Initial commit

app/models/currency.rb

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+# encoding: UTF-8
+# frozen_string_literal: true
+
+class Currency < ApplicationRecord
+
+  # == Constants ============================================================
+
+  OPTIONS_ATTRIBUTES = %i[erc20_contract_address gas_limit gas_price].freeze
+  TOP_POSITION = 1
+
+  # == Attributes ===========================================================
+
+  attr_readonly :id,
+                :type,
+                :base_factor
+
+  # Code is aliased to id because it's more user-friendly primary key.
+  # It's preferred to use code where this attributes are equal.
+  alias_attribute :code, :id
+
+  # == Extensions ===========================================================
+
+  serialize :options, JSON unless Rails.configuration.database_support_json
+
+  include Helpers::ReorderPosition
+
+  OPTIONS_ATTRIBUTES.each do |attribute|
+    define_method attribute do
+      self.options[attribute.to_s]
+    end
+
+    define_method "#{attribute}=".to_sym do |value|
+      self.options = options.merge(attribute.to_s => value)
+    end
+  end
+
+  # == Relationships ========================================================
+
+  belongs_to :blockchain, foreign_key: :blockchain_key, primary_key: :key
+  has_and_belongs_to_many :wallets
+
+  has_one :parent, class_name: 'Currency', foreign_key: :id, primary_key: :parent_id
+
+  # == Validations ==========================================================
+
+  validate on: :create do
+    if ENV['MAX_CURRENCIES'].present? && Currency.count >= ENV['MAX_CURRENCIES'].to_i
+      errors.add(:max, 'Currency limit has been reached')
+    end
+  end
+
+  validates :code, presence: true, uniqueness: { case_sensitive: false }
+
+  validates :position,
+            presence: true,
+            numericality: { greater_than_or_equal_to: TOP_POSITION, only_integer: true }
+
+  validates :parent_id, allow_blank: true,
+            inclusion: { in: ->(_) { Currency.coins_without_tokens.pluck(:id).map(&:to_s) } },
+            if: :coin?
+
+  validates :blockchain_key,
+            inclusion: { in: ->(_) { Blockchain.pluck(:key).map(&:to_s) } },
+            if: :coin?
+
+  validates :type, inclusion: { in: ->(_) { Currency.types.map(&:to_s) } }
+  validates :options, length: { maximum: 1000 }
+  validates :base_factor, numericality: { greater_than_or_equal_to: 1, only_integer: true }
+
+  validates :deposit_fee,
+            :min_deposit_amount,
+            :min_collection_amount,
+            :withdraw_fee,
+            :min_withdraw_amount,
+            :withdraw_limit_24h,
+            :withdraw_limit_72h,
+            :precision,
+            numericality: { greater_than_or_equal_to: 0 }
+
+  # == Scopes ===============================================================
+
+  scope :visible, -> { where(visible: true) }
+  scope :irt, -> { find('irt')}
+  scope :deposit_enabled, -> { where(deposit_enabled: true) }
+  scope :withdrawal_enabled, -> { where(withdrawal_enabled: true) }
+  scope :ordered, -> { order(position: :asc) }
+  scope :coins, -> { where(type: :coin) }
+  scope :fiats, -> { where(type: :fiat) }
+  # This scope select all coins without parent_id, which means that they are not tokens
+  scope :coins_without_tokens, -> { coins.where(parent_id: nil) }
+
+  # == Callbacks ============================================================
+
+  after_initialize :initialize_defaults
+  after_create do
+    link_wallets
+    insert_position(self)
+  end
+
+  before_validation { self.code = code.downcase }
+  before_validation { self.deposit_fee = 0 unless fiat? }
+  before_validation { self.blockchain_key = parent.blockchain_key if token? && blockchain_key.blank? }
+  before_validation(on: :create) { self.position = Currency.count + 1 unless position.present? }
+
+  before_validation do
+    self.erc20_contract_address = erc20_contract_address.try(:downcase) if erc20_contract_address.present?
+  end
+
+  before_update { update_position(self) if position_changed? }
+
+  after_commit :wipe_cache
+
+  # == Class Methods ========================================================
+
+  # NOTE: type column reserved for STI
+  self.inheritance_column = nil
+
+  class << self
+    def codes(options = {})
+      pluck(:id).yield_self do |downcase_codes|
+        case
+        when options.fetch(:bothcase, false)
+          downcase_codes + downcase_codes.map(&:upcase)
+        when options.fetch(:upcase, false)
+          downcase_codes.map(&:upcase)
+        else
+          downcase_codes
+        end
+      end
+    end
+
+    def types
+      %i[fiat coin].freeze
+    end
+  end
+
+  # == Instance Methods =====================================================
+
+  delegate :explorer_transaction, :blockchain_api, :explorer_address, to: :blockchain
+
+  types.each { |t| define_method("#{t}?") { type == t.to_s } }
+
+  def blockchain
+    Rails.cache.fetch("#{code}_blockchain", expires_in: 60) { Blockchain.find_by(key: blockchain_key) }
+  end
+
+  def wipe_cache
+    Rails.cache.delete_matched("currencies*")
+  end
+
+  def initialize_defaults
+    self.options = {} if options.blank?
+  end
+
+  def link_wallets
+    if parent_id.present?
+      # Iterate through active deposit/withdraw wallets
+      Wallet.active.where.not(kind: :fee).with_currency(parent_id).each do |wallet|
+        # Link parent currency with wallet
+        CurrencyWallet.create(currency_id: id, wallet_id: wallet.id)
+      end
+    end
+  end
+
+  # Allows to dynamically check value of id/code:
+  #
+  #   id.btc? # true if code equals to "btc".
+  #   code.eth? # true if code equals to "eth".
+  def id
+    super&.inquiry
+  end
+
+  # subunit (or fractional monetary unit) - a monetary unit
+  # that is valued at a fraction (usually one hundredth)
+  # of the basic monetary unit
+  def subunits=(n)
+    self.base_factor = 10 ** n
+  end
+
+  # This method defines that token currency need to have parent_id and coin type
+  # We use parent_id for token type to inherit some useful info such as blockchain_key from parent currency
+  # For coin currency enough to have only coin type
+  def token?
+    parent_id.present? && coin?
+  end
+
+  def get_price
+    if price.blank? || price.zero?
+      raise "Price for currency #{id} is unknown"
+    else
+      price
+    end
+  end
+
+  def to_blockchain_api_settings
+    # We pass options are available as top-level hash keys and via options for
+    # compatibility with Wallet#to_wallet_api_settings.
+    opt = options.compact.deep_symbolize_keys
+    opt.deep_symbolize_keys.merge(id:          id,
+                                  base_factor: base_factor,
+                                  options:     opt)
+  end
+
+  def dependent_markets
+    Market.where('base_unit = ? OR quote_unit = ?', id, id)
+  end
+
+  def subunits
+    Math.log(base_factor, 10).round
+  end
+end
+
+# == Schema Information
+# Schema version: 20201207134745
+#
+# Table name: currencies
+#
+#  id                    :string(10)       not null, primary key
+#  name                  :string(255)
+#  description           :text(65535)
+#  homepage              :string(255)
+#  blockchain_key        :string(32)
+#  parent_id             :string(255)
+#  type                  :string(30)       default("coin"), not null
+#  deposit_fee           :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
+#  min_withdraw_amount   :decimal(32, 16)  default(0.0), not null
+#  withdraw_limit_24h    :decimal(32, 16)  default(0.0), not null
+#  withdraw_limit_72h    :decimal(32, 16)  default(0.0), not null
+#  position              :integer          not null
+#  options               :json
+#  visible               :boolean          default(TRUE), not null
+#  deposit_enabled       :boolean          default(TRUE), not null
+#  withdrawal_enabled    :boolean          default(TRUE), not null
+#  base_factor           :bigint           default(1), not null
+#  precision             :integer          default(8), not null
+#  icon_url              :string(255)
+#  price                 :decimal(32, 16)  default(1.0), not null
+#  created_at            :datetime         not null
+#  updated_at            :datetime         not null
+#
+# Indexes
+#
+#  index_currencies_on_parent_id  (parent_id)
+#  index_currencies_on_position   (position)
+#  index_currencies_on_visible    (visible)
+#