from django.db import models
from django.contrib.auth.models import User

class ChatSession(models.Model):
    user = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, blank=True)
    session_key = models.CharField(max_length=100, unique=True)
    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"Session {self.session_key} ({self.user})"

class ChatMessage(models.Model):
    session = models.ForeignKey(ChatSession, on_delete=models.CASCADE, related_name='messages')
    is_user = models.BooleanField(default=True)
    message = models.TextField()
    timestamp = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return f"{'User' if self.is_user else 'Bot'}: {self.message[:30]}"