#!/usr/bin/env python

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

import os.path
import sonic_platform

try:
    from sonic_platform_base.psu_base import PsuBase
    from sonic_platform.fan import Fan
except ImportError as e:
    raise ImportError(str(e) + "- required module not found")

FAN_DX010_SPEED_PATH = "/sys/class/hwmon/hwmon{}/fan1_input"
GREEN_LED_PATH = "/sys/devices/platform/leds_dx010/leds/dx010:green:p-{}/brightness"
FAN_MAX_RPM = 11000


class Psu(PsuBase):
    """Platform-specific Psu class"""

    def __init__(self, psu_index):
        PsuBase.__init__(self)
        self.index = psu_index
        self.green_led_path = GREEN_LED_PATH.format(self.index+1)

    def get_fan(self):
        """
        Retrieves object representing the fan module contained in this PSU
        Returns:
            An object dervied from FanBase representing the fan module
            contained in this PSU
        """

        fan_speed_path = FAN_DX010_SPEED_PATH.format(
            str(self.index+8))
        try:
            with open(fan_speed_path) as fan_speed_file:
                fan_speed_rpm = int(fan_speed_file.read())
        except IOError:
            fan_speed = 0

        fan_speed = float(fan_speed_rpm)/FAN_MAX_RPM * 100
        fan = Fan(0)
        fan.fan_speed = int(fan_speed) if int(fan_speed) <= 100 else 100
        return fan

    def set_status_led(self, color):
        """
        Sets the state of the PSU status LED
        Args:
            color: A string representing the color with which to set the PSU status LED
                   Note: Only support green and off
        Returns:
            bool: True if status LED state is set successfully, False if not
        """

        set_status_str = {
            self.STATUS_LED_COLOR_GREEN: '1',
            self.STATUS_LED_COLOR_OFF: '0'
        }.get(color, None)

        if not set_status_str:
            return False

        try:
            with open(self.green_led_path, 'w') as file:
                file.write(set_status_str)
        except IOError:
            return False

        return True