"""
Standards Section Models - Track compliance standards (CBAHI, MOH, CHI, etc.)
"""

from django.db import models
from django.core.validators import FileExtensionValidator

from apps.core.models import TimeStampedModel, UUIDModel, StatusChoices


class StandardSource(UUIDModel, TimeStampedModel):
    """Standard sources like CBAHI, MOH, CHI, JCI, etc."""

    name = models.CharField(max_length=100)
    name_ar = models.CharField(max_length=100, blank=True, verbose_name="Name (Arabic)")
    code = models.CharField(max_length=50, unique=True)
    description = models.TextField(blank=True)
    website = models.URLField(blank=True)
    is_active = models.BooleanField(default=True, db_index=True)

    class Meta:
        ordering = ["name"]
        verbose_name = "Standard Source"
        verbose_name_plural = "Standard Sources"

    def __str__(self):
        return self.name


class StandardCategory(UUIDModel, TimeStampedModel):
    """Group standards by category (Patient Safety, Quality Management, etc.)"""

    name = models.CharField(max_length=100)
    name_ar = models.CharField(max_length=100, blank=True, verbose_name="Name (Arabic)")
    description = models.TextField(blank=True)
    order = models.PositiveIntegerField(default=0, help_text="Display order")
    is_active = models.BooleanField(default=True, db_index=True)

    class Meta:
        ordering = ["order", "name"]
        verbose_name = "Standard Category"
        verbose_name_plural = "Standard Categories"

    def __str__(self):
        return self.name


class Standard(UUIDModel, TimeStampedModel):
    """Actual standard requirements"""

    class ComplianceStatus(models.TextChoices):
        NOT_ASSESSED = "not_assessed", "Not Assessed"
        MET = "met", "Met"
        PARTIALLY_MET = "partially_met", "Partially Met"
        NOT_MET = "not_met", "Not Met"

    code = models.CharField(max_length=50, db_index=True, help_text="e.g., CBAHI-PS-01")
    title = models.CharField(max_length=300)
    title_ar = models.CharField(max_length=300, blank=True, verbose_name="Title (Arabic)")
    description = models.TextField(help_text="Full description of the standard")

    # Relationships
    source = models.ForeignKey(StandardSource, on_delete=models.PROTECT, related_name="standards")
    category = models.ForeignKey(StandardCategory, on_delete=models.PROTECT, related_name="standards")
    department = models.ForeignKey(
        "organizations.Department",
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name="standards",
        help_text="Department-specific standard (null if applicable to all)",
    )

    # Dates
    effective_date = models.DateField(null=True, blank=True, help_text="When standard becomes effective")
    review_date = models.DateField(null=True, blank=True, help_text="Next review date")

    is_active = models.BooleanField(default=True, db_index=True)

    class Meta:
        ordering = ["source", "category", "code"]
        verbose_name = "Standard"
        verbose_name_plural = "Standards"

    def __str__(self):
        return f"{self.code}: {self.title}"


class StandardCompliance(UUIDModel, TimeStampedModel):
    """Track compliance status per department"""

    class ComplianceStatus(models.TextChoices):
        NOT_ASSESSED = "not_assessed", "Not Assessed"
        MET = "met", "Met"
        PARTIALLY_MET = "partially_met", "Partially Met"
        NOT_MET = "not_met", "Not Met"

    department = models.ForeignKey(
        "organizations.Department", on_delete=models.CASCADE, related_name="compliance_records"
    )
    standard = models.ForeignKey(Standard, on_delete=models.CASCADE, related_name="compliance_records")
    status = models.CharField(
        max_length=20, choices=ComplianceStatus.choices, default=ComplianceStatus.NOT_ASSESSED, db_index=True
    )
    last_assessed_date = models.DateField(null=True, blank=True, help_text="Date of last assessment")
    assessor = models.ForeignKey(
        "accounts.User", on_delete=models.SET_NULL, null=True, blank=True, related_name="assessments"
    )
    notes = models.TextField(blank=True, help_text="Assessment notes")
    evidence_summary = models.TextField(blank=True, help_text="Summary of evidence")

    class Meta:
        ordering = ["-created_at"]
        verbose_name = "Standard Compliance"
        verbose_name_plural = "Standard Compliance"
        unique_together = [["department", "standard"]]

    def __str__(self):
        return f"{self.department.name} - {self.standard.code} - {self.status}"


class StandardAttachment(UUIDModel, TimeStampedModel):
    """Proof of compliance - evidence documents"""

    compliance = models.ForeignKey(StandardCompliance, on_delete=models.CASCADE, related_name="attachments")
    file = models.FileField(
        upload_to="standards/attachments/%Y/%m/",
        validators=[
            FileExtensionValidator(
                allowed_extensions=["pdf", "doc", "docx", "xls", "xlsx", "jpg", "jpeg", "png", "zip"]
            )
        ],
    )
    filename = models.CharField(max_length=255, help_text="Original filename")
    description = models.TextField(blank=True, help_text="Attachment description")
    uploaded_by = models.ForeignKey(
        "accounts.User", on_delete=models.SET_NULL, null=True, blank=True, related_name="uploaded_standards_attachments"
    )

    class Meta:
        ordering = ["-created_at"]
        verbose_name = "Standard Attachment"
        verbose_name_plural = "Standard Attachments"

    def __str__(self):
        return f"{self.compliance} - {self.filename}"