nummi/nummi/main/views.py

from django.shortcuts import render, get_object_or_404, redirect
from django.http import HttpResponse
from django.contrib.auth.decorators import login_required
from django.contrib.auth import views as auth_views
from django.contrib.auth.mixins import LoginRequiredMixin
from django.views.generic import ListView
from django.core.paginator import Paginator
from django.db import models
import matplotlib.pyplot as plt
import tempfile

from .models import (
    Transaction,
    TransactionForm,
    Invoice,
    InvoiceForm,
    Category,
    CategoryForm,
    Snapshot,
    SnapshotForm,
)


@login_required
def index(request):
    _transactions = Transaction.objects.all()[:10]
    _categories = Category.objects.all()
    _snapshots = Snapshot.objects.all()[:5]

    context = {
        "transactions": _transactions,
        "categories": _categories,
        "snapshots": _snapshots,
    }
    return render(request, "main/index.html", context)


class LoginView(auth_views.LoginView):
    template_name = "main/login.html"
    next_page = "index"


class LogoutView(auth_views.LogoutView):
    next_page = "login"


class TransactionListView(LoginRequiredMixin, ListView):
    paginate_by = 20
    model = Transaction
    template_name = "main/transactions.html"
    context_object_name = "transactions"


@login_required
def transaction(request, uuid=None):
    _form = None
    _inv_form = None
    _invoices = []
    if request.method == "GET":
        if uuid is None:
            _transaction = Transaction()
        else:
            _transaction = get_object_or_404(Transaction, id=uuid)
    elif request.method == "POST":
        if request.POST["form"] == "transaction":
            _transaction, _ = Transaction.objects.get_or_create(id=uuid)
            _form = TransactionForm(request.POST, instance=_transaction)
            if _form.is_valid():
                _form.save()
            _inv_form = InvoiceForm(instance=Invoice(transaction=_transaction))
        elif request.POST["form"] == "invoice":
            _transaction = get_object_or_404(Transaction, id=uuid)
            _invoice = Invoice(transaction=_transaction)
            _inv_form = InvoiceForm(request.POST, request.FILES, instance=_invoice)
            if _inv_form.is_valid():
                _inv_form.save()

    return render(
        request,
        "main/transaction.html",
        {
            "transaction": _transaction,
            "form": _form or TransactionForm(instance=_transaction),
            "invoices": _invoices or Invoice.objects.filter(transaction=_transaction),
            "invoice_form": _inv_form
            or InvoiceForm(instance=Invoice(transaction=_transaction)),
        },
    )


@login_required
def del_transaction(request, uuid):
    _transaction = get_object_or_404(Transaction, id=uuid)
    _transaction.delete()
    return redirect(index)


@login_required
def invoice(request, uuid):
    _invoice = get_object_or_404(Invoice, id=uuid)
    with _invoice.file.open() as _file:
        return HttpResponse(_file.read(), content_type="application/pdf")


@login_required
def del_invoice(request, uuid, invoice_id):
    _invoice = get_object_or_404(Invoice, id=invoice_id)
    _invoice.delete()
    return redirect(transaction, uuid=uuid)


@login_required
def category(request, uuid=None):
    if request.method == "GET":
        if uuid is None:
            _category = Category()
        else:
            _category = get_object_or_404(Category, id=uuid)
        _form = CategoryForm(instance=_category)
    elif request.method == "POST":
        _category, _ = Category.objects.get_or_create(id=uuid)
        _form = CategoryForm(request.POST, instance=_category)
        if _form.is_valid():
            _form.save()

    return render(
        request,
        "main/category.html",
        {
            "category": _category,
            "form": _form,
            "transactions": Transaction.objects.filter(category=_category),
        },
    )


@login_required
def del_category(request, uuid):
    _category = get_object_or_404(Category, id=uuid)
    _category.delete()
    return redirect(index)


@login_required
def snapshot(request, uuid=None):
    if request.method == "GET":
        if uuid is None:
            _snapshot = Snapshot()
        else:
            _snapshot = get_object_or_404(Snapshot, id=uuid)
        context = {
            "snapshot": _snapshot,
            "form": SnapshotForm(instance=_snapshot),
        }
    elif request.method == "POST":
        try:
            _snapshot = Snapshot.objects.get(id=uuid)
        except Snapshot.DoesNotExist:
            _snapshot = Snapshot(id=uuid)
        _form = SnapshotForm(request.POST, instance=_snapshot)
        if _form.is_valid():
            _form.save()
        context = {
            "snapshot": _snapshot,
            "form": _form,
        }

    return render(
        request,
        "main/snapshot.html",
        context,
    )


@login_required
def snapshot_graph(request, uuid):
    _snapshot = get_object_or_404(Snapshot, id=uuid)
    _categories_p = (
        _snapshot.transactions.filter(value__gt=0)
        .values("category")
        .annotate(sum=models.Sum("value"))
    )
    _categories_m = (
        _snapshot.transactions.filter(value__lt=0)
        .values("category")
        .annotate(sum=models.Sum("value"))
    )

    print(_categories_p)
    print(_categories_m)
    fig, ax = plt.subplots()
    ax.bar(
        [
            "*" if (c := _cat["category"]) is None else Category.objects.get(id=c).name
            for _cat in _categories_p
        ],
        [_cat["sum"] for _cat in _categories_p],
        color="#007339",
    )
    ax.bar(
        [
            "*" if (c := _cat["category"]) is None else Category.objects.get(id=c).name
            for _cat in _categories_m
        ],
        [_cat["sum"] for _cat in _categories_m],
        color="#bf1500",
    )
    ax.grid(color="k", alpha=0.2)
    ax.set(ylabel="Value (€)")
    with tempfile.NamedTemporaryFile(suffix=".svg") as f:
        fig.savefig(f.name)
        f.seek(0)
        return HttpResponse(f.read(), content_type="image/svg+xml")


@login_required
def del_snapshot(request, uuid):
    _snapshot = get_object_or_404(Snapshot, id=uuid)
    _snapshot.delete()
    return redirect(index)