day4.py

import os
import json
from attr import attrs, attrib
from datetime import datetime
from enum import Enum
import re

dir = os.path.dirname(__file__)
file_name =os.path.join(dir, "data.txt")
f = open(file_name)

@attrs(auto_attribs=True)
class Guard:
  id: str
  sleep: list

class Actions(Enum):
  ShiftStart = 0,
  FallAsleep = 1,
  WakeUp = 2,

@attrs(auto_attribs=True)
class Entry:
  time: datetime
  action: Actions
  id: str = None



entries = []
for line in f:
  match = re.match(r"\[(.+)\] (.+)", line)
  action = None
  guard_id = None
  if match[2] == "wakes up":
    action = Actions.WakeUp
  elif match[2] == "falls asleep":
    action = Actions.FallAsleep
  else:
    match2 = re.match(r"Guard #(\d+) begins shift", match[2])
    action = Actions.ShiftStart
    guard_id =match2[1]
  entries.append(Entry(action=action, id=guard_id, time=datetime.strptime(match[1], "%Y-%m-%d %H:%M")))

guards = {}
guard = None
start = None
for entry in sorted(entries, key=lambda x: x.time):
  if guard == None and entry.action != Actions.ShiftStart:
    continue
  if Actions.ShiftStart == entry.action:
    if not guards.get(entry.id, None):
      guards[entry.id] = Guard(id=entry.id, sleep=[0]*60)
    guard = guards[entry.id]
    continue

  if entry.action == Actions.FallAsleep:
    start = entry.time
    continue
  if entry.action == Actions.WakeUp:
    for i in range(start.minute, entry.time.minute):
      guard.sleep[i] += 1

#best = max(guards.values(), key=lambda x: sum(x.sleep))
best = max(guards.values(), key=lambda x: max(x.sleep))

best_minute = best.sleep.index(max(best.sleep))

print(int(best.id) * best_minute)

# with open(file_name) as f:
#     data = json.load(f)