Retrieve epoch numbers for Claim Reward dialog popup

apps/block_scout_web/lib/block_scout_web/channels/stakes_channel.ex

@@ -378,9 +378,25 @@ defmodule BlockScoutWeb.StakesChannel do
         pools = if error != nil do
           %{}
         else
+          block_reward_contract = ContractState.get(:block_reward_contract)
+
           Enum.map(pools_amounts, fn {_, amounts} -> amounts end)
           |> Enum.zip(pools)
           |> Enum.filter(fn {amounts, _} -> amounts.token_reward_sum > 0 || amounts.native_reward_sum > 0 end)
+          |> Enum.map(fn {amounts, pool_staking_address} ->
+            responses =
+              ContractReader.epochs_to_claim_reward_from_request(pool_staking_address, staker)
+              |> ContractReader.perform_requests(%{block_reward: block_reward_contract.address}, block_reward_contract.abi)
+
+            epochs =
+              array_to_ranges(responses[:epochs])
+              |> Enum.map(fn {first, last} ->
+                Integer.to_string(first) <> (if first != last, do: "-" <> Integer.to_string(last), else: "")
+              end)
+            data = Map.put(amounts, :epochs, Enum.join(epochs, ","))
+
+            {data, pool_staking_address}
+          end)
           |> Map.new(fn {val, key} -> {key, val} end)
         end
 
@@ -434,6 +450,22 @@ defmodule BlockScoutWeb.StakesChannel do
     |> String.pad_leading(64, ["0"])
   end
 
+  defp array_to_ranges(numbers, prev_ranges \\ []) do
+    length = Enum.count(numbers)
+    if length > 0 do
+      {first, last, next_index} = get_range(numbers)
+      ranges = prev_ranges ++ [{first, last}]
+      if next_index == 0 || next_index >= length do
+        ranges
+      else
+        Enum.slice(numbers, next_index, length - next_index)
+        |> array_to_ranges(ranges)
+      end
+    else
+      []
+    end
+  end
+
   defp error_reason_to_string(reason) do
     if is_map(reason) && Map.has_key?(reason, :message) && String.length(String.trim(reason.message)) > 0 do
       reason.message
@@ -442,6 +474,18 @@ defmodule BlockScoutWeb.StakesChannel do
     end
   end
 
+  defp get_range(numbers) do
+    last_index = 
+      Enum.with_index(numbers)
+      |> Enum.find_index(fn {n, i} ->
+        if i > 0, do: n != Enum.at(numbers, i - 1) + 1, else: false
+      end)
+    next_index = if last_index == nil, do: Enum.count(numbers), else: last_index
+    first = Enum.at(numbers, 0)
+    last = Enum.at(numbers, next_index - 1)
+    {first, last, next_index}
+  end
+
   defp push_staking_contract(socket) do
     if socket.assigns[:contract_sent] do
       socket

apps/block_scout_web/lib/block_scout_web/templates/stakes/_stakes_modal_claim_reward_content.html.eex

@@ -4,14 +4,18 @@
     <div class="input-group form-group">
       <select pool-select class="form-control">
         <option disabled selected><%= gettext("Choose Pool") %></option>
-        <%= for {pool_staking_address, amounts} <- @pools do %>
-          <option value="<%= pool_staking_address %>">
+        <%= for {pool_staking_address, data} <- @pools do %>
+          <%
+            token_reward_sum = format_token_amount(data.token_reward_sum, @token, digits: 5, ellipsize: false, symbol: false)
+            native_reward_sum = format_token_amount(data.native_reward_sum, @coin, digits: 5, ellipsize: false, symbol: false)
+          %>
+          <option value="<%= pool_staking_address %>" data-token-reward-sum="<%= token_reward_sum %>" data-native-reward-sum="<%= native_reward_sum %>" data-epochs="<%= data.epochs %>">
             <%=
               BlockScoutWeb.AddressView.trimmed_hash(pool_staking_address) <>
               " (" <>
-              format_token_amount(amounts.token_reward_sum, @token, digits: 5, ellipsize: false, symbol: true) <>
+              token_reward_sum <> " " <> @token.symbol <>
               ", " <>
-              format_token_amount(amounts.native_reward_sum, @coin, digits: 5, ellipsize: false, symbol: true) <>
+              native_reward_sum <> " " <> @coin.symbol <>
               ")"
             %>
           </option>
@@ -24,7 +28,7 @@
     <%= if @error do %>
       <%= @error %>
     <% else %>
-      <%= gettext("Unable to find any pools you staked into.") %>
+      <%= gettext("Unable to find any pools you could claim a reward from.") %>
     <% end %>
   </p>
 <% end %>

apps/explorer/lib/explorer/staking/contract_reader.ex

@@ -99,6 +99,12 @@ defmodule Explorer.Staking.ContractReader do
     ]
   end
 
+  def epochs_to_claim_reward_from_request(staking_address, staker) do
+    [
+      epochs: {:block_reward, "epochsToClaimRewardFrom", [staking_address, staker]}
+    ]
+  end
+
   def pool_staking_requests(staking_address, block_number) do
     [
       active_delegators: active_delegators_request(staking_address, block_number)[:active_delegators],

apps/explorer/priv/contracts_abi/posdao/BlockRewardAuRa.json

@@ -1,4 +1,27 @@
 [
+  {
+    "constant": true,
+    "inputs": [
+      {
+        "name": "_poolStakingAddress",
+        "type": "address"
+      },
+      {
+        "name": "_staker",
+        "type": "address"
+      }
+    ],
+    "name": "epochsToClaimRewardFrom",
+    "outputs": [
+      {
+        "name": "epochsToClaimFrom",
+        "type": "uint256[]"
+      }
+    ],
+    "payable": false,
+    "stateMutability": "view",
+    "type": "function"
+  },
   {
     "constant": true,
     "inputs": [],