Add last login tracking, batch date auto-fill, and bug fixes

- Track last_login_at on User model, updated on every successful login
- Show last login date in admin panel user table
- Fix admin/garden date display (datetime strings already contain T separator)
- Fix My Garden Internal Server Error (MySQL does not support NULLS LAST syntax)
- Fix Log Batch infinite loop when user has zero varieties
- Auto-fill batch dates from today when creating a new batch, calculated
  from selected variety's week offsets (germination, greenhouse, garden)
- Update README with new features and batch date auto-fill formula table

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -9,10 +9,11 @@ Sproutly takes the guesswork out of seed starting. Enter your plant varieties on
 ## Features
 
 - **Multi-user** — each user has their own account with fully isolated data
-- **Admin panel** — manage all user accounts: view content, reset passwords, disable, or delete
+- **Admin panel** — manage all user accounts: view content, reset passwords, disable, or delete; shows each user's join date and last login
 - **Dashboard** — at-a-glance view of overdue, today's, and upcoming tasks with a full year planting timeline
 - **Seed Library** — manage plant varieties with frost-relative timing, germination days, sun/water requirements
 - **Garden Tracker** — log growing batches and track status from `planned` → `germinating` → `seedling` → `potted up` → `hardening off` → `garden` → `harvested`
+- **Smart date auto-fill** — when logging a new batch, sow date defaults to today and all subsequent dates (germination, greenhouse, transplant) are calculated automatically from the selected variety's timing
 - **Year Timeline** — visual calendar showing when each variety's stages fall across the year
 - **Ntfy Notifications** — per-user daily summary push notifications to your phone, configurable time, topic, and authentication
 - **Settings** — set your last frost date, fall frost date, location, timezone, and notification preferences
@@ -48,9 +49,10 @@ Access the app at **http://localhost:8053** — create an account to get started
 ### First Steps
 
 1. Register an account on the login screen
-2. Go to **Settings** and enter your last frost date — this anchors all planting schedule calculations
+2. Go to **Settings** and enter your last frost date — this anchors the planting timeline and dashboard calculations
 3. Optionally configure an [ntfy](https://ntfy.sh) topic for push notifications
-4. Add varieties to your **Seed Library** and start logging batches in **My Garden**
+4. Add varieties to your **Seed Library** — each variety stores its frost-relative week offsets and germination days
+5. Head to **My Garden** and log a batch — dates auto-fill based on today and the selected variety's timing
 
 ## Environment Variables
 
@@ -131,7 +133,7 @@ Key endpoints:
 
 Log in with the `ADMIN_EMAIL` / `ADMIN_PASSWORD` credentials from your `.env`. Once logged in, an **Admin** link appears in the sidebar. From there you can:
 
-- View all registered users with their variety and batch counts
+- View all registered users with join date, last login, variety count, and batch count
 - Browse any user's seed library and growing batches
 - Reset a user's password
 - Disable or re-enable an account
@@ -149,6 +151,19 @@ For private ntfy servers or access-controlled topics, the Settings page supports
 | Username & Password | ntfy server with basic auth enabled |
 | API Key / Token | ntfy account access token (generate in ntfy account settings) |
 
+## Batch Date Auto-fill
+
+When logging a new batch, Sproutly pre-fills all date fields based on the selected variety's timing offsets, using **today as the sow date**:
+
+| Field | Calculation |
+|-------|-------------|
+| Sow date | Today |
+| Germination date | Sow date + `days_to_germinate` |
+| Greenhouse / pot-up date | Sow date + (`weeks_to_start` − `weeks_to_greenhouse`) × 7 |
+| Garden transplant date | Sow date + (`weeks_to_start` + `weeks_to_garden`) × 7 |
+
+All dates remain fully editable. Fields are left blank if the variety is missing the relevant timing value.
+
 ## Status
 
 Core infrastructure is functional. UI design and feature set are evolving based on user feedback.

backend/models.py

@@ -44,6 +44,7 @@ class User(Base):
     is_admin = Column(Boolean, default=False, nullable=False)
     is_disabled = Column(Boolean, default=False, nullable=False)
     created_at = Column(DateTime, server_default=func.now())
+    last_login_at = Column(DateTime, nullable=True)
 
     varieties = relationship("Variety", back_populates="user", cascade="all, delete-orphan")
     batches = relationship("Batch", back_populates="user", cascade="all, delete-orphan")

backend/routers/admin.py

@@ -23,7 +23,7 @@ def list_users(db: Session = Depends(get_db), _: User = Depends(get_admin_user))
     return [
         AdminUserOut(
             id=u.id, email=u.email, is_admin=u.is_admin, is_disabled=u.is_disabled,
-            created_at=u.created_at, **_user_stats(db, u.id)
+            created_at=u.created_at, last_login_at=u.last_login_at, **_user_stats(db, u.id)
         )
         for u in users
     ]

backend/routers/auth.py

@@ -1,3 +1,5 @@
+from datetime import datetime, timezone
+
 from fastapi import APIRouter, Depends, HTTPException
 from sqlalchemy.orm import Session
 
@@ -48,6 +50,8 @@ def login(data: UserLogin, db: Session = Depends(get_db)):
         raise HTTPException(status_code=401, detail="Invalid email or password")
     if user.is_disabled:
         raise HTTPException(status_code=403, detail="Account has been disabled")
+    user.last_login_at = datetime.now(timezone.utc)
+    db.commit()
     return {"access_token": create_access_token(user.id), "token_type": "bearer"}
 
 

backend/routers/batches.py

@@ -1,4 +1,5 @@
 from fastapi import APIRouter, Depends, HTTPException
+from sqlalchemy import case
 from sqlalchemy.orm import Session, joinedload
 from typing import List
 
@@ -16,7 +17,7 @@ def list_batches(db: Session = Depends(get_db), current_user: User = Depends(get
         db.query(Batch)
         .options(joinedload(Batch.variety))
         .filter(Batch.user_id == current_user.id)
-        .order_by(Batch.sow_date.desc().nullslast(), Batch.created_at.desc())
+        .order_by(case((Batch.sow_date.is_(None), 1), else_=0), Batch.sow_date.desc(), Batch.created_at.desc())
         .all()
     )
 

backend/schemas.py

@@ -33,6 +33,7 @@ class AdminUserOut(BaseModel):
     is_admin: bool
     is_disabled: bool
     created_at: Optional[datetime]
+    last_login_at: Optional[datetime]
     variety_count: int
     batch_count: int
 

mysql/init.sql

@@ -6,7 +6,8 @@ CREATE TABLE IF NOT EXISTS users (
     hashed_password VARCHAR(255) NOT NULL,
     is_admin BOOLEAN NOT NULL DEFAULT FALSE,
     is_disabled BOOLEAN NOT NULL DEFAULT FALSE,
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    last_login_at TIMESTAMP NULL DEFAULT NULL
 );
 
 CREATE TABLE IF NOT EXISTS varieties (

nginx/html/js/app.js

@@ -133,6 +133,7 @@ const api = {
 // ===== State =====
 let state = {
   varieties: [],
+  varietiesLoaded: false,
   batches: [],
   settings: {},
 };
@@ -150,7 +151,7 @@ function toast(msg, isError = false) {
 // ===== Utility =====
 function fmt(dateStr) {
   if (!dateStr) return '—';
-  const d = new Date(dateStr + 'T00:00:00');
+  const d = new Date(dateStr.includes('T') ? dateStr : dateStr + 'T00:00:00');
   return d.toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' });
 }
 
@@ -408,6 +409,7 @@ function batchCard(b, compact = false) {
 async function loadVarieties() {
   try {
     state.varieties = await api.get('/varieties/');
+    state.varietiesLoaded = true;
     renderVarieties();
   } catch (e) {
     document.getElementById('varieties-container').innerHTML = `<div class="empty-state">Error: ${esc(e.message)}</div>`;
@@ -752,6 +754,7 @@ async function deleteVariety(id) {
 
 // ===== Batch Modals =====
 function batchFormHtml(b = {}) {
+  const isNew = !b.id;
   const varOpts = state.varieties.map(v =>
     `<option value="${v.id}" ${b.variety_id===v.id?'selected':''}>${v.name}${v.variety_name?' ('+v.variety_name+')':''}</option>`
   ).join('');
@@ -760,7 +763,7 @@ function batchFormHtml(b = {}) {
     <div class="form-row">
       <div class="form-group">
         <label class="form-label">Plant Variety *</label>
-        <select id="bf-variety" class="form-select">${varOpts}</select>
+        <select id="bf-variety" class="form-select" ${isNew ? 'onchange="App.autofillBatchDates(this.value)"' : ''}>${varOpts}</select>
       </div>
       <div class="form-group">
         <label class="form-label">Batch Label</label>
@@ -821,10 +824,43 @@ function collectBatchForm() {
   };
 }
 
-function showAddBatchModal() {
+function autofillBatchDates(varietyId) {
+  const v = state.varieties.find(x => x.id === parseInt(varietyId));
+  if (!v) return;
+
+  function addDays(dateStr, days) {
+    const d = new Date(dateStr + 'T00:00:00');
+    d.setDate(d.getDate() + days);
+    return d.toISOString().slice(0, 10);
+  }
+
+  const today = new Date().toISOString().slice(0, 10);
+
+  // Sow = today; other dates calculated as offsets from sow using variety's relative week gaps
+  const sowDate = today;
+  const germDate = v.days_to_germinate
+    ? addDays(sowDate, v.days_to_germinate)
+    : null;
+  const ghDate = v.weeks_to_start != null && v.weeks_to_greenhouse != null
+    ? addDays(sowDate, (v.weeks_to_start - v.weeks_to_greenhouse) * 7)
+    : null;
+  const gardenDate = v.weeks_to_start != null && v.weeks_to_garden != null
+    ? addDays(sowDate, (v.weeks_to_start + v.weeks_to_garden) * 7)
+    : null;
+
+  document.getElementById('bf-sow').value    = sowDate;
+  if (germDate)   document.getElementById('bf-germ').value   = germDate;
+  if (ghDate)     document.getElementById('bf-gh').value     = ghDate;
+  if (gardenDate) document.getElementById('bf-garden').value = gardenDate;
+}
+
+async function showAddBatchModal() {
+  if (!state.varietiesLoaded) {
+    state.varieties = await api.get('/varieties/');
+    state.varietiesLoaded = true;
+  }
   if (!state.varieties.length) {
-    // Load varieties first if not loaded
+    openModal('Log a Batch', '<p style="color:var(--text-muted)">You need to add at least one seed variety before logging a batch. Go to <strong>Seed Library</strong> to add varieties.</p><div class="btn-row" style="margin-top:1rem"><button class="btn btn-secondary" onclick="App.closeModal()">Close</button></div>');
-    api.get('/varieties/').then(v => { state.varieties = v; showAddBatchModal(); });
     return;
   }
   openModal('Log a Batch', `
@@ -834,6 +870,9 @@ function showAddBatchModal() {
       <button class="btn btn-secondary" onclick="App.closeModal()">Cancel</button>
     </div>
   `);
+  // Auto-fill dates for the default selected variety
+  const defaultVarietyId = document.getElementById('bf-variety')?.value;
+  if (defaultVarietyId) autofillBatchDates(defaultVarietyId);
 }
 
 async function submitAddBatch() {
@@ -851,7 +890,7 @@ async function submitAddBatch() {
 
 async function showEditBatchModal(id) {
   try {
-    if (!state.varieties.length) state.varieties = await api.get('/varieties/');
+    if (!state.varietiesLoaded) { state.varieties = await api.get('/varieties/'); state.varietiesLoaded = true; }
     const b = state.batches.find(x => x.id === id) || await api.get(`/batches/${id}`);
     openModal('Edit Batch', `
       ${batchFormHtml(b)}
@@ -909,6 +948,7 @@ async function loadAdmin() {
             <tr>
               <th>Email</th>
               <th>Joined</th>
+              <th>Last Login</th>
               <th>Varieties</th>
               <th>Batches</th>
               <th>Status</th>
@@ -920,6 +960,7 @@ async function loadAdmin() {
               <tr id="admin-row-${u.id}">
                 <td><span class="admin-email">${esc(u.email)}</span>${u.is_admin ? ' <span class="badge-admin">admin</span>' : ''}</td>
                 <td class="admin-date">${fmt(u.created_at)}</td>
+                <td class="admin-date">${u.last_login_at ? fmt(u.last_login_at) : '<span class="text-muted">Never</span>'}</td>
                 <td class="admin-num">${u.variety_count}</td>
                 <td class="admin-num">${u.batch_count}</td>
                 <td><span class="status-pill ${u.is_disabled ? 'disabled' : 'active'}">${u.is_disabled ? 'Disabled' : 'Active'}</span></td>
@@ -1091,7 +1132,7 @@ async function init() {
 // ===== Public API =====
 window.App = {
   showAddVarietyModal, showEditVarietyModal, submitAddVariety, submitEditVariety, deleteVariety,
-  showAddBatchModal, showEditBatchModal, submitAddBatch, submitEditBatch, deleteBatch,
+  showAddBatchModal, showEditBatchModal, submitAddBatch, submitEditBatch, deleteBatch, autofillBatchDates,
   filterVarieties, filterBatches,
   saveSettings, toggleNtfyAuth, sendTestNotification, sendDailySummary,
   adminViewUser, adminResetPassword, adminSubmitReset, adminToggleDisable, adminDeleteUser, adminSwitchTab,