# -*- python -*-

# This example graciously fades out the screen on start and
# in on exit. It is a nice alternative to turning off the
# monitor, just press Control+c when you wake up.


# 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/>.


# The (zero-based) index of the monitors (CRTC:s) to apply
# settings to. An empty list means that all monitors are used,
# but all monitors will have the same settings.
monitors = []


# These settings are lists. This is to allow you to use different
# settings on different monitors. For example, `gamma_red = [1]`,
# this means that the red gamma is 1 on all monitors. But if we
# change this to `gamma_red = [1.0, 1.1]`, the first monitor will
# have the red gamma set to 1,0 and the second monitor will have
# the red gamma set to 1,1. If you have more monitors than used
# in the settings modulo division will be used. For instance, if
# you have four monitors, the third monitor will have the same
# settings as the first monitor, and the fourth monitor will have
# the same settings as the second monitor.

# Gamma correction for the red, green and blue components, respectively.
gamma_red, gamma_green, gamma_blue = [1], [1], [1]

# The red, green and blue brightness, respectively.
# If you zero out green and blue and leave only red, you
# will be able to see what is on the as long as their is
# a difference in the red channel, and it will not affect
# your night vision. This is perfect if want to be able
# able read something on the screen during night (perhaps
# a clock) or directly when you wake up.
redness, greenness, blueness = [0.25], [0], [0]


# Set fade time at start to 15 seconds.
fadein_time = 15
# Do 10 changes per second at start.
fadein_steps = fadein_time * 10

# Set fade time at exit to 30 seconds.
fadeout_time = 30
# Do 10 changes per second at end.
fadeout_steps = fadeout_time * 10


# During sleep mode the changes will occur so we update one every hour.
wait_period = 60 * 60


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
    '''
    purity = 0 if fade is None else 1 - abs(fade)
    for m in range(max(1, len(monitors))):
        # Remove settings from last run.
        start_over()
        
        # Fade out the blue colours component, then the green
        # colours component and lastly the blue colours component.
        r = min(max(0, purity * 3 - 0), 1)
        g = min(max(0, purity * 3 - 1), 1)
        b = min(max(0, purity * 3 - 2), 1)
        r = redness  [m % len(redness)]   * (1 - r) + r
        g = greenness[m % len(greenness)] * (1 - g) + g
        b = blueness [m % len(blueness)]  * (1 - b) + b
        rgb_brightness(r, g, b)
        
        # Flush settings to monitor.
        r = gamma_red  [m % len(gamma_red)]
        g = gamma_green[m % len(gamma_green)]
        b = gamma_blue [m % len(gamma_blue)]
        gamma(r, g, b)
        
        # Flush settings to monitor.
        if len(monitors) == 0:
            (drm if ttymode else randr)()
        else:
            (drm if ttymode else randr)(monitors[m % len(monitors)])


def reset():
    '''
    Invoked to reset the displays
    '''
    for m in range(max(1, len(monitors))):
        # Remove settings from last run.
        start_over()
        
        # Apply gamma correction to monitor.
        r = gamma_red  [m % len(gamma_red)]
        g = gamma_green[m % len(gamma_green)]
        b = gamma_blue [m % len(gamma_blue)]
        gamma(r, g, b)
        
        # Flush settings to monitor.
        if len(monitors) == 0:
            (drm if ttymode else randr)()
        else:
            (drm if ttymode else randr)(monitors[m % len(monitors)])