# -*- python -*-

# This is a small example that inverts the colours when the
# battery's capacity is low.


# Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.



# Invert the colours when the battery capacity is below this threshold.
threshold = 5 # percent


# Current status.
inverted = False

def get_capacity():
    '''
    Get the current capacity and charging status
    
    @return  (:bool, :float)  Whether the battery is discharging and the capacity (in percents)
    '''
    capacity, discharging = None, None
    
    # Get capacity.
    #with open('/sys/class/power_supply/BAT1/capacity', 'r') as file:
    #    capacity = int(file.read().split('\n')[0])
    
    # More accurate capacity.
    charge_full, charge_now = None, None
    with open('/sys/class/power_supply/BAT1/charge_full', 'r') as file:
        charge_full = int(file.read().split('\n')[0])
    with open('/sys/class/power_supply/BAT1/charge_now', 'r') as file:
        charge_now = int(file.read().split('\n')[0])
    capacity = charge_now * 100 / charge_full
    
    # Is the battery discharging?
    with open('/sys/class/power_supply/BAT1/status', 'r') as file:
        discharging = file.read().split('\n')[0] == 'Discharging'
    
    return (discharging, capacity)


# Lets wait only 30 seconds, instead of a minute before running again.
wait_period = 30

# Do not fade in or out.
fadeout_time = None
fadein_time = None


def periodically(year, month, day, hour, minute, second, weekday, fade):
    '''
    :(int, int, int, int, int, int, int, float?)?→void  Place holder for periodically invoked function
    
    Invoked periodically
    
    If you want to control at what to invoke this function next time
    you can set the value of the global variable `wait_period` to the
    number of seconds to wait before invoking this function again.
    The value does not need to be an integer.
    
    @param   year:int     The year
    @param   month:int    The month, 1 = January, 12 = December
    @param   day:int      The day, minimum value is 1, probable maximum value is 31 (*)
    @param   hour:int     The hour, minimum value is 0, maximum value is 23
    @param   minute:int   The minute, minimum value is 0, maximum value is 59
    @param   second:int   The second, minimum value is 0, probable maximum value is 60 (**)
    @param   weekday:int  The weekday, 1 = Monday, 7 = Sunday
    @param   fade:float?  Blueshift can use this function to fade into a state when it start
                          or exits. `fade` can either be negative, zero or positive or `None`,
                          but the magnitude of value cannot exceed 1. When Blueshift starts,
                          this function will be invoked multiple with the time parameters
                          of the time it is invoked and each time `fade` will increase towards
                          1, starting at 0, when the value is 1, the settings should be applied
                          to 100 %. After this this function will be invoked once again with
                          `fade` being `None`. When Blueshift exits the same behaviour is used
                          except, `fade` decrease towards -1 but start slightly below 0, when
                          -1 is reached all settings should be normal. Then Blueshift will NOT
                          invoke this function with `fade` being `None`, instead it will by
                          itself revert all settings and quit.
    
    (*)  Can be exceeded if the calendar system is changed, like in 1712-(02)Feb-30
    (**) See https://en.wikipedia.org/wiki/Leap_second
    '''
    global inverted
    
    (discharging, capacity) = get_capacity()
    should_invert = discharging and (capacity <= threshold)
    
    if should_invert ^ inverted:
        inverted = should_invert
        start_over()
        if should_invert:
            negative()
        monitor_controller()