From 75cf4c9f271fcc424eb0684387f4e8269cd00334 Mon Sep 17 00:00:00 2001
From: Ayrat Badykov <ayratin555@gmail.com>
Date: Tue, 23 Apr 2019 13:27:59 +0300
Subject: [PATCH] add addresses pagination to view

---
 .../lib/block_scout_web/chain.ex              | 15 ++++++++--
 .../controllers/address_controller.ex         | 30 +++++++++++++++++--
 .../templates/address/index.html.eex          |  9 +++++-
 3 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/apps/block_scout_web/lib/block_scout_web/chain.ex b/apps/block_scout_web/lib/block_scout_web/chain.ex
index b2fd0a188d..5903db1144 100644
--- a/apps/block_scout_web/lib/block_scout_web/chain.ex
+++ b/apps/block_scout_web/lib/block_scout_web/chain.ex
@@ -25,7 +25,8 @@ defmodule BlockScoutWeb.Chain do
     InternalTransaction,
     Log,
     TokenTransfer,
-    Transaction
+    Transaction,
+    Wei
   }
 
   alias Explorer.PagingOptions
@@ -82,7 +83,13 @@ defmodule BlockScoutWeb.Chain do
   end
 
   def paging_options(%{"hash" => hash, "fetched_coin_balance" => fetched_coin_balance}) do
-    [paging_options: %{@default_paging_options | key: {fetched_coin_balance, hash}}]
+    with {coin_balance, ""} <- Integer.parse(fetched_coin_balance),
+         {:ok, address_hash} <- string_to_address_hash(hash) do
+      [paging_options: %{@default_paging_options | key: {%Wei{value: Decimal.new(coin_balance)}, address_hash}}]
+    else
+      _ ->
+        [paging_options: @default_paging_options]
+    end
   end
 
   def paging_options(%{
@@ -175,6 +182,10 @@ defmodule BlockScoutWeb.Chain do
     end
   end
 
+  defp paging_params({%Address{hash: hash, fetched_coin_balance: fetched_coin_balance}, _}) do
+    %{"hash" => hash, "fetched_coin_balance" => Decimal.to_string(fetched_coin_balance.value)}
+  end
+
   defp paging_params({%Reward{block: %{number: number}}, _}) do
     %{"block_number" => number, "index" => 0}
   end
diff --git a/apps/block_scout_web/lib/block_scout_web/controllers/address_controller.ex b/apps/block_scout_web/lib/block_scout_web/controllers/address_controller.ex
index a0c443aee6..730b09eb8f 100644
--- a/apps/block_scout_web/lib/block_scout_web/controllers/address_controller.ex
+++ b/apps/block_scout_web/lib/block_scout_web/controllers/address_controller.ex
@@ -1,16 +1,40 @@
 defmodule BlockScoutWeb.AddressController do
   use BlockScoutWeb, :controller
 
+  import BlockScoutWeb.Chain, only: [paging_options: 1, next_page_params: 3, split_list_by_page: 1]
+
   alias Explorer.{Chain, Market}
   alias Explorer.Chain.Address
   alias Explorer.ExchangeRates.Token
 
-  def index(conn, _params) do
+  def index(conn, params) do
+    addresses =
+      params
+      |> paging_options()
+      |> Chain.list_top_addresses()
+
+    {addresses_page, next_page} = split_list_by_page(addresses)
+
+    next_page_path =
+      case next_page_params(next_page, addresses_page, params) do
+        nil ->
+          nil
+
+        next_page_params ->
+          address_path(
+            conn,
+            :index,
+            next_page_params
+          )
+      end
+
     render(conn, "index.html",
-      address_tx_count_pairs: Chain.list_top_addresses(),
+      address_tx_count_pairs: addresses_page,
+      page_address_count: Enum.count(addresses_page),
       address_count: Chain.count_addresses_with_balance_from_cache(),
       exchange_rate: Market.get_exchange_rate(Explorer.coin()) || Token.null(),
-      total_supply: Chain.total_supply()
+      total_supply: Chain.total_supply(),
+      next_page_path: next_page_path
     )
   end
 
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/address/index.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/address/index.html.eex
index e0a10a8e65..cf4e0efb95 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/address/index.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/address/index.html.eex
@@ -3,7 +3,9 @@
     <div class="card-body">
       <h1><%= gettext "Addresses" %></h1>
       <p>
-        <%= gettext "Showing 250 addresses of" %>
+        <%= gettext "Showing " %>
+        <%= Cldr.Number.to_string!(@page_address_count, format: "#,###") %>
+        <%= gettext " addresses of" %>
         <%= Cldr.Number.to_string!(@address_count, format: "#,###") %>
         <%= gettext "total addresses with a balance" %>
       </p>
@@ -15,6 +17,11 @@
             total_supply: @total_supply, tx_count: tx_count,
             validation_count: validation_count(address) %>
         <% end %>
+        <%= if @next_page_path do %>
+          <a href="<%= "#{@next_page_path}" %>" class="button button-secondary button-small float-right mt-4">
+            <%= gettext("Next") %>
+          </a>
+        <% end %>
       </span>
     </div>
   </div>