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


class CertificateIssuance(models.Model):
    class Source(models.IntegerChoices):
        TLMS = 0
        LAB = 1
        MANUAL = 2

    recipient = models.ForeignKey("labs.CertificateRecipient", on_delete=models.CASCADE)
    cert_type = models.ForeignKey("labs.CertificateType", on_delete=models.CASCADE)
    cert_number = models.CharField(max_length=32, unique=True, db_collation="utf8mb4_0900_ai_ci")
    cert_snapshot = models.JSONField(
        default=dict,
        help_text=(
            "The snapshot of the certificate. It is used to generate the certificate PDF. "
            "Contains the recipient's name, the certificate type...."
        ),
    )
    issued_at = models.DateTimeField(default=timezone.now)
    file_storage_provider = models.CharField(max_length=16, null=True, blank=True)
    file_bucket = models.CharField(max_length=32, null=True, blank=True)
    file_object_key = models.CharField(max_length=255, null=True, blank=True)
    file_content_type = models.CharField(max_length=64, null=True, blank=True)
    tlms_course_id = models.CharField(max_length=32, null=True, blank=True)
    source = models.IntegerField(choices=Source.choices, default=Source.TLMS)

    class Meta:
        db_table = "certificate_issuances"

    def get_file_public_url(self) -> str:
        return f"{settings.ALIYUN_CDN_URL}/{self.file_object_key}"