#!/usr/bin/env python


from watch_path import Watch_Path


class Customized_Watch_Path(Watch_Path):
    """
    Customizes `watch_path` class
    """

    def __init__(self, ignore_empty, **kwargs):
        """
        Adds `ignore_empty` to initialization parameters of class
        """
        super(watch_path, self).__init__(**kwargs)
        self.update(ignore_empty = ignore_empty)

    def next(self):
        """
        Adds logic to ignore empty/non-existent paths
        """
        try:
            new_time_stamp = self.file_modified_time(self['path'])
        except OSError as e:
            print(e)
            if self['ignore_empty'] is not True:
                self.throw(GeneratorExit)

        if new_time_stamp != self['time_stamp']:
            self['time_stamp'] = new_time_stamp
            return self['callback'](path = self['path'],
                                    time_stamp = new_time_stamp,
                                    **self['callback_kwargs'])


def custom_callback(**kwargs):
    print("Detected disturbances in {path}".format(path = kwargs['path']))


if __main__ == '__name__':
    """
    Code that is run if this file is executed as a script instead of imported
    """
    custom_file_watcher = Customized_Watch_Path(callback = custom_callback
                                                path = 'test.txt',
                                                ignore_empty = True)

    try:
        for callback_results in custom_file_watcher:
            if callback_results:
                print(callback_results['stdout'].decode('UTF-8'))

            sleep(1)

    except KeyboardInterrupt:
        print('Stopping watcher and exiting...')