from django.db import models
from datetime import datetime, timedelta
from django.conf import settings
from zoneinfo import ZoneInfo
from common.util.time import format_duration
from django.db.models import Sum, F


class Game(models.Model):
    name = models.CharField(max_length=255)
    wikidata = models.CharField(max_length=50)

    def __str__(self):
        return self.name


class Purchase(models.Model):
    game = models.ForeignKey("Game", on_delete=models.CASCADE)
    platform = models.ForeignKey("Platform", on_delete=models.CASCADE)
    date_purchased = models.DateField()
    date_refunded = models.DateField(blank=True, null=True)

    def __str__(self):
        return f"{self.game} ({self.platform})"


class Platform(models.Model):
    name = models.CharField(max_length=255)
    group = models.CharField(max_length=255)

    def __str__(self):
        return self.name


class SessionQuerySet(models.QuerySet):
    def total_duration(self):
        result = self.aggregate(
            duration=Sum(F("duration_calculated") + F("duration_manual"))
        )
        return format_duration(result["duration"])


class Session(models.Model):
    purchase = models.ForeignKey("Purchase", on_delete=models.CASCADE)
    timestamp_start = models.DateTimeField()
    timestamp_end = models.DateTimeField(blank=True, null=True)
    duration_manual = models.DurationField(blank=True, null=True, default=timedelta(0))
    duration_calculated = models.DurationField(blank=True, null=True)
    note = models.TextField(blank=True, null=True)

    objects = SessionQuerySet.as_manager()

    def __str__(self):
        mark = ", manual" if self.duration_manual != None else ""
        return f"{str(self.purchase)} {str(self.timestamp_start.date())} ({self.duration_formatted()}{mark})"

    def finish_now(self):
        self.timestamp_end = datetime.now(ZoneInfo(settings.TIME_ZONE))

    def duration_seconds(self) -> timedelta:
        manual = timedelta(0)
        calculated = timedelta(0)
        if not self.duration_manual in (None, 0, timedelta(0)):
            manual = self.duration_manual
        if self.timestamp_end != None and self.timestamp_start != None:
            calculated = self.timestamp_end - self.timestamp_start
        return timedelta(seconds=(manual + calculated).total_seconds())

    def duration_formatted(self) -> str:
        result = format_duration(self.duration_seconds(), "%H:%m")
        return result

    @property
    def duration_sum(self) -> str:
        return Session.objects.all().total_duration()

    def save(self, *args, **kwargs):
        if self.timestamp_start != None and self.timestamp_end != None:
            self.duration_calculated = self.timestamp_end - self.timestamp_start
        else:
            self.duration_calculated = timedelta(0)
        super(Session, self).save(*args, **kwargs)