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# frozen_string_literal: true
# Copyright (c) 2018-2019 Zerocracy, Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the 'Software'), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
require_relative 'key'
require_relative 'id'
require_relative 'wallet'
require_relative 'amount'
# Tax transaction.
#
# Author:: Yegor Bugayenko (yegor256@gmail.com)
# Copyright:: Copyright (c) 2018 Yegor Bugayenko
# License:: MIT
module Zold
# A single tax payment
class Tax
# The exact score a wallet can/must buy in order to pay taxes.
EXACT_SCORE = 8
# The maximum allowed amount in one transaction.
# The correct amount should be 1 ZLD, but we allow bigger amounts
# now since the amount of nodes in the network is still small. When
# the network grows up, let's put this number back to 1 ZLD.
MAX_PAYMENT = Amount.new(zld: 16.0)
# This is how much we charge per one transaction per hour
# of storage. A wallet of 4096 transactions will pay
# approximately 16ZLD per year.
# Here is the formula: 16.0 / (365 * 24) / 4096 = 1915
# But I like the 1917 number better.
FEE = Amount.new(zents: 1917)
# The maximum debt we can tolerate at the wallet. If the debt
# is bigger than this threshold, nodes must stop accepting PUSH.
TRIAL = Amount.new(zld: 1.0)
# Text prefix for taxes details
PREFIX = 'TAXES'
private_constant :PREFIX
# When score strengths were updated. The numbers here indicate the
# strengths we accepted before these dates.
MILESTONES = {
Txn.parse_time('2018-11-30T00:00:00Z') => 6,
Txn.parse_time('2018-12-09T00:00:00Z') => 7
}.freeze
private_constant :MILESTONES
def initialize(wallet, ignore_score_weakness: false, strength: Score::STRENGTH)
raise "The wallet must be of type Wallet: #{wallet.class.name}" unless wallet.is_a?(Wallet)
@wallet = wallet
@ignore_score_weakness = ignore_score_weakness
@strength = strength
end
# Check whether this tax payment already exists in the wallet.
def exists?(details)
!@wallet.txns.find { |t| t.details.start_with?("#{PREFIX} ") && t.details == details }.nil?
end
def details(best)
"#{PREFIX} #{best.reduced(EXACT_SCORE)}"
end
def pay(pvt, best)
@wallet.sub([MAX_PAYMENT, debt].min, best.invoice, pvt, details(best))
end
def in_debt?
debt > TRIAL
end
def to_text
"A=#{@wallet.age.round} hours, F=#{FEE.to_i}z/th, T=#{@wallet.txns.count}t, Paid=#{paid}"
end
def debt
FEE * @wallet.txns.count * @wallet.age - paid
end
def paid
txns = @wallet.txns
scored = txns.map do |t|
pfx, body = t.details.split(' ', 2)
next if pfx != PREFIX || body.nil?
score = Score.parse(body)
next if !score.valid? || score.value != EXACT_SCORE
if score.strength < @strength && !@ignore_score_weakness
next unless MILESTONES.find { |d, s| t.date < d && score.strength >= s }
end
next if t.amount > MAX_PAYMENT
t
end.compact.uniq(&:details)
scored.empty? ? Amount::ZERO : scored.map(&:amount).inject(&:+) * -1
end
end
end