create admin site with finance summary and graph

teachers/admin.py

@@ -1,13 +1,17 @@
+import json
+
 from django import forms
 from django.contrib import admin
 from django.contrib.auth.admin import UserAdmin
 from django.contrib.auth.forms import UserCreationForm
 from django.contrib.auth.models import User
 from django.utils.translation import ugettext_lazy as _
+from django.db.models import Avg, Sum
+from django.db.models.functions import Trunc
 
-from .models import Teacher, TeacherSalary
+from .models import Teacher, TeacherSalary, FinanceSummary
 from easyschool.utils import ExportCsvMixin
-
+from students.models import StudentFee
 
 # Change User Creation Form
 class UserCreationFormExtended(UserCreationForm):
@@ -95,3 +99,57 @@ def get_actions(self, request):
     actions = [
         'export_as_csv',
     ]
+
+@admin.register(FinanceSummary)
+class FinanceSummaryAdmin(admin.ModelAdmin):
+    change_list_template = 'admin/sale_summary_change_list.html'
+
+    def changelist_view(self, request, extra_context=None):
+        response = super().changelist_view(
+            request,
+            extra_context=extra_context,
+        )
+
+        monthly_salaries = TeacherSalary.objects.annotate(
+            month=Trunc('paid_on', 'month')).values('month').annotate(total=Sum('total_amount'))
+        monthly_fees = StudentFee.objects.annotate(
+            month=Trunc('date_submitted', 'month')).values('month').annotate(total=Sum('total_amount'))
+
+        data = {}
+        for salary in monthly_salaries:
+            month_year = "{}-{}".format(salary['month'].month, salary['month'].year)
+            data[month_year] = {
+                "salaries": salary['total'],
+                "fees": 0
+            }
+
+        for fee in monthly_fees:
+            month_year = "{}-{}".format(fee['month'].month, fee['month'].year)
+            data[month_year]['fees'] = fee['total']
+
+
+        # Prepare data to graph format
+        labels, salaries, fees = ([] for i in range(3))
+        for key, value in data.items():
+            labels.append(key)
+            salaries.append(value['salaries'])
+            fees.append(value['fees'])
+
+
+        # Scructure of graph_data is defined by Graph.js
+        graph_data = {
+            'labels': labels,
+            'datasets': [{
+                'label': "Teacher",
+                'backgroundColor': "blue",
+                'data': salaries
+            }, {
+                'label': "Student",
+                'backgroundColor': "red",
+                'data': fees
+            }]
+        }
+
+        response.context_data['data'] = data
+        response.context_data['graph_data'] = json.dumps(graph_data)
+        return response

teachers/migrations/0002_teachersalary.py

@@ -0,0 +1,25 @@
+# Generated by Django 3.1.2 on 2020-10-27 12:34
+
+import datetime
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('teachers', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='TeacherSalary',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('valid_until', models.DateField(default=datetime.date(2020, 11, 1), verbose_name='Valid Until')),
+                ('total_amount', models.PositiveIntegerField(default=0)),
+                ('paid_on', models.DateTimeField(auto_now_add=True)),
+                ('teacher', models.ForeignKey(on_delete=django.db.models.deletion.PROTECT, to='teachers.teacher')),
+            ],
+        ),
+    ]

teachers/models.py

@@ -37,8 +37,15 @@ class TeacherSalary(models.Model):
     paid_on = models.DateTimeField(auto_now_add=True)
 
     def __str__(self):
-        return f'Fee : {self.student.full_name()} {str(self.date_submitted)}'
+        return f'Salary : {self.teacher.full_name} {str(self.paid_on)}'
 
     @property
     def month_name(self):
-        return calendar.month_name[valid_until.month]
+        return calendar.month_name[valid_until.month]
+
+
+class FinanceSummary(TeacherSalary):
+    class Meta:
+        proxy = True
+        verbose_name = 'Finance Summary'
+        verbose_name_plural = 'Finance Summary'

teachers/templates/admin/sale_summary_change_list.html

@@ -0,0 +1,66 @@
+{% extends 'admin/change_list.html' %}
+{% block content_title %}
+  <h1>Finance Summary </h1>
+{% endblock %}
+
+{% load humanize %}
+{% block result_list %}
+
+<canvas id="myChart" width="400" height="400"></canvas>
+<div class=”results”>
+  <table>
+    <thead>
+      <tr>
+        <th>
+          <div class=”text”>
+            Month
+          </div>
+        </th>
+        <th>
+          <div class=”text”>
+            Salaries
+          </div>
+        </th>
+        <th>
+          <div class=”text”>
+            Fees
+          </div>
+        </th>
+      </tr>
+    </thead>
+    <tbody>
+      {% for key, value in data.items %}
+      <tr class="{% cycle 'row1' 'row2' %}">
+        <td> {{ key }} </td>
+        <td> {{ value.salaries }} </td>
+        <td> {{ value.fees }} </td>
+      </tr>
+      {% endfor %}
+    </tbody>
+  </table>
+</div>
+
+<script src="https://cdn.jsdelivr.net/npm/chart.js@2.8.0"></script>
+<script type="text/javascript">
+var ctx = document.getElementById("myChart").getContext("2d");
+var data = JSON.parse("{{ graph_data | escapejs }}")
+
+var myBarChart = new Chart(ctx, {
+  type: 'bar',
+  data: data,
+  options: {
+    responsive: false,
+    barValueSpacing: 20,
+    scales: {
+      yAxes: [{
+        ticks: {
+          min: 0,
+        }
+      }]
+    }
+  }
+});
+
+</script>
+{% endblock %}
+{% block pagination %}{% endblock %}