From 28096cd4902194d87d1b5e6ef00d0432e1e8f64c Mon Sep 17 00:00:00 2001
From: Herculino Trotta <netotrotta@gmail.com>
Date: Sat, 30 Nov 2024 02:18:02 -0300
Subject: [PATCH] feat: paginate exchange rates

---
 app/apps/currencies/urls.py                   |  5 -
 app/apps/currencies/views/exchange_rates.py   | 12 ++-
 .../exchange_rates/fragments/list.html        |  3 +-
 .../exchange_rates/fragments/table.html       | 95 +++++++++++++++++--
 app/templates/exchange_rates/pages/index.html |  2 +-
 5 files changed, 99 insertions(+), 18 deletions(-)

diff --git a/app/apps/currencies/urls.py b/app/apps/currencies/urls.py
index d93a4ef..f05d3fe 100644
--- a/app/apps/currencies/urls.py
+++ b/app/apps/currencies/urls.py
@@ -23,11 +23,6 @@ urlpatterns = [
         views.exchange_rates_list_pair,
         name="exchange_rates_list_pair",
     ),
-    path(
-        "exchange-rates/pair/<str:from_currency>/<str:to_currency>",
-        views.exchange_rates_list_pair,
-        name="exchange_rates_list_pair",
-    ),
     path("exchange-rates/add/", views.exchange_rate_add, name="exchange_rate_add"),
     path(
         "exchange-rates/<int:pk>/edit/",
diff --git a/app/apps/currencies/views/exchange_rates.py b/app/apps/currencies/views/exchange_rates.py
index 624933f..7312672 100644
--- a/app/apps/currencies/views/exchange_rates.py
+++ b/app/apps/currencies/views/exchange_rates.py
@@ -1,5 +1,6 @@
 from django.contrib import messages
 from django.contrib.auth.decorators import login_required
+from django.core.paginator import Paginator
 from django.db.models import F, CharField, Value
 from django.db.models.functions import Concat
 from django.http import HttpResponse
@@ -50,7 +51,10 @@ def exchange_rates_list(request):
 @only_htmx
 @login_required
 @require_http_methods(["GET"])
-def exchange_rates_list_pair(request, from_currency=None, to_currency=None):
+def exchange_rates_list_pair(request):
+    from_currency = request.GET.get("from")
+    to_currency = request.GET.get("to")
+
     if from_currency and to_currency:
         exchange_rates = ExchangeRate.objects.filter(
             from_currency__code=from_currency, to_currency__code=to_currency
@@ -58,11 +62,17 @@ def exchange_rates_list_pair(request, from_currency=None, to_currency=None):
     else:
         exchange_rates = ExchangeRate.objects.all().order_by("-date")
 
+    page_number = request.GET.get("page", 1)
+    paginator = Paginator(exchange_rates, 100)
+    page_obj = paginator.get_page(page_number)
+
     return render(
         request,
         "exchange_rates/fragments/table.html",
         {
             "exchange_rates": exchange_rates,
+            "paginator": paginator,
+            "page_obj": page_obj,
             "from_currency": from_currency,
             "to_currency": to_currency,
         },
diff --git a/app/templates/exchange_rates/fragments/list.html b/app/templates/exchange_rates/fragments/list.html
index 41134c1..cb5cc28 100644
--- a/app/templates/exchange_rates/fragments/list.html
+++ b/app/templates/exchange_rates/fragments/list.html
@@ -27,7 +27,8 @@
         {% for pair in pairings %}
           <li class="nav-item" role="presentation">
             <button class="nav-link" hx-indicator="#exchange-rates-table"
-                    hx-get="{% url 'exchange_rates_list_pair' from_currency=pair.1 to_currency=pair.2 %}"
+                    hx-get="{% url 'exchange_rates_list_pair' %}"
+                    hx-vals='{"from": "{{ pair.1 }}", "to": "{{ pair.2 }}"}'
                     hx-target="#exchange-rates-table" data-bs-toggle="tab" type="button" role="tab"
                     aria-controls="#exchange-rates-table" aria-selected="false">{{ pair.0 }}</button>
           </li>
diff --git a/app/templates/exchange_rates/fragments/table.html b/app/templates/exchange_rates/fragments/table.html
index a105bb9..0b4c007 100644
--- a/app/templates/exchange_rates/fragments/table.html
+++ b/app/templates/exchange_rates/fragments/table.html
@@ -1,11 +1,7 @@
 {% load currency_display %}
 {% load i18n %}
-{% if from_currency and to_currency %}
-<div class="card-body show-loading" hx-get="{% url 'exchange_rates_list_pair' from_currency=from_currency to_currency=to_currency %}" hx-trigger="updated from:window" hx-swap="outerHTML">
-{% else %}
-<div class="card-body show-loading" hx-get="{% url 'exchange_rates_list_pair' %}" hx-trigger="updated from:window" hx-swap="outerHTML">
-{% endif %}
-  {% if exchange_rates %}
+<div class="card-body show-loading" hx-get="{% url 'exchange_rates_list_pair' %}" hx-trigger="updated from:window" hx-swap="outerHTML" hx-vals='{"page": "{{ page_obj.number }}", "from": "{{ from_currency|default_if_none:"" }}", "to": "{{ to_currency|default_if_none:"" }}"}'>
+  {% if page_obj %}
   <div class="table-responsive">
     <table class="table table-hover text-nowrap">
       <thead>
@@ -17,7 +13,7 @@
         </tr>
       </thead>
       <tbody>
-        {% for exchange_rate in exchange_rates %}
+        {% for exchange_rate in page_obj %}
         <tr class="exchange-rate">
           <td class="col-auto">
             <div class="btn-group" role="group" aria-label="{% translate 'Actions' %}">
@@ -43,9 +39,9 @@
                       _="install prompt_swal"><i class="fa-solid fa-trash fa-fw"></i></a>
             </div>
           </td>
-          <td class="col">{{ exchange_rate.date|date:"SHORT_DATETIME_FORMAT" }}</td>
-          <td class="col"><span class="badge rounded-pill text-bg-secondary">{{ exchange_rate.from_currency.code }}</span> x <span class="badge rounded-pill text-bg-secondary">{{ exchange_rate.to_currency.code }}</span></td>
-          <td class="col">1 {{ exchange_rate.from_currency.code }} ≅ {% currency_display amount=exchange_rate.rate prefix=exchange_rate.to_currency.prefix suffix=exchange_rate.to_currency.suffix decimal_places=exchange_rate.to_currency.decimal_places%}</td>
+          <td class="col-3">{{ exchange_rate.date|date:"SHORT_DATETIME_FORMAT" }}</td>
+          <td class="col-3"><span class="badge rounded-pill text-bg-secondary">{{ exchange_rate.from_currency.code }}</span> x <span class="badge rounded-pill text-bg-secondary">{{ exchange_rate.to_currency.code }}</span></td>
+          <td class="col-3">1 {{ exchange_rate.from_currency.code }} ≅ {% currency_display amount=exchange_rate.rate prefix=exchange_rate.to_currency.prefix suffix=exchange_rate.to_currency.suffix decimal_places=exchange_rate.to_currency.decimal_places%}</td>
         </tr>
         {% endfor %}
       </tbody>
@@ -54,4 +50,83 @@
   {% else %}
     <c-msg.empty title="{% translate "No exchange rates" %}" :remove-padding="True"></c-msg.empty>
   {% endif %}
+
+  {% if page_obj.has_other_pages %}
+  <div class="mt-auto">
+    <input value="{{ page_obj.number }}" name="page" type="hidden" id="page">
+
+    <nav aria-label="{% translate 'Page navigation' %}">
+    <ul class="pagination justify-content-center mt-5">
+      <li class="page-item">
+        <a class="page-link tw-cursor-pointer {% if not page_obj.has_previous %}disabled{% endif %}"
+           hx-get="{% if page_obj.has_previous %}{% url 'exchange_rates_list_pair' %}{% endif %}"
+           hx-vals='{"page": 1, "from": "{{ from_currency|default_if_none:"" }}", "to": "{{ to_currency|default_if_none:"" }}"}'
+           hx-include="#filter, #order"
+           hx-target="#exchange-rates-table"
+           aria-label="Primeira página"
+           hx-swap="show:top">
+          <span aria-hidden="true">&laquo;</span>
+        </a>
+      </li>
+      {% for page_number in page_obj.paginator.page_range %}
+              {% comment %}
+                  This conditional allows us to display up to 3 pages before and after the current page
+                  If you decide to remove this conditional, all the pages will be displayed
+
+                  You can change the 3 to any number you want e.g
+                  To display only 5 pagination items, change the 3 to 2 (2 before and 2 after the current page)
+              {% endcomment %}
+              {% if page_number <= page_obj.number|add:3 and page_number >= page_obj.number|add:-3 %}
+                  {% if page_obj.number == page_number %}
+                      <li class="page-item active">
+                          <a class="page-link tw-cursor-pointer">
+                              {{ page_number }}
+                          </a>
+                      </li>
+                  {% else %}
+                      <li class="page-item">
+                          <a class="page-link tw-cursor-pointer"
+                             hx-get="{% url 'exchange_rates_list_pair' %}"
+                             hx-vals='{"page": {{ page_number }}, "from": "{{ from_currency|default_if_none:"" }}", "to": "{{ to_currency|default_if_none:"" }}"}'
+                             hx-target="#exchange-rates-table"
+                             hx-swap="show:top">
+                              {{ page_number }}
+                          </a>
+                      </li>
+                  {% endif %}
+              {% endif %}
+      {% endfor %}
+      {% if page_obj.number|add:3 < page_obj.paginator.num_pages %}
+        <li class="page-item">
+          <a class="page-link disabled"
+             aria-label="...">
+            <span aria-hidden="true">...</span>
+          </a>
+        </li>
+        <li class="page-item">
+          <a class="page-link tw-cursor-pointer"
+             hx-get="{% url 'exchange_rates_list_pair' %}" hx-target="#exchange-rates-table"
+             hx-vals='{"page": {{ page_obj.paginator.num_pages }}, "from": "{{ from_currency|default_if_none:"" }}", "to": "{{ to_currency|default_if_none:"" }}"}'
+             hx-include="#filter, #order"
+             hx-swap="show:top"
+             aria-label="Última página">
+            <span aria-hidden="true">{{ page_obj.paginator.num_pages }}</span>
+          </a>
+        </li>
+      {% endif %}
+      <li class="page-item">
+        <a class="page-link {% if not page_obj.has_next %}disabled{% endif %} tw-cursor-pointer"
+           hx-get="{% if page_obj.has_next %}{% url 'exchange_rates_list_pair' %}{% endif %}"
+           hx-vals='{"page": {{ page_obj.paginator.num_pages }}, "from": "{{ from_currency|default_if_none:"" }}", "to": "{{ to_currency|default_if_none:"" }}"}'
+           hx-include="#filter, #order"
+           hx-swap="show:top"
+           hx-target="#exchange-rates-table"
+           aria-label="Next">
+          <span aria-hidden="true">&raquo;</span>
+        </a>
+      </li>
+    </ul>
+  </nav>
+  </div>
+  {% endif %}
 </div>
diff --git a/app/templates/exchange_rates/pages/index.html b/app/templates/exchange_rates/pages/index.html
index 5527f7a..1afd684 100644
--- a/app/templates/exchange_rates/pages/index.html
+++ b/app/templates/exchange_rates/pages/index.html
@@ -4,5 +4,5 @@
 {% block title %}{% translate 'Exchange Rates' %}{% endblock %}
 
 {% block content %}
-<div hx-get="{% url 'exchange_rates_list' %}" hx-trigger="load, updated from:window" class="show-loading"></div>
+<div hx-get="{% url 'exchange_rates_list' %}" hx-trigger="load" class="show-loading"></div>
 {% endblock %}