From a5b9621a727458fbd8d68b2f46444d049d951b90 Mon Sep 17 00:00:00 2001
From: Victor Baranov <baranov.viktor.27@gmail.com>
Date: Wed, 5 Aug 2020 17:34:11 +0300
Subject: [PATCH] Finally fix pagination at top tokens page

---
 .../block_scout_web/lib/block_scout_web/chain.ex | 16 +++++++++++++---
 .../controllers/tokens/tokens_controller.ex      | 15 ++-------------
 apps/explorer/lib/explorer/chain.ex              |  7 ++++---
 3 files changed, 19 insertions(+), 19 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 2c45e0f577..c338d446dd 100644
--- a/apps/block_scout_web/lib/block_scout_web/chain.ex
+++ b/apps/block_scout_web/lib/block_scout_web/chain.ex
@@ -41,7 +41,7 @@ defmodule BlockScoutWeb.Chain do
     end
   end
 
-  @page_size 50
+  @page_size 10
   @default_paging_options %PagingOptions{page_size: @page_size + 1}
   @address_hash_len 40
   @tx_block_hash_len 64
@@ -108,6 +108,16 @@ defmodule BlockScoutWeb.Chain do
     end
   end
 
+  def paging_options(%{"contract_address_hash" => contract_address_hash, "holder_count" => holder_count}) do
+    with {holder_count, ""} <- Integer.parse(holder_count),
+         {:ok, contract_address_hash} <- string_to_address_hash(contract_address_hash) do
+      [paging_options: %{@default_paging_options | key: {holder_count, contract_address_hash}}]
+    else
+      _ ->
+        [paging_options: @default_paging_options]
+    end
+  end
+
   def paging_options(%{
         "block_number" => block_number_string,
         "transaction_index" => transaction_index_string,
@@ -206,8 +216,8 @@ defmodule BlockScoutWeb.Chain do
     %{"hash" => hash, "fetched_coin_balance" => Decimal.to_string(fetched_coin_balance.value)}
   end
 
-  defp paging_params({%Token{contract_address_hash: contract_address_hash}, _}) do
-    %{"contract_address_hash" => contract_address_hash}
+  defp paging_params(%Token{contract_address_hash: contract_address_hash, holder_count: holder_count}) do
+    %{"contract_address_hash" => contract_address_hash, "holder_count" => holder_count}
   end
 
   defp paging_params({%Reward{block: %{number: number}}, _}) do
diff --git a/apps/block_scout_web/lib/block_scout_web/controllers/tokens/tokens_controller.ex b/apps/block_scout_web/lib/block_scout_web/controllers/tokens/tokens_controller.ex
index 383280f264..0a133d9f7f 100644
--- a/apps/block_scout_web/lib/block_scout_web/controllers/tokens/tokens_controller.ex
+++ b/apps/block_scout_web/lib/block_scout_web/controllers/tokens/tokens_controller.ex
@@ -8,18 +8,8 @@ defmodule BlockScoutWeb.TokensController do
   alias Phoenix.View
 
   def index(conn, %{"type" => "JSON"} = params) do
-    full_options =
-      Keyword.merge(
-        [
-          necessity_by_association: %{
-            [contract_address: :contract_address] => :optional
-          }
-        ],
-        paging_options(params)
-      )
-
     tokens =
-      full_options
+      params
       |> paging_options()
       |> Chain.list_top_tokens()
 
@@ -31,7 +21,7 @@ defmodule BlockScoutWeb.TokensController do
           nil
 
         next_page_params ->
-          address_path(
+          tokens_path(
             conn,
             :index,
             Map.delete(next_page_params, "type")
@@ -64,7 +54,6 @@ defmodule BlockScoutWeb.TokensController do
 
     render(conn, "index.html",
       current_path: current_path(conn),
-      address_count: Chain.address_estimated_count(),
       total_supply: total_supply
     )
   end
diff --git a/apps/explorer/lib/explorer/chain.ex b/apps/explorer/lib/explorer/chain.ex
index 0267f06819..d25cffd8a6 100644
--- a/apps/explorer/lib/explorer/chain.ex
+++ b/apps/explorer/lib/explorer/chain.ex
@@ -1735,7 +1735,6 @@ defmodule Explorer.Chain do
 
     base_query
     |> page_tokens(paging_options)
-    |> join_associations(necessity_by_association)
     |> limit(^paging_options.page_size)
     |> Repo.all()
   end
@@ -3165,9 +3164,11 @@ defmodule Explorer.Chain do
 
   defp page_tokens(query, %PagingOptions{key: nil}), do: query
 
-  defp page_tokens(query, %PagingOptions{key: {contract_address_hash}}) do
+  defp page_tokens(query, %PagingOptions{key: {holder_count, contract_address_hash}}) do
     from(token in query,
-      where: token.contract_address_hash > ^contract_address_hash
+      where:
+        (token.holder_count == ^holder_count and token.contract_address_hash > ^contract_address_hash) or
+          token.holder_count < ^holder_count
     )
   end