from django.db import models
from django_choices_field import TextChoicesField
from core.models.base import BaseModel
from core.models.customer import Customer
from core.models.account import AccountAddress
from core.models.enums import ServiceChoices
from core.models.profile import TeamProfile


class Project(BaseModel):
    """Project records for customers"""
    customer = models.ForeignKey(Customer, on_delete=models.PROTECT, related_name='projects')

    # Optional: tie to a specific account address; if not provided, a freeform address is required
    account_address = models.ForeignKey(
        AccountAddress,
        on_delete=models.PROTECT,
        related_name='projects',
        blank=True,
        null=True,
        help_text="If set, the project uses this account address; otherwise, fill the address fields below",
    )

    # Optional: if account_address is set, this is the scope of the project
    scope = models.ForeignKey(
        'core.ProjectScope',
        on_delete=models.SET_NULL,
        related_name='projects',
        blank=True,
        null=True,
    )

    # Freeform address used only when account_address is not provided
    street_address = models.CharField(max_length=255, blank=True, null=True)
    city = models.CharField(max_length=100, blank=True, null=True)
    state = models.CharField(max_length=100, blank=True, null=True)
    zip_code = models.CharField(max_length=20, blank=True, null=True)

    name = models.CharField(max_length=200, blank=True)
    date = models.DateField()
    status = TextChoicesField(
        choices_enum=ServiceChoices,
        default=ServiceChoices.SCHEDULED,
        help_text="Current status of the project",
    )
    team_members = models.ManyToManyField(TeamProfile, related_name='projects')
    notes = models.TextField(blank=True, null=True)
    labor = models.DecimalField(max_digits=10, decimal_places=2)
    amount = models.DecimalField(max_digits=10, decimal_places=2, default=0.00)
    calendar_event_id = models.CharField(max_length=255, blank=True, null=True,
                                         help_text="External calendar event ID")
    wave_service_id = models.CharField(max_length=255, blank=True, null=True,
                                       help_text="Wave service ID")

    class Meta:
        ordering = ['-date']
        indexes = [
            models.Index(fields=['customer', 'date']),
            models.Index(fields=['status', 'date']),
            models.Index(fields=['account_address', 'date']),
        ]
        constraints = [
            # Enforce mutual exclusivity/requirement between account_address and freeform address
            models.CheckConstraint(
                name='project_addr_xor_check',
                condition=(
                    # Case A: account_address is set, AND all freeform fields are NULL
                        (
                                models.Q(account_address__isnull=False)
                                & models.Q(street_address__isnull=True)
                                & models.Q(city__isnull=True)
                                & models.Q(state__isnull=True)
                                & models.Q(zip_code__isnull=True)
                        )
                        |  # Case B: account_address is NULL, AND all freeform fields are non-NULL
                        (
                                models.Q(account_address__isnull=True)
                                & models.Q(street_address__isnull=False)
                                & models.Q(city__isnull=False)
                                & models.Q(state__isnull=False)
                                & models.Q(zip_code__isnull=False)
                        )
                ),
            ),
        ]
        verbose_name = "Project"
        verbose_name_plural = "Projects"

    # python
    def clean(self):
        """Validate project data"""
        from django.core.exceptions import ValidationError

        # Normalize blanks to None so DB constraint and logic align
        def _blank_to_none(v):
            return None if isinstance(v, str) and not v.strip() else v

        self.street_address = _blank_to_none(self.street_address)
        self.city = _blank_to_none(self.city)
        self.state = _blank_to_none(self.state)
        self.zip_code = _blank_to_none(self.zip_code)

        has_account_address = self.account_address is not None
        has_freeform = all([self.street_address, self.city, self.state, self.zip_code])

        # Enforce XOR between account_address and freeform address
        if has_account_address and has_freeform:
            raise ValidationError("Provide either an account address or a freeform address, not both.")
        if not has_account_address and not has_freeform:
            raise ValidationError("Provide a freeform address when no account address is selected.")

        # If an account_address is provided, ensure it belongs to the same customer
        if self.account_address and self.account_address.account.customer_id != self.customer_id:
            raise ValidationError("Selected account address must belong to the specified customer.")

    def __str__(self):
        if self.account_address:
            addr_info = f" ({self.account_address.account.name} - {self.account_address.street_address})"
        else:
            parts = [p for p in [self.street_address, self.city, self.state, self.zip_code] if p]
            addr_info = f" ({', '.join(parts)})" if parts else ""
        return f"Project for {self.customer.name}{addr_info} on {self.date}"