from django.db import models
from django.conf import settings
from django.utils import timezone


class WorkLog(models.Model):
    date       = models.DateField('Дата', default=timezone.localdate, db_index=True)
    technician = models.ForeignKey(
        settings.AUTH_USER_MODEL, on_delete=models.PROTECT,
        related_name='work_logs', verbose_name='Исполнитель',
    )
    location   = models.ForeignKey(
        'locations.Location', on_delete=models.SET_NULL,
        null=True, blank=True,
        related_name='work_logs', verbose_name='Локация',
    )
    # Устаревший грубый вид (~7 типов); для новых записей не заполняется.
    work_type = models.ForeignKey(
        'core.Directory', on_delete=models.PROTECT,
        limit_choices_to={'directory_type__code': 'worklog_type', 'is_active': True},
        related_name='worklogs_by_type', verbose_name='Вид работ',
        null=True, blank=True,
    )
    catalog_work = models.ForeignKey(
        'core.Directory', on_delete=models.PROTECT,
        limit_choices_to={'directory_type__code': 'it_work', 'is_active': True},
        related_name='worklogs_by_catalog', verbose_name='Типовая работа',
        null=True, blank=True,
    )
    details = models.JSONField('Уточнения', default=dict, blank=True)
    description = models.TextField('Комментарий', blank=True)
    result      = models.TextField('Результат', blank=True)
    hours_spent = models.DecimalField('Затрачено часов', max_digits=5, decimal_places=1,
                                      null=True, blank=True)

    equipment = models.ForeignKey(
        'it_manager.Equipment', on_delete=models.SET_NULL,
        null=True, blank=True,
        related_name='work_logs', verbose_name='Оборудование',
    )
    ticket = models.ForeignKey(
        'it_manager.Ticket', on_delete=models.SET_NULL,
        null=True, blank=True,
        related_name='work_logs', verbose_name='Заявка',
    )

    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        verbose_name        = 'Выполненная работа'
        verbose_name_plural = 'Журнал выполненных работ'
        ordering = ['-date', '-created_at']
        indexes = [
            models.Index(fields=['date', 'technician']),
        ]

    def __str__(self):
        if self.catalog_work_id:
            title = self.catalog_work.name
        elif self.work_type_id:
            title = self.work_type.name
        else:
            title = (self.description or '—')[:40]
        return f'{title} — {self.technician} — {self.date:%d.%m.%Y}'

    @property
    def display_title(self) -> str:
        from apps.it_manager.work_directory import worklog_display_title
        return worklog_display_title(self)


class ServiceCall(models.Model):
    date_time  = models.DateTimeField('Дата и время', default=timezone.now, db_index=True)
    caller     = models.ForeignKey(
        settings.AUTH_USER_MODEL, on_delete=models.PROTECT,
        related_name='service_calls_made', verbose_name='Кто обратился',
    )
    handler    = models.ForeignKey(
        settings.AUTH_USER_MODEL, on_delete=models.SET_NULL,
        null=True, blank=True,
        related_name='service_calls_handled', verbose_name='Принял обращение',
    )
    channel = models.ForeignKey(
        'core.Directory', on_delete=models.PROTECT,
        limit_choices_to={'directory_type__code': 'servicecall_channel', 'is_active': True},
        related_name='servicecalls_by_channel', verbose_name='Канал',
    )
    location   = models.ForeignKey(
        'locations.Location', on_delete=models.SET_NULL,
        null=True, blank=True,
        related_name='service_calls', verbose_name='Локация',
    )
    description  = models.TextField('Описание обращения')
    resolution   = models.TextField('Решение', blank=True)
    minutes_spent = models.PositiveSmallIntegerField('Затрачено минут', null=True, blank=True)

    ticket = models.ForeignKey(
        'it_manager.Ticket', on_delete=models.SET_NULL,
        null=True, blank=True,
        related_name='service_calls', verbose_name='Связанная заявка',
        help_text='Если обращение переросло в тикет',
    )
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name        = 'Обращение'
        verbose_name_plural = 'Обращения'
        ordering = ['-date_time']
        indexes = [
            models.Index(fields=['date_time', 'handler']),
        ]

    def __str__(self):
        return (f'{self.channel.name} — {self.caller} — '
                f'{self.date_time:%d.%m.%Y %H:%M}')

    @property
    def duration_display(self):
        if not self.minutes_spent:
            return '—'
        if self.minutes_spent < 60:
            return f'{self.minutes_spent} мин.'
        h, m = divmod(self.minutes_spent, 60)
        return f'{h}ч {m}м' if m else f'{h}ч'