import sys
from collections import defaultdict
from datetime import datetime, timedelta
import math

from common import parse_timestamp

content = open(sys.argv[1]).read().strip()

lines = content.splitlines()
current_chapter = ''

total_chapters = 0
completed_chapters = set()

today = datetime.now().replace(hour=0,minute=0,second=0,microsecond=0)
this_week = today - timedelta(days=7)

total_hours = 0.0
day_hours = 0.0
week_hours = 0.0

oldest_timestamp = datetime.now()

i = 0
while i < len(lines):
    line = lines[i].strip()

    if line.startswith('#'):
        current_chapter = line[line.find(' ')+1:]
        total_chapters += 1
    else:
        completed_chapters.add(current_chapter)
        
    if line.startswith('@start'):
        start = parse_timestamp(line.removeprefix('@start '))

        if start < oldest_timestamp:
            oldest_timestamp = start

        i += 1
        line = lines[i].strip()

        end = parse_timestamp(line.removeprefix('@stop '))
        delta = end - start
        hours = delta.seconds / 60 / 60

        total_hours += hours
        if start > this_week:
            week_hours += hours
        if start > today:
            day_hours += hours

    i += 1

completed_chapters = len(completed_chapters)

num_days = (datetime.now() - oldest_timestamp).days or 1
hours_per_day = total_hours / num_days

hours_per_chapter = total_hours / completed_chapters
hours_to_completion = hours_per_chapter * (total_chapters - completed_chapters)
days_to_completion = math.ceil(hours_to_completion / hours_per_day)

completion_date = datetime.now() + timedelta(days=days_to_completion)

completion_percentage = completed_chapters/total_chapters*100

print(f'Started on: {oldest_timestamp.strftime("%Y-%m-%d")}')
print(f'Progress: [{completed_chapters}/{total_chapters}] ({round(completion_percentage, 2)}%)')
print(f'Total: {round(total_hours, 2)}h')
print(f'Week: {round(week_hours, 2)}h')
print(f'Day: {round(day_hours, 2)}h')
print(f'Hours per day: {round(hours_per_day, 2)}h')
print(f'Hours to completion: {round(hours_to_completion, 2)}h')
print(f'Completion date: {completion_date.strftime("%Y-%m-%d")}')