require 'cgi'

def strip_html(text)
  attribute_key = /[\w:_-]+/
  attribute_value = /(?:[A-Za-z0-9]+|(?:'[^']*?'|"[^"]*?"))/
  attribute = /(?:#{attribute_key}(?:\s*=\s*#{attribute_value})?)/
  attributes = /(?:#{attribute}(?:\s+#{attribute})*)/
  tag_key = attribute_key
  tag = %r{<[!/?\[]?(?:#{tag_key}|--)(?:\s+#{attributes})?\s*(?:[!/?\]]+|--)?>}
  text.gsub(tag, '').gsub(/\s+/, ' ').strip
end

module RFC822
  EmailAddress = begin
    qtext = '[^\\x0d\\x22\\x5c\\x80-\\xff]'
    dtext = '[^\\x0d\\x5b-\\x5d\\x80-\\xff]'
    atom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-' +
      '\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+'
    quoted_pair = '\\x5c[\\x00-\\x7f]'
    domain_literal = "\\x5b(?:#{dtext}|#{quoted_pair})*\\x5d"
    quoted_string = "\\x22(?:#{qtext}|#{quoted_pair})*\\x22"
    domain_ref = atom
    sub_domain = "(?:#{domain_ref}|#{domain_literal})"
    word = "(?:#{atom}|#{quoted_string})"
    domain = "#{sub_domain}(?:\\x2e#{sub_domain})*"
    local_part = "#{word}(?:\\x2e#{word})*"
    addr_spec = "#{local_part}\\x40#{domain}"
    pattern = /\A#{addr_spec}\z/
  end
end

INTMATCH = /\A\d+\z/

def parseparam(vpstr, vdefault, vtype, vpositivelist = nil, 
              vmatchregexpr = nil, vmin = 0, vmax = 999999)
    
    # nil strings are treated as empty strings
    vpstr = "" if vpstr.nil? && vtype == "str"    
    if !vpstr.nil? then
      begin
        result = case vtype
          when "bool" then
            if ["true", true, "1", 1].include?(vpstr) then true
              else false end
          when "int", "id" then
           if (vpstr == "") || ( vpstr.class == String && (INTMATCH =~ vpstr).nil? ) then result = vdefault else 
             if vpositivelist.nil? || vpositivelist.include?(vpstr.to_i) then result = vpstr.to_i
              else result = vdefault end
           end
            if vtype == "id" then result.to_s else result end
          when "str" then
            if (vmax >= vmin) && ( (vpstr.length < vmin) ||
                                   (vpstr.length > vmax) ) then
               result = vdefault
            else   
              if vpositivelist then
               if vpositivelist.include?(vpstr) then 
                  result = vpstr.to_s
               else 
                  result = vdefault
               end
              else
               result = vpstr.to_s
              end
              
              if vmatchregexpr then
                if (vmatchregexpr =~ result).nil? then
                  result = vdefault
                else
                  result = vpstr.to_s 
                end
              end
            end
            result
          when "date" then if vpstr.year == "" then vdefault else vpstr end
          when "htmlescape" then CGI::escapeHTML(vpstr.to_s)
          when "email" then 
            if (RFC822::EmailAddress =~ vpstr).nil? then
              vdefault
            else 
              vpstr.to_s
            end
        end
      rescue
        result = vdefault
      end
      return result
    else
      return vdefault
    end
end