import uuid

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


class BlockType(models.TextChoices):
    RICHTEXT = "richtext", "Rich Text"
    IMAGE = "image", "Image"
    VIDEO = "video", "Video"
    EMBED = "embed", "Embed"
    DOWNLOAD = "download", "Download"


class ScanStatus(models.TextChoices):
    PENDING = "pending", "Pending"
    CLEAN = "clean", "Clean"
    INFECTED = "infected", "Infected"
    ERROR = "error", "Error"


class MediaAsset(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    uploaded_by = models.ForeignKey(
        settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="media_assets"
    )
    org_id = models.UUIDField(db_index=True)
    file_name = models.CharField(max_length=255)
    file_path = models.CharField(max_length=1000)
    file_size = models.PositiveBigIntegerField()  # bytes
    mime_type = models.CharField(max_length=100, blank=True)
    extension = models.CharField(max_length=20, blank=True)
    scan_status = models.CharField(
        max_length=20, choices=ScanStatus.choices, default=ScanStatus.PENDING
    )
    scan_result = models.TextField(blank=True)
    alt_text = models.CharField(max_length=500, blank=True)  # WCAG 2.1 AA
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        db_table = "cms_media_asset"
        ordering = ["-created_at"]

    def __str__(self):
        return self.file_name


class ContentBlock(models.Model):
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    page = models.ForeignKey(
        "courses.Page", on_delete=models.CASCADE, related_name="content_blocks"
    )
    order = models.PositiveIntegerField(default=0)
    block_type = models.CharField(max_length=20, choices=BlockType.choices)
    # Richtext: HTML body string
    body = models.TextField(blank=True)
    # Image/video/download: reference to MediaAsset
    media_asset = models.ForeignKey(
        MediaAsset, null=True, blank=True, on_delete=models.SET_NULL, related_name="blocks"
    )
    # Embed: external URL
    embed_url = models.URLField(max_length=1000, blank=True)
    # WCAG 2.1 AA: alt text required for image blocks
    alt_text = models.CharField(max_length=500, blank=True)
    # Shared metadata
    caption = models.CharField(max_length=500, blank=True)
    extra = models.JSONField(default=dict, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = "cms_content_block"
        ordering = ["order"]
        constraints = [
            models.UniqueConstraint(fields=["page", "order"], name="unique_page_block_order"),
        ]

    def __str__(self):
        return f"{self.page_id} / {self.block_type} block {self.order}"


class CourseTheme(models.Model):
    """Per-course visual theme configuration."""
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    course = models.OneToOneField(
        "courses.Course", on_delete=models.CASCADE, related_name="theme"
    )
    primary_color = models.CharField(max_length=7, default="#000000")  # hex
    secondary_color = models.CharField(max_length=7, default="#ffffff")
    logo = models.ForeignKey(
        MediaAsset, null=True, blank=True, on_delete=models.SET_NULL, related_name="course_logos"
    )
    extra = models.JSONField(default=dict, blank=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = "cms_course_theme"