# letter2html.py -- (c)2019 Henrique Moreira
"""
  letter2html.py - simple Python functions to convert text to HTML
"""

#
# test this script
#
def test_letter2html (outFile, inArgs):
  args = inArgs
  assert translateTable.nConverts>0
  tbl = TranslateTable( debug=1 )
  return 0


class TranslateTable:
  def __init__ (self, debug=0):
    xlate = {
      0xc0:'À', 0xc1:'Á', 0xc2:'Â', 0xc3:'Ã', 0xc4:'Ä', 0xc5:'Å',
      0xc6:'Ae', 0xc7:'Ç',
      0xc8:'È', 0xc9:'É', 0xca:'E', 0xcb:'E',
      0xcc:'Ì', 0xcd:'Í', 0xce:'I', 0xcf:'I',
      0xd0:'Th', 0xd1:'N',
      0xd2:'Ò', 0xd3:'Ó', 0xd4:'O', 0xd5:'O', 0xd6:'O', 0xd8:'O',
      0xd9:'Ù', 0xda:'Ù', 0xdb:'U', 0xdc:'U',
      0xdd:'Y', 0xde:'th', 0xdf:'ss',
      0xe0:'à', 0xe1:'á', 0xe2:'â', 0xe3:'ã', 0xe4:'ä', 0xe5:'å',
      0xe6:'ae', 0xe7:'c',
      0xe8:'è', 0xe9:'é', 0xea:'e', 0xeb:'e',
      0xec:'ì', 0xed:'í', 0xee:'i', 0xef:'i',
      0xf0:'th', 0xf1:'n',
      0xf2:'ò', 0xf3:'ó', 0xf4:'o', 0xf5:'o', 0xf6:'o', 0xf8:'o',
      0xf9:'ù', 0xfa:'ú', 0xfb:'u', 0xfc:'u',
      0xfd:'y', 0xfe:'th', 0xff:'y',
      0xa1:'!', 0xa2:'{cent}', 0xa3:'{pound}', 0xa4:'{currency}',
      0xa5:'¥',
      0xa6:'|', # broken bar
      0xa7:'{section}', 0xa8:'{umlaut}',
      0xa9:'&copy;', 0xaa:'{^a}', 0xab:'<<', 0xac:'&not;',
      0xad:'-', 0xae:'{R}', 0xaf:'_', 0xb0:'{degrees}',
      0xb1:'{+/-}', 0xb2:'{^2}', 0xb3:'{^3}', 0xb4:"'",
      0xb5:'{micro}', 0xb6:'{paragraph}', 0xb7:'*',
      0xb8:'&ccedil;',
      0xb9:'{^1}', 0xba:'{^o}', 0xbb:'>>', 
      0xbc:'{1/4}', 0xbd:'{1/2}', 0xbe:'{3/4}',
      0xbf:'?', # inverted question mark
      0xd7:'*', # multiplication sign
      0xf7:'/', # division sign
      }
    self.nConverts = len( xlate )
    self.hash_convertions( debug, relate=xlate )


  def hash_convertions (self, debug, **vars):
    if debug>=2:
      for aKey, val in vars.items():
        print( "key: <b>{}</b>".format( aKey ), "is: <pre>", val ,"</pre>\n")
        print("<hr>")
    digConv = vars[ "relate" ]
    used = [0] * 256
    if debug>0:
      def hint_str (info, k):
        hint = "<a {} href='https://www.fileformat.info/info/unicode/char/{:04x}/index.htm'>{}</a>".format( "target='_blank'", k, info )
        return hint
      for kind in ["&", ""]:
        for k, html in digConv.items():
          aLen = len( html )
          assert aLen>0
          first = html[ 0 ].lower()
          if used[ k ]>0:
            continue
          bas = "k: 0x{:02x}".format(k) + " " + hint_str( "{:d}d".format(k, k), k )
          if kind=="":
            show = html.replace( "<", "&lt;" ).replace( ">", "&gt;" )
            print(bas, "; html is:", show, "<BR/>")
            used[ k ] += 1
          else:
            if html.find( kind )==0:
              print(bas, "; html string is:", html, "<BR/>")
              used[ k ] += 1
              if first=="&":
                isOk = html.endswith( ";" )
                assert isOk
      k = 0x7f
      while True:
        k += 1
        if k >= 256:
          break
        if k==0xa0:
          print("<hr>Now ASCII after 0xA0 (160d)<br>")
        if used[ k ]<=0:
          hint = hint_str("info", k)
          print("<p>unused k:", "0x{:02x} #{:03};".format(k, k), hint, "</p>")
    return True


def latin1_to_html (s):
  """This takes a UNICODE string and replaces Latin-1 characters with
      something equivalent in html. It returns a plain ASCII string. 
      This function makes a best effort to convert Latin-1 characters into 
      ASCII equivalents. It does not just strip out the Latin-1 characters.
      All characters in the standard 7-bit ASCII range are preserved. 
      In the 8th bit range all the Latin-1 accented letters are converted 
      to unaccented equivalents. Most symbol characters are converted to 
      something meaningful. Anything not converted is deleted.
  """

  r = ''
  for i in s:
      if xlate.has_key(ord(i)):
          r += xlate[ord(i)]
      elif ord(i) >= 0x80:
          pass
      else:
          r += str(i)
  return r


#
# Global / singletons
#
translateTable = TranslateTable()


#
# Test suite
#
if __name__ == "__main__":
  import sys
  outFile = sys.stdout;
  code = test_letter2html( outFile, sys.argv[ 1: ] )
  sys.exit( code )