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


class LabInstance(models.Model):
    class LabInstanceStatus(models.TextChoices):
        CREATING = "creating"
        CREATING_FAILED = "creating_failed"
        RUNNING = "running"
        TERMINATING = "terminating"
        TERMINATING_FAILED = "terminating_failed"
        TERMINATED = "terminated"
        TIMEOUT = "timeout"  # This is a virtual status for user

    class LabAccessType(models.TextChoices):
        CREDITS = "credits"
        WORKSHOP = "workshop"
        INTERNAL = "internal"

    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    lab_code = models.CharField(max_length=20)
    cloud_provider = models.CharField(max_length=20, default="aws")
    region_name = models.CharField(max_length=40)
    tidb_version = models.CharField(max_length=20, null=True, blank=True)
    tidb_environment = models.CharField(max_length=40, null=True, blank=True)
    resources = models.JSONField(default=dict)
    unique_tag = models.CharField(
        max_length=100,
        unique=True,
        blank=True,
        null=True,
        help_text="Can be used as the name of AWS resources.",
    )
    status = models.CharField(
        max_length=20,
        choices=LabInstanceStatus.choices,
        default=LabInstanceStatus.CREATING,
    )
    user_serverless_cluster = models.ForeignKey(
        "labs.UserServerlessCluster",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
    )
    create_job = models.ForeignKey(
        "labs.LabJob",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name="create_lab_instance",
    )
    terminate_job = models.ForeignKey(
        "labs.LabJob",
        on_delete=models.CASCADE,
        null=True,
        blank=True,
        related_name="terminate_lab_instance",
    )
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    ready_at = models.DateTimeField(null=True, blank=True)
    scheduled_terminate_at = models.DateTimeField(null=True, blank=True)
    start_terminating_at = models.DateTimeField(null=True, blank=True)
    terminated_at = models.DateTimeField(null=True, blank=True)
    exited_at = models.DateTimeField(
        null=True, blank=True, help_text="The time when the user exits the lab"
    )
    access_type = models.CharField(
        max_length=20,
        choices=LabAccessType.choices,
        null=True,
        blank=True,
        help_text="The access type of the lab instance",
    )
    # access_detail is a JSON field that contains additional details about the lab access
    # {
    #     "workshop_name": "Workshop Name",  # for WORKSHOP access type
    #     "redemption_id": 1,                # for CREDITS access type
    # }
    access_detail = models.JSONField(
        default=dict,
        help_text="Additional details about the lab access (e.g., workshop name)",
    )
    xip_domain = models.CharField(max_length=32, default="sslip.io")

    class Meta:
        db_table = "lab_instances"

    def get_user_status(self) -> LabInstanceStatus:
        """
        Get the status of the lab instance from the user's perspective.
        """
        if self.status in [
            self.LabInstanceStatus.CREATING,
            self.LabInstanceStatus.CREATING_FAILED,
            self.LabInstanceStatus.RUNNING,
        ]:
            return self.status

        if self.status in [
            self.LabInstanceStatus.TERMINATING,
            self.LabInstanceStatus.TERMINATING_FAILED,
            self.LabInstanceStatus.TERMINATED,
        ]:
            if not self.exited_at:
                return self.LabInstanceStatus.TIMEOUT
            else:
                return self.LabInstanceStatus.TERMINATED

        raise ValueError(f"Invalid lab instance status: {self.status}")