feat: enhance snippet management with import/export functionality and size display

CLAUDE.md

@@ -15,7 +15,7 @@ Instructions for Claude Code when working on this project.
 
 ## Current Status
 
-**Completed**: Phases 0-8 (All core functionality including storage monitoring)
-**Next**: Phase 9 - Export/Import
+**Completed**: Phases 0-9 (All core functionality including import/export)
+**Next**: Phase 10 - Dataset Management
 
 See `docs/dev-plan.md` for complete roadmap and technical details.

docs/dev-plan.md

@@ -170,16 +170,22 @@ Astrolabe is a focused tool for managing, editing, and previewing Vega-Lite visu
 
 ---
 
-### **Phase 9: Export/Import**
+### **Phase 9: Export/Import** ✅ **COMPLETE**
 **Goal**: Portability and backup
 
-- [ ] Export single snippet as JSON file (include metadata)
-- [ ] Export all snippets as JSON bundle
-- [ ] Import snippets from JSON (with conflict resolution)
-- [ ] Drag-and-drop import
-- [ ] Export published vs draft options
+**Deliverables**:
+- Export all snippets to JSON file with auto-generated filename (astrolabe-snippets-YYYY-MM-DD.json)
+- Import snippets from JSON with automatic format detection
+- Support for both Astrolabe native format and external formats
+- Automatic field mapping and normalization (createdAt → created, content → spec, draft → draftSpec)
+- "imported" tag automatically added to externally imported snippets
+- ID conflict resolution with automatic regeneration
+- Additive import (merges with existing snippets, no overwrites)
+- Success/error feedback with import count
+- File picker integration with header Import/Export links
+- Snippet size display in list (shows KB for snippets ≥ 1 KB, right-aligned)
 
-**Deliverable**: Full backup/restore capability
+**Note**: Drag-and-drop import and selective export options deferred to future phases
 
 ---
 
@@ -305,15 +311,15 @@ Astrolabe is a focused tool for managing, editing, and previewing Vega-Lite visu
 
 ## Current Status
 
-**Completed**: Phases 0-8 (Storage, UI, editor, rendering, persistence, CRUD, organization, draft/published workflow, storage monitoring)
-**Next**: Phase 9 - Export/Import
+**Completed**: Phases 0-9 (Storage, UI, editor, rendering, persistence, CRUD, organization, draft/published workflow, storage monitoring, import/export)
+**Next**: Phase 10 - Dataset Management
 **See**: `CLAUDE.md` for concise current state summary
 
 ---
 
 ## Implemented Features
 
-### Core Capabilities (Phases 0-8)
+### Core Capabilities (Phases 0-9)
 - Three-panel resizable layout with memory and persistence
 - Monaco Editor v0.47.0 with Vega-Lite v5 schema validation
 - Live Vega-Lite rendering with debounced updates and error display
@@ -326,6 +332,8 @@ Astrolabe is a focused tool for managing, editing, and previewing Vega-Lite visu
 - Status indicator lights (green/yellow) showing draft state
 - Context-aware Publish/Revert buttons with color coding
 - Storage monitoring with visual progress bar and warning states
+- Export/Import functionality with format auto-detection
+- Snippet size display (right-aligned, shown for ≥ 1 KB)
 - Retro Windows 2000 aesthetic throughout
 
 ### Technical Implementation
@@ -339,3 +347,5 @@ Astrolabe is a focused tool for managing, editing, and previewing Vega-Lite visu
 - **Data Model**: Phase 0 schema with `spec` (published) and `draftSpec` (working) fields
 - **Storage Calculation**: Blob API for accurate byte counting of snippet data
 - **Flexbox Layout**: Scrollable snippet list with fixed metadata and storage monitor at bottom
+- **Import/Export**: Format detection, field normalization, ID conflict resolution, additive merging
+- **Size Display**: Per-snippet size calculation with conditional rendering (≥ 1 KB threshold)

index.html

@@ -19,9 +19,10 @@
             <span class="header-title">Astrolabe</span>
         </div>
         <div class="header-links">
-            <span class="header-link">Import</span>
-            <span class="header-link">Export</span>
-            <span class="header-link">Help</span>
+            <span class="header-link" id="import-link">Import</span>
+            <span class="header-link" id="export-link">Export</span>
+            <span class="header-link" id="help-link">Help</span>
+            <input type="file" id="import-file-input" accept=".json" style="display: none;" />
         </div>
     </div>
 

src/js/app.js

@@ -89,12 +89,33 @@ document.addEventListener('DOMContentLoaded', function () {
         });
     });
 
-    // Header links - show placeholder
-    document.querySelectorAll('.header-link').forEach(link => {
-        link.addEventListener('click', function () {
+    // Header links
+    const importLink = document.getElementById('import-link');
+    const exportLink = document.getElementById('export-link');
+    const helpLink = document.getElementById('help-link');
+    const importFileInput = document.getElementById('import-file-input');
+
+    if (importLink && importFileInput) {
+        importLink.addEventListener('click', function () {
+            importFileInput.click();
+        });
+
+        importFileInput.addEventListener('change', function () {
+            importSnippets(this);
+        });
+    }
+
+    if (exportLink) {
+        exportLink.addEventListener('click', function () {
+            exportSnippets();
+        });
+    }
+
+    if (helpLink) {
+        helpLink.addEventListener('click', function () {
             alert('Coming soon in a future phase!');
         });
-    });
+    }
 
     // View mode toggle buttons
     document.getElementById('view-draft').addEventListener('click', () => {

src/js/snippet-manager.js

@@ -239,6 +239,11 @@ function renderSnippetList(searchQuery = null) {
             dateText = formatSnippetDate(snippet.modified);
         }
 
+        // Calculate snippet size
+        const snippetSize = new Blob([JSON.stringify(snippet)]).size;
+        const sizeKB = snippetSize / 1024;
+        const sizeHTML = sizeKB >= 1 ? `<span class="snippet-size">${sizeKB.toFixed(0)} KB</span>` : '';
+
         // Determine status: green if no draft changes, yellow if has draft
         const hasDraft = JSON.stringify(snippet.spec) !== JSON.stringify(snippet.draftSpec);
         const statusClass = hasDraft ? 'draft' : 'published';
@@ -249,6 +254,7 @@ function renderSnippetList(searchQuery = null) {
                     <div class="snippet-name">${snippet.name}</div>
                     <div class="snippet-date">${dateText}</div>
                 </div>
+                ${sizeHTML}
                 <div class="snippet-status ${statusClass}"></div>
             </li>
         `;
@@ -846,3 +852,125 @@ function updateStorageMonitor() {
     }
 }
 
+// Export all snippets to JSON file
+function exportSnippets() {
+    const snippets = SnippetStorage.loadSnippets();
+
+    if (snippets.length === 0) {
+        alert('No snippets to export');
+        return;
+    }
+
+    // Create JSON blob
+    const jsonString = JSON.stringify(snippets, null, 2);
+    const blob = new Blob([jsonString], { type: 'application/json' });
+
+    // Create download link
+    const url = URL.createObjectURL(blob);
+    const link = document.createElement('a');
+    link.href = url;
+    link.download = `astrolabe-snippets-${new Date().toISOString().slice(0, 10)}.json`;
+
+    // Trigger download
+    document.body.appendChild(link);
+    link.click();
+    document.body.removeChild(link);
+    URL.revokeObjectURL(url);
+}
+
+// Normalize external snippet format to Astrolabe format
+function normalizeSnippet(externalSnippet) {
+    // Check if already in Astrolabe format (has 'created' field as ISO string)
+    const isAstrolabeFormat = externalSnippet.created &&
+                             typeof externalSnippet.created === 'string' &&
+                             externalSnippet.created.includes('T');
+
+    if (isAstrolabeFormat) {
+        // Already in correct format, just ensure all fields exist
+        return {
+            id: externalSnippet.id || generateSnippetId(),
+            name: externalSnippet.name || generateSnippetName(),
+            created: externalSnippet.created,
+            modified: externalSnippet.modified || externalSnippet.created,
+            spec: externalSnippet.spec || {},
+            draftSpec: externalSnippet.draftSpec || externalSnippet.spec || {},
+            comment: externalSnippet.comment || "",
+            tags: externalSnippet.tags || [],
+            datasetRefs: externalSnippet.datasetRefs || [],
+            meta: externalSnippet.meta || {}
+        };
+    }
+
+    // External format - map fields
+    const createdDate = externalSnippet.createdAt ?
+                       new Date(externalSnippet.createdAt).toISOString() :
+                       new Date().toISOString();
+
+    return {
+        id: generateSnippetId(), // Generate new ID to avoid conflicts
+        name: externalSnippet.name || generateSnippetName(),
+        created: createdDate,
+        modified: createdDate,
+        spec: externalSnippet.content || externalSnippet.spec || {},
+        draftSpec: externalSnippet.draft || externalSnippet.draftSpec || externalSnippet.content || externalSnippet.spec || {},
+        comment: externalSnippet.comment || "",
+        tags: ["imported"], // Add 'imported' tag
+        datasetRefs: [],
+        meta: {}
+    };
+}
+
+// Import snippets from JSON file
+function importSnippets(fileInput) {
+    const file = fileInput.files[0];
+    if (!file) return;
+
+    const reader = new FileReader();
+    reader.onload = function(e) {
+        try {
+            const importedData = JSON.parse(e.target.result);
+
+            // Handle both single snippet and array of snippets
+            const snippetsToImport = Array.isArray(importedData) ? importedData : [importedData];
+
+            if (snippetsToImport.length === 0) {
+                alert('No snippets found in file');
+                return;
+            }
+
+            // Normalize and merge with existing snippets
+            const existingSnippets = SnippetStorage.loadSnippets();
+            const existingIds = new Set(existingSnippets.map(s => s.id));
+
+            let importedCount = 0;
+            snippetsToImport.forEach(snippet => {
+                const normalized = normalizeSnippet(snippet);
+
+                // Ensure no ID conflicts
+                while (existingIds.has(normalized.id)) {
+                    normalized.id = generateSnippetId();
+                }
+
+                existingSnippets.push(normalized);
+                existingIds.add(normalized.id);
+                importedCount++;
+            });
+
+            // Save all snippets
+            if (SnippetStorage.saveSnippets(existingSnippets)) {
+                alert(`Successfully imported ${importedCount} snippet${importedCount !== 1 ? 's' : ''}`);
+                renderSnippetList();
+            }
+
+        } catch (error) {
+            console.error('Import error:', error);
+            alert('Failed to import snippets. Please check that the file is valid JSON.');
+        }
+
+        // Clear file input
+        fileInput.value = '';
+    };
+
+    reader.readAsText(file);
+}
+

src/styles.css

@@ -458,6 +458,14 @@ body {
     margin-top: 1px;
 }
 
+.snippet-size {
+    font-size: 10px;
+    color: #808080;
+    margin-left: auto;
+    margin-right: 8px;
+    flex-shrink: 0;
+}
+
 .editor-placeholder {
     background: #ffffff;
     border: 2px inset #c0c0c0;