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


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

    _port_start = 1
    _port_end = 54
    _qsfp_port_start = 49
    _ports_in_block = 54

    _port_to_eeprom_mapping = {}
    _global_port_pres_dict = {}

    _port_to_i2c_mapping = {
        1: 8,
        2: 9,
        3: 10,
        4: 11,
        5: 12,
        6: 13,
        7: 14,
        8: 15,
        9: 16,
        10: 17,
        11: 18,
        12: 19,
        13: 20,
        14: 21,
        15: 22,
        16: 23,
        17: 24,
        18: 25,
        19: 26,
        20: 27,
        21: 28,
        22: 29,
        23: 30,
        24: 31,
        25: 32,
        26: 33,
        27: 34,
        28: 35,
        29: 36,
        30: 37,
        31: 38,
        32: 39,
        33: 40,
        34: 41,
        35: 42,
        36: 43,
        37: 44,
        38: 45,
        39: 46,
        40: 47,
        41: 48,
        42: 49,
        43: 50,
        44: 51,
        45: 52,
        46: 53,
        47: 54,
        48: 55,
        49: 56,
        50: 57,
        51: 60,
        52: 61,
        53: 62,
        54: 63,
    }

    _qsfp_ports = list(range(_qsfp_port_start, _ports_in_block + 1))

    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

        path = "/sys/bus/i2c/devices/{0}-0050/sfp_is_present"
        port_ps = path.format(self._port_to_i2c_mapping[port_num])

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

        try:
            reg_value = reg_file.readline().rstrip()
        except IOError as e:
            time.sleep(1)

            try:
                reg_value = reg_file.readline().rstrip()
            except IOError as e:
                print("Error:try again to read file failed: %s %s" % (str(e), port_ps))
                reg_file.close()
                return False

            reg_file.close()
            if reg_value == '1':
                return True

        reg_file.close()
        if reg_value == '1':
            return True

        return False

    def init_global_port_presence(self):
        for port_num in range(self.port_start, (self.port_end + 1)):
            self._global_port_pres_dict[port_num] = '0'

    def __init__(self):
        eeprom_path = '/sys/bus/i2c/devices/{0}-0050/sfp_eeprom'
        for x in range(self._port_start, 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

        self.init_global_port_presence()
        SfpUtilBase.__init__(self)

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

        path = "/sys/bus/i2c/devices/{0}-0050/sfp_port_reset"
        port_ps = path.format(self._port_to_i2c_mapping[port_num])

        try:
            reg_file = open(port_ps, 'w')
        except IOError as e:
            print("Error: unable to open file: %s" % str(e))
            return False

        # toggle reset
        reg_file.seek(0)
        reg_file.write('1')
        time.sleep(1)
        reg_file.seek(0)
        reg_file.write('0')
        reg_file.close()
        return True

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

        pre_value = self.get_presence(port_num)
        if pre_value == False:
            return False

        path = "/sys/bus/i2c/devices/{0}-0050/sfp_lpmode"
        port_ps = path.format(self._port_to_i2c_mapping[port_num])

        try:
            reg_file = open(port_ps, 'w')
        except IOError as e:
            print("Error: unable to open file: %s" % str(e))
            return False

        reg_file.seek(0)

        if lpmode == 1:
            reg_file.write('1')
        elif lpmode == 0:
            reg_file.write('0')
        reg_file.close()

        return True

    def get_low_power_mode(self, port_num):
        # Check for invalid port_num

        if port_num < self._qsfp_port_start or port_num > self._port_end:
            return False

        pre_value = self.get_presence(port_num)
        if pre_value == False:
            return False

        path = "/sys/bus/i2c/devices/{0}-0050/sfp_lpmode"
        port_ps = path.format(self._port_to_i2c_mapping[port_num])

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

        try:
            reg_value = reg_file.readline().rstrip()
        except IOError as e:
            print("Error: unable to open file:%s %s" % (str(e), port_ps))
            reg_file.close()
            return False

        reg_file.close()

        if reg_value == '1':
            return True

        return False

    def get_transceiver_change_event(self):
        port_dict = {}
        while True:
            for port_num in range(self.port_start, (self.port_end + 1)):
                presence = self.get_presence(port_num)

                if(presence and self._global_port_pres_dict[port_num] == '0'):
                    self._global_port_pres_dict[port_num] = '1'
                    port_dict[port_num] = '1'
                elif(not presence and
                     self._global_port_pres_dict[port_num] == '1'):
                    self._global_port_pres_dict[port_num] = '0'
                    port_dict[port_num] = '0'

                if(len(port_dict) > 0):
                    return True, port_dict

            time.sleep(0.5)

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

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

    @property
    def qsfp_ports(self):
        return self._qsfp_ports

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