import pytomlpp
import os 
import random
import sys
from time import sleep
from threading import Thread


def printHelpInfo():
    print("""Usage: wallpyper [command]
Commands:
    quit, stop              shutdown wallpyper
    set <theme>             set <theme> theme
    help, --help, -h        print this information""")

def runCommand(commandName, output=False):
    if output:
        os.system(commandName)
    else:
        os.system(commandName + ">/dev/null")


def killBack4():
    '''
    back4.sh will output artifacts if run more 2 processes
    It function read PID in /tmp/back4.sh.pid, and kill process.
    '''
    try:
        with open('/tmp/back4.sh.pid','r') as file:
            for pid in file:
                runCommand(f'kill {pid}')
    except FileNotFoundError:
        pass

def killLastSession():
    killBack4()

    try:
        with open('/tmp/wallpyper.pid','r') as file:
            for pid in file:
                runCommand(f'kill {pid}')
    except FileNotFoundError:
        pass
    
    with open('/tmp/wallpyper.pid','w') as file:
        file.write(str(os.getpid()))


def getConfig():
    configFileName = os.path.expanduser('~')+'/.config/wallpyper/config.toml'
    
    with open(configFileName) as file: return pytomlpp.loads(file.read())


def setWallpaper(wallpaperName):
    killBack4()
    if wallpaperName[-4:] != '.gif':
        runCommand(f'feh --bg-scale "{wallpaperName}"')
    else:
        runCommand(f'back4.sh auto "{wallpaperName}" & echo $! > /tmp/back4.sh.pid',True)
        # > tmp/back4.sh.pid write PID for kill()


def setRandomWallpaper(path):
    wallpaperName = path+random.choices(os.listdir(path))[0]
    setWallpaper(wallpaperName)


def setDynamicWallpaper(path, delay):
    while True:
        setRandomWallpaper(path)
        sleep(delay)


def setTheme(themeName = None):
    killLastSession()

    config = getConfig()

    if themeName == None:
        themeName = config["default_theme"]

    
    theme = config[themeName]

    if theme["type"] == "static":
        try: 
            if theme["random"]: setRandomWallpaper(theme["path"])
            else: setWallpaper(theme["url"])
        except KeyError:
            setWallpaper(theme["url"])
    
    elif theme["type"] == "dynamic":
        delay = list(map(int,theme["delay"].split(":")))
        delay.reverse()
        while len(delay) < 3:
            delay.append(0)

        delay = delay[0] + delay[1]*60 + delay[2]*3600

        wallpyperThread = Thread(target=setDynamicWallpaper, args=(theme["path"],delay,))
        wallpyperThread.start()
    
    else:
        printHelpInfo()
        sys.exit(0)