on-add.context

#!/usr/bin/env python3

"""
Ensure Taskwarrior's context tags are automatically applied to new tasks.
Conversely, when tasks are added via Reminders, ensure their list is applied as
a project and a tag.

Concrete examples:

    If a reminder is created in the "Work" list, then:
        a task is created with `project:Work` and `+work`.

    If a task is created under the "life" context, then:
        a reminder is created in the "Life" list, and `+life` is applied.

    If a task is created without a context, then:
        a reminder is created in the default list, which is also applied as
        project.
"""

import re
import json
import subprocess
import sys


def get_config():
    p = subprocess.Popen(["/usr/local/bin/task", "show"], stdout=subprocess.PIPE,
        stderr=subprocess.PIPE)

    stdout, stderr = [x.decode('utf-8') for x in p.communicate()]
    raw_output = stdout.rstrip().split('\n')

    config = dict()
    config_regex = re.compile(r'^(?P<key>[^\s]+)\s+(?P<value>[^\s].*$)')

    for line in raw_output:
        match = config_regex.match(line)
        if match:
            config[match.group('key')] = match.group('value').strip()

    return config


def process(task):
    config = get_config()

    task.setdefault("tags", [])

    if 'project' in task:
        task['tags'] += [task['project'].lower().replace(" ", "_")]
        return

    context = config.get("context")

    if not context:
        return

    task['tags'] += [context]
    task.setdefault('project', context.title())


def main(stdin, stdout):
    task = json.loads(stdin.readline())
    msg = process(task)
    print(json.dumps(task))
    if msg:
        print('could not add context tag: '+msg)

if __name__ == '__main__':
    main(sys.stdin, sys.stdout)