lua_complete.lua

local lua_complete = {}
lua_complete.data = {}

lua_complete.__loadData = function(parent, parent_name)
  -- check whether parent_name was passed
  if  parent_name == nil then
    parent_name = ""
    -- add . to parent_name when it's not empty
  elseif parent_name ~= "" then
    parent_name = parent_name .. "."
  end

  -- loop through dictionary
  for child_name,child in pairs(parent) do
    table.insert(lua_complete.data, parent_name..child_name)
    -- recursivly call getData 
    -- TODO check for recursive entries properly
    if type(child)  ==  "table" and 
      not string.match(parent_name, child_name) and
      not string.match(parent_name, "lua_complete") and
      child_name ~= "_G" then
      lua_complete.__loadData(child, parent_name..child_name)
    end
  end
end

function lua_complete.__sortData()
  -- sort the data before writing so the suggetions are more relavent
  function dots(str)
    -- used to compare to strings to check how many (.) it has
    count = 0
    pos = -1
    while true do
      pos = string.find(str, "\[.\]", pos+1)
      if pos == nil then
        break
      end
      count = count + 1
    end
    return count
  end

  function compare(a, b)
    -- Campare function used for sorting
    -- Compares based on 2 conditions how many (.) is has and alfabatical order
    dota = dots(a)
    dotb = dots(b)
    if dota == dotb then
      return a < b
    else
      return dota < dotb
    end

  end
  -- Sort the data
  table.sort(lua_complete.data, compare)
end


function lua_complete.__writeData()
  -- Write the data to file
  for _,val in ipairs(lua_complete.data) do
    lua_complete.file:write(val..'\n')
  end
end


function lua_complete.reload()
  -- This function recreats the dictionary
  -- Create cache dir if it doesn't exist
  local cache_dir = vim.fn.stdpath("cache").."/lua_complete"
  if vim.fn.isdirectory(cache_dir) == 0 then
    vim.fn.mkdir(cache_dir)
  end
  -- run the loading prossess in a different thread (WIP)
  -- co = coroutine.create(function()
  lua_complete.file = io.open(cache_dir.."/lua_dictionary.txt","w")
  lua_complete.__loadData(_G)
  lua_complete.__sortData()
  lua_complete.__writeData()
  -- free resources
  lua_complete.file:close()
  lua_complete.data = nil
  --end)
  -- coroutine.resume(co)
end

function lua_complete.load()
  -- Loads the dictionary on luafiles
  local fname = vim.fn.stdpath("cache").."/lua_complete/lua_dictionary.txt"
  -- Create dictionary if it doesn't exist
  if vim.fn.filereadable(fname) == 0 then
    lua_complete.reload()
  end
  -- vim commands
  vim.cmd("augroup Lua_Complete")
  vim.cmd("autocmd!")
  vim.cmd("au Filetype lua setlocal complete+=k")
  vim.cmd("au Filetype lua setlocal dictionary+="..fname)
  vim.cmd("au Filetype lua setlocal iskeyword+=.")
  vim.cmd("au Filetype lua setlocal iskeyword+=:")
  vim.cmd("augroup END")
end

return lua_complete