From 6d5b29a230008c5cf1ed243143679de0489086be Mon Sep 17 00:00:00 2001
From: KKlochko <KKlochko@protonmail.com>
Date: Tue, 25 Mar 2025 22:04:03 +0200
Subject: [PATCH] Add the Pagination component.

---
 .../components/my_components.ex               |   2 +
 .../components/my_components/pagination.ex    | 125 ++++++++++++++++++
 2 files changed, 127 insertions(+)
 create mode 100644 lib/decentralised_book_index_web/components/my_components/pagination.ex

diff --git a/lib/decentralised_book_index_web/components/my_components.ex b/lib/decentralised_book_index_web/components/my_components.ex
index d763714..b1cb0ae 100644
--- a/lib/decentralised_book_index_web/components/my_components.ex
+++ b/lib/decentralised_book_index_web/components/my_components.ex
@@ -5,6 +5,8 @@ defmodule DecentralisedBookIndexWeb.Components.MyComponents do
     quote do
       import MyComponents.AuthorCard, only: [author_card: 1]
       import MyComponents.AuthorSearch, only: [author_search: 1]
+
+      import MyComponents.Pagination, only: [pagination: 1]
     end
   end
 end
diff --git a/lib/decentralised_book_index_web/components/my_components/pagination.ex b/lib/decentralised_book_index_web/components/my_components/pagination.ex
new file mode 100644
index 0000000..8753e0f
--- /dev/null
+++ b/lib/decentralised_book_index_web/components/my_components/pagination.ex
@@ -0,0 +1,125 @@
+defmodule DecentralisedBookIndexWeb.Components.MyComponents.Pagination do
+  use Phoenix.Component
+  use DecentralisedBookIndexWeb, :verified_routes
+
+  attr :endpoint, :string, required: true
+  attr :page, :map, required: true
+  attr :page_params, :list, required: true
+  attr :params, :list, required: true
+
+  def pagination(assigns) do
+    assigns = assign(assigns, :current_page_number, get_current_page(assigns.page))
+
+    ~H"""
+    <nav aria-label="Page navigation example" class="flex justify-center">
+      <ul class="inline-flex -space-x-px text-base h-10 mx-auto">
+        <li class="pl-auto">
+          <.button_link
+            data-role="previous-page"
+            kind="primary"
+            inverse
+            patch={"#{@endpoint}?#{page_params_which(@page, @params, "prev")}"}
+            class="flex items-center justify-center px-4 h-10 ms-0 leading-tight text-gray-500 bg-white border border-e-0 border-gray-300 rounded-s-lg hover:bg-gray-100 hover:text-gray-700 dark:bg-gray-800 dark:border-gray-700 dark:text-gray-400 dark:hover:bg-gray-700 dark:hover:text-white"
+            disabled={!AshPhoenix.LiveView.prev_page?(@page)}
+          >
+            Previous
+          </.button_link>
+        </li>
+        <%= for number <- get_page_numbers(@page) do %>
+          <%= if number == @current_page_number do %>
+            <li>
+              <a href={"#{@endpoint}?#{page_params_number(@page_params, @params, number)}"}
+                 aria-current="page"
+                 class="flex items-center justify-center px-4 h-10 text-blue-600 border border-gray-300 bg-blue-50 hover:bg-blue-100 hover:text-blue-700 dark:border-gray-700 dark:bg-gray-700 dark:text-white">{number}</a>
+            </li>
+          <% else %>
+            <li>
+              <a href={"#{@endpoint}?#{page_params_number(@page_params, @params, number)}"}
+                 class="flex items-center justify-center px-4 h-10 leading-tight text-gray-500 bg-white border border-gray-300 hover:bg-gray-100 hover:text-gray-700 dark:bg-gray-800 dark:border-gray-700 dark:text-gray-400 dark:hover:bg-gray-700 dark:hover:text-white">{number}</a>
+            </li>
+          <% end %>
+        <% end %>
+        <li>
+          <.button_link
+            data-role="next-page"
+            kind="primary"
+            inverse
+            patch={"#{@endpoint}?#{page_params_which(@page, @params, "next")}"}
+            class="flex items-center justify-center px-4 h-10 leading-tight text-gray-500 bg-white border border-gray-300 rounded-e-lg hover:bg-gray-100 hover:text-gray-700 dark:bg-gray-800 dark:border-gray-700 dark:text-gray-400 dark:hover:bg-gray-700 dark:hover:text-white"
+            disabled={!AshPhoenix.LiveView.next_page?(@page)}
+          >
+            Next
+          </.button_link>
+        </li>
+      </ul>
+    </nav>
+    """
+  end
+
+  attr :kind, :string,
+    values: ~w(base primary error),
+    default: "base"
+
+  attr :inverse, :boolean, default: false
+  attr :class, :string, default: ""
+  attr :rest, :global, include: ~w(navigate disabled patch)
+
+  slot :inner_block
+
+  defp button_link(assigns) do
+    ~H"""
+    <.link
+      class={[
+        @rest[:disabled] && "opacity-60 grayscale pointer-events-none",
+        @class
+      ]}
+      {@rest}
+    >
+      {render_slot(@inner_block)}
+    </.link>
+    """
+  end
+
+  defp get_page_numbers(pages) do
+    %{count: count, limit: limit} = pages
+
+    max_number =
+      count/limit
+      |> :math.ceil()
+      |> Kernel.trunc()
+
+    1..max_number
+  end
+
+  defp get_current_page(pages) do
+    %{offset: offset, limit: limit} = pages
+
+    Kernel.trunc(offset/limit) +1
+  end
+
+  def page_params_which(page, params, which) do
+    page_params =
+      case AshPhoenix.LiveView.page_link_params(page, which) do
+        :invalid -> []
+        list -> list
+      end
+
+    page_params
+    |> Enum.into(params, fn {k, v} -> {Atom.to_string(k), v} end)
+    |> to_uri_params()
+  end
+
+  def page_params_number(page_params, params, number) do
+    limit = Keyword.get(page_params, :limit)
+    offset = limit*(number-1)
+
+    params
+    |> Map.put("limit", limit)
+    |> Map.put("offset", offset)
+    |> to_uri_params()
+  end
+
+  defp to_uri_params(params) do
+    URI.encode_query(params)
+  end
+end