import sys, re, clipboard, json, webbrowser
from urllib import parse

def main(encoded):
    """
    Extracts task name, note and due date from an OmniFocus task URL
    and returns a dictionary.
    """
    task_name = None
    task_note = None
    due_date = None

    # Patterns to match the task name and the
    # task note in the OmniFocus URL.
    # The URL will look this:
    # omnifocus:///task/cahy7K5409b?name=Task%20name&parallel=true&due=2017-05-19%2017:00&project=My%20Project
    name_pattern = re.compile(r'name=([^&]+)&')
    note_pattern = re.compile(r'note=([^&]+)&')
    due_date_pattern = re.compile(r'due=([^&]+)&')

    # Get the task name from the URL and
    # replace URL-encoded characters
    # (e.g., replace %20 with a space)
    name_match = name_pattern.search(encoded)

    if name_match is not None:
        task_name = parse.unquote(name_match.groups()[0])

    # Get the task note (if present) from the URL and
    # replace URL-encoded characters
    note_match = note_pattern.search(encoded)

    if note_match is not None:
        task_note = parse.unquote(note_match.groups()[0])

    # Get the due date (if present) from the URL and
    # replace URL-encoded characters
    due_date_match = due_date_pattern.search(encoded)

    if due_date_match is not None:
        due_date = parse.unquote(due_date_match.groups()[0])

    # Create a dictionary with the task name,
    # task note (if present) and due date (if present).
    task_info = {'name': task_name}

    if task_note is not None:
        task_info['note'] = task_note
    else:
        task_info['note'] = '(None)'

    if due_date is not None:
        task_info['due_date'] = due_date
    else:
        task_info['due_date'] = '(None)'

    # Write the dictionary to a JSON string
    # and copy the string to the clipboard.
    task_info_json = json.dumps(task_info)
    clipboard.set(task_info_json)

    # Finally, open OmniFocus to continue running the workflow
    webbrowser.open('omnifocus://')

if __name__ == "__main__":
    main(sys.argv[1])