use coinmarketcap for total_supply by default

apps/explorer/lib/explorer/chain.ex

@@ -2374,7 +2374,7 @@ defmodule Explorer.Chain do
   end
 
   defp supply_module do
-    Application.get_env(:explorer, :supply, Explorer.Chain.Supply.ProofOfAuthority)
+    Application.get_env(:explorer, :supply, Explorer.Chain.Supply.CoinMarketCap)
   end
 
   @doc """

apps/explorer/lib/explorer/chain/supply/coin_market_cap.ex

@@ -0,0 +1,22 @@
+defmodule Explorer.Chain.Supply.CoinMarketCap do
+  @moduledoc """
+  Defines the supply API for calculating supply for coins from coinmarketcap.
+  """
+
+  use Explorer.Chain.Supply
+
+  alias Explorer.ExchangeRates.Token
+  alias Explorer.Market
+
+  def circulating do
+    exchange_rate().available_supply
+  end
+
+  def total do
+    exchange_rate().total_supply
+  end
+
+  def exchange_rate do
+    Market.get_exchange_rate(Explorer.coin()) || Token.null()
+  end
+end

apps/explorer/lib/explorer/exchange_rates/source/coin_gecko.ex

@@ -26,6 +26,7 @@ defmodule Explorer.ExchangeRates.Source.CoinGecko do
 
       %Token{
         available_supply: to_decimal(item["total_supply"]),
+        total_supply: to_decimal(item["total_supply"]),
         btc_value: btc_value,
         id: id,
         last_updated: last_updated,

apps/explorer/lib/explorer/exchange_rates/source/coin_market_cap.ex

@@ -17,6 +17,7 @@ defmodule Explorer.ExchangeRates.Source.CoinMarketCap do
 
       %Token{
         available_supply: to_decimal(item["available_supply"]),
+        total_supply: to_decimal(item["total_supply"]),
         btc_value: to_decimal(item["price_btc"]),
         id: item["id"],
         last_updated: last_updated,

apps/explorer/lib/explorer/exchange_rates/source/transaction_and_log.ex

@@ -26,6 +26,7 @@ defmodule Explorer.ExchangeRates.Source.TransactionAndLog do
   defp build_struct(original_token) do
     %Token{
       available_supply: to_decimal(Chain.circulating_supply()),
+      total_supply: 0,
       btc_value: original_token.btc_value,
       id: original_token.id,
       last_updated: original_token.last_updated,

apps/explorer/lib/explorer/exchange_rates/token.ex

@@ -7,6 +7,7 @@ defmodule Explorer.ExchangeRates.Token do
   Represents an exchange rate for a given token.
 
    * `:available_supply` - Available supply of a token
+   * `:total_supply` - Max Supply
    * `:btc_value` - The Bitcoin value of the currency
    * `:id` - ID of a currency
    * `:last_updated` - Timestamp of when the value was last updated
@@ -18,6 +19,7 @@ defmodule Explorer.ExchangeRates.Token do
   """
   @type t :: %__MODULE__{
           available_supply: Decimal.t(),
+          total_supply: Decimal.t(),
           btc_value: Decimal.t(),
           id: String.t(),
           last_updated: DateTime.t(),
@@ -28,8 +30,8 @@ defmodule Explorer.ExchangeRates.Token do
           volume_24h_usd: Decimal.t()
         }
 
-  @enforce_keys ~w(available_supply btc_value id last_updated market_cap_usd name symbol usd_value volume_24h_usd)a
+  @enforce_keys ~w(available_supply total_supply btc_value id last_updated market_cap_usd name symbol usd_value volume_24h_usd)a
-  defstruct ~w(available_supply btc_value id last_updated market_cap_usd name symbol usd_value volume_24h_usd)a
+  defstruct ~w(available_supply total_supply btc_value id last_updated market_cap_usd name symbol usd_value volume_24h_usd)a
 
   def null,
     do: %__MODULE__{
@@ -37,6 +39,7 @@ defmodule Explorer.ExchangeRates.Token do
       id: nil,
       name: nil,
       available_supply: nil,
+      total_supply: nil,
       usd_value: nil,
       volume_24h_usd: nil,
       market_cap_usd: nil,
@@ -51,6 +54,7 @@ defmodule Explorer.ExchangeRates.Token do
         id: id,
         name: name,
         available_supply: available_supply,
+        total_supply: total_supply,
         usd_value: usd_value,
         volume_24h_usd: volume_24h_usd,
         market_cap_usd: market_cap_usd,
@@ -58,17 +62,20 @@ defmodule Explorer.ExchangeRates.Token do
         last_updated: last_updated
       }) do
     # symbol is first because it is the key used for lookup in `Explorer.ExchangeRates`'s ETS table
-    {symbol, id, name, available_supply, usd_value, volume_24h_usd, market_cap_usd, btc_value, last_updated}
+    {symbol, id, name, available_supply, total_supply, usd_value, volume_24h_usd, market_cap_usd, btc_value,
+     last_updated}
   end
 
   def from_tuple(
-        {symbol, id, name, available_supply, usd_value, volume_24h_usd, market_cap_usd, btc_value, last_updated}
+        {symbol, id, name, available_supply, total_supply, usd_value, volume_24h_usd, market_cap_usd, btc_value,
+         last_updated}
       ) do
     %__MODULE__{
       symbol: symbol,
       id: id,
       name: name,
       available_supply: available_supply,
+      total_supply: total_supply,
       usd_value: usd_value,
       volume_24h_usd: volume_24h_usd,
       market_cap_usd: market_cap_usd,

apps/explorer/test/explorer/chain_test.exs

@@ -3273,6 +3273,7 @@ defmodule Explorer.ChainTest do
   end
 
   test "total_supply/0" do
+    Application.put_env(:explorer, :supply, Explorer.Chain.Supply.ProofOfAuthority)
     height = 2_000_000
     insert(:block, number: height)
     expected = ProofOfAuthority.initial_supply() + height
@@ -3281,6 +3282,7 @@ defmodule Explorer.ChainTest do
   end
 
   test "circulating_supply/0" do
+    Application.put_env(:explorer, :supply, Explorer.Chain.Supply.ProofOfAuthority)
     assert Chain.circulating_supply() == ProofOfAuthority.circulating()
   end
 

apps/explorer/test/support/fakes/one_coin_source.ex

@@ -10,6 +10,7 @@ defmodule Explorer.ExchangeRates.Source.OneCoinSource do
   def format_data(_) do
     pseudo_token = %Token{
       available_supply: Decimal.new(10_000_000),
+      total_supply: Decimal.new(10_000_000_000),
       btc_value: Decimal.new(1),
       id: "",
       last_updated: Timex.now(),