Created graphs in the dashboard with the evolution by account

expenses_manager/expenses/models.py

@@ -1,8 +1,10 @@
+from datetime import date
 from decimal import Decimal
 from django.db import models
 from django.conf import settings
 from django.db.models import Sum
 from django.db.models.fields import related
+from django.db.models.functions import ExtractMonth
 
 class Category(models.Model):
     name = models.CharField(max_length=100)
@@ -58,6 +60,41 @@ class Account(models.Model):
         )
         return self.initial_balance + income_total - expenses_total
     
+    def monthly_balance(self, year=None):
+        year = year or date.today().year
+        
+        incomes = (
+            self.incomes
+            .filter(date__year=year)
+            .annotate(month=ExtractMonth('date'))
+            .values('month')
+            .annotate(total=Sum('amount'))
+        )
+        
+        expenses = (
+            self.expenses
+            .filter(date__year=year)
+            .annotate(month=ExtractMonth('date'))
+            .values('month')
+            .annotate(total=Sum('amount'))
+        )
+        
+        income_map = {i['month']: i['total'] for i in incomes}
+        expenses_map = {e['month']: e['total'] for e in expenses}
+        
+        balance = self.initial_balance
+        data = []
+        
+        for month in range(1, 13):
+            balance += income_map.get(month, 0)
+            balance -= expenses_map.get(month, 0)
+            
+            data.append({
+                'month': month,
+                'balance': float(balance),
+            })
+        return data
+    
     def __str__(self):
         return self.name
 

expenses_manager/expenses/templates/expenses/dashboard.html

@@ -225,7 +225,7 @@
     <!-- Chart -->
     <!-- ========================= -->
     
-    <h3>Distribución mensual (año completo)</h3>
+    <h2>Distribución mensual (año completo)</h2>
 
     <canvas id="expensesChart"></canvas>
 
@@ -249,5 +249,44 @@
     
     <hr>
 
+    <h2>Evolución anual por cuenta ({{ selected_year }})</h2>
+
+    <div class="dashboard-grid">
+        {% for acc in accounts_charts %}
+            <div class="card card-chart">
+                <h3>{{ acc.name }}</h3>
+                <p><strong>Saldo actual:</strong> {{ acc.current_balance|floatformat:2 }} €</p>
+
+                <canvas id="accountChart{{ acc.id }}"></canvas>
+            </div>
+        {% endfor %}
+    </div>
+
+    <script>
+        const monthLabels = {{ chart_labels|safe }};
+
+        {% for acc in accounts_charts %}
+            new Chart(
+                document.getElementById('accountChart{{ acc.id }}'),
+                {
+                    type: 'line',
+                    data: {
+                        labels: monthLabels,
+                        datasets: [{
+                            label: 'Saldo',
+                            data: {{ acc.data|safe }},
+                            fill: true,
+                            tension: 0.3,
+                        }]
+                    },
+                    options: {
+                        responsive: true,
+                        maintainAspectRatio: false
+                    }
+                }
+            );
+        {% endfor %}
+    </script>
+
 
 {% endblock %}

expenses_manager/expenses/views.py

@@ -482,6 +482,21 @@ def dashboard(request):
                 'difference_abs': abs(difference),
             })
     
+    # ------------------
+    # Previous expenses by category
+    # ------------------
+    accounts_charts = []
+    for account in accounts:
+        monthly_data = account.monthly_balance(selected_year)
+        m_balance = [row['balance'] for row in monthly_data]
+        
+        accounts_charts.append({
+            'id': account.id,
+            'name': account.name,
+            'data': m_balance,
+            'current_balance': account.current_balance(),
+        })
+    
     # Send the data to the dashboard
     return render(request, 'expenses/dashboard.html', {
         'by_category': by_category, 
@@ -506,6 +521,7 @@ def dashboard(request):
         'selected_account': account_id,
         'selected_account_obj': selected_account_obj,
         'kpi_balance': kpi_balance,
+        'accounts_charts': accounts_charts,
     })