local util = require('util')

return function(app)

  local config = { -- default
    name = "XRForge",
    baseurl="/",
    title="My XRForge experiences",
    subtitle="Portable XR experiences for Phone, VRheadset & desktop.",
    admin_title = "XRForge Admin",
    admin_subtitle = "Manage your XR experiences here",
    disk_dir = ".",
    manyfold_instance_1 = "https://xrforge.isvery.ninja",
    manyfold_instance_2 = "",
    manyfold_instance_3 = "",
    sync_interval = 30,
    sync_strategy = "recent"
  }

  local configfile  = "xrforge.lua"
  local savedconfig = util.readfile( app.bindir .. configfile, 'r', true) -- check local config
                      or LoadAsset(configfile)                 -- then internal saved config

  if savedconfig then 
    local eval = function(str) return load(str)() end
    local status, result = pcall(eval, savedconfig )  -- Pass "string" as the first argument
    if not status then 
      print("error: xrforge.lua contains errors:") 
    else
      config = result -- overrule default config
    end
  end 

  app.on('set', function(k,v)
    if k == 'app.opts' then
      app.opts = v 
      app.opts.updated = os.time()
      local newconfig = "app.on('init', function()\n\tprint('config loaded')\nend)\n\nreturn " .. util.dump(app.opts)
      newconfig = newconfig:gsub("^}$","  init = function() print('xrforge.lua config loaded') end\n}")
      util.writefile( app.bindir .. configfile, newconfig )
      print("stored xrforge.lua")
    end
  end)

  -- store local config if not exist
  if not util.readfile( app.bindir .. configfile, 'r', true) then
    app.set('app.opts', config )
  end

  return config
end