Implement skimming deposit collection mechanism based on wallet max_b…

…alance (closes #1653) (#1735)

* Added Wallet Service Specs

* Implement skimming deposit collection mechanism for bitcoin

* Implement skimming deposit collection mechanism for eth

* Implement skimming deposit collection mechanism for ripple

* Enumerize Wallet kind

* Edit skiming mechanism for ripple wallet

* Edit skiming mechanism for eth wallet

* Use hash instead array for deposit collections

* Update specs with new skiming mechanism and add specs for ripple

* Add min_collection_amount method to currency

* Move load_balance! request to blockchain service and add specs for wallet service

* Add min_collection_amount column to currency and move spread deposit method to protected

app/controllers/admin/currencies_controller.rb

@@ -54,6 +54,7 @@ def permitted_currency_attributes
         icon_url
         quick_withdraw_limit
         min_deposit_amount
+        min_collection_amount
         withdraw_fee
         deposit_fee
         enabled

app/models/currency.rb

@@ -22,6 +22,7 @@ class Currency < ActiveRecord::Base
 
   validates :quick_withdraw_limit,
             :min_deposit_amount,
+            :min_collection_amount,
             :withdraw_fee,
             :deposit_fee,
             numericality: { greater_than_or_equal_to: 0 }
@@ -147,25 +148,26 @@ def must_not_disable_all_markets
 end
 
 # == Schema Information
-# Schema version: 20181004114428
+# Schema version: 20181126101312
 #
 # Table name: currencies
 #
-#  id                   :string(10)       not null, primary key
-#  blockchain_key       :string(32)
-#  symbol               :string(1)        not null
-#  type                 :string(30)       default("coin"), not null
-#  deposit_fee          :decimal(32, 16)  default(0.0), not null
-#  quick_withdraw_limit :decimal(32, 16)  default(0.0), not null
-#  min_deposit_amount   :decimal(32, 16)  default(0.0), not null
-#  withdraw_fee         :decimal(32, 16)  default(0.0), not null
-#  options              :string(1000)     default({}), not null
-#  enabled              :boolean          default(TRUE), not null
-#  base_factor          :integer          default(1), not null
-#  precision            :integer          default(8), not null
-#  icon_url             :string(255)
-#  created_at           :datetime         not null
-#  updated_at           :datetime         not null
+#  id                    :string(10)       not null, primary key
+#  blockchain_key        :string(32)
+#  symbol                :string(1)        not null
+#  type                  :string(30)       default("coin"), not null
+#  deposit_fee           :decimal(32, 16)  default(0.0), not null
+#  quick_withdraw_limit  :decimal(32, 16)  default(0.0), not null
+#  min_deposit_amount    :decimal(32, 16)  default(0.0), not null
+#  min_collection_amount :decimal(32, 16)  default(0.0), not null
+#  withdraw_fee          :decimal(32, 16)  default(0.0), not null
+#  options               :string(1000)     default({}), not null
+#  enabled               :boolean          default(TRUE), not null
+#  base_factor           :integer          default(1), not null
+#  precision             :integer          default(8), not null
+#  icon_url              :string(255)
+#  created_at            :datetime         not null
+#  updated_at            :datetime         not null
 #
 # Indexes
 #

app/models/wallet.rb

@@ -1,8 +1,17 @@
 # encoding: UTF-8
 # frozen_string_literal: true
 
+
 class Wallet < ActiveRecord::Base
-  KIND = %w[hot warm cold deposit fee].freeze
+  extend Enumerize
+
+  # We use this attribute values rules for wallet kinds:
+  # 1** - for deposit wallets.
+  # 2** - for fee wallets.
+  # 3** - for withdraw wallets (sorted by security hot < warm < cold).
+  ENUMERIZED_KINDS = { deposit: 100, fee: 200, hot: 310, warm: 320, cold: 330 }.freeze
+  enumerize :kind, in: ENUMERIZED_KINDS, scope: true
+
   GATEWAYS = %w[bitcoind bitcoincashd litecoind geth dashd rippled bitgo].freeze
   SETTING_ATTRIBUTES = %i[ uri
                            secret
@@ -22,29 +31,58 @@ class Wallet < ActiveRecord::Base
   validates :address, presence: true
 
   validates :status,  inclusion: { in: %w[active disabled] }
-  validates :kind,    inclusion: { in: KIND }
   validates :gateway, inclusion: { in: GATEWAYS }
 
   validates :nsig,        numericality: { greater_than_or_equal_to: 1, only_integer: true }
   validates :max_balance, numericality: { greater_than_or_equal_to: 0 }
   validates :uri, url: { allow_blank: true }
 
   scope :active,   -> { where(status: :active) }
-  scope :deposit,  -> { where(kind: :deposit) }
-  scope :withdraw, -> { where.not(kind: :deposit) }
+  scope :deposit,  -> { where(kind: kinds(deposit: true, values: true)) }
+  scope :fee,      -> { where(kind: kinds(fee: true, values: true)) }
+  scope :withdraw, -> { where(kind: kinds(withdraw: true, values: true)) }
+  scope :ordered,  -> { order(kind: :asc) }
 
   before_validation do
     next unless blockchain_api&.supports_cash_addr_format? && address?
     self.address = CashAddr::Converter.to_cash_address(address)
   end
 
+  class << self
+    def kinds(options={})
+      ENUMERIZED_KINDS
+        .yield_self do |kinds|
+          case
+          when options.fetch(:deposit, false)
+            kinds.select { |_k, v| v / 100 == 1 }
+          when options.fetch(:fee, false)
+            kinds.select { |_k, v| v / 100 == 2 }
+          when options.fetch(:withdraw, false)
+            kinds.select { |_k, v| v / 100 == 3 }
+          else
+            kinds
+          end
+        end
+        .yield_self do |kinds|
+          case
+          when options.fetch(:keys, false)
+            kinds.keys
+          when options.fetch(:values, false)
+            kinds.values
+          else
+            kinds
+          end
+        end
+    end
+  end
+
   def wallet_url
     blockchain.explorer_address.gsub('#{address}', address) if blockchain
   end
 end
 
 # == Schema Information
-# Schema version: 20180813105100
+# Schema version: 20181017114624
 #
 # Table name: wallets
 #
@@ -53,7 +91,7 @@ def wallet_url
 #  currency_id    :string(10)
 #  name           :string(64)
 #  address        :string(255)      not null
-#  kind           :string(32)       not null
+#  kind           :integer          not null
 #  nsig           :integer
 #  gateway        :string(20)       default(""), not null
 #  settings       :string(1000)     default({}), not null
@@ -63,3 +101,10 @@ def wallet_url
 #  created_at     :datetime         not null
 #  updated_at     :datetime         not null
 #
+# Indexes
+#
+#  index_wallets_on_currency_id                      (currency_id)
+#  index_wallets_on_kind                             (kind)
+#  index_wallets_on_kind_and_currency_id_and_status  (kind,currency_id,status)
+#  index_wallets_on_status                           (status)
+#

app/services/wallet_service.rb

@@ -46,13 +46,48 @@ def create_address!
 
     protected
 
-    def destination_wallet(deposit)
-      # TODO: Dynamicly check wallet balance and select destination wallet.
-      # For keeping it simple we will collect all deposits to hot wallet.
+    def spread_deposit(deposit)
+      left_amount = deposit.amount
+      collection_spread = Hash.new(0)
+      currency = deposit.currency
+      destination_wallets(deposit).each do |wallet|
+        break if left_amount == 0
+        blockchain_client = BlockchainClient[Blockchain.find_by_key(wallet.blockchain_key).key]
+        wallet_balance = blockchain_client.load_balance!(wallet.address, deposit.currency)
+        amount_for_wallet = [wallet.max_balance - wallet_balance, left_amount].min
+        # If free amount for current wallet too small we will not able to collect it.
+        # So we try to collect it to next wallets.
+        next if amount_for_wallet < currency.min_collection_amount
+        left_amount -= amount_for_wallet
+        # If amount left is too small we will not able to collect it.
+        # So we collect everything to current wallet.
+        if left_amount < currency.min_collection_amount
+          amount_for_wallet += left_amount
+          left_amount = 0
+        end
+        collection_spread[wallet.address] = amount_for_wallet if amount_for_wallet > 0
+      rescue => e
+        # If have exception move to next wallet
+        report_exception(e)
+      end
+      # If deposit doesn't fit to any wallet collect it to last wallet.
+      # Last wallet is considered to be the most secure.
+      if left_amount > 0
+        collection_spread[destination_wallets(deposit).last.address] += left_amount
+        left_amount = 0
+      end
+      unless collection_spread.values.sum == deposit.amount
+        raise Error, "Deposit spread failed deposit.amount != collection_spread.values.sum"
+      end
+      collection_spread
+    end
+
+    def destination_wallets(deposit)
       Wallet
         .active
         .withdraw
-        .find_by(currency_id: deposit.currency_id, kind: :hot)
+        .ordered
+        .where(currency_id: deposit.currency_id)
     end
   end
 end

app/services/wallet_service/bitcoind.rb

@@ -9,18 +9,19 @@ def create_address(options = {})
     end
 
     def collect_deposit!(deposit, options={})
-      destination_address = destination_wallet(deposit).address
       pa = deposit.account.payment_address
 
-      # this will automatically deduct fee from amount
+      # This will automatically deduct fee from amount so we can withdraw exact amount.
       options = options.merge( subtract_fee: true )
-
-      client.create_withdrawal!(
-        { address: pa.address },
-        { address: destination_address },
-        deposit.amount,
-        options
-      )
+      spread_hash = spread_deposit(deposit)
+      spread_hash.map do |address, amount|
+        client.create_withdrawal!(
+          { address: pa.address },
+          { address: address},
+          amount,
+          options
+        )
+      end
     end
 
     def build_withdrawal!(withdraw, options = {})

app/services/wallet_service/geth.rb

@@ -13,11 +13,11 @@ def create_address(options = {})
     end
 
     def collect_deposit!(deposit, options={})
-      destination_address = destination_wallet(deposit).address
+      destination_wallets = destination_wallets(deposit)
       if deposit.currency.code.eth?
-        collect_eth_deposit!(deposit, destination_address, options)
+        collect_eth_deposit!(deposit, destination_wallets, options)
       else
-        collect_erc20_deposit!(deposit, destination_address, options)
+        collect_erc20_deposit!(deposit, destination_wallets, options)
       end
     end
 
@@ -30,12 +30,12 @@ def build_withdrawal!(withdraw)
     end
 
     def deposit_collection_fees(deposit, value=DEFAULT_ERC20_FEE_VALUE, options={})
-      fees_wallet = erc20_fee_wallet
+      fee_wallet = erc20_fee_wallet
       destination_address = deposit.account.payment_address.address
       options = DEFAULT_ETH_FEE.merge options
 
       client.create_eth_withdrawal!(
-        { address: fees_wallet.address, secret: fees_wallet.secret },
+        { address: fee_wallet.address, secret: fee_wallet.secret },
         { address: destination_address },
         value,
         options
@@ -47,35 +47,38 @@ def deposit_collection_fees(deposit, value=DEFAULT_ERC20_FEE_VALUE, options={})
     def erc20_fee_wallet
       Wallet
         .active
-        .withdraw
         .find_by(currency_id: :eth, kind: :fee)
     end
 
-    def collect_eth_deposit!(deposit, destination_address, options={})
+    def collect_eth_deposit!(deposit, destination_wallets, options={})
       # Default values for Ethereum tx fees.
       options = DEFAULT_ETH_FEE.merge options
-
-      # We can't collect all funds we need to subtract gas fees.
-      amount = deposit.amount_to_base_unit! - options[:gas_limit] * options[:gas_price]
       pa = deposit.account.payment_address
-      client.create_eth_withdrawal!(
-        { address: pa.address, secret: pa.secret },
-        { address: destination_address },
-        amount,
-        options
-      )
+      spread_hash = spread_deposit(deposit)
+      spread_hash.map do |address, amount|
+        spread_amount = amount * deposit.currency.base_factor - options[:gas_limit] * options[:gas_price]
+        client.create_eth_withdrawal!(
+            { address: pa.address, secret: pa.secret },
+            { address: address},
+            spread_amount.to_i,
+            options
+        )
+      end
     end
 
-    def collect_erc20_deposit!(deposit, destination_address, options={})
+    def collect_erc20_deposit!(deposit, destination_wallets, options={})
       pa = deposit.account.payment_address
 
-      client.create_erc20_withdrawal!(
-        { address: pa.address, secret: pa.secret },
-        { address: destination_address },
-        deposit.amount_to_base_unit!,
-        options.merge(contract_address: deposit.currency.erc20_contract_address )
-      )
-
+      spread_hash = spread_deposit(deposit)
+      spread_hash.map do |address, amount|
+        spread_amount = amount * deposit.currency.base_factor
+        client.create_erc20_withdrawal!(
+            { address: pa.address, secret: pa.secret },
+            { address: address},
+            spread_amount.to_i,
+            options.merge( contract_address: deposit.currency.erc20_contract_address )
+        )
+      end
     end
 
     def build_eth_withdrawal!(withdraw)

app/services/wallet_service/rippled.rb

@@ -11,15 +11,16 @@ def create_address(options = {})
     end
 
     def collect_deposit!(deposit, options={})
-      destination_address = destination_wallet(deposit).address
       pa = deposit.account.payment_address
-
-      client.create_withdrawal!(
-        { address: pa.address, secret: pa.secret },
-        { address: destination_address },
-        deposit.amount,
-        options
-      )
+      spread_hash = spread_deposit(deposit)
+      spread_hash.map do |address, amount|
+        client.create_withdrawal!(
+          { address: pa.address, secret: pa.secret },
+          { address: address },
+          amount,
+          options
+        )
+      end
     end
 
     def build_withdrawal!(withdraw, options = {})

app/views/admin/currencies/show.html.erb

@@ -33,9 +33,12 @@
             <dt>Deposit fee (fiat only)</dt>
             <dd><%= f.text_field :deposit_fee, class: 'form-control' %></dd>
 
-            <dt>Min Deposit amount</dt>
+            <dt>Min deposit amount</dt>
             <dd><%= f.text_field :min_deposit_amount, class: 'form-control' %></dd>
 
+            <dt>Min collection amount</dt>
+            <dd><%= f.text_field :min_collection_amount, class: 'form-control' %></dd>
+
             <% if @currency.coin? || @currency.new_record? %>
               <% if @currency.new_record? || @currency.erc20_contract_address? %>
                 <dt>ERC20 contract address</dt>

app/views/admin/wallets/show.html.erb

@@ -25,7 +25,7 @@
           <%= f.text_field :address, class: 'form-control mb-3' %>
 
           <label>Kind</label>
-          <%= f.select :kind, Wallet::KIND.map { |k| [k.capitalize, k] }, {selected: @wallet.kind}, {class: 'form-control mb-3'} %>
+          <%= f.select :kind, Wallet::kinds(keys: true).map { |k| [k.capitalize, k] }, {selected: @wallet.kind}, {class: 'form-control mb-3'} %>
         </div>
       </div>
     </div>