use xpinyin database in luatex

luapinyin.tex

\documentclass{minimal}
\usepackage{luacode}
\usepackage{luatexja-ruby}

\makeatletter
\def\xpinyin@@pinyin@struct{\vrule width 0pt depth 0.5ex}
\makeatother

\begin{luacode*}
xpinyin = {}

-- create map_token table
xpinyin.map_token = {}
for ascii = 97, 122 do
  xpinyin.map_token[string.char(ascii)] = { token.create(ascii, 11) }
end

xpinyin.map_token[1] = { token.create('=') }
xpinyin.map_token[2] = { token.create('\'') }
xpinyin.map_token[3] = { token.create('v') }
xpinyin.map_token[4] = { token.create('`') }
xpinyin.map_token[5] = { token.create('i') }
xpinyin.map_token[6] = { token.create('"') }

do
  local bgroup = token.create(string.byte('{'), 1)
  local egroup = token.create(string.byte('}'), 2)
  xpinyin.bgroup = bgroup
  xpinyin.egroup = egroup
  xpinyin.ruby_token = token.create('ltjruby')
  xpinyin.struct_token = token.create('xpinyin@@pinyin@struct')

  local token = xpinyin.map_token
  token['ā'] = { unpack(token[1]), unpack(token['a'])}
  token['á'] = { unpack(token[2]), unpack(token['a'])}
  token['ǎ'] = { unpack(token[3]), unpack(token['a'])}
  token['à'] = { unpack(token[4]), unpack(token['a'])}
  token['ō'] = { unpack(token[1]), unpack(token['o'])}
  token['ó'] = { unpack(token[2]), unpack(token['o'])}
  token['ǒ'] = { unpack(token[3]), unpack(token['o'])}
  token['ò'] = { unpack(token[4]), unpack(token['o'])}
  token['ē'] = { unpack(token[1]), unpack(token['e'])}
  token['é'] = { unpack(token[2]), unpack(token['e'])}
  token['ě'] = { unpack(token[3]), unpack(token['e'])}
  token['è'] = { unpack(token[4]), unpack(token['e'])}
  token['ū'] = { unpack(token[1]), unpack(token['u'])}
  token['ú'] = { unpack(token[2]), unpack(token['u'])}
  token['ǔ'] = { unpack(token[3]), unpack(token['u'])}
  token['ù'] = { unpack(token[4]), unpack(token['u'])}
  token['ḿ'] = { unpack(token[2]), unpack(token['m'])}
  token['ń'] = { unpack(token[2]), unpack(token['n'])}
  token['ň'] = { unpack(token[3]), unpack(token['n'])}
  token['ǹ'] = { unpack(token[4]), unpack(token['n'])}
  token['ī'] = { unpack(token[1]), unpack(token[ 5 ])}
  token['í'] = { unpack(token[2]), unpack(token[ 5 ])}
  token['ǐ'] = { unpack(token[3]), unpack(token[ 5 ])}
  token['ì'] = { unpack(token[4]), unpack(token[ 5 ])}
  token['ü'] = { bgroup, unpack(token[6]), unpack(token['u']), egroup}
  token['ǖ'] = { unpack(token[1]), unpack(token['ü'])}
  token['ǘ'] = { unpack(token[2]), unpack(token['ü'])}
  token['ǚ'] = { unpack(token[3]), unpack(token['ü'])}
  token['ǜ'] = { unpack(token[4]), unpack(token['ü'])}
end

function xpinyin.toruby (toks)
  local depth = 0
  local data = xpinyin.data
  local map_token = xpinyin.map_token
  local new_toks = {}
  for _, tok in ipairs(toks) do
    if tok.cmdname == 'left_brace' then
      depth = depth + 1
    end
    if tok.cmdname == 'right_brace' then
      depth = depth - 1
    end
    if tok.cmdname == 'letter' and depth == 0 and xpinyin.data[tok.mode] then
      table.insert(new_toks, xpinyin.ruby_token)
      table.insert(new_toks, xpinyin.bgroup)
      table.insert(new_toks, tok)
      table.insert(new_toks, xpinyin.egroup)
      table.insert(new_toks, xpinyin.bgroup)
      table.insert(new_toks, xpinyin.struct_token)
      for char in string.utfcharacters(xpinyin.data[tok.mode]) do
        local py_toks = map_token[char]
        for i = 1,#py_toks do
          table.insert(new_toks, py_toks[i])
        end
      end
      table.insert(new_toks, xpinyin.egroup)
    else
      table.insert(new_toks, tok)
    end
  end
  token.put_next (new_toks)
end

xpinyin.data = {}
function xpinyin.insert (index, str)
  xpinyin.data[index] = stripped_str
end
\end{luacode*}

\makeatletter
\def\xpinyin#1{\directlua{xpinyin.toruby(token.scan_toks(false,false))}{#1}}
\def\withpinyin#1#2{\ltjruby{#1}{\xpinyin@@pinyin@struct #2}}
\def\setpinyin#1#2{\directlua{xpinyin.data[table.unpack(string.utfvalues([[#1]]))] = [[#2]]}}
\makeatother

\begingroup
    \def\XPYU#1#2#3{\directlua{xpinyin.data[#2] = [[#3]]}}
    \def\XPYUM#1#2#3{\directlua{xpinyin.data[#2] = [[\getfirst #3\nil]]}}
    \def\getfirst#1,#2\nil{#1}
    \input{xpinyin-database.def}
\endgroup

% Differences with xpinyin.sty
%
% \pinyin easy input is not provided, copies the
% macros from xpinyin.sty may work, though
%
% In any grouping xpinyin is disabled
%
% In case of multiple reading characters, only the first reading is taken
\begin{document}
\xpinyin{親文字\textgt{\xpinyin{親文\withpinyin{字}{zhi}}\ltjruby{親|文|字}{おや|も|じ}}}
\end{document}