workx_backend/expense/models.py

from django.db import models
from employee.models import Employee


class CompanyBankAccount(models.Model):
    name = models.CharField(max_length=50)
    logo = models.ImageField(upload_to='banks', null=True, blank=True)

    def __str__(self):
        return self.name


class Category(models.Model):
    name = models.CharField(max_length=30)

    def __str__(self):
        return self.name


class Expense(models.Model):
    PAYMENT_MODE = (
        ("REIMBURSE", "REIMBURSE"),
        ("PERK", "PERK")
    )
    title = models.CharField(max_length=50)
    category = models.ForeignKey(Category, on_delete=models.CASCADE)
    expense_id = models.CharField(max_length=15)
    date_of_creation = models.DateField()
    team_member = models.ForeignKey(Employee, on_delete=models.CASCADE)
    company_bank_account = models.ForeignKey(CompanyBankAccount, on_delete=models.CASCADE)
    repayment_mode = models.CharField(max_length=10, choices=PAYMENT_MODE, default="REIMBURSE")

    @property
    def expense_total(self):
        items = self.items.all()
        total = 0
        for item in items:
            total += item.item_total
        return total


class Item(models.Model):
    name = models.CharField(max_length=100)
    rate = models.DecimalField(max_digits=15, decimal_places=2)
    quantity = models.IntegerField()
    expense = models.ForeignKey(Expense, on_delete=models.CASCADE)
    attachment = models.ImageField(upload_to='expense_item')

    @property
    def item_total(self):
        return self.amount * self.quantity

    def __str__(self):
        return self.name