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


class ProjectMembership(models.Model):
    project = models.ForeignKey(
        "projects.Project", on_delete=models.CASCADE, related_name="memberships"
    )
    employee = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.PROTECT,
        related_name="project_memberships",
    )
    role = models.CharField(max_length=100, default="Участник")
    planned_percent = models.DecimalField(max_digits=5, decimal_places=2, default=0)
    starts_on = models.DateField(null=True, blank=True)
    ends_on = models.DateField(null=True, blank=True)

    class Meta:
        constraints = [
            models.UniqueConstraint(
                fields=["project", "employee"], name="project_member_unique"
            ),
            models.CheckConstraint(
                condition=models.Q(planned_percent__gte=0, planned_percent__lte=100),
                name="project_member_percent",
            ),
            models.CheckConstraint(
                condition=models.Q(ends_on__isnull=True)
                | models.Q(starts_on__isnull=True)
                | models.Q(ends_on__gte=models.F("starts_on")),
                name="project_member_dates",
            ),
        ]