local Property = require('orm.class.property')

_G.asc = Property({
    parse = function (self)
        return "`" .. self.__table__ .. "`.`" .. self.colname .. "` ASC"
    end
})

_G.desc = Property({
    parse = function (self)
        return "`" .. self.__table__ .. "`.`" .. self.colname .. "` DESC"
    end
})

_G.MAX = Property({
    parse = function (self)
        return "MAX(`" .. self.__table__ .. "`.`" .. self.colname .. "`)"
    end
})

_G.MIN = Property({
    parse = function (self)
        return "MIN(`" .. self.__table__ .. "`.`" .. self.colname .. "`)"
    end
})

_G.COUNT = Property({
    parse = function (self)
        return "COUNT(`" .. self.__table__ .. "`.`" .. self.colname .. "`)"
    end
})

_G.SUM = Property({
    parse = function (self)
        return "SUM(" .. self.colname .. ")"
    end
})

-- Escape text values to prevent sql injection
function _G.escapeValue(own_table, colname, colvalue)

  local coltype = own_table:get_column(colname)
  if coltype and coltype.settings.escape_value then

    local fieldtype = coltype.field.__type__
    if fieldtype:find("text") or fieldtype:find("char") then

      if (DB.type == "sqlite3" or DB.type == "mysql" or DB.type == "postgresql") then

        -- See https://keplerproject.github.io/luasql/manual.html for a list of
        -- database drivers that support this method
        colvalue = db.connect:escape(colvalue)
      elseif (DB.type == "oracle") then
        BACKTRACE(WARNING, "Can't autoescape values for oracle databases (Tried to escape field `" .. colname .. "`)");
      end

    end

  end

  return colvalue;

end