import uuid

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


class FormulaDocument(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="formulas")
    title = models.CharField(max_length=120)
    source = models.TextField(blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        ordering = ["-updated_at"]


class FormulaRevision(models.Model):
    document = models.ForeignKey(FormulaDocument, on_delete=models.CASCADE, related_name="revisions")
    source = models.TextField()
    created_at = models.DateTimeField(auto_now_add=True)


class LatexCourse(models.Model):
    slug = models.SlugField(unique=True)
    title = models.CharField(max_length=120)
    description = models.TextField(blank=True)
    order = models.PositiveIntegerField(default=0)
    is_published = models.BooleanField(default=False)

    def __str__(self):
        return self.title


class LatexLesson(models.Model):
    course = models.ForeignKey(LatexCourse, on_delete=models.CASCADE, related_name="lessons")
    slug = models.SlugField()
    title = models.CharField(max_length=120)
    content = models.TextField()
    example_source = models.TextField(blank=True)
    order = models.PositiveIntegerField(default=0)

    class Meta:
        constraints = [
            models.UniqueConstraint(fields=("course", "slug"), name="unique_course_lesson")
        ]
        ordering = ["order"]


class LatexExercise(models.Model):
    lesson = models.ForeignKey(LatexLesson, on_delete=models.CASCADE, related_name="exercises")
    prompt = models.TextField()
    expected_source = models.TextField()
    explanation = models.TextField(blank=True)
    order = models.PositiveIntegerField(default=0)


class LatexAttempt(models.Model):
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="latex_attempts")
    exercise = models.ForeignKey(LatexExercise, on_delete=models.PROTECT)
    submitted_source = models.TextField()
    is_correct = models.BooleanField()
    created_at = models.DateTimeField(auto_now_add=True)


class HandwritingRecognitionJob(models.Model):
    class Status(models.TextChoices):
        PENDING = "pending", "等待"
        COMPLETE = "complete", "完成"
        FAILED = "failed", "失败"

    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    status = models.CharField(max_length=16, choices=Status.choices, default=Status.PENDING)
    result = models.JSONField(default=dict, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)