import streamlit as st
import epitran
import langcodes
from langcodes import LanguageTagError
from pathlib import Path
from operator import itemgetter
# TODO: reverse transliterate? 


def get_lang_description_from_mapping_name(string_to_check):  
  if "generic-Latn" == string_to_check: 
    return "Generic Latin Script"
    
  if len(string_to_check)<2:
    return None       

  substrings = string_to_check.split("-")
  substrings = substrings[0, 1] # remove the last one
  string_to_check = "-".join(substrings)
  
  
  try:
    description = None
    lang = langcodes.get(string_to_check)
    if lang: 
      items = []
      for key, value in lang.describe().items():
        if key == "language":
          iso_code = lang.to_alpha3()
          value = f"[{value}](https://iso639-3.sil.org/code/{iso_code})"
        items.append(f"{key}: {value}")
        
    
      description = ", ".join(items)
    return description


def get_valid_epitran_mappings_list():
  map_path = Path(epitran.__path__[0]) / "data" / "map"
  map_files = map_path.glob("*.*")
  valid_mappings = [map_file.stem for map_file in map_files]
  problem_mappings = ['generic-Latn',
 'tur-Latn-bab',
 'ood-Latn-sax',
 'vie-Latn-so',
 'vie-Latn-ce',
 'vie-Latn-no',
 'kaz-Cyrl-bab'] # https://github.com/dmort27/epitran/issues/98
  filtered_mappings = [mapping for mapping in valid_mappings if mapping not in problem_mappings]
  
  return filtered_mappings 


if __name__ == "__main__":

  st.write("# Phonemize your text with [Epitran](https://github.com/dmort27/epitran)!")

  st.write("Epitran is a library and tool for transliterating orthographic text as IPA (International Phonetic Alphabet), by Mortensen, David R.  and Dalmia, Siddharth and Littell, Patrick.") 
  
  valid_epitran_mappings = get_valid_epitran_mappings_list()
  index_of_swa_latn = valid_epitran_mappings.index("swa-Latn")
  st.write(f"It supports converting many writing sytems to IPA symbols, including approximately {len(valid_epitran_mappings)} languages/scripts, listed below:")

  #st.write(valid_epitran_mappings)
  
  selected_mapping = st.selectbox("Select input language/script:", valid_epitran_mappings, index=index_of_swa_latn)
  description = get_lang_description_from_mapping_name(selected_mapping)
  st.write(f"Selected input language/script: {description}")
  
  
#  iso_lang_code = st.text_input(
#    label="Three-letter ISO-639-3 (https://iso639-3.sil.org/) language code", 
#    value="swa"
#    )
#  st.write(f"iso code is {iso_lang_code}")
#  
#  iso_script_code = st.text_input(
#    label="ISO 15924 (https://unicode.org/iso15924/iso15924-codes.html) script code, e.g. 'Latn' for Latin script, 'Hans' for Chinese script, etc.", 
#    value="Latn"
#    )
#  st.write(f'iso code is {iso_script_code}')
  
  input_text = st.text_area(label="Whatever you type here will be transliterated!", value="Gari langu linaloangama limejaa na mikunga")
  
#  combined_code = "-".join([iso_lang_code, iso_script_code])
#  st.write(f"Combined code: {combined_code}")
  st.info("attempting to instantiate epitran transliterator for your language/script")
  epi = epitran.Epitran(selected_mapping)

  st.info(f"transliterating `{input_text}`\n\tusing {selected_mapping}...")  
  transliteration = epi.transliterate(input_text)
  
  st.success(transliteration)