feat: add backend support for hierarchical subtasks

- Create migration 005 to add parent_id and level columns to todos tables
- Fix migration 003 to use correct table name (note_todos instead of todos)
- Update POST /api/notes/:id/todos to accept parent_id parameter
- Update POST /api/todos to accept parent_id for global todos
- Add automatic level calculation based on parent depth
- Update GET endpoints to return parent_id and level fields
- Add validation to ensure parent todo exists before creating subtask
- Support CASCADE DELETE for subtasks when parent is deleted

routes/notes.routes.js

@@ -61,7 +61,7 @@ router.get('/', async (req, res) => {
     // Charger les todos, images, fichiers et tags pour chaque note
     for (const note of notes) {
       const todos = await getAll(`
-        SELECT id, text, completed, position
+        SELECT id, text, completed, position, parent_id, level
         FROM note_todos
         WHERE note_id = $1
         ORDER BY position ASC, id ASC
@@ -391,10 +391,13 @@ router.delete('/:id/image', async (req, res) => {
 
 /**
  * POST /api/notes/:id/todos
- * Ajouter un todo à une note
+ * Ajouter un todo à une note (supports subtasks via parent_id)
  */
 router.post('/:id/todos',
-  [body('text').trim().notEmpty().withMessage('Le texte est requis')],
+  [
+    body('text').trim().notEmpty().withMessage('Le texte est requis'),
+    body('parent_id').optional().isInt()
+  ],
   async (req, res) => {
     try {
       const errors = validationResult(req);
@@ -408,17 +411,27 @@ router.post('/:id/todos',
         return res.status(404).json({ error: 'Note non trouvée' });
       }
 
-      const { text } = req.body;
+      const { text, parent_id } = req.body;
+      let level = 0;
 
-      logger.info(`[CREATE TODO] Ajout todo à note ${req.params.id}: "${text}"`);
+      // Si c'est un subtask, vérifier que le parent existe et calculer le niveau
+      if (parent_id) {
+        const parent = await getOne('SELECT id, level FROM note_todos WHERE id = $1 AND note_id = $2', [parent_id, req.params.id]);
+        if (!parent) {
+          return res.status(404).json({ error: 'Todo parent non trouvé' });
+        }
+        level = (parent.level || 0) + 1;
+      }
+
+      logger.info(`[CREATE TODO] Ajout todo à note ${req.params.id}: "${text}"${parent_id ? ` (subtask of ${parent_id})` : ''}`);
 
       const result = await runQuery(`
-        INSERT INTO note_todos (note_id, text, position)
-        VALUES ($1, $2, (SELECT COALESCE(MAX(position), 0) + 1 FROM note_todos WHERE note_id = $3))
+        INSERT INTO note_todos (note_id, text, parent_id, level, position)
+        VALUES ($1, $2, $3, $4, (SELECT COALESCE(MAX(position), 0) + 1 FROM note_todos WHERE note_id = $5 AND COALESCE(parent_id, 0) = COALESCE($6, 0)))
         RETURNING *
-      `, [req.params.id, text, req.params.id]);
+      `, [req.params.id, text, parent_id || null, level, req.params.id, parent_id || null]);
 
-      logger.info(`[CREATE TODO] Todo créé - ID: ${result.id}, note_id: ${req.params.id}`);
+      logger.info(`[CREATE TODO] Todo créé - ID: ${result.id}, note_id: ${req.params.id}, level: ${level}`);
 
       await runQuery('UPDATE notes SET updated_at = CURRENT_TIMESTAMP WHERE id = $1', [req.params.id]);
 
@@ -426,7 +439,9 @@ router.post('/:id/todos',
         id: result.id,
         text,
         completed: false,
-        position: 0
+        position: result.position || 0,
+        parent_id: parent_id || null,
+        level: level
       });
     } catch (error) {
       logger.error('Erreur lors de l\'ajout du todo:', error);

routes/todos.routes.js

@@ -19,7 +19,7 @@ router.get('/', async (req, res) => {
     // Essayer d'abord avec le champ priority (nouvelle version)
     try {
       const todos = await getAll(`
-        SELECT id, text, completed, priority, in_progress, created_at
+        SELECT id, text, completed, priority, in_progress, parent_id, level, created_at
         FROM global_todos
         WHERE user_id = $1
         ORDER BY priority DESC, created_at DESC
@@ -38,7 +38,7 @@ router.get('/', async (req, res) => {
       `, [req.user.id]);
 
       // Ajouter priority=false et in_progress=false par défaut pour compatibilité frontend
-      const todosWithPriority = todos.map(t => ({ ...t, priority: false, in_progress: false }));
+      const todosWithPriority = todos.map(t => ({ ...t, priority: false, in_progress: false, parent_id: null, level: 0 }));
       res.json(todosWithPriority);
     }
   } catch (error) {
@@ -49,10 +49,13 @@ router.get('/', async (req, res) => {
 
 /**
  * POST /api/todos
- * Créer un nouveau todo global
+ * Créer un nouveau todo global (supports subtasks via parent_id)
  */
 router.post('/',
-  [body('text').trim().notEmpty().withMessage('Le texte est requis')],
+  [
+    body('text').trim().notEmpty().withMessage('Le texte est requis'),
+    body('parent_id').optional().isInt()
+  ],
   async (req, res) => {
     try {
       const errors = validationResult(req);
@@ -60,17 +63,27 @@ router.post('/',
         return res.status(400).json({ error: 'Données invalides', details: errors.array() });
       }
 
-      const { text } = req.body;
+      const { text, parent_id } = req.body;
+      let level = 0;
 
-      logger.info(`[CREATE GLOBAL TODO] Début création - user_id: ${req.user.id}, text: "${text}"`);
+      // Si c'est un subtask, vérifier que le parent existe et calculer le niveau
+      if (parent_id) {
+        const parent = await getOne('SELECT id, level FROM global_todos WHERE id = $1 AND user_id = $2', [parent_id, req.user.id]);
+        if (!parent) {
+          return res.status(404).json({ error: 'Todo parent non trouvé' });
+        }
+        level = (parent.level || 0) + 1;
+      }
+
+      logger.info(`[CREATE GLOBAL TODO] Début création - user_id: ${req.user.id}, text: "${text}"${parent_id ? ` (subtask of ${parent_id})` : ''}`);
 
       const result = await runQuery(`
-        INSERT INTO global_todos (user_id, text)
-        VALUES ($1, $2)
+        INSERT INTO global_todos (user_id, text, parent_id, level)
+        VALUES ($1, $2, $3, $4)
         RETURNING *
-      `, [req.user.id, text]);
+      `, [req.user.id, text, parent_id || null, level]);
 
-      logger.info(`[CREATE GLOBAL TODO] Todo global créé avec succès - ID: ${result.id}, user: ${req.user.username}`);
+      logger.info(`[CREATE GLOBAL TODO] Todo global créé avec succès - ID: ${result.id}, user: ${req.user.username}, level: ${level}`);
 
       res.status(201).json({
         id: result.id,
@@ -78,6 +91,8 @@ router.post('/',
         completed: false,
         priority: false,
         in_progress: false,
+        parent_id: parent_id || null,
+        level: level,
         created_at: new Date().toISOString()
       });
     } catch (error) {