From 352ee9d7bf781b9d73bd0bdfc31589189af41188 Mon Sep 17 00:00:00 2001
From: Victor Baranov <baranov.viktor.27@gmail.com>
Date: Tue, 29 Sep 2020 12:42:37 +0300
Subject: [PATCH] AMB bridged tokens

---
 CHANGELOG.md                                  |   1 +
 apps/block_scout_web/assets/css/app.scss      |   1 +
 .../assets/css/components/_label.scss         |  19 ++
 apps/block_scout_web/config/config.exs        |   5 +-
 .../tokens/bridged_tokens_controller.ex       |   3 +-
 .../templates/bridged_tokens/_tile.html.eex   |  31 +-
 .../templates/bridged_tokens/index.html.eex   |   1 +
 .../templates/layout/_topnav.html.eex         |   2 +-
 .../views/bridged_tokens_view.ex              |  19 ++
 .../lib/block_scout_web/views/tokens_view.ex  |   4 +-
 apps/explorer/lib/explorer/chain.ex           | 282 +++++++++++++-----
 .../lib/explorer/chain/bridged_token.ex       |   8 +-
 .../20200929075625_add_bridged_token_type.exs |   9 +
 .../set_amb_bridged_metadata_for_tokens.ex    |  39 +++
 ...> set_omni_bridged_metadata_for_tokens.ex} |   8 +-
 apps/indexer/lib/indexer/supervisor.ex        |  19 +-
 16 files changed, 356 insertions(+), 95 deletions(-)
 create mode 100644 apps/block_scout_web/assets/css/components/_label.scss
 create mode 100644 apps/explorer/priv/repo/migrations/20200929075625_add_bridged_token_type.exs
 create mode 100644 apps/indexer/lib/indexer/set_amb_bridged_metadata_for_tokens.ex
 rename apps/indexer/lib/indexer/{set_bridged_metadata_for_tokens.ex => set_omni_bridged_metadata_for_tokens.ex} (80%)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d61f364197..705fa4f3e6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 ## Current
 
 ### Features
+- [#3320](https://github.com/poanetwork/blockscout/pull/3320) - Bridged tokens from AMB extensions support
 - [#3311](https://github.com/poanetwork/blockscout/pull/3311) - List of addresses with restricted access option
 - [#3293](https://github.com/poanetwork/blockscout/pull/3293) - Composite market cap for xDai: TokenBridge + OmniBridge
 - [#3282](https://github.com/poanetwork/blockscout/pull/3282), [#3318](https://github.com/poanetwork/blockscout/pull/3318) - Import bridged tokens custom metadata
diff --git a/apps/block_scout_web/assets/css/app.scss b/apps/block_scout_web/assets/css/app.scss
index e81af0781f..ded845b4b5 100644
--- a/apps/block_scout_web/assets/css/app.scss
+++ b/apps/block_scout_web/assets/css/app.scss
@@ -117,6 +117,7 @@ $fa-font-path: "~@fortawesome/fontawesome-free/webfonts";
 @import "components/_erc721_token_image_container";
 @import "components/_inventory_token_instance_image_container";
 @import "components/_external_link";
+@import "components/_label";
 
 @import "theme/dark-theme";
 
diff --git a/apps/block_scout_web/assets/css/components/_label.scss b/apps/block_scout_web/assets/css/components/_label.scss
new file mode 100644
index 0000000000..20dd9fa3d5
--- /dev/null
+++ b/apps/block_scout_web/assets/css/components/_label.scss
@@ -0,0 +1,19 @@
+.bridged-token-label {
+    display: inline-block;
+    padding: 5px;
+    background: #f5f6fa;
+    color: #a3a9b5;
+    border-radius: 5px;
+    font-size: 10px;
+    &.right {
+        float: right;
+    }
+    &.omni {
+        background: $primary;
+        color: white;
+    }
+    &.amb {
+        background: $secondary;
+        color: white;
+    }
+}
\ No newline at end of file
diff --git a/apps/block_scout_web/config/config.exs b/apps/block_scout_web/config/config.exs
index 4f696156ea..4d5d3c6fe8 100644
--- a/apps/block_scout_web/config/config.exs
+++ b/apps/block_scout_web/config/config.exs
@@ -36,8 +36,9 @@ config :block_scout_web,
   api_url: System.get_env("API_URL"),
   apps_menu: if(System.get_env("APPS_MENU", "false") == "true", do: true, else: false),
   external_apps: System.get_env("EXTERNAL_APPS"),
-  multi_token_bridge_mediator: System.get_env("MULTI_TOKEN_BRIDGE_MEDIATOR"),
-  foreign_json_rpc: System.get_env("FOREIGN_JSON_RPC"),
+  omni_bridge_mediator: System.get_env("OMNI_BRIDGE_MEDIATOR"),
+  amb_bridge_mediators: System.get_env("AMB_BRIDGE_MEDIATORS"),
+  foreign_json_rpc: System.get_env("FOREIGN_JSON_RPC", ""),
   gas_price: System.get_env("GAS_PRICE", nil),
   restricted_list: System.get_env("RESTRICTED_LIST", nil),
   restricted_list_key: System.get_env("RESTRICTED_LIST_KEY", nil)
diff --git a/apps/block_scout_web/lib/block_scout_web/controllers/tokens/bridged_tokens_controller.ex b/apps/block_scout_web/lib/block_scout_web/controllers/tokens/bridged_tokens_controller.ex
index 815077567f..3aeea6602f 100644
--- a/apps/block_scout_web/lib/block_scout_web/controllers/tokens/bridged_tokens_controller.ex
+++ b/apps/block_scout_web/lib/block_scout_web/controllers/tokens/bridged_tokens_controller.ex
@@ -31,11 +31,12 @@ defmodule BlockScoutWeb.BridgedTokensController do
     items =
       tokens_page
       |> Enum.with_index(1)
-      |> Enum.map(fn {token, index} ->
+      |> Enum.map(fn {[token, bridged_token], index} ->
         View.render_to_string(
           BridgedTokensView,
           "_tile.html",
           token: token,
+          bridged_token: bridged_token,
           index: index
         )
       end)
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/bridged_tokens/_tile.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/bridged_tokens/_tile.html.eex
index 094a16442a..49cad1f047 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/bridged_tokens/_tile.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/bridged_tokens/_tile.html.eex
@@ -7,10 +7,33 @@
   </td>
   <td class="stakes-td">
     <% token = token_display_name(@token) %>
-    <%= link(token,
-      to: token_path(BlockScoutWeb.Endpoint, :show, @token.contract_address_hash),
-      "data-test": "token_link",
-      class: "text-truncate") %>
+    <div>
+      <%= link(token,
+        to: token_path(BlockScoutWeb.Endpoint, :show, @token.contract_address_hash),
+        "data-test": "token_link",
+        class: "text-truncate") %>
+      <%= if @bridged_token.type do %>
+        <div class="bridged-token-label right <%= @bridged_token.type %>"><%= String.upcase(@bridged_token.type) %></div>
+      <% end %>
+      <%= if owl_token_amb?(@token.contract_address.hash) do %>
+        <span
+          data-toggle="tooltip"
+          data-placement="top"
+          data-html="true"
+          title="<%= owl_token_amb_info() %>">
+          <i style="color: #f7b32b;" class="fa fa-info-circle ml-1" data-test="owl_info"></i>
+        </span>
+      <% end %>
+      <%= if owl_token_omni?(@token.contract_address.hash) do %>
+        <span
+          data-toggle="tooltip"
+          data-placement="top"
+          data-html="true"
+          title="<%= owl_token_omni_info() %>">
+          <i style="color: #f7b32b;" class="fa fa-info-circle ml-1" data-test="owl_info"></i>
+        </span>
+      <% end %>
+    </div>
   </td>
   <td class="stakes-td">
     <%= render BlockScoutWeb.AddressView,
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/bridged_tokens/index.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/bridged_tokens/index.html.eex
index 5b76450d69..6277ab16cd 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/bridged_tokens/index.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/bridged_tokens/index.html.eex
@@ -2,6 +2,7 @@
   <div class="card">
     <div class="card-body" data-async-load data-async-listing="<%= @current_path %>">
       <h1 class="card-title"><%= gettext "Bridged Tokens" %></h1>
+	  <p class="card-subtitle">List of the tokens bridged through OmniBridge <span class="bridged-token-label omni">OMNI</span> and Arbitrary Message Bridge <span class="bridged-token-label amb">AMB</span> extensions</p>
 
     <%= render BlockScoutWeb.CommonComponentsView, "_pagination_container.html", position: "top", cur_page_number: "1", show_pagination_limit: true, data_next_page_button: true, data_prev_page_button: true %>
 
diff --git a/apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex b/apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex
index c8b4a8f7b5..32e1d4ea9a 100644
--- a/apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex
+++ b/apps/block_scout_web/lib/block_scout_web/templates/layout/_topnav.html.eex
@@ -78,7 +78,7 @@
               <%= gettext("Accounts") %>
             <% end %>
           </li>
-          <%= if Application.get_env(:block_scout_web, :multi_token_bridge_mediator) && Application.get_env(:block_scout_web, :multi_token_bridge_mediator) != "" do %>
+          <%= if Application.get_env(:block_scout_web, :omni_bridge_mediator) && Application.get_env(:block_scout_web, :omni_bridge_mediator) != "" do %>
             <li class="nav-item dropdown">
               <a href="#" role="button" id="navbarTokensDropdown" class="nav-link topnav-nav-link dropdown-toggle" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                 <span class="nav-link-icon">
diff --git a/apps/block_scout_web/lib/block_scout_web/views/bridged_tokens_view.ex b/apps/block_scout_web/lib/block_scout_web/views/bridged_tokens_view.ex
index 4a105aaa40..8b1d3659a5 100644
--- a/apps/block_scout_web/lib/block_scout_web/views/bridged_tokens_view.ex
+++ b/apps/block_scout_web/lib/block_scout_web/views/bridged_tokens_view.ex
@@ -3,10 +3,29 @@ defmodule BlockScoutWeb.BridgedTokensView do
 
   alias Explorer.Chain.Token
 
+  @owl_token_amb "0x0905Ab807F8FD040255F0cF8fa14756c1D824931"
+  @owl_token_omni "0x750eCf8c11867Ce5Dbc556592c5bb1E0C6d16538"
+
   def decimals?(%Token{decimals: nil}), do: false
   def decimals?(%Token{decimals: _}), do: true
 
   def token_display_name(%Token{name: nil}), do: ""
 
   def token_display_name(%Token{name: name}), do: name
+
+  def owl_token_amb?(address_hash) do
+    to_string(address_hash) == String.downcase(@owl_token_amb)
+  end
+
+  def owl_token_omni?(address_hash) do
+    to_string(address_hash) == String.downcase(@owl_token_omni)
+  end
+
+  def owl_token_amb_info do
+    "<div class='token-bridge-market-cap-header'>Bridged through AMB extension OWL token, which supports <i>burnOwl</i> method.</div>"
+  end
+
+  def owl_token_omni_info do
+    "<div class='token-bridge-market-cap-header'>Bridged through OmniBridge OWL token. It doesn't support <i>burnOwl</i> method.</div>"
+  end
 end
diff --git a/apps/block_scout_web/lib/block_scout_web/views/tokens_view.ex b/apps/block_scout_web/lib/block_scout_web/views/tokens_view.ex
index 7589dc5ef5..bde196fa85 100644
--- a/apps/block_scout_web/lib/block_scout_web/views/tokens_view.ex
+++ b/apps/block_scout_web/lib/block_scout_web/views/tokens_view.ex
@@ -7,9 +7,9 @@ defmodule BlockScoutWeb.TokensView do
   def decimals?(%Token{decimals: _}), do: true
 
   def bridged_tokens_enabled? do
-    multi_token_bridge_mediator = Application.get_env(:block_scout_web, :multi_token_bridge_mediator)
+    omni_bridge_mediator = Application.get_env(:block_scout_web, :omni_bridge_mediator)
 
-    multi_token_bridge_mediator && multi_token_bridge_mediator !== ""
+    omni_bridge_mediator && omni_bridge_mediator !== ""
   end
 
   def token_display_name(%Token{name: nil, symbol: nil}), do: ""
diff --git a/apps/explorer/lib/explorer/chain.ex b/apps/explorer/lib/explorer/chain.ex
index 5e8de20254..02073f3505 100644
--- a/apps/explorer/lib/explorer/chain.ex
+++ b/apps/explorer/lib/explorer/chain.ex
@@ -24,6 +24,8 @@ defmodule Explorer.Chain do
 
   import EthereumJSONRPC, only: [integer_to_quantity: 1, json_rpc: 2, fetch_block_internal_transactions: 2]
 
+  require Logger
+
   alias ABI.{TypeDecoder, TypeEncoder}
   alias Ecto.Adapters.SQL
   alias Ecto.{Changeset, Multi}
@@ -1820,11 +1822,19 @@ defmodule Explorer.Chain do
   end
 
   defp fetch_top_bridged_tokens(paging_options) do
+    bridged_tokens_query =
+      from(bt in BridgedToken,
+        select: bt
+      )
+
     base_query =
       from(t in Token,
+        left_join: bt in subquery(bridged_tokens_query),
+        on: t.contract_address_hash == bt.home_token_contract_address_hash,
         where: t.total_supply > ^0,
         where: t.bridged,
         order_by: [desc: t.holder_count, asc: t.name],
+        select: [t, bt],
         preload: [:contract_address]
       )
 
@@ -3581,9 +3591,62 @@ defmodule Explorer.Chain do
   end
 
   @doc """
-  Fetches bridged tokens metadata.
+  Processes AMB tokens from mediators addresses provided
+  """
+  def process_amb_tokens do
+    amb_bridge_mediators_var = Application.get_env(:block_scout_web, :amb_bridge_mediators)
+    amb_bridge_mediators = (amb_bridge_mediators_var && String.split(amb_bridge_mediators_var, ",")) || []
+
+    json_rpc_named_arguments = Application.get_env(:explorer, :json_rpc_named_arguments)
+
+    foreign_json_rpc = Application.get_env(:block_scout_web, :foreign_json_rpc)
+
+    eth_call_foreign_json_rpc_named_arguments =
+      compose_foreign_json_rpc_named_arguments(json_rpc_named_arguments, foreign_json_rpc)
+
+    amb_bridge_mediators
+    |> Enum.each(fn amb_bridge_mediator_hash ->
+      with {:ok, bridge_contract_hash_resp} <-
+             get_bridge_contract_hash(amb_bridge_mediator_hash, json_rpc_named_arguments),
+           bridge_contract_hash <- decode_contract_address_hash_response(bridge_contract_hash_resp),
+           {:ok, destination_chain_id_resp} <- get_destination_chain_id(bridge_contract_hash, json_rpc_named_arguments),
+           foreign_chain_id <- decode_contract_integer_response(destination_chain_id_resp),
+           {:ok, home_token_contract_hash_resp} <-
+             get_erc677_token_hash(amb_bridge_mediator_hash, json_rpc_named_arguments),
+           home_token_contract_hash_string <- decode_contract_address_hash_response(home_token_contract_hash_resp),
+           {:ok, home_token_contract_hash} <- Chain.string_to_address_hash(home_token_contract_hash_string),
+           {:ok, foreign_mediator_contract_hash_resp} <-
+             get_foreign_mediator_contract_hash(amb_bridge_mediator_hash, json_rpc_named_arguments),
+           foreign_mediator_contract_hash <- decode_contract_address_hash_response(foreign_mediator_contract_hash_resp),
+           {:ok, foreign_token_contract_hash_resp} <-
+             get_erc677_token_hash(foreign_mediator_contract_hash, eth_call_foreign_json_rpc_named_arguments),
+           foreign_token_contract_hash_string <-
+             decode_contract_address_hash_response(foreign_token_contract_hash_resp),
+           {:ok, foreign_token_contract_hash} <- Chain.string_to_address_hash(foreign_token_contract_hash_string) do
+        insert_bridged_token_metadata(home_token_contract_hash, %{
+          foreign_chain_id: foreign_chain_id,
+          foreign_token_address_hash: foreign_token_contract_hash,
+          custom_metadata: nil,
+          type: "amb"
+        })
+
+        set_token_bridged_status(home_token_contract_hash, true)
+      else
+        result ->
+          Logger.debug([
+            "failed to fetch metadata for token bridged with AMB mediator #{amb_bridge_mediator_hash}",
+            inspect(result)
+          ])
+      end
+    end)
+
+    :ok
+  end
+
+  @doc """
+  Fetches bridged tokens metadata from OmniBridge.
   """
-  def fetch_bridged_tokens_metadata(token_addresses) do
+  def fetch_omni_bridged_tokens_metadata(token_addresses) do
     Enum.each(token_addresses, fn token_address_hash ->
       created_from_int_tx_success_query =
         from(
@@ -3627,7 +3690,7 @@ defmodule Explorer.Chain do
           set_token_bridged_status(token_address_hash, false)
 
         created_from_int_tx && created_from_int_tx_success ->
-          extract_bridged_token_metadata_wrapper(token_address_hash, created_from_int_tx_success)
+          extract_omni_bridged_token_metadata_wrapper(token_address_hash, created_from_int_tx_success)
 
         true ->
           :ok
@@ -3637,18 +3700,18 @@ defmodule Explorer.Chain do
     :ok
   end
 
-  defp extract_bridged_token_metadata_wrapper(token_address_hash, created_from_int_tx_success) do
-    multi_token_bridge_mediator = Application.get_env(:block_scout_web, :multi_token_bridge_mediator)
+  defp extract_omni_bridged_token_metadata_wrapper(token_address_hash, created_from_int_tx_success) do
+    omni_bridge_mediator = Application.get_env(:block_scout_web, :omni_bridge_mediator)
     %{transaction_hash: transaction_hash} = created_from_int_tx_success
 
-    if multi_token_bridge_mediator && multi_token_bridge_mediator !== "" do
-      {:ok, multi_token_bridge_mediator_hash} = Chain.string_to_address_hash(multi_token_bridge_mediator)
+    if omni_bridge_mediator && omni_bridge_mediator !== "" do
+      {:ok, omni_bridge_mediator_hash} = Chain.string_to_address_hash(omni_bridge_mediator)
 
       created_by_amb_mediator_query =
         from(
           it in InternalTransaction,
           where: it.transaction_hash == ^transaction_hash,
-          where: it.to_address_hash == ^multi_token_bridge_mediator_hash
+          where: it.to_address_hash == ^omni_bridge_mediator_hash
         )
 
       created_by_amb_mediator =
@@ -3656,10 +3719,10 @@ defmodule Explorer.Chain do
         |> Repo.all()
 
       if Enum.count(created_by_amb_mediator) > 0 do
-        extract_bridged_token_metadata(
+        extract_omni_bridged_token_metadata(
           token_address_hash,
-          multi_token_bridge_mediator,
-          multi_token_bridge_mediator_hash
+          omni_bridge_mediator,
+          omni_bridge_mediator_hash
         )
       else
         set_token_bridged_status(token_address_hash, false)
@@ -3667,61 +3730,24 @@ defmodule Explorer.Chain do
     end
   end
 
-  defp extract_bridged_token_metadata(token_address_hash, multi_token_bridge_mediator, multi_token_bridge_mediator_hash) do
+  defp extract_omni_bridged_token_metadata(token_address_hash, omni_bridge_mediator, omni_bridge_mediator_hash) do
     json_rpc_named_arguments = Application.get_env(:explorer, :json_rpc_named_arguments)
-    # keccak 256 from getTokenInterfacesVersion()
-    get_token_interfaces_version_signature = "0x859ba28c"
-    # keccak 256 from foreignTokenAddress(address)
-    foreign_token_address_signature = "0x47ac7d6a"
-    # keccak 256 from bridgeContract()
-    bridge_contract_signature = "0xcd596583"
-    # keccak 256 from destinationChainId()
-    destination_chain_id_signature = "0xb0750611"
-
-    token_address_hash_abi_encoded =
-      [token_address_hash.bytes]
-      |> TypeEncoder.encode([:address])
-      |> Base.encode16()
-
-    foreign_token_address_method = foreign_token_address_signature <> token_address_hash_abi_encoded
 
     with {:ok, _} <-
-           get_token_interfaces_version_signature
-           |> Contract.eth_call_request(token_address_hash, 1, nil, nil)
-           |> json_rpc(json_rpc_named_arguments),
+           get_token_interfaces_version_signature(token_address_hash, json_rpc_named_arguments),
          {:ok, foreign_token_address_abi_encoded} <-
-           foreign_token_address_method
-           |> Contract.eth_call_request(
-             multi_token_bridge_mediator,
-             1,
-             nil,
-             nil
-           )
-           |> json_rpc(json_rpc_named_arguments),
-         {:ok, bridge_contract} <-
-           bridge_contract_signature
-           |> Contract.eth_call_request(multi_token_bridge_mediator_hash, 1, nil, nil)
-           |> json_rpc(json_rpc_named_arguments) do
-      "0x" <> foreign_token_address_no_prefix = foreign_token_address_abi_encoded
-
-      <<_prefix::binary-size(24), foreign_token_address_hash_string_raw::binary()>> = foreign_token_address_no_prefix
-
-      foreign_token_address_hash_string = "0x" <> foreign_token_address_hash_string_raw
-
+           get_foreign_token_address(omni_bridge_mediator, token_address_hash, json_rpc_named_arguments),
+         {:ok, bridge_contract_hash_resp} <-
+           get_bridge_contract_hash(omni_bridge_mediator_hash, json_rpc_named_arguments) do
+      foreign_token_address_hash_string = decode_contract_address_hash_response(foreign_token_address_abi_encoded)
       {:ok, foreign_token_address_hash} = Chain.string_to_address_hash(foreign_token_address_hash_string)
 
-      "0x" <> bridge_contract_no_prefix = bridge_contract
-      <<_prefix::binary-size(24), multi_token_bridge_hash_string_raw::binary()>> = bridge_contract_no_prefix
-
-      multi_token_bridge_hash_string = "0x" <> multi_token_bridge_hash_string_raw
+      multi_token_bridge_hash_string = decode_contract_address_hash_response(bridge_contract_hash_resp)
 
       {:ok, foreign_chain_id_abi_encoded} =
-        destination_chain_id_signature
-        |> Contract.eth_call_request(multi_token_bridge_hash_string, 1, nil, nil)
-        |> json_rpc(json_rpc_named_arguments)
+        get_destination_chain_id(multi_token_bridge_hash_string, json_rpc_named_arguments)
 
-      "0x" <> foreign_chain_id_abi_encoded_no_prefix = foreign_chain_id_abi_encoded
-      {foreign_chain_id, _} = Integer.parse(foreign_chain_id_abi_encoded_no_prefix, 16)
+      foreign_chain_id = decode_contract_integer_response(foreign_chain_id_abi_encoded)
 
       foreign_json_rpc = Application.get_env(:block_scout_web, :foreign_json_rpc)
 
@@ -3731,38 +3757,135 @@ defmodule Explorer.Chain do
       insert_bridged_token_metadata(token_address_hash, %{
         foreign_chain_id: foreign_chain_id,
         foreign_token_address_hash: foreign_token_address_hash,
-        custom_metadata: custom_metadata
+        custom_metadata: custom_metadata,
+        type: "omni"
       })
 
       set_token_bridged_status(token_address_hash, true)
     end
   end
 
+  defp get_bridge_contract_hash(mediator_hash, json_rpc_named_arguments) do
+    # keccak 256 from bridgeContract()
+    bridge_contract_signature = "0xcd596583"
+
+    perform_eth_call_request(bridge_contract_signature, mediator_hash, json_rpc_named_arguments)
+  end
+
+  defp get_erc677_token_hash(mediator_hash, json_rpc_named_arguments) do
+    # keccak 256 from erc677token()
+    erc677_token_signature = "0x18d8f9c9"
+
+    perform_eth_call_request(erc677_token_signature, mediator_hash, json_rpc_named_arguments)
+  end
+
+  defp get_foreign_mediator_contract_hash(mediator_hash, json_rpc_named_arguments) do
+    # keccak 256 from mediatorContractOnOtherSide()
+    mediator_contract_on_other_side_signature = "0x871c0760"
+
+    perform_eth_call_request(mediator_contract_on_other_side_signature, mediator_hash, json_rpc_named_arguments)
+  end
+
+  defp get_destination_chain_id(bridge_contract_hash, json_rpc_named_arguments) do
+    # keccak 256 from destinationChainId()
+    destination_chain_id_signature = "0xb0750611"
+
+    perform_eth_call_request(destination_chain_id_signature, bridge_contract_hash, json_rpc_named_arguments)
+  end
+
+  defp get_token_interfaces_version_signature(token_address_hash, json_rpc_named_arguments) do
+    # keccak 256 from getTokenInterfacesVersion()
+    get_token_interfaces_version_signature = "0x859ba28c"
+
+    perform_eth_call_request(get_token_interfaces_version_signature, token_address_hash, json_rpc_named_arguments)
+  end
+
+  defp get_foreign_token_address(omni_bridge_mediator, token_address_hash, json_rpc_named_arguments) do
+    # keccak 256 from foreignTokenAddress(address)
+    foreign_token_address_signature = "0x47ac7d6a"
+
+    token_address_hash_abi_encoded =
+      [token_address_hash.bytes]
+      |> TypeEncoder.encode([:address])
+      |> Base.encode16()
+
+    foreign_token_address_method = foreign_token_address_signature <> token_address_hash_abi_encoded
+
+    perform_eth_call_request(foreign_token_address_method, omni_bridge_mediator, json_rpc_named_arguments)
+  end
+
+  defp perform_eth_call_request(method, destination, json_rpc_named_arguments)
+       when not is_nil(json_rpc_named_arguments) do
+    method
+    |> Contract.eth_call_request(destination, 1, nil, nil)
+    |> json_rpc(json_rpc_named_arguments)
+  end
+
+  defp perform_eth_call_request(_method, _destination, json_rpc_named_arguments)
+       when is_nil(json_rpc_named_arguments) do
+    :error
+  end
+
+  def decode_contract_address_hash_response(resp) do
+    case resp do
+      "0x000000000000000000000000" <> address ->
+        "0x" <> address
+
+      _ ->
+        nil
+    end
+  end
+
+  def decode_contract_integer_response(resp) do
+    case resp do
+      "0x" <> integer_encoded ->
+        {integer_value, _} = Integer.parse(integer_encoded, 16)
+        integer_value
+
+      _ ->
+        nil
+    end
+  end
+
   defp set_token_bridged_status(token_address_hash, status) do
-    target_token = Repo.get!(Token, token_address_hash)
-    token = Changeset.change(target_token, bridged: status)
+    case Repo.get(Token, token_address_hash) do
+      %Explorer.Chain.Token{bridged: bridged} = target_token ->
+        if !bridged do
+          token = Changeset.change(target_token, bridged: status)
 
-    Repo.update(token)
+          Repo.update(token)
+        end
+
+      _ ->
+        :ok
+    end
   end
 
   defp insert_bridged_token_metadata(token_address_hash, %{
          foreign_chain_id: foreign_chain_id,
          foreign_token_address_hash: foreign_token_address_hash,
-         custom_metadata: custom_metadata
+         custom_metadata: custom_metadata,
+         type: type
        }) do
-    {:ok, _} =
-      Repo.insert(
-        %BridgedToken{
-          home_token_contract_address_hash: token_address_hash,
-          foreign_chain_id: foreign_chain_id,
-          foreign_token_contract_address_hash: foreign_token_address_hash,
-          custom_metadata: custom_metadata
-        },
-        on_conflict: :nothing
-      )
+    target_token = Repo.get(Token, token_address_hash)
+
+    if target_token do
+      {:ok, _} =
+        Repo.insert(
+          %BridgedToken{
+            home_token_contract_address_hash: token_address_hash,
+            foreign_chain_id: foreign_chain_id,
+            foreign_token_contract_address_hash: foreign_token_address_hash,
+            custom_metadata: custom_metadata,
+            type: type
+          },
+          on_conflict: :nothing
+        )
+    end
   end
 
-  # get_bridged_token_custom_metadata function currently gets Balancer token composite tokens with their weights
+  # Fetches custom metadata for bridged tokens from the node.
+  # Currently, gets Balancer token composite tokens with their weights
   # from foreign chain 
   defp get_bridged_token_custom_metadata(foreign_token_address_hash, json_rpc_named_arguments, foreign_json_rpc)
        when not is_nil(foreign_json_rpc) and foreign_json_rpc !== "" do
@@ -3823,7 +3946,8 @@ defmodule Explorer.Chain do
     nil
   end
 
-  defp compose_foreign_json_rpc_named_arguments(json_rpc_named_arguments, foreign_json_rpc) do
+  defp compose_foreign_json_rpc_named_arguments(json_rpc_named_arguments, foreign_json_rpc)
+       when foreign_json_rpc != "" do
     {_, eth_call_foreign_json_rpc_named_arguments} =
       Keyword.get_and_update(json_rpc_named_arguments, :transport_options, fn transport_options ->
         {_, updated_transport_options} =
@@ -3835,6 +3959,16 @@ defmodule Explorer.Chain do
     eth_call_foreign_json_rpc_named_arguments
   end
 
+  defp compose_foreign_json_rpc_named_arguments(_json_rpc_named_arguments, foreign_json_rpc)
+       when foreign_json_rpc == "" do
+    nil
+  end
+
+  defp compose_foreign_json_rpc_named_arguments(json_rpc_named_arguments, _foreign_json_rpc)
+       when is_nil(json_rpc_named_arguments) do
+    nil
+  end
+
   defp update_transport_options_set_foreign_json_rpc(transport_options, foreign_json_rpc) do
     Keyword.get_and_update(transport_options, :method_to_url, fn method_to_url ->
       {_, updated_method_to_url} =
diff --git a/apps/explorer/lib/explorer/chain/bridged_token.ex b/apps/explorer/lib/explorer/chain/bridged_token.ex
index b9d3fae300..8db227606b 100644
--- a/apps/explorer/lib/explorer/chain/bridged_token.ex
+++ b/apps/explorer/lib/explorer/chain/bridged_token.ex
@@ -15,13 +15,16 @@ defmodule Explorer.Chain.BridgedToken do
   * `foreign_token_contract_address_hash` - Foreign token's contract hash
   * `home_token_contract_address` - The `t:Address.t/0` of the home token's contract
   * `home_token_contract_address_hash` - Home token's contract hash foreign key
+  * `custom_metadata` - Arbitrary string with custom metadata. For instance, tokens/weights for Balance tokens
+  * `type` - omni/amb
   """
   @type t :: %BridgedToken{
           foreign_chain_id: Decimal.t(),
           foreign_token_contract_address_hash: Hash.Address.t(),
           home_token_contract_address: %Ecto.Association.NotLoaded{} | Address.t(),
           home_token_contract_address_hash: Hash.Address.t(),
-          custom_metadata: String.t()
+          custom_metadata: String.t(),
+          type: String.t()
         }
 
   @derive {Poison.Encoder,
@@ -45,6 +48,7 @@ defmodule Explorer.Chain.BridgedToken do
     field(:foreign_chain_id, :decimal)
     field(:foreign_token_contract_address_hash, Hash.Address)
     field(:custom_metadata, :string)
+    field(:type, :string)
 
     belongs_to(
       :home_token_contract_address,
@@ -59,7 +63,7 @@ defmodule Explorer.Chain.BridgedToken do
   end
 
   @required_attrs ~w(home_token_contract_address_hash)a
-  @optional_attrs ~w(foreign_chain_id foreign_token_contract_address_hash custom_metadata)a
+  @optional_attrs ~w(foreign_chain_id foreign_token_contract_address_hash custom_metadata type)a
 
   @doc false
   def changeset(%BridgedToken{} = bridged_token, params \\ %{}) do
diff --git a/apps/explorer/priv/repo/migrations/20200929075625_add_bridged_token_type.exs b/apps/explorer/priv/repo/migrations/20200929075625_add_bridged_token_type.exs
new file mode 100644
index 0000000000..b8a6c30f45
--- /dev/null
+++ b/apps/explorer/priv/repo/migrations/20200929075625_add_bridged_token_type.exs
@@ -0,0 +1,9 @@
+defmodule Explorer.Repo.Migrations.AddBridgedTokenType do
+  use Ecto.Migration
+
+  def change do
+    alter table(:bridged_tokens) do
+      add(:type, :string, null: true)
+    end
+  end
+end
diff --git a/apps/indexer/lib/indexer/set_amb_bridged_metadata_for_tokens.ex b/apps/indexer/lib/indexer/set_amb_bridged_metadata_for_tokens.ex
new file mode 100644
index 0000000000..b12e93872b
--- /dev/null
+++ b/apps/indexer/lib/indexer/set_amb_bridged_metadata_for_tokens.ex
@@ -0,0 +1,39 @@
+defmodule Indexer.SetAmbBridgedMetadataForTokens do
+  @moduledoc """
+  Sets token metadata for bridged tokens from AMB extensions.
+  """
+
+  use GenServer
+
+  require Logger
+
+  alias Explorer.Chain
+
+  def start_link([init_opts, gen_server_opts]) do
+    start_link(init_opts, gen_server_opts)
+  end
+
+  def start_link(init_opts, gen_server_opts) do
+    GenServer.start_link(__MODULE__, init_opts, gen_server_opts)
+  end
+
+  @impl GenServer
+  def init(_opts) do
+    send(self(), :process_amb_tokens)
+
+    {:ok, %{}}
+  end
+
+  @impl GenServer
+  def handle_info(:process_amb_tokens, state) do
+    fetch_amb_bridged_tokens_metadata()
+
+    {:noreply, state}
+  end
+
+  defp fetch_amb_bridged_tokens_metadata do
+    :ok = Chain.process_amb_tokens()
+
+    Logger.debug(fn -> "Bridged status fetched for AMB tokens" end)
+  end
+end
diff --git a/apps/indexer/lib/indexer/set_bridged_metadata_for_tokens.ex b/apps/indexer/lib/indexer/set_omni_bridged_metadata_for_tokens.ex
similarity index 80%
rename from apps/indexer/lib/indexer/set_bridged_metadata_for_tokens.ex
rename to apps/indexer/lib/indexer/set_omni_bridged_metadata_for_tokens.ex
index 9c15939a1c..13a06779d0 100644
--- a/apps/indexer/lib/indexer/set_bridged_metadata_for_tokens.ex
+++ b/apps/indexer/lib/indexer/set_omni_bridged_metadata_for_tokens.ex
@@ -1,4 +1,4 @@
-defmodule Indexer.SetBridgedMetadataForTokens do
+defmodule Indexer.SetOmniBridgedMetadataForTokens do
   @moduledoc """
   Peiodically checks unprocessed tokens and sets bridged status.
   """
@@ -34,15 +34,15 @@ defmodule Indexer.SetBridgedMetadataForTokens do
 
     {:ok, token_addresses} = Chain.unprocessed_token_addresses_to_reveal_bridged_tokens()
 
-    fetch_bridged_tokens_metadata(token_addresses)
+    fetch_omni_bridged_tokens_metadata(token_addresses)
 
     Process.send_after(self(), :reveal_unprocessed_tokens, interval)
 
     {:noreply, state}
   end
 
-  defp fetch_bridged_tokens_metadata(token_addresses) do
-    :ok = Chain.fetch_bridged_tokens_metadata(token_addresses)
+  defp fetch_omni_bridged_tokens_metadata(token_addresses) do
+    :ok = Chain.fetch_omni_bridged_tokens_metadata(token_addresses)
 
     Logger.debug(fn -> "Bridged status fetched for tokens" end)
   end
diff --git a/apps/indexer/lib/indexer/supervisor.ex b/apps/indexer/lib/indexer/supervisor.ex
index 4c65a93506..f105c0eaec 100644
--- a/apps/indexer/lib/indexer/supervisor.ex
+++ b/apps/indexer/lib/indexer/supervisor.ex
@@ -5,7 +5,7 @@ defmodule Indexer.Supervisor do
 
   use Supervisor
 
-  alias Indexer.{Block, PendingOpsCleaner, SetBridgedMetadataForTokens}
+  alias Indexer.{Block, PendingOpsCleaner, SetAmbBridgedMetadataForTokens, SetOmniBridgedMetadataForTokens}
   alias Indexer.Block.{Catchup, Realtime}
 
   alias Indexer.Fetcher.{
@@ -129,15 +129,24 @@ defmodule Indexer.Supervisor do
       {PendingOpsCleaner, [[], []]}
     ]
 
-    multi_token_bridge_mediator = Application.get_env(:block_scout_web, :multi_token_bridge_mediator)
+    omni_bridge_mediator = Application.get_env(:block_scout_web, :omni_bridge_mediator)
 
-    all_fetchers =
-      if multi_token_bridge_mediator && multi_token_bridge_mediator !== "" do
-        [{SetBridgedMetadataForTokens, [[], []]} | basic_fetchers]
+    extended_fetchers =
+      if omni_bridge_mediator && omni_bridge_mediator !== "" do
+        [{SetOmniBridgedMetadataForTokens, [[], []]} | basic_fetchers]
       else
         basic_fetchers
       end
 
+    amb_bridge_mediators = Application.get_env(:block_scout_web, :amb_bridge_mediators)
+
+    all_fetchers =
+      if amb_bridge_mediators && amb_bridge_mediators !== "" do
+        [{SetAmbBridgedMetadataForTokens, [[], []]} | extended_fetchers]
+      else
+        extended_fetchers
+      end
+
     Supervisor.init(
       all_fetchers,
       strategy: :one_for_one