Meaningful confirmation and error messages

[dessert1]

Here are some return messages one currently sees (I omitted the traceback output of hatc -a free):

$ hatc -a free "now + 1 min"
{'msg': 'Done'}
$ hatc -m 1 _ "now + 2 min"
{'msg': 'Done'}
$ hatc -r1
{'msg': 'Queued'}
$ hatc -l
Job queue is empty
$ hatc -r1
{'msg': 'Queued'}
$ hatc -m 1 _ "now + 2 min"
{'error': {'msg': '1'}}

• -a, -m and -r should return a confirmative message, e.g.

  $ hatc -a free "now + 1 min" bash
  Added job 1: free in bash at 2018-02-10T19:32:45
  $ hatc -a "free -m" "now + 10 min"
  Added job 2: free -m without a shell at 2018-02-10T19:32:50
  $ hatc -m 1 free "now + 2 min" bash
  Modified job 1: free in bash at 2018-02-10T19:33:57
  $ hatc -r2
  Removed job 2: free -m without a shell at 2018-02-10T19:32:50
  

• All three should inform whether a job was actually added/modified/deleted and which it was – if it fails, it should print the job queue, but of course only if it's not empty.

  $ hatc -a free
  Error: Missing time specification, consult hatc --help for usage information.
  $ hatc -a free garbage
  Error: Unrecognized time specification, consult hatc --help for usage information.
  $ hatc -a "" "now + 1 min"
  Error: Missing command specification, consult hatc --help for usage information.
  $ hatc -r2
  There's currently no job 2 in the job queue.
  [imagine output of hatc -l with a job 1 in it here]
  $ hatc -r1
  Removed job 1: free in bash at 2018-02-10T19:33:57
  $ hatc -r1
  Job queue is empty.
  

[dessert1]

Just discovered “No backward time travel support” and it made me laugh – keep this easter egg, but make it a proper error message as well please.

[heemayl]

@dessert1 😸 . In the queue.