From 9cf34bd6c1da9c7c67bdaa0d1bc85bedac1cafd3 Mon Sep 17 00:00:00 2001
From: Nikita Pozdniakov <nikitosing4@mail.ru>
Date: Sun, 10 Sep 2023 14:54:36 +0300
Subject: [PATCH 1/3] Fix contracts' output decoding

---
 CHANGELOG.md                                  |   1 +
 .../views/api/v2/smart_contract_view.ex       |  27 ++--
 .../views/smart_contract_view.ex              |  81 +---------
 .../api/v2/smart_contract_controller_test.exs | 142 ++++++++++++++++++
 .../views/smart_contract_view_test.exs        |  49 +++---
 .../lib/explorer/smart_contract/reader.ex     | 112 ++++++++++++++
 6 files changed, 295 insertions(+), 117 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3d874f87ca..c766d2207b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@
 
 ### Fixes
 
+- [#8431](https://github.com/blockscout/blockscout/pull/8431) - Fix contracts' output decoding
 - [#8354](https://github.com/blockscout/blockscout/pull/8354) - Hotfix for proper addresses' tokens displaying
 - [#8350](https://github.com/blockscout/blockscout/pull/8350) - Add Base Mainnet support for tx actions
 - [#8282](https://github.com/blockscout/blockscout/pull/8282) - NFT fetcher improvements
diff --git a/apps/block_scout_web/lib/block_scout_web/views/api/v2/smart_contract_view.ex b/apps/block_scout_web/lib/block_scout_web/views/api/v2/smart_contract_view.ex
index 6a35a0c6fb..1c102bf0cc 100644
--- a/apps/block_scout_web/lib/block_scout_web/views/api/v2/smart_contract_view.ex
+++ b/apps/block_scout_web/lib/block_scout_web/views/api/v2/smart_contract_view.ex
@@ -1,6 +1,8 @@
 defmodule BlockScoutWeb.API.V2.SmartContractView do
   use BlockScoutWeb, :view
 
+  import Explorer.SmartContract.Reader, only: [zip_tuple_values_with_types: 2]
+
   alias ABI.FunctionSelector
   alias BlockScoutWeb.API.V2.{Helper, TransactionView}
   alias BlockScoutWeb.SmartContractView
@@ -284,28 +286,31 @@ defmodule BlockScoutWeb.API.V2.SmartContractView do
     %{"type" => type, "value" => render_json(value, type)}
   end
 
-  def render_json(value, type) when type in [:address, "address", "address payable"] do
-    SmartContractView.cast_address(value)
-  end
-
-  def render_json(value, type) when type in [:string, "string"] do
-    to_string(value)
-  end
-
   def render_json(value, type) when is_tuple(value) do
     value
-    |> SmartContractView.zip_tuple_values_with_types(type)
+    |> zip_tuple_values_with_types(type)
     |> Enum.map(fn {type, value} ->
       render_json(value, type)
     end)
   end
 
   def render_json(value, type) when is_list(value) do
+    type =
+      if String.ends_with?(type, "[]") do
+        String.slice(type, 0..-3)
+      else
+        type
+      end
+
     value |> Enum.map(&render_json(&1, type))
   end
 
-  def render_json(value, _type) when is_binary(value) do
-    SmartContractView.binary_to_utf_string(value)
+  def render_json(value, type) when type in [:address, "address", "address payable"] do
+    SmartContractView.cast_address(value)
+  end
+
+  def render_json(value, type) when type in [:string, "string"] do
+    to_string(value)
   end
 
   def render_json(value, _type) do
diff --git a/apps/block_scout_web/lib/block_scout_web/views/smart_contract_view.ex b/apps/block_scout_web/lib/block_scout_web/views/smart_contract_view.ex
index 4a96a93adb..f0245adc2d 100644
--- a/apps/block_scout_web/lib/block_scout_web/views/smart_contract_view.ex
+++ b/apps/block_scout_web/lib/block_scout_web/views/smart_contract_view.ex
@@ -1,6 +1,8 @@
 defmodule BlockScoutWeb.SmartContractView do
   use BlockScoutWeb, :view
 
+  import Explorer.SmartContract.Reader, only: [zip_tuple_values_with_types: 2]
+
   alias Explorer.Chain
   alias Explorer.Chain.{Address, Transaction}
   alias Explorer.Chain.Hash.Address, as: HashAddress
@@ -72,7 +74,7 @@ defmodule BlockScoutWeb.SmartContractView do
       String.starts_with?(type, "bytes") ->
         values =
           value
-          |> Enum.map_join(", ", &binary_to_utf_string(&1))
+          |> Enum.join(", ")
 
         render_array_type_value(type, values, fetch_name(names, index))
 
@@ -107,6 +109,9 @@ defmodule BlockScoutWeb.SmartContractView do
   def values_with_type(value, string, names, index, _components) when string in ["string", :string],
     do: render_type_value("string", Helper.sanitize_input(value), fetch_name(names, index))
 
+  def values_with_type(value, "bytes" <> _ = bytes_type, names, index, _components),
+    do: render_type_value(bytes_type, Helper.sanitize_input(value), fetch_name(names, index))
+
   def values_with_type(value, bytes, names, index, _components) when bytes in [:bytes],
     do: render_type_value("bytes", Helper.sanitize_input(value), fetch_name(names, index))
 
@@ -114,7 +119,7 @@ defmodule BlockScoutWeb.SmartContractView do
     do: render_type_value("bool", Helper.sanitize_input(to_string(value)), fetch_name(names, index))
 
   def values_with_type(value, type, names, index, _components),
-    do: render_type_value(type, Helper.sanitize_input(binary_to_utf_string(value)), fetch_name(names, index))
+    do: render_type_value(type, Helper.sanitize_input(value), fetch_name(names, index))
 
   def values_with_type(value, :error, _components),
     do: render_type_value("error", Helper.sanitize_input(value), "error")
@@ -158,78 +163,6 @@ defmodule BlockScoutWeb.SmartContractView do
     end)
   end
 
-  def zip_tuple_values_with_types(value, type) do
-    types_string =
-      type
-      |> String.slice(6..-2)
-
-    types =
-      if String.trim(types_string) == "" do
-        []
-      else
-        types_string
-        |> String.split(",")
-      end
-
-    {tuple_types, _} =
-      types
-      |> Enum.reduce({[], nil}, fn val, acc ->
-        {arr, to_merge} = acc
-
-        if to_merge do
-          compose_array_if_to_merge(arr, val, to_merge)
-        else
-          compose_array_else(arr, val, to_merge)
-        end
-      end)
-
-    values_list =
-      value
-      |> Tuple.to_list()
-
-    Enum.zip(tuple_types, values_list)
-  end
-
-  def compose_array_if_to_merge(arr, val, to_merge) do
-    if count_string_symbols(val)["]"] > count_string_symbols(val)["["] do
-      updated_arr = update_last_list_item(arr, val)
-      {updated_arr, !to_merge}
-    else
-      updated_arr = update_last_list_item(arr, val)
-      {updated_arr, to_merge}
-    end
-  end
-
-  def compose_array_else(arr, val, to_merge) do
-    if count_string_symbols(val)["["] > count_string_symbols(val)["]"] do
-      # credo:disable-for-next-line
-      {arr ++ [val], !to_merge}
-    else
-      # credo:disable-for-next-line
-      {arr ++ [val], to_merge}
-    end
-  end
-
-  defp update_last_list_item(arr, new_val) do
-    arr
-    |> Enum.with_index()
-    |> Enum.map(fn {item, index} ->
-      if index == Enum.count(arr) - 1 do
-        item <> "," <> new_val
-      else
-        item
-      end
-    end)
-  end
-
-  defp count_string_symbols(str) do
-    str
-    |> String.graphemes()
-    |> Enum.reduce(%{"[" => 0, "]" => 0}, fn char, acc ->
-      Map.update(acc, char, 1, &(&1 + 1))
-    end)
-  end
-
   def binary_to_utf_string(item) do
     case Integer.parse(to_string(item)) do
       {item_integer, ""} ->
diff --git a/apps/block_scout_web/test/block_scout_web/controllers/api/v2/smart_contract_controller_test.exs b/apps/block_scout_web/test/block_scout_web/controllers/api/v2/smart_contract_controller_test.exs
index 863345a903..6799c10396 100644
--- a/apps/block_scout_web/test/block_scout_web/controllers/api/v2/smart_contract_controller_test.exs
+++ b/apps/block_scout_web/test/block_scout_web/controllers/api/v2/smart_contract_controller_test.exs
@@ -702,6 +702,148 @@ defmodule BlockScoutWeb.API.V2.SmartContractControllerTest do
                "method_id" => Base.encode16(id, case: :lower)
              } in response
     end
+
+    test "get correct bytes value 1", %{conn: conn} do
+      abi = [
+        %{
+          "inputs" => [],
+          "name" => "all_messages_hash",
+          "outputs" => [
+            %{
+              "internalType" => "bytes32",
+              "name" => "",
+              "type" => "bytes32"
+            }
+          ],
+          "stateMutability" => "view",
+          "type" => "function"
+        }
+      ]
+
+      id_1 =
+        abi
+        |> ABI.parse_specification()
+        |> Enum.at(0)
+        |> Map.fetch!(:method_id)
+
+      target_contract = insert(:smart_contract, abi: abi)
+      address_hash_string = to_string(target_contract.address_hash)
+
+      EthereumJSONRPC.Mox
+      |> expect(
+        :json_rpc,
+        fn [
+             %{
+               id: id,
+               method: "eth_call",
+               params: [
+                 %{data: "0x1dd69d06", to: ^address_hash_string},
+                 "latest"
+               ]
+             }
+           ],
+           _opts ->
+          {:ok,
+           [
+             %{
+               id: id,
+               jsonrpc: "2.0",
+               result: "0x0000000000000000000000000000000000000000000000000000000000000000"
+             }
+           ]}
+        end
+      )
+
+      request = get(conn, "/api/v2/smart-contracts/#{target_contract.address_hash}/methods-read")
+      assert response = json_response(request, 200)
+
+      assert %{
+               "inputs" => [],
+               "name" => "all_messages_hash",
+               "outputs" => [
+                 %{
+                   "value" => "0x0000000000000000000000000000000000000000000000000000000000000000",
+                   "type" => "bytes32"
+                 }
+               ],
+               "stateMutability" => "view",
+               "type" => "function",
+               "method_id" => Base.encode16(id_1, case: :lower),
+               "names" => ["bytes32"]
+             } in response
+    end
+
+    test "get correct bytes value 2", %{conn: conn} do
+      abi = [
+        %{
+          "inputs" => [],
+          "name" => "FRAUD_STRING",
+          "outputs" => [
+            %{
+              "internalType" => "bytes",
+              "name" => "",
+              "type" => "bytes"
+            }
+          ],
+          "stateMutability" => "view",
+          "type" => "function"
+        }
+      ]
+
+      id_2 =
+        abi
+        |> ABI.parse_specification()
+        |> Enum.at(0)
+        |> Map.fetch!(:method_id)
+
+      target_contract = insert(:smart_contract, abi: abi)
+      address_hash_string = to_string(target_contract.address_hash)
+
+      EthereumJSONRPC.Mox
+      |> expect(
+        :json_rpc,
+        fn [
+             %{
+               id: id,
+               method: "eth_call",
+               params: [
+                 %{data: "0x46b2eb9b", to: ^address_hash_string},
+                 "latest"
+               ]
+             }
+           ],
+           _opts ->
+          {:ok,
+           [
+             %{
+               id: id,
+               jsonrpc: "2.0",
+               result:
+                 "0x000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000000322d2d5468697320697320612062616420737472696e672e204e6f626f64792073617973207468697320737472696e672e2d2d0000000000000000000000000000"
+             }
+           ]}
+        end
+      )
+
+      request = get(conn, "/api/v2/smart-contracts/#{target_contract.address_hash}/methods-read")
+      assert response = json_response(request, 200)
+
+      assert %{
+               "inputs" => [],
+               "name" => "FRAUD_STRING",
+               "outputs" => [
+                 %{
+                   "value" =>
+                     "0x2d2d5468697320697320612062616420737472696e672e204e6f626f64792073617973207468697320737472696e672e2d2d",
+                   "type" => "bytes"
+                 }
+               ],
+               "stateMutability" => "view",
+               "type" => "function",
+               "method_id" => Base.encode16(id_2, case: :lower),
+               "names" => ["bytes"]
+             } in response
+    end
   end
 
   describe "/smart-contracts/{address_hash}/query-read-method" do
diff --git a/apps/block_scout_web/test/block_scout_web/views/smart_contract_view_test.exs b/apps/block_scout_web/test/block_scout_web/views/smart_contract_view_test.exs
index 7ba53f18ce..cb63435730 100644
--- a/apps/block_scout_web/test/block_scout_web/views/smart_contract_view_test.exs
+++ b/apps/block_scout_web/test/block_scout_web/views/smart_contract_view_test.exs
@@ -8,47 +8,32 @@ defmodule BlockScoutWeb.SmartContractViewTest do
   describe "values_with_type/1" do
     test "complex data type case" do
       value =
-        {<<156, 209, 70, 119, 249, 170, 85, 105, 179, 187, 179, 81, 252, 214, 125, 17, 21, 170, 86, 58, 225, 98, 66,
-           118, 211, 212, 230, 127, 179, 214, 249, 38>>, 23_183_417, true,
+        {"0x9cd14677f9aa5569b3bbb351fcd67d1115aa563ae1624276d3d4e67fb3d6f926", 23_183_417, true,
          [
            {<<164, 118, 64, 69, 133, 31, 23, 170, 96, 182, 200, 232, 182, 32, 114, 190, 169, 83, 133, 33>>,
             [
-              <<15, 103, 152, 165, 96, 121, 58, 84, 195, 188, 254, 134, 169, 60, 222, 30, 115, 8, 125, 148, 76, 14, 162,
-                5, 68, 19, 125, 65, 33, 57, 104, 133>>,
-              <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 191, 61, 111, 131, 12, 226, 99, 202, 233, 135, 25, 57, 130, 25, 44,
-                217, 144, 68, 43, 83>>
-            ],
-            <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 170, 178, 96, 212, 241, 78, 0, 0>>},
+              "0x0f6798a560793a54c3bcfe86a93cde1e73087d944c0ea20544137d4121396885",
+              "0x000000000000000000000000bf3d6f830ce263cae987193982192cd990442b53"
+            ], "0x000000000000000000000000000000000000000000000000aab260d4f14e0000"},
            {<<164, 118, 64, 69, 133, 31, 23, 170, 96, 182, 200, 232, 182, 32, 114, 190, 169, 83, 133, 33>>,
             [
-              <<221, 242, 82, 173, 27, 226, 200, 155, 105, 194, 176, 104, 252, 55, 141, 170, 149, 43, 167, 241, 99, 196,
-                161, 22, 40, 245, 90, 77, 245, 35, 179, 239>>,
-              <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0>>,
-              <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 191, 61, 111, 131, 12, 226, 99, 202, 233, 135, 25, 57, 130, 25, 44,
-                217, 144, 68, 43, 83>>
-            ],
-            <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 170, 178, 96, 212, 241, 78, 0, 0>>},
+              "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef",
+              "0x0000000000000000000000000000000000000000000000000000000000000000",
+              "0x000000000000000000000000bf3d6f830ce263cae987193982192cd990442b53"
+            ], "0x000000000000000000000000000000000000000000000000aab260d4f14e0000"},
            {<<166, 139, 214, 89, 169, 22, 127, 61, 60, 1, 186, 151, 118, 161, 32, 141, 174, 143, 0, 59>>,
             [
-              <<47, 154, 96, 152, 212, 80, 58, 18, 119, 121, 186, 151, 95, 95, 107, 4, 248, 66, 54, 43, 24, 9, 243, 70,
-                152, 158, 154, 188, 11, 77, 237, 182>>,
-              <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 191, 61, 111, 131, 12, 226, 99, 202, 233, 135, 25, 57, 130, 25, 44,
-                217, 144, 68, 43, 83>>,
-              <<0, 5, 0, 0, 36, 155, 252, 47, 60, 200, 214, 143, 107, 107, 247, 35, 14, 160, 168, 237, 133, 61, 231, 49,
-                0, 0, 0, 0, 0, 0, 2, 79>>
-            ],
-            <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 170, 178, 96, 212, 241, 78, 0, 0>>},
+              "0x2f9a6098d4503a127779ba975f5f6b04f842362b1809f346989e9abc0b4dedb6",
+              "0x000000000000000000000000bf3d6f830ce263cae987193982192cd990442b53",
+              "0x00050000249bfc2f3cc8d68f6b6bf7230ea0a8ed853de731000000000000024f"
+            ], "0x000000000000000000000000000000000000000000000000aab260d4f14e0000"},
            {<<254, 68, 107, 239, 29, 191, 122, 254, 36, 232, 30, 5, 188, 139, 39, 28, 27, 169, 165, 96>>,
             [
-              <<39, 51, 62, 219, 139, 220, 212, 10, 10, 233, 68, 251, 18, 27, 94, 45, 98, 234, 120, 38, 131, 148, 102,
-                84, 160, 245, 230, 7, 169, 8, 213, 120>>,
-              <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 42, 95, 197, 45, 138, 86, 59, 47, 24, 28, 106, 82, 125, 66, 46, 21,
-                146, 201, 236, 250>>,
-              <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 166, 139, 214, 89, 169, 22, 127, 61, 60, 1, 186, 151, 118, 161, 32,
-                141, 174, 143, 0, 59>>,
-              <<0, 5, 0, 0, 36, 155, 252, 47, 60, 200, 214, 143, 107, 107, 247, 35, 14, 160, 168, 237, 133, 61, 231, 49,
-                0, 0, 0, 0, 0, 0, 2, 79>>
-            ], <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1>>}
+              "0x27333edb8bdcd40a0ae944fb121b5e2d62ea782683946654a0f5e607a908d578",
+              "0x0000000000000000000000002a5fc52d8a563b2f181c6a527d422e1592c9ecfa",
+              "0x000000000000000000000000a68bd659a9167f3d3c01ba9776a1208dae8f003b",
+              "0x00050000249bfc2f3cc8d68f6b6bf7230ea0a8ed853de731000000000000024f"
+            ], "0x0000000000000000000000000000000000000000000000000000000000000001"}
          ]}
 
       type = "tuple[bytes32,uint256,bool,tuple[address,bytes32[],bytes][]]"
diff --git a/apps/explorer/lib/explorer/smart_contract/reader.ex b/apps/explorer/lib/explorer/smart_contract/reader.ex
index 4fa3e8dadf..6222438d4f 100644
--- a/apps/explorer/lib/explorer/smart_contract/reader.ex
+++ b/apps/explorer/lib/explorer/smart_contract/reader.ex
@@ -754,6 +754,27 @@ defmodule Explorer.SmartContract.Reader do
     Map.put_new(output, "value", Encoder.unescape(value))
   end
 
+  defp new_value(%{"type" => "tuple" <> _types = type} = output, values, index) do
+    value = Enum.at(values, index)
+
+    result =
+      if String.ends_with?(type, "[]") do
+        value
+        |> Enum.map(fn tuple -> new_value(%{"type" => String.slice(type, 0..-3)}, [tuple], 0) end)
+        |> flat_arrays_map()
+      else
+        value
+        |> zip_tuple_values_with_types(type)
+        |> Enum.map(fn {type, part_value} ->
+          new_value(%{"type" => type}, [part_value], 0)
+        end)
+        |> flat_arrays_map()
+        |> List.to_tuple()
+      end
+
+    Map.put_new(output, "value", result)
+  end
+
   defp new_value(output, [value], _index) do
     Map.put_new(output, "value", value)
   end
@@ -762,6 +783,97 @@ defmodule Explorer.SmartContract.Reader do
     Map.put_new(output, "value", Enum.at(values, index))
   end
 
+  defp flat_arrays_map(%{"value" => value}) do
+    flat_arrays_map(value)
+  end
+
+  defp flat_arrays_map(value) when is_list(value) do
+    Enum.map(value, &flat_arrays_map/1)
+  end
+
+  defp flat_arrays_map(value) when is_tuple(value) do
+    value
+    |> Tuple.to_list()
+    |> flat_arrays_map()
+    |> List.to_tuple()
+  end
+
+  defp flat_arrays_map(value) do
+    value
+  end
+
+  def zip_tuple_values_with_types(value, type) do
+    types_string =
+      type
+      |> String.slice(6..-2)
+
+    types =
+      if String.trim(types_string) == "" do
+        []
+      else
+        types_string
+        |> String.split(",")
+      end
+
+    {tuple_types, _} =
+      types
+      |> Enum.reduce({[], nil}, fn val, acc ->
+        {arr, to_merge} = acc
+
+        if to_merge do
+          compose_array_if_to_merge(arr, val, to_merge)
+        else
+          compose_array_else(arr, val, to_merge)
+        end
+      end)
+
+    values_list =
+      value
+      |> Tuple.to_list()
+
+    Enum.zip(tuple_types, values_list)
+  end
+
+  def compose_array_if_to_merge(arr, val, to_merge) do
+    if count_string_symbols(val)["]"] > count_string_symbols(val)["["] do
+      updated_arr = update_last_list_item(arr, val)
+      {updated_arr, !to_merge}
+    else
+      updated_arr = update_last_list_item(arr, val)
+      {updated_arr, to_merge}
+    end
+  end
+
+  def compose_array_else(arr, val, to_merge) do
+    if count_string_symbols(val)["["] > count_string_symbols(val)["]"] do
+      # credo:disable-for-next-line
+      {arr ++ [val], !to_merge}
+    else
+      # credo:disable-for-next-line
+      {arr ++ [val], to_merge}
+    end
+  end
+
+  defp update_last_list_item(arr, new_val) do
+    arr
+    |> Enum.with_index()
+    |> Enum.map(fn {item, index} ->
+      if index == Enum.count(arr) - 1 do
+        item <> "," <> new_val
+      else
+        item
+      end
+    end)
+  end
+
+  defp count_string_symbols(str) do
+    str
+    |> String.graphemes()
+    |> Enum.reduce(%{"[" => 0, "]" => 0}, fn char, acc ->
+      Map.update(acc, char, 1, &(&1 + 1))
+    end)
+  end
+
   @spec bytes_to_string(<<_::_*8>>) :: String.t()
   defp bytes_to_string(value) do
     if value do

From 993189f1183b3ff65c21ae31c322a7d642bef623 Mon Sep 17 00:00:00 2001
From: Nikita Pozdniakov <nikitosing4@mail.ru>
Date: Mon, 11 Sep 2023 13:22:03 +0300
Subject: [PATCH 2/3] Refactor zip_tuple_values_with_types/2

---
 .../lib/explorer/smart_contract/reader.ex     | 45 ++++++++-----------
 1 file changed, 19 insertions(+), 26 deletions(-)

diff --git a/apps/explorer/lib/explorer/smart_contract/reader.ex b/apps/explorer/lib/explorer/smart_contract/reader.ex
index 6222438d4f..3729cbe722 100644
--- a/apps/explorer/lib/explorer/smart_contract/reader.ex
+++ b/apps/explorer/lib/explorer/smart_contract/reader.ex
@@ -802,6 +802,7 @@ defmodule Explorer.SmartContract.Reader do
     value
   end
 
+  @spec zip_tuple_values_with_types(tuple, binary) :: [{binary, any}]
   def zip_tuple_values_with_types(value, type) do
     types_string =
       type
@@ -815,18 +816,18 @@ defmodule Explorer.SmartContract.Reader do
         |> String.split(",")
       end
 
-    {tuple_types, _} =
+    {tuple_types_reversed, _} =
       types
-      |> Enum.reduce({[], nil}, fn val, acc ->
+      |> Enum.reduce({[], false}, fn val, acc ->
         {arr, to_merge} = acc
 
-        if to_merge do
-          compose_array_if_to_merge(arr, val, to_merge)
-        else
-          compose_array_else(arr, val, to_merge)
-        end
+        compose_array(to_merge, arr, val)
       end)
 
+    tuple_types =
+      tuple_types_reversed
+      |> Enum.reverse()
+
     values_list =
       value
       |> Tuple.to_list()
@@ -834,36 +835,28 @@ defmodule Explorer.SmartContract.Reader do
     Enum.zip(tuple_types, values_list)
   end
 
-  def compose_array_if_to_merge(arr, val, to_merge) do
+  defp compose_array(true, arr, val) do
+    updated_arr = update_last_list_item(arr, val)
+
     if count_string_symbols(val)["]"] > count_string_symbols(val)["["] do
-      updated_arr = update_last_list_item(arr, val)
-      {updated_arr, !to_merge}
+      {updated_arr, false}
     else
-      updated_arr = update_last_list_item(arr, val)
-      {updated_arr, to_merge}
+      {updated_arr, true}
     end
   end
 
-  def compose_array_else(arr, val, to_merge) do
+  defp compose_array(to_merge, arr, val) do
     if count_string_symbols(val)["["] > count_string_symbols(val)["]"] do
-      # credo:disable-for-next-line
-      {arr ++ [val], !to_merge}
+      {[val | arr], !to_merge}
     else
-      # credo:disable-for-next-line
-      {arr ++ [val], to_merge}
+      {[val | arr], to_merge}
     end
   end
 
   defp update_last_list_item(arr, new_val) do
-    arr
-    |> Enum.with_index()
-    |> Enum.map(fn {item, index} ->
-      if index == Enum.count(arr) - 1 do
-        item <> "," <> new_val
-      else
-        item
-      end
-    end)
+    [last_element | remain] = arr
+
+    [last_element <> "," <> new_val | remain]
   end
 
   defp count_string_symbols(str) do

From 4ecd6a77e60e8a58e6e223d05cfd2d8f718c9a71 Mon Sep 17 00:00:00 2001
From: Maxim Filonov <53992153+sl1depengwyn@users.noreply.github.com>
Date: Mon, 11 Sep 2023 14:01:16 +0300
Subject: [PATCH 3/3] Refactor zip_tuple_values_with_types/2

---
 .../lib/explorer/smart_contract/reader.ex     | 62 ++++++-------------
 1 file changed, 20 insertions(+), 42 deletions(-)

diff --git a/apps/explorer/lib/explorer/smart_contract/reader.ex b/apps/explorer/lib/explorer/smart_contract/reader.ex
index 3729cbe722..19b8a86af1 100644
--- a/apps/explorer/lib/explorer/smart_contract/reader.ex
+++ b/apps/explorer/lib/explorer/smart_contract/reader.ex
@@ -813,19 +813,29 @@ defmodule Explorer.SmartContract.Reader do
         []
       else
         types_string
-        |> String.split(",")
+        |> String.graphemes()
       end
 
-    {tuple_types_reversed, _} =
-      types
-      |> Enum.reduce({[], false}, fn val, acc ->
-        {arr, to_merge} = acc
-
-        compose_array(to_merge, arr, val)
-      end)
-
     tuple_types =
-      tuple_types_reversed
+      types
+      |> Enum.reduce(
+        {[""], 0},
+        fn
+          ",", {types_acc, 0} ->
+            {["" | types_acc], 0}
+
+          char, {[acc | types_acc], bracket_stack} ->
+            new_bracket_stack =
+              case char do
+                "[" -> bracket_stack + 1
+                "]" -> bracket_stack - 1
+                _ -> bracket_stack
+              end
+
+            {[acc <> char | types_acc], new_bracket_stack}
+        end
+      )
+      |> elem(0)
       |> Enum.reverse()
 
     values_list =
@@ -835,38 +845,6 @@ defmodule Explorer.SmartContract.Reader do
     Enum.zip(tuple_types, values_list)
   end
 
-  defp compose_array(true, arr, val) do
-    updated_arr = update_last_list_item(arr, val)
-
-    if count_string_symbols(val)["]"] > count_string_symbols(val)["["] do
-      {updated_arr, false}
-    else
-      {updated_arr, true}
-    end
-  end
-
-  defp compose_array(to_merge, arr, val) do
-    if count_string_symbols(val)["["] > count_string_symbols(val)["]"] do
-      {[val | arr], !to_merge}
-    else
-      {[val | arr], to_merge}
-    end
-  end
-
-  defp update_last_list_item(arr, new_val) do
-    [last_element | remain] = arr
-
-    [last_element <> "," <> new_val | remain]
-  end
-
-  defp count_string_symbols(str) do
-    str
-    |> String.graphemes()
-    |> Enum.reduce(%{"[" => 0, "]" => 0}, fn char, acc ->
-      Map.update(acc, char, 1, &(&1 + 1))
-    end)
-  end
-
   @spec bytes_to_string(<<_::_*8>>) :: String.t()
   defp bytes_to_string(value) do
     if value do