views.py

from __future__ import annotations

import time
from dataclasses import dataclass

from django.core.paginator import Paginator
from django.http import HttpRequest
from django.http import HttpResponse
from django.shortcuts import render
from django.views.decorators.http import require_GET
from django.views.decorators.http import require_http_methods
from django.views.decorators.http import require_POST
from faker import Faker

from django_htmx.middleware import HtmxDetails
from example.forms import OddNumberForm


# Typing pattern recommended by django-stubs:
# https://github.com/typeddjango/django-stubs#how-can-i-create-a-httprequest-thats-guaranteed-to-have-an-authenticated-user
class HtmxHttpRequest(HttpRequest):
    htmx: HtmxDetails


@require_GET
def index(request: HtmxHttpRequest) -> HttpResponse:
    return render(request, "index.html")


@require_GET
def favicon(request: HtmxHttpRequest) -> HttpResponse:
    return HttpResponse(
        (
            '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100">'
            + '<text y=".9em" font-size="90">🦊</text>'
            + "</svg>"
        ),
        content_type="image/svg+xml",
    )


# CSRF Demo


@require_GET
def csrf_demo(request: HtmxHttpRequest) -> HttpResponse:
    return render(request, "csrf-demo.html")


@require_POST
def csrf_demo_checker(request: HtmxHttpRequest) -> HttpResponse:
    form = OddNumberForm(request.POST)
    if form.is_valid():
        number = form.cleaned_data["number"]
        number_is_odd = number % 2 == 1
    else:
        number_is_odd = False
    return render(
        request,
        "csrf-demo-checker.html",
        {"form": form, "number_is_odd": number_is_odd},
    )


# Error demo


@require_GET
def error_demo(request: HtmxHttpRequest) -> HttpResponse:
    return render(request, "error-demo.html")


@require_GET
def error_demo_trigger(request: HtmxHttpRequest) -> HttpResponse:
    1 / 0
    return render(request, "error-demo.html")  # unreachable


# Middleware tester

# This uses two views - one to render the form, and the second to render the
# table of attributes.


@require_GET
def middleware_tester(request: HtmxHttpRequest) -> HttpResponse:
    return render(request, "middleware-tester.html")


@require_http_methods(["DELETE", "POST", "PUT"])
def middleware_tester_table(request: HtmxHttpRequest) -> HttpResponse:
    return render(
        request,
        "middleware-tester-table.html",
        {"timestamp": time.time()},
    )


# Partial rendering example


# This dataclass acts as a stand-in for a database model - the example app
# avoids having a database for simplicity.


@dataclass
class Person:
    id: int
    name: str


faker = Faker()
people = [Person(id=i, name=faker.name()) for i in range(1, 235)]


@require_GET
def partial_rendering(request: HtmxHttpRequest) -> HttpResponse:
    # Standard Django pagination
    page_num = request.GET.get("page", "1")
    page = Paginator(object_list=people, per_page=10).get_page(page_num)

    # The htmx magic - use a different, minimal base template for htmx
    # requests, allowing us to skip rendering the unchanging parts of the
    # template.
    if request.htmx:
        base_template = "_partial.html"
    else:
        base_template = "_base.html"

    return render(
        request,
        "partial-rendering.html",
        {
            "base_template": base_template,
            "page": page,
        },
    )