wall-changer

wall-changer.py

#!/usr/bin/env python3
import argparse
import os
import random
import shlex
import subprocess


_DIR = os.path.expanduser('~/.wall-changer')
if not os.path.exists(_DIR):
    os.mkdir(_DIR)

_CURRENT = os.path.join(_DIR, 'current')
_REGISTERED = os.path.join(_DIR, 'db')

for f in (_CURRENT, _REGISTERED):
    if not os.path.exists(f):
        open(f, 'w').close()


def set_groups(groups):
    print("setting groups to", '-'.join(groups))
    with open(_CURRENT, 'r') as data:
        line = data.readline().strip()
    with open(_CURRENT, 'w') as data:
        try:
            _, group, image = line.split(' ', 2)
            print(groups, group, image, file=data)
        except ValueError:
            group = None
            print(groups, file=data)
    if group not in groups:
        change_to_groups(groups)


def get_current():
    current = None
    group = None
    with open(_CURRENT) as data:
        line = data.readline().strip()
        try:
            groups, group, current = line.split(' ', 2)
        except ValueError:
            groups = line
    return groups, group, current
    

def change():
    groups, _, current = get_current()
    change_to_groups(groups, current)


def change_to_groups(groups, avoid=None):
    matching = []
    with open(_REGISTERED) as db:
        for line in db:
            g, i = line.strip().split(' ', 1)
            if g in groups and i != avoid and os.path.exists(i[1:-1]):
                matching.append((g, i))
    if not matching:
        print("No matching wallpapers found for groups",
              '-'.join(groups))
        return
    result = random.choice(matching)
    print("Changing wallpaper to", result[1])
    with open(_CURRENT, 'w') as current:
        print(groups, *result, file=current)
    subprocess.run(shlex.split("feh --bg-fill {}".format(result[1])))


def interactive():
    result = subprocess.run("dmenu",
                            stdin=subprocess.DEVNULL,
                            stdout=subprocess.PIPE)
    groups = result.stdout.decode().strip()
    if groups:
        set_groups(groups)
    else:
        change()


def register(image, group):
    print("Registering image", image, "as group", group)
    changed = False
    with open(_REGISTERED) as db, open(_REGISTERED+'.tmp', 'w') as out:
        for line in db:
            g, i = line.strip().split(' ', 1)
            if i == image:
                g = group
                changed = True
            print(g, i, file=out)
        if not changed:
            print(group, image, file=out)
    os.rename(_REGISTERED+'.tmp', _REGISTERED)


def remove():
    _, _, current = get_current()
    with open(_REGISTERED) as db, open(_REGISTERED+'.tmp', 'w') as out:
        for line in db:
            g, i = line.strip().split(' ', 1)
            if i != current:
                print(g, i, file=out)
    os.rename(_REGISTERED+'.tmp', _REGISTERED)
    change()


if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    group = parser.add_mutually_exclusive_group()
    group.add_argument("-c", "--change", action='store_true')
    group.add_argument("-r", "--register", nargs=2)
    group.add_argument("-g", "--groups")
    group.add_argument("--bad", action='store_true')
    args = parser.parse_args()
    if args.change:
        change()
    elif args.register:
        image, group = args.register
        if len(group) != 1 or not group.isdigit():
            print("Group must be 0-9")
            exit(-1)
        if not os.path.exists(image):
            print("File '{}' not found".format(image))
            exit(-1)
        register('"{}"'.format(image), group)
    elif args.groups:
        set_groups(args.groups)
    elif args.bad:
        remove()
    else:
        interactive()