from django.db import models


class Lesson(models.Model):
    slug = models.SlugField(unique=True)
    order = models.PositiveIntegerField(default=0)
    title_fa = models.CharField(max_length=200)
    title_en = models.CharField(max_length=200)
    description_fa = models.TextField()
    content_fa = models.TextField()
    category = models.CharField(max_length=50, default='basics')
    is_published = models.BooleanField(default=True)

    class Meta:
        ordering = ['order']

    def __str__(self):
        return self.title_fa


class Command(models.Model):
    lesson = models.ForeignKey(Lesson, related_name='commands', on_delete=models.CASCADE)
    command = models.CharField(max_length=300)
    description_fa = models.CharField(max_length=300)
    example_output = models.TextField(blank=True)
    order = models.PositiveIntegerField(default=0)

    class Meta:
        ordering = ['order']


class UserProgress(models.Model):
    session_key = models.CharField(max_length=100)
    lesson = models.ForeignKey(Lesson, on_delete=models.CASCADE)
    completed = models.BooleanField(default=False)
    completed_at = models.DateTimeField(null=True, blank=True)

    class Meta:
        unique_together = ['session_key', 'lesson']