from django.db import models
from core import settings

User = settings.AUTH_USER_MODEL

class Enrollment(models.Model):
    user = models.ForeignKey(
        User,
        on_delete=models.CASCADE,
        related_name='enrollments',
    )
    course = models.ForeignKey(
        "Course",
        on_delete=models.CASCADE,
        related_name='enrollments',
    )
    enrolled_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        unique_together = (('user', 'course'),)
        verbose_name = "การลงทะเบียนเรียน"
        verbose_name_plural = "การลงทะเบียนเรียน"

    def __str__(self):
        return f"{self.user} enrolled in {self.course}"

class LessonProgress(models.Model):
    user = models.ForeignKey(
        User,
        on_delete=models.CASCADE,
        related_name='lesson_progress',
    )
    lesson = models.ForeignKey(
        "Lesson",
        on_delete=models.CASCADE,
        related_name='progress_records',
    )
    completed = models.BooleanField(default=False)
    complete_at = models.DateTimeField(auto_now_add=True)
    class Meta:
        unique_together = (('user', 'lesson'),)
        verbose_name = "ความคืบหน้าบทเรียน"
        verbose_name_plural = "ความคืบหน้าบทเรียน"

class Course(models.Model):
    title = models.CharField(max_length=200)
    description = models.TextField()
    published = models.BooleanField(default=False)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name = "หลักสูตร"
        verbose_name_plural = "หลักสูตร"

    def __str__(self):
        return self.title

class Lesson(models.Model):
    course = models.ForeignKey(
        Course,
        related_name='lessons',
        on_delete=models.CASCADE
    )
    title = models.CharField(max_length=200)
    content = models.TextField()
    order = models.PositiveIntegerField(default=0)

    class Meta:
        verbose_name = "บทเรียน"
        verbose_name_plural = "บทเรียน"

    def __str__(self):
        return f"{self.course.title} - {self.title}"