From 348a8acc1e5fd9359d7ee0d12937cc22c729e2c6 Mon Sep 17 00:00:00 2001
From: Nikita Pozdniakov <nikitosing4@mail.ru>
Date: Mon, 17 Jul 2023 22:31:37 +0700
Subject: [PATCH] Add parsing constructor arguments for sourcify contracts

---
 apps/explorer/lib/explorer/chain.ex           | 34 +++++++++++++++++--
 .../smart_contract/solidity/verifier.ex       | 34 +++++++++++++++++++
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/apps/explorer/lib/explorer/chain.ex b/apps/explorer/lib/explorer/chain.ex
index dd4200d0f0..e2ed916029 100644
--- a/apps/explorer/lib/explorer/chain.ex
+++ b/apps/explorer/lib/explorer/chain.ex
@@ -98,6 +98,7 @@ defmodule Explorer.Chain do
   alias Explorer.Market.MarketHistoryCache
   alias Explorer.{PagingOptions, Repo}
   alias Explorer.SmartContract.Helper
+  alias Explorer.SmartContract.Solidity.Verifier
   alias Explorer.Tags.{AddressTag, AddressToTag}
 
   alias Dataloader.Ecto, as: DataloaderEcto
@@ -1913,7 +1914,7 @@ defmodule Explorer.Chain do
           if smart_contract do
             CheckBytecodeMatchingOnDemand.trigger_check(address_result, smart_contract)
             LookUpSmartContractSourcesOnDemand.trigger_fetch(address_result, smart_contract)
-            address_result
+            check_and_update_constructor_args(address_result)
           else
             LookUpSmartContractSourcesOnDemand.trigger_fetch(address_result, nil)
 
@@ -1936,6 +1937,35 @@ defmodule Explorer.Chain do
     end
   end
 
+  defp check_and_update_constructor_args(
+         %SmartContract{address_hash: address_hash, constructor_arguments: nil} = smart_contract
+       ) do
+    if args = Verifier.parse_constructor_arguments_for_sourcify_contract(address_hash, smart_contract.abi) do
+      smart_contract |> SmartContract.changeset(%{constructor_arguments: args}) |> Repo.update()
+      %SmartContract{smart_contract | constructor_arguments: args}
+    else
+      smart_contract
+    end
+  end
+
+  defp check_and_update_constructor_args(
+         %Address{
+           hash: address_hash,
+           contract_code: deployed_bytecode,
+           smart_contract: %SmartContract{constructor_arguments: nil} = smart_contract
+         } = address
+       ) do
+    if args =
+         Verifier.parse_constructor_arguments_for_sourcify_contract(address_hash, smart_contract.abi, deployed_bytecode) do
+      smart_contract |> SmartContract.changeset(%{constructor_arguments: args}) |> Repo.update()
+      %Address{address | smart_contract: %SmartContract{smart_contract | constructor_arguments: args}}
+    else
+      address
+    end
+  end
+
+  defp check_and_update_constructor_args(other), do: other
+
   defp add_twin_info_to_contract(address_result, address_verified_twin_contract, _hash)
        when is_nil(address_verified_twin_contract),
        do: address_result
@@ -4310,7 +4340,7 @@ defmodule Explorer.Chain do
       verified_contract_twin_additional_sources = get_contract_additional_sources(verified_contract_twin, options)
 
       %{
-        :verified_contract => verified_contract_twin,
+        :verified_contract => check_and_update_constructor_args(verified_contract_twin),
         :additional_sources => verified_contract_twin_additional_sources
       }
     else
diff --git a/apps/explorer/lib/explorer/smart_contract/solidity/verifier.ex b/apps/explorer/lib/explorer/smart_contract/solidity/verifier.ex
index 57c11709ab..50cd34a24d 100644
--- a/apps/explorer/lib/explorer/smart_contract/solidity/verifier.ex
+++ b/apps/explorer/lib/explorer/smart_contract/solidity/verifier.ex
@@ -13,6 +13,7 @@ defmodule Explorer.SmartContract.Solidity.Verifier do
 
   alias ABI.{FunctionSelector, TypeDecoder}
   alias Explorer.Chain
+  alias Explorer.Chain.Data
   alias Explorer.SmartContract.RustVerifierInterface
   alias Explorer.SmartContract.Solidity.CodeCompiler
 
@@ -533,4 +534,37 @@ defmodule Explorer.SmartContract.Solidity.Verifier do
   def parse_boolean(false), do: false
 
   def parse_boolean(_), do: false
+
+  def parse_constructor_arguments_for_sourcify_contract(address_hash, abi) do
+    parse_constructor_arguments_for_sourcify_contract(address_hash, abi, Chain.smart_contract_bytecode(address_hash))
+  end
+
+  def parse_constructor_arguments_for_sourcify_contract(address_hash, abi, deployed_bytecode)
+      when is_binary(deployed_bytecode) do
+    creation_tx_input =
+      case Chain.smart_contract_creation_tx_bytecode(address_hash) do
+        %{init: init, created_contract_code: _created_contract_code} ->
+          "0x" <> init_without_0x = init
+          init_without_0x
+
+        _ ->
+          nil
+      end
+
+    with true <- has_constructor_with_params?(abi),
+         check_function <- parse_constructor_and_return_check_function(abi),
+         false <- is_nil(creation_tx_input) || deployed_bytecode == "0x",
+         {meta, meta_length} <- extract_meta_from_deployed_bytecode(deployed_bytecode),
+         [_bytecode, constructor_args] <- String.split(creation_tx_input, meta <> meta_length),
+         ^constructor_args <- check_function.(constructor_args) do
+      constructor_args
+    else
+      _ ->
+        nil
+    end
+  end
+
+  def parse_constructor_arguments_for_sourcify_contract(address_hash, abi, deployed_bytecode) do
+    parse_constructor_arguments_for_sourcify_contract(address_hash, abi, Data.to_string(deployed_bytecode))
+  end
 end