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

try:
    import os
    import logging
    import time
    import select
    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 = 1
    PORT_END = 32
    PORTS_IN_BLOCK = 32
    IOM_1_PORT_START = 1
    IOM_1_PORT_END = 12
    IOM_2_PORT_START = 13
    IOM_2_PORT_END = 22
    IOM_3_PORT_START = 23
    IOM_3_PORT_END = 32

    BASE_VAL_PATH = "/sys/class/i2c-adapter/i2c-{0}/{0}-003e/"
    OIR_FD_PATH = "/sys/devices/platform/dell_ich.0/sci_int_gpio_sus6"

    oir_fd = -1
    epoll = -1
    _port_to_eeprom_mapping = {}
    _port_to_i2c_mapping = {
           0: [0, 00], # Dummy Entry
           1: [9, 18],
           2: [9, 19],
           3: [9, 20],
           4: [9, 21],
           5: [9, 22],
           6: [9, 23],
           7: [9, 24],
           8: [9, 25],
           9: [8, 26],
           10: [8, 27],
           11: [8, 28],
           12: [8, 29],
           13: [8, 31],  # reordered
           14: [8, 30],
           15: [8, 33],  # reordered
           16: [8, 32],
           17: [7, 34],
           18: [7, 35],
           19: [7, 36],
           20: [7, 37],
           21: [7, 38],
           22: [7, 39],
           23: [7, 40],
           24: [7, 41],
           25: [6, 42],
           26: [6, 43],
           27: [6, 44],
           28: [6, 45],
           29: [6, 46],
           30: [6, 47],
           31: [6, 48],
           32: [6, 49]
           }

    @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, self.PORTS_IN_BLOCK + 1)

    @property
    def iom1_port_start(self):
        return self.IOM_1_PORT_START

    @property
    def iom1_port_end(self):
        return self.IOM_1_PORT_END

    @property
    def iom2_port_start(self):
        return self.IOM_2_PORT_START

    @property
    def iom2_port_end(self):
        return self.IOM_2_PORT_END

    @property
    def iom3_port_start(self):
        return self.IOM_3_PORT_START

    @property
    def iom3_port_end(self):
        return self.IOM_3_PORT_END

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

    @property
    def port_to_i2c_mapping(self):
        return self._port_to_i2c_mapping

    def __init__(self):
        eeprom_path = "/sys/class/i2c-adapter/i2c-{0}/i2c-{1}/{1}-0050/eeprom"

        for x in range(0, self.port_end+1):
            self.port_to_eeprom_mapping[x] = eeprom_path.format(
                self.port_to_i2c_mapping[x][0],
                self.port_to_i2c_mapping[x][1])

        SfpUtilBase.__init__(self)

    def __del__(self):
        if self.oir_fd != -1:
                self.epoll.unregister(self.oir_fd.fileno())
                self.epoll.close()
                self.oir_fd.close()

    def normalize_port(self, port_num):
        # Check for invalid port_num
        if port_num < self.port_start or port_num > self.port_end:
            return -1, -1
        # port_num and i2c match
        if port_num >= self.iom1_port_start and port_num <= self.iom1_port_end:
            i2c_line = 14
        elif (port_num >= self.iom2_port_start and
                port_num <= self.iom2_port_end):
            i2c_line = 15
        elif (port_num >= self.iom3_port_start and
                port_num <= self.iom3_port_end):
            i2c_line = 16

        # Rationalize port settings
        if port_num >= self.iom1_port_start and port_num <= self.iom1_port_end:
            port_num = port_num - 1
        elif port_num >= self.iom2_port_start and port_num <= self.iom2_port_end:
            port_num = (port_num - 1) % 12
        elif (port_num >= self.iom3_port_start and
                port_num <= self.iom3_port_end):
            port_num = (port_num - 1) % 22

        return i2c_line, port_num


    def get_presence(self, port_num):

        i2c_line, port_num = self.normalize_port(port_num)
        if port_num == -1:
            return False

        try:
            qsfp_path = self.BASE_VAL_PATH.format(i2c_line)+"qsfp_modprs"
            reg_file = open(qsfp_path, "r")

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

        content = reg_file.readline().rstrip()

        # Absence of IOM throws read error
        if (content == 'read error'):
            return False

        # content is a string containing the hex representation of the register
        reg_value = int(content, 16)

        # Mask off the bit corresponding to our port
        mask = (1 << port_num)

        # ModPrsL is active low
        if reg_value & mask == 0:
            return True

        return False

    def get_low_power_mode(self, port_num):

        i2c_line, port_num = self.normalize_port(port_num)
        if port_num == -1:
            return False

        try:
                qsfp_path = self.BASE_VAL_PATH.format(i2c_line)+"qsfp_lpmode"
                reg_file = open(qsfp_path, "r")

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

        content = reg_file.readline().rstrip()

        # Absence of IOM throws read error
        if (content == 'read error'):
            return False

        # content is a string containing the hex representation of the register
        reg_value = int(content, 16)

        # Mask off the bit corresponding to our port
        mask = (1 << port_num)

        # LPMode is active high
        if reg_value & mask == 0:
            return False

        return True

    def set_low_power_mode(self, port_num, lpmode):

        i2c_line, port_num = self.normalize_port(port_num)
        if port_num == -1:
            return False

        try:
                qsfp_path = self.BASE_VAL_PATH.format(i2c_line)+"qsfp_lpmode"
                reg_file = open(qsfp_path, "r+")


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

        content = reg_file.readline().rstrip()

        # Absence of IOM throws read error
        if (content == 'read error'):
            return False

        # content is a string containing the hex representation of the register
        reg_value = int(content, 16)

        # Mask off the bit corresponding to our port
        mask = (1 << port_num)
        # LPMode is active high; set or clear the bit accordingly
        if lpmode is True:
            reg_value = reg_value | mask
        else:
            reg_value = reg_value & ~mask

        # Convert our register value back to a hex string and write back
        content = hex(reg_value)

        reg_file.seek(0)
        reg_file.write(content)
        reg_file.close()

        return True

    def reset(self, port_num):

        i2c_line, port_num = self.normalize_port(port_num)
        if port_num == -1:
            return False

        try:
                qsfp_path = self.BASE_VAL_PATH.format(i2c_line)+"qsfp_lpmode"
                reg_file = open(qsfp_path, "r+")

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

        content = reg_file.readline().rstrip()

        # File content is a string containing the hex representation of th
        reg_value = int(content, 16)

        # Mask off the bit corresponding to our port
        mask = (1 << port_num)

        # ResetL is active low
        reg_value = reg_value & ~mask

        # Convert our register value back to a hex string and write back
        reg_file.seek(0)
        reg_file.write(hex(reg_value))
        reg_file.close()

        # Sleep 1 second to allow it to settle
        time.sleep(1)

        # Flip the bit back high and write back to the register to take
        # port out of reset
        try:
                qsfp_path = self.BASE_VAL_PATH.format(i2c_line)+"qsfp_lpmode"
                reg_file = open(qsfp_path, "w+")

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

        reg_value = reg_value | mask
        reg_file.seek(0)
        reg_file.write(hex(reg_value))
        reg_file.close()

        return True

    def get_register(self, reg_file):
            retval = 'ERR'

            if (not os.path.isfile(reg_file)):
                print reg_file,  'not found !'
                return retval

            try:
                with open(reg_file, 'r') as fd:
                    retval = fd.read()
            except Exception as error:
                logging.error("Unable to open ", reg_file, "file !")

            retval = retval.rstrip('\r\n')
            retval = retval.lstrip(" ")
            return retval

    def check_interrupts(self, port_dict):
            retval = 0
            is_port_dict_updated = False
            # Read the QSFP ABS interrupt & status registers
            cpld2_abs_int = self.get_register(
                        "/sys/class/i2c-adapter/i2c-14/14-003e/qsfp_abs_int")
            cpld2_abs_sta = self.get_register(
                        "/sys/class/i2c-adapter/i2c-14/14-003e/qsfp_abs_sta")
            cpld3_abs_int = self.get_register(
                        "/sys/class/i2c-adapter/i2c-15/15-003e/qsfp_abs_int")
            cpld3_abs_sta = self.get_register(
                        "/sys/class/i2c-adapter/i2c-15/15-003e/qsfp_abs_sta")
            cpld4_abs_int = self.get_register(
                        "/sys/class/i2c-adapter/i2c-16/16-003e/qsfp_abs_int")
            cpld4_abs_sta = self.get_register(
                        "/sys/class/i2c-adapter/i2c-16/16-003e/qsfp_abs_sta")

            if (cpld2_abs_int == 'ERR' or cpld2_abs_sta == 'ERR' or
                    cpld3_abs_int == 'ERR' or cpld3_abs_sta == 'ERR' or
                    cpld4_abs_int == 'ERR' or cpld4_abs_sta == 'ERR'):
                return -1

            cpld2_abs_int = int(cpld2_abs_int, 16)
            cpld2_abs_sta = int(cpld2_abs_sta, 16)
            cpld3_abs_int = int(cpld3_abs_int, 16)
            cpld3_abs_sta = int(cpld3_abs_sta, 16)
            cpld4_abs_int = int(cpld4_abs_int, 16)
            cpld4_abs_sta = int(cpld4_abs_sta, 16)

            # Make it contiguous (discard reserved bits)
            interrupt_reg = (cpld2_abs_int & 0xfff) |\
                            ((cpld3_abs_int & 0x3ff) << 12) |\
                            ((cpld4_abs_int & 0x3ff) << 22)
            status_reg = (cpld2_abs_sta & 0xfff) |\
                         ((cpld3_abs_sta & 0x3ff) << 12) |\
                         ((cpld4_abs_sta & 0x3ff) << 22)

            port = self.port_start
            while port <= self.port_end:
                if interrupt_reg & (1 << port):
                    # update only if atleast one port has generated
                    # interrupt
                    is_port_dict_updated = True
                    if status_reg & (1 << port):
                        # status reg 1 => optics is removed
                        port_dict[port] = '0'
                    else:
                        # status reg 0 => optics is inserted
                        port_dict[port] = '1'
                port += 1
            return retval, is_port_dict_updated

    def get_transceiver_change_event(self, timeout=0):
            port_dict = {}
            try:
                # We get notified when there is an SCI interrupt from GPIO SUS6
                # Open the sysfs file and register the epoll object
                self.oir_fd = open(self.OIR_FD_PATH, "r")
                if self.oir_fd != -1:
                    # Do a dummy read before epoll register
                    self.oir_fd.read()
                    self.epoll = select.epoll()
                    self.epoll.register(self.oir_fd.fileno(),
                                        select.EPOLLIN & select.EPOLLET)
                else:
                    print("get_transceiver_change_event : unable to create fd")
                    return False, {}

                # Check for missed interrupts by invoking self.check_interrupts
                # which will update the port_dict.
                while True:
                    interrupt_count_start = self.get_register(self.OIR_FD_PATH)

                    retval, is_port_dict_updated = \
                        self.check_interrupts(port_dict)
                    if ((retval == 0) and (is_port_dict_updated is True)):
                        return True, port_dict

                    interrupt_count_end = self.get_register(self.OIR_FD_PATH)

                    if (interrupt_count_start == 'ERR' or
                            interrupt_count_end == 'ERR'):
                        print("get_transceiver_change_event : \
                            unable to retrive interrupt count")
                        break

                    # check_interrupts() itself may take upto 100s of msecs.
                    # We detect a missed interrupt based on the count
                    if interrupt_count_start == interrupt_count_end:
                        break

                # Block until an xcvr is inserted or removed with timeout = -1
                events = self.epoll.poll(
                    timeout=timeout if timeout != 0 else -1)
                if events:
                    # check interrupts and return the port_dict
                    retval, is_port_dict_updated = \
                                              self.check_interrupts(port_dict)
                    if (retval != 0):
                        return False, {}

                return True, port_dict
            except:
                return False, {}
            finally:
                if self.oir_fd != -1:
                    self.epoll.unregister(self.oir_fd.fileno())
                    self.epoll.close()
                    self.oir_fd.close()
                    self.oir_fd = -1
                    self.epoll = -1

            return False, {}