require 'rexml/document'
require 'gate'

class Net
  def initialize(file1, file2)
    ### kontrola existence souborů
    raise "Soubor #{file1} neexistuje" unless File.exists?(file1)
    raise "Soubor #{file2} neexistuje" unless File.exists?(file2)
    
    ### načtení souboru s hradly
    @f1 = File.new(file1)
    load_gates
    
    ### zjistíme cestu, jak procházet hradla
    find_trace
    
    ### načtení a zpracování datového souboru
    @f2 = File.new(file2)
    process_data
    
  end
  
  def load_gates
    doc = REXML::Document.new(@f1)
    
    @inputs = []
    doc.elements.each("*/input") { |e| @inputs << e.attributes['id'] }
    
    @gates = []
    doc.elements.each("*/gate") { |gate| add_gate gate }
    
    @outputs = []
    doc.elements.each("*/output") { |e| @outputs << e.attributes['id'] }
  end
  
  def add_gate gate
    g = Gate.new(gate.attributes['type'])
    gate.elements.each("input") { |i| g.input = i.attributes['id'] }
    gate.elements.each("output") { |o| g.output = o.attributes['id'] }
    @gates << g
  end
  
  def find_trace
    @trace = []
    
    inputs = @inputs.clone
    last_inputs = nil
    gates = @gates
    
    until gates.empty?
      gates.each_index do |i|
        gate = gates[i]
        
        if gate.has(inputs)
          inputs << gate.output
          @trace << gates.delete_at(i)
        end
      end
      
      raise 'Byl nalezen cyklus' if inputs == last_inputs
      last_inputs = inputs.clone
    end
  end
  
  def process_data
    @results = []
    until @f2.eof?
      line = @f2.readline
      vars = {}
      @inputs.each_index { |i| vars[@inputs[i]] = line[i]-48 }
      
      @trace.each do |gate|
        vars[gate.output] = gate.result(vars)
      end
      
      res = []
      @outputs.each do |id|
        res << vars[id]
      end
      
      puts res.join
    end
  end
  
  attr_reader :inputs, :outputs, :trace
end