gistfile1.builder

require "date"
require "time"


# converts base10 integers into NewBase60
def num_to_sxg(num=nil)
  sxg        = ""
  vocabulary = "0123456789ABCDEFGHJKLMNPQRSTUVWXYZ_abcdefghijkmnopqrstuvwxyz"

  return 0 if num.nil? || num.zero?

  while num > 0 do
    mod = num % 60
    sxg = "#{vocabulary[mod,1]}#{sxg}"
    num = (num - mod) / 60
  end

  sxg
end


# converts base10 integers into NewBase60 padding with leading zeroes
def num_to_sxgf(num, padding)
  str = num_to_sxg(num)

  padding = 1 if padding.nil?
  padding -= str.length

  while padding > 0
    str = "0#{str}"
    padding -= 1
  end

  str
end


# converts NewBase60 into base10 integer
def sxg_to_num(str)
  num = 0

  str.length.times do |index| # iterate over each letter
    char = str[index]         # grab the ascii value of the current letter

    if (48..57).include?(char)
      char -= 48
    elsif (65..72).include?(char)
      char -= 55
    elsif (char == 73 || char == 108) # typo capital I, lowercase l to 1
      char = 1
    elsif (74..78).include?(char)
      char -= 56
    elsif (char == 79) # error correct typo capital O to 0
      char = 0
    elsif (80..90).include?(char)
      char -= 57
    elsif (char==95) # underscore
      char = 34
    elsif (97..107).include?(char)
      char -= 62
    elsif (109..122).include?(char)
      char -= 63
    else
      char = 0 # treat all other noise as 0
    end

    num = 60 * num + char
  end

  num
end

# converts NewBase60 characters into a Time object
def sxg_to_time(str)
  # days since epoch * seconds * minutes * hours + timezone 
  Time.at(sxg_to_num(str) * 60 * 60 * 24 + Time.now.gmtoff.abs)
end

# converts Time object into a NewBase60 characters
def time_to_sxg(time)
  the_when   = time + Time.now.gmtoff.abs
  epoch_days = the_when.to_i / 60 / 60 / 24
  num_to_sxg(epoch_days)
end