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 ExtUtils.writeFile( name, content )
    local f = assert( io.open( name, "w" ) )
    local content = f:write( content )
    f:close()
end

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

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

function getICfg()
  local cfg = {}
  for k, v in pairs( Helix.Core.Server.GetInstanceConfigData() ) do
    cfg[ k ] = trim( v )
  end
return cfg
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()
-- todo: split the user list into another table
  end
  if ExtUtils.manifest[ "key" ] == nil then
    ExtUtils.manifest = getManifest()
  end
end

return ExtUtils