Add worker name pills on history page + per-worker payroll chart

Work History:
- Worker names now display as rounded pill badges instead of comma-
  separated text, making them easier to scan (both server-rendered
  list view and JS calendar detail view)

Payroll Dashboard:
- New "By Worker" toggle on the Monthly Payroll chart card
- Dropdown to select an active worker with payment history
- Stacked bar chart shows monthly breakdown: base pay, overtime,
  bonuses (positive), deductions, loan repayments, advances (negative)
- All data pre-computed server-side with 2 aggregate queries and
  embedded as JSON — switching workers is instant, no AJAX needed
- Only workers with actual payment history appear in the dropdown
- Legend items auto-hide when a component has no data for that worker

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

core/templates/core/payroll_dashboard.html

@@ -114,11 +114,44 @@
         <div class="col-lg-6 mb-4 mb-lg-0">
             <div class="card shadow-sm border-0 h-100">
                 <div class="card-header py-3 bg-white">
-                    <h6 class="m-0 font-weight-bold" style="color: #0f172a;">Monthly Payroll Totals</h6>
+                    {# === CHART TOGGLE: Overall vs By Worker === #}
+                    {# Two small buttons to switch between the total line chart #}
+                    {# and a per-worker stacked bar chart breakdown. #}
+                    <div class="d-flex justify-content-between align-items-center">
+                        <h6 class="m-0 font-weight-bold" style="color: var(--primary-dark);">Monthly Payroll</h6>
+                        <div class="btn-group btn-group-sm" role="group" aria-label="Chart view toggle">
+                            <button type="button" class="btn btn-sm btn-accent" id="btnOverall">
+                                <i class="fas fa-chart-line fa-sm me-1"></i>Overall
+                            </button>
+                            <button type="button" class="btn btn-sm btn-outline-secondary" id="btnByWorker">
+                                <i class="fas fa-user fa-sm me-1"></i>By Worker
+                            </button>
+                        </div>
+                    </div>
                 </div>
                 <div class="card-body">
+                    {# --- Overall view (default): the existing line chart --- #}
+                    <div id="monthlyOverallView">
                         <canvas id="monthlyChart" height="200"></canvas>
                     </div>
+
+                    {# --- By Worker view (hidden): worker dropdown + stacked bar --- #}
+                    <div id="monthlyWorkerView" style="display: none;">
+                        <div class="mb-3">
+                            <select id="workerChartSelect" class="form-select form-select-sm">
+                                <option value="">-- Select Worker --</option>
+                            </select>
+                        </div>
+                        <div id="workerChartContainer">
+                            <canvas id="workerChart" height="200"></canvas>
+                        </div>
+                        {# Placeholder shown when no worker is selected #}
+                        <div id="workerChartPlaceholder" class="text-center py-4 text-muted">
+                            <i class="fas fa-chart-bar fa-2x mb-2 d-block opacity-50"></i>
+                            <span>Select a worker to see their payment breakdown</span>
+                        </div>
+                    </div>
+                </div>
             </div>
         </div>
         <div class="col-lg-6">
@@ -641,6 +674,7 @@
 {{ chart_labels_json|json_script:"chartLabelsJson" }}
 {{ chart_totals_json|json_script:"chartTotalsJson" }}
 {{ project_chart_json|json_script:"projectChartJson" }}
+{{ worker_chart_json|json_script:"workerChartJson" }}
 
 <script>
 document.addEventListener('DOMContentLoaded', function() {
@@ -652,6 +686,7 @@ document.addEventListener('DOMContentLoaded', function() {
     const chartLabels = JSON.parse(document.getElementById('chartLabelsJson').textContent);
     const chartTotals = JSON.parse(document.getElementById('chartTotalsJson').textContent);
     const projectChartData = JSON.parse(document.getElementById('projectChartJson').textContent);
+    const workerChartData = JSON.parse(document.getElementById('workerChartJson').textContent);
 
     // === HELPER: Format currency ===
     function fmt(val) {
@@ -768,6 +803,204 @@ document.addEventListener('DOMContentLoaded', function() {
         console.warn('Project chart failed to render:', e);
     }
 
+    // =================================================================
+    // CHART TOGGLE — Switch between "Overall" line chart and
+    // "By Worker" stacked bar chart in the Monthly Payroll card.
+    // =================================================================
+
+    var btnOverall = document.getElementById('btnOverall');
+    var btnByWorker = document.getElementById('btnByWorker');
+    var monthlyOverallView = document.getElementById('monthlyOverallView');
+    var monthlyWorkerView = document.getElementById('monthlyWorkerView');
+
+    if (btnOverall && btnByWorker) {
+        // Switch to "Overall" — show the line chart, hide the worker view
+        btnOverall.addEventListener('click', function() {
+            monthlyOverallView.style.display = '';
+            monthlyWorkerView.style.display = 'none';
+            btnOverall.className = 'btn btn-sm btn-accent';
+            btnByWorker.className = 'btn btn-sm btn-outline-secondary';
+        });
+
+        // Switch to "By Worker" — hide line chart, show worker dropdown + bar chart
+        btnByWorker.addEventListener('click', function() {
+            monthlyOverallView.style.display = 'none';
+            monthlyWorkerView.style.display = '';
+            btnByWorker.className = 'btn btn-sm btn-accent';
+            btnOverall.className = 'btn btn-sm btn-outline-secondary';
+        });
+    }
+
+    // =================================================================
+    // CHART.JS — Per-Worker Breakdown (Stacked Bar Chart)
+    // Shows base pay, overtime, bonuses as positive bars going up,
+    // and deductions, loan repayments, advance payments going down.
+    // =================================================================
+
+    var workerChartSelect = document.getElementById('workerChartSelect');
+    var workerChartContainer = document.getElementById('workerChartContainer');
+    var workerChartPlaceholder = document.getElementById('workerChartPlaceholder');
+    var workerChartInstance = null;  // Track so we can destroy before re-creating
+
+    if (workerChartSelect) {
+        // Hide the chart canvas initially (show placeholder instead)
+        if (workerChartContainer) workerChartContainer.style.display = 'none';
+
+        // Populate the worker dropdown from pre-computed data
+        // (already sorted alphabetically by the server)
+        Object.keys(workerChartData).forEach(function(workerId) {
+            var opt = document.createElement('option');
+            opt.value = workerId;
+            opt.textContent = workerChartData[workerId].name;
+            workerChartSelect.appendChild(opt);
+        });
+
+        // When a worker is selected, render their stacked bar chart
+        workerChartSelect.addEventListener('change', function() {
+            var workerId = this.value;
+            var canvasEl = document.getElementById('workerChart');
+
+            // No worker selected — show placeholder, hide chart
+            if (!workerId) {
+                if (workerChartPlaceholder) workerChartPlaceholder.style.display = '';
+                if (workerChartContainer) workerChartContainer.style.display = 'none';
+                if (workerChartInstance) {
+                    workerChartInstance.destroy();
+                    workerChartInstance = null;
+                }
+                return;
+            }
+
+            // Worker selected — hide placeholder, show chart canvas
+            if (workerChartPlaceholder) workerChartPlaceholder.style.display = 'none';
+            if (workerChartContainer) workerChartContainer.style.display = '';
+
+            // Destroy the previous chart before creating a new one
+            if (workerChartInstance) {
+                workerChartInstance.destroy();
+                workerChartInstance = null;
+            }
+
+            var data = workerChartData[workerId];
+            if (!data) return;
+
+            // Pull out monthly values into separate arrays (one per component)
+            var basePay = data.months.map(function(m) { return m.base; });
+            var overtime = data.months.map(function(m) { return m.overtime; });
+            var bonus = data.months.map(function(m) { return m.bonus; });
+            var newLoan = data.months.map(function(m) { return m.new_loan; });
+            // Deductive items shown as negative values (bars go below zero)
+            var deduction = data.months.map(function(m) { return -m.deduction; });
+            var loanRepayment = data.months.map(function(m) { return -m.loan_repayment; });
+            var advance = data.months.map(function(m) { return -m.advance; });
+
+            // Build datasets — only include types that have non-zero data
+            // so the legend doesn't show irrelevant items
+            var datasets = [];
+
+            if (basePay.some(function(v) { return v > 0; })) {
+                datasets.push({
+                    label: 'Base Pay',
+                    data: basePay,
+                    backgroundColor: '#10b981',
+                    stack: 'positive',
+                });
+            }
+            if (overtime.some(function(v) { return v > 0; })) {
+                datasets.push({
+                    label: 'Overtime',
+                    data: overtime,
+                    backgroundColor: '#f59e0b',
+                    stack: 'positive',
+                });
+            }
+            if (bonus.some(function(v) { return v > 0; })) {
+                datasets.push({
+                    label: 'Bonus',
+                    data: bonus,
+                    backgroundColor: '#3b82f6',
+                    stack: 'positive',
+                });
+            }
+            if (newLoan.some(function(v) { return v > 0; })) {
+                datasets.push({
+                    label: 'New Loan',
+                    data: newLoan,
+                    backgroundColor: '#8b5cf6',
+                    stack: 'positive',
+                });
+            }
+            if (deduction.some(function(v) { return v < 0; })) {
+                datasets.push({
+                    label: 'Deductions',
+                    data: deduction,
+                    backgroundColor: '#ef4444',
+                    stack: 'negative',
+                });
+            }
+            if (loanRepayment.some(function(v) { return v < 0; })) {
+                datasets.push({
+                    label: 'Loan Repayments',
+                    data: loanRepayment,
+                    backgroundColor: '#991b1b',
+                    stack: 'negative',
+                });
+            }
+            if (advance.some(function(v) { return v < 0; })) {
+                datasets.push({
+                    label: 'Advance Payments',
+                    data: advance,
+                    backgroundColor: '#7c3aed',
+                    stack: 'negative',
+                });
+            }
+
+            try {
+                workerChartInstance = new Chart(canvasEl, {
+                    type: 'bar',
+                    data: {
+                        labels: chartLabels,
+                        datasets: datasets,
+                    },
+                    options: {
+                        responsive: true,
+                        maintainAspectRatio: false,
+                        plugins: {
+                            tooltip: {
+                                callbacks: {
+                                    label: function(context) {
+                                        var val = context.parsed.y;
+                                        var prefix = val >= 0 ? '+' : '';
+                                        return context.dataset.label + ': ' + prefix + fmt(val);
+                                    }
+                                }
+                            },
+                            legend: {
+                                position: 'bottom',
+                                labels: {
+                                    boxWidth: 12,
+                                    padding: 8,
+                                    font: { size: 11 }
+                                }
+                            }
+                        },
+                        scales: {
+                            x: { stacked: true },
+                            y: {
+                                stacked: true,
+                                ticks: {
+                                    callback: function(val) { return 'R ' + val.toLocaleString(); }
+                                }
+                            }
+                        }
+                    }
+                });
+            } catch (e) {
+                console.warn('Worker chart failed to render:', e);
+            }
+        });
+    }
+
     // =================================================================
     // OVERTIME MODAL — Build table rows using DOM methods (no innerHTML)
     // =================================================================

core/templates/core/work_history.html

@@ -404,9 +404,14 @@
                 tdProj.appendChild(strong);
                 tr.appendChild(tdProj);
 
-                // Workers
+                // Workers — each name gets a small pill badge for readability
                 var tdWork = document.createElement('td');
-                tdWork.textContent = entry.workers.join(', ');
+                entry.workers.forEach(function(name) {
+                    var pill = document.createElement('span');
+                    pill.className = 'badge rounded-pill bg-light text-dark fw-normal border me-1 mb-1';
+                    pill.textContent = name;
+                    tdWork.appendChild(pill);
+                });
                 tr.appendChild(tdWork);
 
                 // Supervisor
@@ -603,12 +608,12 @@
                             <td class="align-middle">
                                 {# When filtering by a specific worker, show only that worker. Otherwise show all workers. #}
                                 {% if filtered_worker_obj %}
-                                    {{ filtered_worker_obj.name }}
+                                    <span class="badge rounded-pill bg-light text-dark fw-normal border">{{ filtered_worker_obj.name }}</span>
                                 {% else %}
                                     {% for w in log.workers.all %}
-                                        {{ w.name }}{% if not forloop.last %}, {% endif %}
+                                        <span class="badge rounded-pill bg-light text-dark fw-normal border me-1 mb-1">{{ w.name }}</span>
                                     {% endfor %}
-                                    <span class="badge bg-secondary ms-1">{{ log.workers.count }}</span>
+                                    <span class="badge rounded-pill bg-secondary">{{ log.workers.count }}</span>
                                 {% endif %}
                             </td>
                             <td class="align-middle">

core/views.py

@@ -900,6 +900,98 @@ def payroll_dashboard(request):
                 'data': monthly_data,
             })
 
+    # === CHART DATA: Per-Worker Monthly Breakdown ===
+    # Pre-compute payment breakdown for each active worker over the last 6 months.
+    # This powers the "By Worker" toggle on the Monthly Payroll Totals chart.
+    # Only ~14 workers x 6 months = tiny dataset, so we embed it all as JSON
+    # and switching between workers is instant (no server round-trips).
+
+    # Starting date for the 6-month window (first day of the oldest chart month)
+    six_months_ago_date = datetime.date(chart_months[0][0], chart_months[0][1], 1)
+
+    # Query 1: Total amount paid per worker per month.
+    # Uses database-level grouping — one query for ALL workers at once.
+    worker_monthly_paid_qs = PayrollRecord.objects.filter(
+        worker__active=True,
+        date__gte=six_months_ago_date,
+    ).values(
+        'worker_id',
+        month=TruncMonth('date'),
+    ).annotate(total=Sum('amount_paid'))
+
+    # Build a fast lookup dict: {(worker_id, year, month): total_paid}
+    worker_paid_lookup = {}
+    for row in worker_monthly_paid_qs:
+        key = (row['worker_id'], row['month'].year, row['month'].month)
+        worker_paid_lookup[key] = float(row['total'])
+
+    # Query 2: Paid adjustment totals grouped by worker, type, and month.
+    # "Paid" means the adjustment has a linked PayrollRecord.
+    # We group by the PayrollRecord's date (not the adjustment date)
+    # so it lines up with when the payment actually happened.
+    worker_monthly_adj_qs = PayrollAdjustment.objects.filter(
+        payroll_record__isnull=False,
+        worker__active=True,
+        payroll_record__date__gte=six_months_ago_date,
+    ).values(
+        'worker_id',
+        'type',
+        month=TruncMonth('payroll_record__date'),
+    ).annotate(total=Sum('amount'))
+
+    # Build a fast lookup dict: {(worker_id, year, month, type): total_amount}
+    worker_adj_lookup = {}
+    for row in worker_monthly_adj_qs:
+        key = (row['worker_id'], row['month'].year, row['month'].month, row['type'])
+        worker_adj_lookup[key] = float(row['total'])
+
+    # Build the final data structure for JavaScript.
+    # For each worker with payment history, create 6 monthly entries showing
+    # how their pay breaks down into base pay, overtime, bonuses, etc.
+    #
+    # Base pay is reverse-engineered from the net total:
+    #   amount_paid = base + overtime + bonus + new_loan - deduction - loan_repayment - advance
+    #   So: base = amount_paid - overtime - bonus - new_loan + deduction + loan_repayment + advance
+    worker_chart_data = {}
+    for worker in Worker.objects.filter(active=True).order_by('name'):
+        months_data = []
+        has_any_data = False
+
+        for y, m in chart_months:
+            total_paid = worker_paid_lookup.get((worker.id, y, m), 0)
+            overtime = worker_adj_lookup.get((worker.id, y, m, 'Overtime'), 0)
+            bonus = worker_adj_lookup.get((worker.id, y, m, 'Bonus'), 0)
+            new_loan = worker_adj_lookup.get((worker.id, y, m, 'New Loan'), 0)
+            deduction = worker_adj_lookup.get((worker.id, y, m, 'Deduction'), 0)
+            loan_repayment = worker_adj_lookup.get((worker.id, y, m, 'Loan Repayment'), 0)
+            advance = worker_adj_lookup.get((worker.id, y, m, 'Advance Payment'), 0)
+
+            # Reverse-engineer base pay from the net total
+            base_pay = total_paid - overtime - bonus - new_loan + deduction + loan_repayment + advance
+            # Clamp to zero — a negative base can happen if adjustments exceed day-rate earnings
+            base_pay = max(base_pay, 0)
+
+            if total_paid > 0:
+                has_any_data = True
+
+            months_data.append({
+                'base': round(base_pay, 2),
+                'overtime': round(overtime, 2),
+                'bonus': round(bonus, 2),
+                'new_loan': round(new_loan, 2),
+                'deduction': round(deduction, 2),
+                'loan_repayment': round(loan_repayment, 2),
+                'advance': round(advance, 2),
+                'total': round(total_paid, 2),
+            })
+
+        # Only include workers who actually received at least one payment
+        if has_any_data:
+            worker_chart_data[str(worker.id)] = {
+                'name': worker.name,
+                'months': months_data,
+            }
+
     # --- Loans ---
     loan_filter = request.GET.get('loan_status', 'active')
     if loan_filter == 'history':
@@ -948,6 +1040,7 @@ def payroll_dashboard(request):
         'chart_labels_json': chart_labels,
         'chart_totals_json': chart_totals,
         'project_chart_json': project_chart_data,
+        'worker_chart_json': worker_chart_data,
         'overtime_data_json': all_ot_data,
         'today': today,  # For pre-filling date fields in modals
         'active_loans_count': active_loans_count,