_library_root() -> str:
+    """
+    The effective root the Library browser scans: the persisted
+    'library_path' setting if it's set and exists, otherwise the
+    COURSES_LIBRARY_PATH/--library-path default.
+    """
+    settings = load_settings()
+    override = (settings.get('library_path') or '').strip()
+    if override and os.path.isdir(override):
+        return override
+    return LIBRARY_PATH
 
 
 class ProgressTracker:
@@ -617,15 +627,25 @@ def browse_directories():
 @app.route('/library')
 def browse_library():
     """
-    Scan the configured courses library and return courses grouped by
+    Lazily list one directory level of the courses library at a time, so
-    parent directory, so the UI can offer a click-through picker instead
+    the UI can start collapsed at the top level and drill down on click
-    of requiring a typed filesystem path.
+    instead of scanning/rendering the whole tree upfront. Defaults to the
+    effective library root (persisted setting, or the
+    COURSES_LIBRARY_PATH/--library-path default); the 'path' query param
+    lets the browser descend, but is restricted to stay within that root.
     """
-    library_path = request.args.get('path', LIBRARY_PATH)
+    library_root = os.path.abspath(get_library_root())
-    result = scan_course_library(library_path)
+    requested_path = request.args.get('path', library_root)
+    target_path = os.path.abspath(requested_path)
+
+    if not (target_path == library_root or target_path.startswith(library_root + os.sep)):
+        return jsonify({'error': 'Path outside library root', 'items': [], 'errors': ['Access denied']}), 403
+
+    result = list_library_directory(target_path)
     return jsonify({
-        'library_path': library_path,
+        'library_path': library_root,
-        'groups': result['groups'],
+        'current_path': target_path,
+        'items': result['items'],
         'errors': result['errors']
     })
 
@@ -637,6 +657,7 @@ def settings_page():
     return render_template(
         'settings.html',
         settings=current,
+        default_library_path=LIBRARY_PATH,
         theme_choices=sorted(SETTINGS_CHOICES['theme']),
         font_family_choices=['system', 'sans', 'serif', 'monospace'],
         font_size_choices=['small', 'medium', 'large', 'xlarge'],

templates/course_dashboard.html

@@ -680,55 +680,84 @@
         function loadLibrary() {
             const libraryCard = document.getElementById('library-card');
             if (!libraryCard) return;
+            fetchLibraryLevel(null, document.getElementById('library-groups'), true);
+        }
 
-            fetch('/library')
+        function fetchLibraryLevel(path, container, isRoot) {
+            const url = path ? `/library?path=${encodeURIComponent(path)}` : '/library';
+            fetch(url)
                 .then(r => r.json())
                 .then(data => {
-                    document.getElementById('library-path-bar').textContent =
+                    if (isRoot) {
-                        `Scanning ${data.library_path}`;
+                        document.getElementById('library-path-bar').textContent =
-
+                            `Scanning ${data.library_path}`;
-                    const container = document.getElementById('library-groups');
-                    const groupNames = Object.keys(data.groups).sort((a, b) => a.localeCompare(b));
-
-                    if (groupNames.length === 0) {
-                        const reason = (data.errors && data.errors.length)
-                            ? data.errors.join(' ')
-                            : `No course folders found under ${data.library_path}.`;
-                        container.innerHTML = `<p style="color:#999;">${reason} You can still load a course by path below.</p>`;
-                        return;
                     }
-
+                    renderLibraryLevel(data, container, isRoot);
-                    container.innerHTML = groupNames.map((group, i) => `
-                        <div class="tree-item">
-                            <div class="tree-header directory" onclick="toggleTree(this)">
-                                <div class="tree-title">
-                                    <span class="tree-icon">📁</span>
-                                    <span class="tree-name">${group}</span>
-                                    <span class="tree-stats">${data.groups[group].length} course${data.groups[group].length === 1 ? '' : 's'}</span>
-                                </div>
-                                <button class="tree-toggle">▶</button>
-                            </div>
-                            <div class="tree-content">
-                                ${data.groups[group].map(course => `
-                                    <div class="lesson-item"
-                                         onclick="loadCoursePath('${course.path.replace(/'/g, "\\'")}')">
-                                        <div class="lesson-title">
-                                            <span class="lesson-icon">🎓</span>
-                                            <span>${course.name}</span>
-                                        </div>
-                                        <span class="lesson-meta">${course.media_files} media file${course.media_files === 1 ? '' : 's'}</span>
-                                    </div>
-                                `).join('')}
-                            </div>
-                        </div>
-                    `).join('');
                 })
                 .catch(() => {
-                    document.getElementById('library-groups').innerHTML =
+                    container.innerHTML =
                         '<p style="color:#ff6b6b;">Could not reach the library scanner.</p>';
                 });
         }
 
+        function renderLibraryLevel(data, container, isRoot) {
+            if (!data.items || data.items.length === 0) {
+                const reason = (data.errors && data.errors.length)
+                    ? data.errors.join(' ')
+                    : (isRoot ? `No course folders found under ${data.library_path}.` : 'No courses in here.');
+                container.innerHTML = `<p style="color:#999; padding: 6px 0;">${reason}${isRoot ? ' You can still load a course by path below.' : ''}</p>`;
+                return;
+            }
+
+            container.innerHTML = data.items.map(item => {
+                if (item.type === 'course') {
+                    return `
+                        <div class="lesson-item"
+                             onclick="loadCoursePath('${item.path.replace(/'/g, "\\'")}')">
+                            <div class="lesson-title">
+                                <span class="lesson-icon">🎓</span>
+                                <span>${item.name}</span>
+                            </div>
+                            <span class="lesson-meta">${item.media_files} media file${item.media_files === 1 ? '' : 's'}</span>
+                        </div>
+                    `;
+                }
+                return `
+                    <div class="tree-item">
+                        <div class="tree-header directory" onclick="toggleLibraryDir(this, '${item.path.replace(/'/g, "\\'")}')">
+                            <div class="tree-title">
+                                <span class="tree-icon">📁</span>
+                                <span class="tree-name">${item.name}</span>
+                            </div>
+                            <button class="tree-toggle">▶</button>
+                        </div>
+                        <div class="tree-content" data-loaded="false"></div>
+                    </div>
+                `;
+            }).join('');
+        }
+
+        function toggleLibraryDir(headerEl, path) {
+            const content = headerEl.nextElementSibling;
+            const toggle = headerEl.querySelector('.tree-toggle');
+            if (!content || !content.classList.contains('tree-content')) return;
+
+            if (content.classList.contains('expanded')) {
+                content.classList.remove('expanded');
+                toggle.textContent = '▶';
+                return;
+            }
+
+            content.classList.add('expanded');
+            toggle.textContent = '▼';
+
+            if (content.dataset.loaded === 'true') return; // already fetched this branch
+
+            content.innerHTML = '<p style="color:#999; padding: 6px 0;">Loading...</p>';
+            content.dataset.loaded = 'true';
+            fetchLibraryLevel(path, content, false);
+        }
+
         function loadCoursePath(path) {
             fetch('/load_course', {
                 method: 'POST',

templates/settings.html

@@ -312,6 +312,21 @@
             </div>
         </div>
 
+        <div class="card">
+            <h2>Library</h2>
+            <div class="setting-row" style="flex-direction: column; align-items: stretch; gap: 8px;">
+                <label for="library_path">Default courses directory
+                    <span class="setting-desc">Where the Library browser starts. Leave blank to use the server default ({{ default_library_path }}).</span>
+                </label>
+                <div style="display: flex; gap: 10px;">
+                    <input type="text" id="library_path" class="hex-input" style="flex: 1; width: auto; font-family: var(--font-family);"
+                           placeholder="{{ default_library_path }}" value="{{ settings.library_path }}">
+                    <button class="btn" onclick="saveLibraryPath()">Save</button>
+                </div>
+                <span id="library-path-status" style="font-size: 0.85em; min-height: 1.2em;"></span>
+            </div>
+        </div>
+
         <div class="actions">
             <button class="btn btn-secondary" onclick="resetSettings()">Reset to Defaults</button>
             <span id="save-status">✓ Saved</span>
@@ -380,6 +395,31 @@
             }
         });
 
+        function saveLibraryPath() {
+            const input = document.getElementById('library_path');
+            const status = document.getElementById('library-path-status');
+            fetch('/api/settings', {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({ library_path: input.value.trim() })
+            })
+            .then(r => r.json())
+            .then(data => {
+                if (data.success) {
+                    status.style.color = '#28a745';
+                    status.textContent = '✓ Saved — reload the main page to see it take effect';
+                    showSaved();
+                } else {
+                    status.style.color = '#ff6b6b';
+                    status.textContent = data.error || 'Could not save';
+                }
+            })
+            .catch(err => {
+                status.style.color = '#ff6b6b';
+                status.textContent = 'Could not reach the server';
+            });
+        }
+
         function resetSettings() {
             fetch('/api/settings/reset', { method: 'POST' })
                 .then(r => r.json())