ssn_exercise.rb

# Determine whether a string contains a Social Security number.
def has_ssn?(string)
  if /\d{3}-\d{2}-\d{4}/.match(string)
    true
  else
    false
  end
end

# Return the Social Security number from a string.
def grab_ssn(string)
  if /\d{3}-\d{2}-\d{4}/.match(string)
    m = /\d{3}-\d{2}-\d{4}/.match(string)
    return m[0]
  end
end

# Return all of the Social Security numbers from a string.
def grab_all_ssns(string)
  ssn_array = []
  while /\d{3}-\d{2}-\d{4}/.match(string)
    m = /\d{3}-\d{2}-\d{4}/.match(string)
    ssn_array << m[0]
    string = m.post_match
  end
  return ssn_array
end

# Obfuscate all of the Social Security numbers in a string. Example: XXX-XX-4430.
def hide_all_ssns(string)
  if /\d{3}-\d{2}-\d{4}/.match(string)
    @pusher = ""
    while /\d{3}-\d{2}-\d{4}/.match(string)
      m = /\d{3}-\d{2}-\d{4}/.match(string)
      @pusher << m.pre_match
      @pusher << m[0].replace("XXX-XX-#{m[0][7,4]}")
      string = m.post_match
      if !/\d{3}-\d{2}-\d{4}/.match(string)
        @pusher << m.post_match
      end
    end
    @pusher
  else 
    string
  end
end

# Ensure all of the Social Security numbers use dashes for delimiters.
# Example: 480.01.4430 and 480014430 would both be 480-01-4430.
def format_ssns(string)
  if /\d{9}/.match(string) || /\d{3}.\d{2}.\d{4}/.match(string)
    @pusher = ""
    while /\d{9}/.match(string) || /\d{3}.\d{2}.\d{4}/.match(string)
      m1 = /\d{9}/.match(string)
      m2 = /\d{3}.\d{2}.\d{4}/.match(string)
      if m1 && m2
        if m1.post_match.length < m2.post_match.length
          @pusher << m2.pre_match
          @pusher << m2[0].replace("#{m2[0][0,3]}-#{m2[0][4,2]}-#{m2[0][7,4]}")
          string = m2.post_match
          @last_push = m2
        elsif m1.post_match.length > m2.post_match.length
          @pusher << m1.pre_match
          r1 = m1[0].slice(0,3)
          r2 = m1[0].slice(3,2)
          r3 = m1[0].slice(5,4)
          @pusher << "#{r1}-#{r2}-#{r3}"
          string = m1.post_match
          @last_push = m1
        end
      elsif m1
        @pusher << m1.pre_match
        r1 = m1[0].slice(0,3)
        r2 = m1[0].slice(3,2)
        r3 = m1[0].slice(5,4)
        @pusher << "#{r1}-#{r2}-#{r3}"
        string = m1.post_match
        @last_push = m1
      elsif m2
        @pusher << m2.pre_match
        @pusher << m2[0].replace("#{m2[0][0,3]}-#{m2[0][4,2]}-#{m2[0][7,4]}")
        string = m2.post_match
        @last_push = m2
      end
      
      if !/\d{9}/.match(string) && !/\d{3}.\d{2}.\d{4}/.match(string)
        @pusher << @last_push.post_match
      end
    end
    @pusher
  else
    string
  end
end