from django.db import models


class StatusChoices(models.TextChoices):
    APPLIED = "APPLIED", "Applied"
    SCREENING = "SCREENING", "Screening"
    INTERVIEW = "INTERVIEW", "Interview"
    OFFER = "OFFER", "Offer"
    REJECTED = "REJECTED", "Rejected"
    WITHDRAWN = "WITHDRAWN", "Withdrawn"


class JobApplication(models.Model):
    company_name = models.CharField(max_length=255)
    position_title = models.CharField(max_length=255)
    status = models.CharField(
        max_length=20,
        choices=StatusChoices.choices,
        default=StatusChoices.APPLIED,
    )
    notes = models.TextField(blank=True, default="")
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        ordering = ["-updated_at"]

    def __str__(self) -> str:
        return f"{self.company_name} - {self.position_title}"


class JobUpdate(models.Model):
    job_application = models.ForeignKey(
        JobApplication,
        on_delete=models.CASCADE,
        related_name="updates",
    )
    from_status = models.CharField(
        max_length=20,
        choices=StatusChoices.choices,
        null=True,
        blank=True,
    )
    to_status = models.CharField(
        max_length=20,
        choices=StatusChoices.choices,
    )
    notes = models.TextField(blank=True, default="")
    created_at = models.DateTimeField(auto_now_add=True)

    # Store metrics as JSON at update time for historical accuracy
    metrics = models.JSONField(default=dict, blank=True)

    class Meta:
        ordering = ["-created_at"]
        verbose_name = "Job Update"
        verbose_name_plural = "Job Updates"

    def __str__(self) -> str:
        return f"Update #{self.id}: {self.job_application.company_name} → {self.to_status}"