#############################################################################
# Celestica
#
# Module contains an implementation of SONiC Platform Base API and
# provides the Chassis information which are available in the platform
#
#############################################################################

import sys
import re
import os
import subprocess
import json

try:
    from sonic_platform_base.chassis_base import ChassisBase
    from sonic_platform.fan import Fan
    from sonic_platform.psu import Psu
    from sonic_platform.component import Component
    from sonic_platform.thermal import Thermal
    from sonic_platform.sfp import Sfp
    from sonic_platform.eeprom import Tlv
except ImportError as e:
    raise ImportError(str(e) + "- required module not found")

NUM_FAN_TRAY = 3
NUM_FAN = 1
NUM_PSU = 2
NUM_THERMAL = 7
NUM_SFP = 52
NUM_COMPONENT = 3
RESET_REGISTER = "0x112"
HOST_REBOOT_CAUSE_PATH = "/host/reboot-cause/previous-reboot-cause.txt"
PMON_REBOOT_CAUSE_PATH = "/usr/share/sonic/platform/api_files/reboot-cause/previous-reboot-cause.txt"
HOST_CHK_CMD = "docker > /dev/null 2>&1"


class Chassis(ChassisBase):
    """Platform-specific Chassis class"""

    def __init__(self):
        ChassisBase.__init__(self)
        self.config_data = {}
        for fant_index in range(0, NUM_FAN_TRAY):
            for fan_index in range(0, NUM_FAN):
                fan = Fan(fant_index, fan_index)
                self._fan_list.append(fan)
        for index in range(0, NUM_PSU):
            psu = Psu(index)
            self._psu_list.append(psu)
        for index in range(0, NUM_THERMAL):
            thermal = Thermal(index)
            self._thermal_list.append(thermal)
        # sfp index start from 1
        self._sfp_list.append(None)
        for index in range(1, NUM_SFP+1):
            sfp = Sfp(index)
            self._sfp_list.append(sfp)
        for index in range(0, NUM_COMPONENT):
            component = Component(index)
            self._component_list.append(component)
        self._reboot_cause_path = HOST_REBOOT_CAUSE_PATH if self.__is_host(
        ) else PMON_REBOOT_CAUSE_PATH

        self._eeprom = Tlv()

    def __is_host(self):
        return os.system(HOST_CHK_CMD) == 0

    def __read_txt_file(self, file_path):
        try:
            with open(file_path, 'r') as fd:
                data = fd.read()
                return data.strip()
        except IOError:
            pass
        return None

    def get_base_mac(self):
        """
        Retrieves the base MAC address for the chassis
        Returns:
            A string containing the MAC address in the format
            'XX:XX:XX:XX:XX:XX'
        """
        return self._eeprom.get_mac()

    def get_serial(self):
        """
        Retrieves the hardware serial number for the chassis
        Returns:
            A string containing the hardware serial number for this chassis.
        """
        return self._eeprom.get_serial()

    def get_system_eeprom_info(self):
        """
        Retrieves the full content of system EEPROM information for the chassis
        Returns:
            A dictionary where keys are the type code defined in
            OCP ONIE TlvInfo EEPROM format and values are their corresponding
            values.
        """
        return self._eeprom.get_eeprom()

    def get_reboot_cause(self):
        """
        Retrieves the cause of the previous reboot

        Returns:
            A tuple (string, string) where the first element is a string
            containing the cause of the previous reboot. This string must be
            one of the predefined strings in this class. If the first string
            is "REBOOT_CAUSE_HARDWARE_OTHER", the second string can be used
            to pass a description of the reboot cause.
        """
        description = 'None'
        reboot_cause = self.REBOOT_CAUSE_HARDWARE_OTHER
        hw_reboot_cause = self._component_list[0].get_register_value(RESET_REGISTER)
        sw_reboot_cause = self.__read_txt_file(
            self._reboot_cause_path) or "Unknown"

        if hw_reboot_cause == "0x55":
            reboot_cause = self.REBOOT_CAUSE_NON_HARDWARE
            description = sw_reboot_cause
        elif hw_reboot_cause == "0x11":
            reboot_cause = self.REBOOT_CAUSE_POWER_LOSS
        elif hw_reboot_cause == "0x33":
            reboot_cause = self.REBOOT_CAUSE_WATCHDOG
        else:
            reboot_cause = self.REBOOT_CAUSE_HARDWARE_OTHER
            description = 'Unknown reason'

        return (reboot_cause, description)

    def get_watchdog(self):
        """
        Retreives hardware watchdog device on this chassis
        Returns:
            An object derived from WatchdogBase representing the hardware
            watchdog device
        """
        if self._watchdog is None:
            from sonic_platform.watchdog import Watchdog
            self._watchdog = Watchdog()

        return self._watchdog