--- Utilities static class.
-- @type UTILS
UTILS = {}


--from http://lua-users.org/wiki/CopyTable
UTILS.DeepCopy = function(object)
  local lookup_table = {}
  local function _copy(object)
    if type(object) ~= "table" then
      return object
    elseif lookup_table[object] then
      return lookup_table[object]
    end
    local new_table = {}
    lookup_table[object] = new_table
    for index, value in pairs(object) do
      new_table[_copy(index)] = _copy(value)
    end
    return setmetatable(new_table, getmetatable(object))
  end
  local objectreturn = _copy(object)
  return objectreturn
end


-- porting in Slmod's serialize_slmod2
UTILS.OneLineSerialize = function( tbl )  -- serialization of a table all on a single line, no comments, made to replace old get_table_string function

  lookup_table = {}
  
  local function _Serialize( tbl )

    if type(tbl) == 'table' then --function only works for tables!
    
      if lookup_table[tbl] then
        return lookup_table[object]
      end

      local tbl_str = {}
      
      lookup_table[tbl] = tbl_str
      
      tbl_str[#tbl_str + 1] = '{'

      for ind,val in pairs(tbl) do -- serialize its fields
        local ind_str = {}
        if type(ind) == "number" then
          ind_str[#ind_str + 1] = '['
          ind_str[#ind_str + 1] = tostring(ind)
          ind_str[#ind_str + 1] = ']='
        else --must be a string
          ind_str[#ind_str + 1] = '['
          ind_str[#ind_str + 1] = routines.utils.basicSerialize(ind)
          ind_str[#ind_str + 1] = ']='
        end

        local val_str = {}
        if ((type(val) == 'number') or (type(val) == 'boolean')) then
          val_str[#val_str + 1] = tostring(val)
          val_str[#val_str + 1] = ','
          tbl_str[#tbl_str + 1] = table.concat(ind_str)
          tbl_str[#tbl_str + 1] = table.concat(val_str)
      elseif type(val) == 'string' then
          val_str[#val_str + 1] = routines.utils.basicSerialize(val)
          val_str[#val_str + 1] = ','
          tbl_str[#tbl_str + 1] = table.concat(ind_str)
          tbl_str[#tbl_str + 1] = table.concat(val_str)
        elseif type(val) == 'nil' then -- won't ever happen, right?
          val_str[#val_str + 1] = 'nil,'
          tbl_str[#tbl_str + 1] = table.concat(ind_str)
          tbl_str[#tbl_str + 1] = table.concat(val_str)
        elseif type(val) == 'table' then
          if ind == "__index" then
          --  tbl_str[#tbl_str + 1] = "__index"
          --  tbl_str[#tbl_str + 1] = ','   --I think this is right, I just added it
          else

            val_str[#val_str + 1] = _Serialize(val)
            val_str[#val_str + 1] = ','   --I think this is right, I just added it
            tbl_str[#tbl_str + 1] = table.concat(ind_str)
            tbl_str[#tbl_str + 1] = table.concat(val_str)
          end
        elseif type(val) == 'function' then
        --  tbl_str[#tbl_str + 1] = "function " .. tostring(ind)
        --  tbl_str[#tbl_str + 1] = ','   --I think this is right, I just added it
        else
--          env.info('unable to serialize value type ' .. routines.utils.basicSerialize(type(val)) .. ' at index ' .. tostring(ind))
--          env.info( debug.traceback() )
        end
  
      end
      tbl_str[#tbl_str + 1] = '}'
      return table.concat(tbl_str)
    else
      return tostring(tbl)
    end
  end
  
  local objectreturn = _Serialize(tbl)
  return objectreturn
end

--porting in Slmod's "safestring" basic serialize
UTILS.BasicSerialize = function(s)
  if s == nil then
    return "\"\""
  else
    if ((type(s) == 'number') or (type(s) == 'boolean') or (type(s) == 'function') or (type(s) == 'table') or (type(s) == 'userdata') ) then
      return tostring(s)
    elseif type(s) == 'string' then
      s = string.format('%q', s)
      return s
    end
  end
end


UTILS.ToDegree = function(angle)
  return angle*180/math.pi
end

UTILS.ToRadian = function(angle)
  return angle*math.pi/180
end

UTILS.MetersToNM = function(meters)
  return meters/1852
end

UTILS.MetersToFeet = function(meters)
  return meters/0.3048
end

UTILS.NMToMeters = function(NM)
  return NM*1852
end

UTILS.FeetToMeters = function(feet)
  return feet*0.3048
end

UTILS.MpsToKnots = function(mps)
  return mps*3600/1852
end

UTILS.MpsToKmph = function(mps)
  return mps*3.6
end

UTILS.KnotsToMps = function(knots)
  return knots*1852/3600
end

UTILS.KmphToMps = function(kmph)
  return kmph/3.6
end


--- From http://lua-users.org/wiki/SimpleRound
-- use negative idp for rounding ahead of decimal place, positive for rounding after decimal place
function UTILS.Round( num, idp )
  local mult = 10 ^ ( idp or 0 )
  return math.floor( num * mult + 0.5 ) / mult
end

-- porting in Slmod's dostring
function UTILS.DoString( s )
  local f, err = loadstring( s )
  if f then
    return true, f()
  else
    return false, err
  end
end