module Focus
  class Host
    def initialize(file = "/etc/hosts")
      @file = file
      read!
    end

    def get_index
      start_index = @all_lines.find_index { |line| /### FOCUS:start \(automaticaly generated\) ###/i === line }
      stop_index = @all_lines.find_index { |line| /### FOCUS:stop \(automaticaly generated\) ###/i === line }
      { start: start_index + 1, stop: stop_index - 1 } if start_index && stop_index
    end

    def read!
      @all_lines = File.read(@file).split("\n")
      index = get_index
      @data = []
      if index
        selected_lines = @all_lines[index[:start]..index[:stop]]
        @data = selected_lines.map { |line| line.split(/\s+/) }.map { |ip, host| { ip: ip, host: host } }
      end
    end

    def overwrite!
      index = get_index
      if index
        count = index[:stop] - index[:start]
        @all_lines << "" if @all_lines[index[:start] - 2] != ""
        @all_lines.slice!(index[:start] - 1, count + 3)
      else
        @all_lines << "" if @all_lines.last != ""
      end

      @all_lines << "### FOCUS:start (automaticaly generated) ###"
      @data.each do |managed|
        @all_lines << "#{managed[:ip]} #{managed[:host]}"
      end
      @all_lines << "### FOCUS:stop (automaticaly generated) ###"
      @all_lines << ""

      command = "sudo su -c 'echo \"#{@all_lines.join("\n")}\" > #{@file}'"
      `#{command}`
    end

    def block!(config)
      puts "Blocking the hosts".green
      read!
      config.block_hosts.each do |block_host|
        puts block_host.red
        @data << { host: block_host, ip: "127.0.0.1" }
        @data << { host: "www.#{block_host}", ip: "127.0.0.1" }
      end
      @data.uniq!
      overwrite!
      puts "Done!".green
    end

    def restore!(config)
      puts "Restoring blocked hosts".green
      @data = []
      overwrite!
      puts "Done!".green
    end
  end
end