import logging
import os
import sys
from datetime import date, datetime, timedelta
from random import randint

from caldav import DAVClient
from dotenv import find_dotenv, load_dotenv

from printer import p

logging.basicConfig(
    format="{asctime} {levelname:8} {name}: {message}",
    datefmt="%Y-%m-%d %H:%M:%S",
    style="{",
    stream=sys.stdout,
    force=True,
)

log = logging.getLogger("todo-receipt")
log.setLevel(logging.DEBUG)

if load_dotenv(find_dotenv(usecwd=True)):
    log.debug("Loaded .env")
else:
    log.debug("Didn't find .env")

CALDAV_URL = os.getenv("CALDAV_URL")
CALDAV_USERNAME = os.getenv("CALDAV_USERNAME")
CALDAV_PASSWORD = os.getenv("CALDAV_PASSWORD")

day = timedelta(days=1)
week = timedelta(days=7)
today = date.today()
yesterday = today - day
tomorrow = today + day
next_week = today + week


def coerce_date(datetime):
    try:
        return datetime.date()
    except:
        return datetime


def shuffle_with_priority(tasks):
    return sorted(
        tasks,
        key=lambda task: (
            task.icalendar_component.get("priority", 5),
            randint(0, 10),
        ),
    )


with DAVClient(
    url=CALDAV_URL, username=CALDAV_USERNAME, password=CALDAV_PASSWORD
) as client:
    log.debug("Loading calendars")
    principal = client.principal()
    calendars = principal.calendars()

    events = []
    todos = []

    for c in calendars:
        log.debug(f"Fetching from {c.name}")
        if c.name not in ["Schedule"]:
            log.debug("Fetching events and todos")
            events.extend(c.events())
            todos.extend(c.todos())
        else:
            log.debug("Finding cancelled classes")
            for event in c.events():
                if event.icalendar_component.get("status") == "CANCELED":
                    log.debug(
                        f"Found cancelled class {event.icalendar_component.get('summary')}"
                    )
                    events.append(event)

    must_do = []
    should_do = []
    want_to_do = []

    log.debug("Processing todos")
    for task in todos:
        due = task.get_due()
        if due is None:
            want_to_do.append(task)
            continue

        task.expand_rrule(yesterday, next_week)
        due = coerce_date(due)

        try:
            start = coerce_date(task.icalendar_component.get("dtstart").dt or yesterday)
        except:
            start = yesterday

        if today < start:
            continue

        if due < tomorrow:
            must_do.append(task)
        elif due < next_week:
            should_do.append(task)
        else:
            want_to_do.append(task)

    scheduled = []

    log.debug("Processing events")
    for event in events:
        event.expand_rrule(yesterday, next_week)
        start_day = coerce_date(event.icalendar_component.get("dtstart").dt)
        end_day = coerce_date(event.icalendar_component.get("dtend").dt)

        if end_day < today or today < start_day:
            continue
        else:
            scheduled.append(event)

    should_want = shuffle_with_priority(should_do) + shuffle_with_priority(want_to_do)

    categories = {
        "Must do": must_do,
        "Should do": should_want[:3],
        "Want to do": should_want[3:6],
    }
    if len(should_want) > 6:
        categories["Leftover"] = should_want[7:]

with p:
    log.debug("Printing output")
    p.title(" TODO List ", size=4)
    p.subtitle(datetime.today().strftime("%Y-%m-%d"))
    p.ln()

    if scheduled:
        p.textln("Scheduled:")
        for event in scheduled:
            summary = event.icalendar_component["summary"]
            if event.icalendar_component.get("status") == "CANCELED":
                summary += " (CANCELED)"
            start = event.icalendar_component.get("dtstart").dt
            p.textln(f"[ ] {summary} @ {start.strftime('%H:%M')}")
    else:
        p.textln("Scheduled: (None)")

    for k, v in categories.items():
        p.ln()
        if v:
            p.textln(f"{k}:")
            for task in v:
                p.textln(f"[ ] {task.icalendar_component['summary']}")
        else:
            p.textln(f"{k}: (None)")