local ExtUtils = {}
local cjson = require "cjson"

function ExtUtils.slurpFile( name )
    local f = assert( io.open( name, "rb" ) )
    local content = f:read( "*all" )
    f:close()
    return content
end

function getManifest()
  local fn = Helix.Core.Server.GetArchDirFileName( "manifest.json" )
  return cjson.decode( ExtUtils.slurpFile( fn ) )
end

function ExtUtils.trim( s )
   return ( s:gsub( "^%s*(.-)%s*$", "%1" ) )
end

function split(s, delimiter)
    if s == nil or s == '' then
      return nil
    end
    local result = {};
    for match in (s..delimiter):gmatch("(.-)"..delimiter) do
      table.insert(result, match);
    end
    return result;
end

function getICfg()
  local cfg = {}
  for k, v in pairs( Helix.Core.Server.GetInstanceConfigData() ) do
    if k == "num_level" then
      cfg[ k ] = tonumber( ExtUtils.trim( v ) )
    else
      cfg[ k ] = ExtUtils.trim( v )
    end
  end
  -- Set a default to 0 (no restrictions) if no level set
  if cfg[ "num_level" ] == nil then
    cfg[ "num_level" ] = 0
  end

  return cfg
end

function ExtUtils.getUsers()
  local userstr = ExtUtils.iCfgData[ "exempt_users" ]
  return split( userstr, " ")
end

function ExtUtils.getLevel()
  return ExtUtils.iCfgData[ "num_level" ]
end

function ExtUtils.UserNeedsRestrictions()
  local listusers = ExtUtils.getUsers()
  if listusers ~= nil then
     for k, u in pairs(listusers) do
        if Helix.Core.Server.GetVar( "user" ) == u then
           return false
        end
     end
  end
  return true
end


function ExtUtils.msgHeader()
  return ExtUtils.manifest[ "name" ] .. "/" .. ExtUtils.manifest[ "key" ] .. "/" ..
         ExtUtils.manifest[ "version_name" ] .. ":  "
end

ExtUtils.manifest = {}
ExtUtils.iCfgData = {}

function ExtUtils.init()
  if ExtUtils.iCfgData[ "specName" ] == nil then
    ExtUtils.iCfgData = getICfg()
  end
  if ExtUtils.manifest[ "key" ] == nil then
    ExtUtils.manifest = getManifest()
  end
end

return ExtUtils