from django.db import models


class Contact(models.Model):
    """Контакт в социальном графе."""

    name = models.CharField(max_length=255, verbose_name='Имя')
    email = models.EmailField(blank=True, verbose_name='Email')
    phone = models.CharField(max_length=50, blank=True, verbose_name='Телефон')
    organization = models.CharField(max_length=255, blank=True, verbose_name='Организация')
    position = models.CharField(max_length=255, blank=True, verbose_name='Должность')
    notes = models.TextField(blank=True, verbose_name='Заметки')
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        ordering = ['name']
        verbose_name = 'Контакт'
        verbose_name_plural = 'Контакты'

    def __str__(self):
        return self.name


RELATION_TYPES = [
    ('colleague', 'Коллега'),
    ('friend', 'Друг'),
    ('family', 'Родственник'),
    ('acquaintance', 'Знакомый'),
    ('business', 'Деловой партнёр'),
    ('other', 'Другое'),
]


class Relation(models.Model):
    """Связь между двумя контактами."""

    source = models.ForeignKey(
        Contact,
        on_delete=models.CASCADE,
        related_name='relations_as_source',
        verbose_name='Источник',
    )
    target = models.ForeignKey(
        Contact,
        on_delete=models.CASCADE,
        related_name='relations_as_target',
        verbose_name='Цель',
    )
    relation_type = models.CharField(
        max_length=50,
        choices=RELATION_TYPES,
        default='acquaintance',
        verbose_name='Тип связи',
    )
    description = models.CharField(max_length=255, blank=True, verbose_name='Описание')
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        unique_together = ('source', 'target')
        verbose_name = 'Связь'
        verbose_name_plural = 'Связи'

    def __str__(self):
        return f'{self.source} → {self.target} ({self.relation_type})'