#!/usr/bin/env python3

import subprocess
import re
import time

#_snapshots = open("zfs.txt","r").read()
_snapshots = subprocess.check_output("/usr/sbin/zfs list -t snapshot -Hpo name,creation".split())

LABELS=("frequent","hourly","daily","weekly","monthly","yearly","backup-zfs","bashclub-zfs")
RE_LABELSEARCH = re.compile("|".join(LABELS))
_datasets = {}
for _datastore,_snapshot,_creation in re.findall("^([\w_./-]+)@([\w_.-]+)\t(\d+)",_snapshots.decode('utf-8'),re.M):
    if _datastore not in _datasets:
        _datasets[_datastore] = {}
    _label = RE_LABELSEARCH.search(_snapshot)
    if _label:
        _label = _label.group(0)
    else:
        _label = "other"
    if _label not in _datasets[_datastore]:
        _datasets[_datastore][_label] = []
    _datasets[_datastore][_label].append((_snapshot,int(_creation)))

for _datastore in _datasets.keys():
    print(_datastore)
    print("-"*40)
    for _label in _datasets[_datastore].keys():
        _data = _datasets[_datastore][_label]
        _first = time.strftime("%d.%m.%Y %H:%M:%S",time.localtime(_data[0][1]))
        _last = time.strftime("%d.%m.%Y %H:%M:%S",time.localtime(_data[-1][1]))
        _count = len(_data)
        print(f" {_label} {_count}")
        print(f"   {_first} {_data[0][0]}")
        if _count > 1:
            print(f"   {_last} {_data[-1][0]}")
    print("")