# 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 = 0
    PORT_END = 31
    PORTS_IN_BLOCK = 32
    QSFP_PORT_START = 0
    QSFP_PORT_END = 31

    _port_to_eeprom_mapping = {}
    port_to_i2c_mapping = {
        0: 22,
        1: 23,
        2: 24,
        3: 25,
        4: 26,
        5: 27,
        6: 28,
        7: 29,
        8: 30,
        9: 31,
        10: 32,
        11: 33,
        12: 34,
        13: 35,
        14: 36,
        15: 37,
        16: 6,
        17: 7,
        18: 8,
        19: 9,
        20: 10,
        21: 11,
        22: 12,
        23: 13,
        24: 14,
        25: 15,
        26: 16,
        27: 17,
        28: 18,
        29: 19,
        30: 20,
        31: 21
    }

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

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

    @property
    def qsfp_port_start(self):
        return self.QSFP_PORT_START

    @property
    def qsfp_port_end(self):
        return self.QSFP_PORT_END

    @property
    def qsfp_ports(self):
        return range(0, self.PORTS_IN_BLOCK + 1)

    @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):
            port_eeprom_path = eeprom_path.format(self.port_to_i2c_mapping[x])
            self.port_to_eeprom_mapping[x] = port_eeprom_path
        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

        try:
            reg_file = open("/sys/class/swps/port"+str(port_num)+"/present")
        except IOError as e:
            print "Error: unable to open file: %s" % str(e)
            return False

        reg_value = int(reg_file.readline().rstrip())

        if reg_value == 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

        try:
            reg_file = open("/sys/class/swps/port"+str(port_num)+"/lpmod")
        except IOError as e:
            print "Error: unable to open file: %s" % str(e)

        reg_value = int(reg_file.readline().rstrip())

        if reg_value == 0:
            return False

        return True

    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

        try:
            reg_file = open("/sys/class/swps/port"+str(port_num)+"/lpmod", "r+")
        except IOError as e:
            print "Error: unable to open file: %s" % str(e)
            return False

        reg_value = int(reg_file.readline().rstrip())

        # LPMode is active high; set or clear the bit accordingly
        if lpmode is True:
            reg_value = 1
        else:
            reg_value = 0

        reg_file.write(hex(reg_value))
        reg_file.close()

        return True

    def reset(self, port_num):
        QSFP_RESET_REGISTER_DEVICE_FILE = "/sys/class/swps/port"+str(port_num)+"/reset"
        # Check for invalid port_num
        if port_num < self.port_start or port_num > self.port_end:
            return False

        try:
            reg_file = open(QSFP_RESET_REGISTER_DEVICE_FILE, "r+")
        except IOError as e:
            print "Error: unable to open file: %s" % str(e)
            return False

        reg_value = 0
        reg_file.write(hex(reg_value))
        reg_file.close()

        # Sleep 2 second to allow it to settle
        time.sleep(2)

        # Flip the value back write back to the register to take port out of reset
        try:
            reg_file = open(QSFP_RESET_REGISTER_DEVICE_FILE, "r+")
        except IOError as e:
            print "Error: unable to open file: %s" % str(e)
            return False

        reg_value = 1
        reg_file.write(hex(reg_value))
        reg_file.close()

        return True

    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