# sfputil.py
#
# Platform-specific SFP transceiver interface for SONiC
#

try:
    import time
    from sonic_sfp.sfputilbase import SfpUtilBase
except ImportError as e:
    raise ImportError("%s - required module not found" % str(e))


class SfpUtil(SfpUtilBase):
    """Platform-specific SfpUtil class"""

    PORT_START = 48
    PORT_END = 49
    PORTS_IN_BLOCK = 1

    EEPROM_OFFSET = 44

    _port_to_eeprom_mapping = {}

    @property
    def port_start(self):
        return self.PORT_START

    @property
    def port_end(self):
        return self.PORT_END

    @property
    def qsfp_ports(self):
        return range(0)

    @property
    def port_to_eeprom_mapping(self):
        return self._port_to_eeprom_mapping

    def __init__(self):
        eeprom_path = "/sys/class/i2c-adapter/i2c-{0}/{0}-0050/eeprom"

        for x in range(0, self.port_end + 1):
            if x >= self.port_start and x <= self.port_end:
                self._port_to_eeprom_mapping[x] = eeprom_path.format(x - self.EEPROM_OFFSET)
            else:
                self._port_to_eeprom_mapping[x] = eeprom_path.format(x - x)

        SfpUtilBase.__init__(self)

    def get_presence(self, port_num):
        # Check for invalid port_num
        if port_num < self.port_start or port_num > self.port_end:
            return False
        
        presence_path = "/sys/devices/platform/delta-et6248brb-gpio.0/SFP/sfp_mod_p{}"

        try:
            reg_file = open(presence_path.format(port_num - 47))
        except IOError as e:
            print "Error: unable to open file: %s" % str(e)
            return False

        if int(reg_file.readline()) == 0:
            return True

        return False

    def get_low_power_mode(self, port_num):
        # Check for invalid port_num
        if port_num < self.port_start or port_num > self.port_end:
            return False

        return False

    def set_low_power_mode(self, port_num, lpmode):
        # Check for invalid port_num
        if port_num < self.port_start or port_num > self.port_end:
            return False

        return False

    def reset(self, port_num):
        # Check for invalid port_num
        if port_num < self.port_start or port_num > self.port_end:
            return False

        return False

    def get_transceiver_change_event(self):
        """
        TODO: This function need to be implemented
        when decide to support monitoring SFP(Xcvrd)
        on this platform.
        """
        raise NotImplementedError