import math
import random
from django.conf import settings
from django.db import models
from django.utils import timezone
from django.utils.text import slugify
from django.utils.translation import gettext_lazy as _
from apps.profiles.models.institution import Institution


class PostCategory(models.Model):
    name = models.CharField(
        max_length=255,
        verbose_name=_('Category Name')
    )
    slug = models.SlugField(
        max_length=255,
        unique=True,
        allow_unicode=True,
        verbose_name=_('Slug / URL Identifier')
    )
    language = models.CharField(
        max_length=10,
        default='en',
        choices=settings.LANGUAGES,
        verbose_name=_('Language')
    )
    description = models.TextField(
        blank=True,
        null=True,
        verbose_name=_('Category Description')
    )
    created_at = models.DateTimeField(
        auto_now_add=True,
        verbose_name=_('Created At')
    )

    class Meta:
        ordering = ('name',)
        verbose_name = _('Post Category')
        verbose_name_plural = _('Post Categories')

    def __str__(self):
        return f"{self.name} ({self.language})"

    def save(self, *args, **kwargs):
        if not self.slug:
            base_slug = slugify(self.name, allow_unicode=True) or f"category-{random.randint(1000, 9999)}"
            slug = base_slug
            counter = 1
            while PostCategory.objects.filter(slug=slug).exclude(pk=self.pk).exists():
                slug = f"{base_slug}-{counter}"
                counter += 1
            self.slug = slug
        super().save(*args, **kwargs)


class PostTag(models.Model):
    name = models.CharField(
        max_length=100,
        unique=True,
        verbose_name=_('Tag Name')
    )
    slug = models.SlugField(
        max_length=100,
        unique=True,
        allow_unicode=True,
        verbose_name=_('Slug')
    )

    class Meta:
        ordering = ('name',)
        verbose_name = _('Post Tag')
        verbose_name_plural = _('Post Tags')

    def __str__(self):
        return self.name

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.name, allow_unicode=True) or f"tag-{random.randint(1000, 9999)}"
        super().save(*args, **kwargs)


class Post(models.Model):
    class PostType(models.TextChoices):
        NEWS = 'news', _('News & Announcements')
        ARTICLE = 'article', _('Analytical Article')
        REPORT = 'report', _('Field & Diplomatic Report')
        INTERVIEW = 'interview', _('Expert Interview')

    class Status(models.TextChoices):
        DRAFT = 'draft', _('Draft')
        REVIEW = 'review', _('Under Review')
        PUBLISHED = 'published', _('Published')
        ARCHIVED = 'archived', _('Archived')

    class LanguageChoices(models.TextChoices):
        FA = 'fa', _('Persian')
        AR = 'ar', _('Arabic')
        EN = 'en', _('English')
        UR = 'ur', _('Urdu')
        FR = 'fr', _('French')

    title = models.CharField(
        max_length=255,
        verbose_name=_('Post Title')
    )
    slug = models.SlugField(
        max_length=255,
        unique=True,
        allow_unicode=True,
        blank=True,
        null=True,
        verbose_name=_('Slug / URL Identifier')
    )
    post_type = models.CharField(
        max_length=50,
        choices=PostType.choices,
        default=PostType.ARTICLE,
        verbose_name=_('Post Type')
    )
    category = models.ForeignKey(
        PostCategory,
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='posts',
        verbose_name=_('Category')
    )
    language = models.CharField(
        max_length=10,
        choices=LanguageChoices.choices,
        default=LanguageChoices.EN,
        verbose_name=_('Language')
    )
    status = models.CharField(
        max_length=20,
        choices=Status.choices,
        default=Status.PUBLISHED,
        verbose_name=_('Publication Status')
    )
    author = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name='cms_posts',
        verbose_name=_('Author')
    )
    institution = models.ForeignKey(
        Institution,
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='cms_posts',
        verbose_name=_('Associated Institution')
    )
    author_role_label = models.CharField(
        max_length=150,
        blank=True,
        null=True,
        verbose_name=_('Author Role Label'),
        help_text=_('e.g. Senior Researcher, Center Director, Diplomatic Envoy')
    )
    author_custom_avatar = models.ImageField(
        upload_to='cms/avatars/%Y/%m/',
        blank=True,
        null=True,
        verbose_name=_('Custom Author Avatar')
    )
    featured_image = models.ImageField(
        upload_to='cms/featured/%Y/%m/',
        blank=True,
        null=True,
        verbose_name=_('Featured Cover Image')
    )
    excerpt = models.TextField(
        blank=True,
        null=True,
        verbose_name=_('Excerpt / Summary'),
        help_text=_('Brief summary for search results and cards.')
    )
    content = models.TextField(
        verbose_name=_('Rich Text / Markdown Content')
    )
    tags = models.JSONField(
        default=list,
        blank=True,
        verbose_name=_('Tags')
    )
    reading_time_minutes = models.PositiveIntegerField(
        default=3,
        verbose_name=_('Reading Time (Minutes)')
    )
    views_count = models.PositiveIntegerField(
        default=0,
        verbose_name=_('Views Count')
    )
    likes_count = models.PositiveIntegerField(
        default=0,
        verbose_name=_('Likes Count')
    )
    is_featured = models.BooleanField(
        default=False,
        verbose_name=_('Is Featured')
    )
    publish_date = models.DateTimeField(
        default=timezone.now,
        verbose_name=_('Publish Date')
    )
    created_at = models.DateTimeField(
        auto_now_add=True,
        verbose_name=_('Created At')
    )
    updated_at = models.DateTimeField(
        auto_now=True,
        verbose_name=_('Updated At')
    )

    class Meta:
        ordering = ('-is_featured', '-publish_date')
        verbose_name = _('Post')
        verbose_name_plural = _('Posts')

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

    def save(self, *args, **kwargs):
        if not self.slug:
            base_slug = slugify(self.title, allow_unicode=True) or f"post-{random.randint(1000, 9999)}"
            slug = base_slug
            counter = 1
            while Post.objects.filter(slug=slug).exclude(pk=self.pk).exists():
                slug = f"{base_slug}-{counter}"
                counter += 1
            self.slug = slug

        # Calculate reading time based on word count (~200 words/min)
        if self.content:
            word_count = len(self.content.split())
            self.reading_time_minutes = max(1, math.ceil(word_count / 200))

        super().save(*args, **kwargs)

    def is_liked_by(self, user):
        if not user or not user.is_authenticated:
            return False
        return self.likes.filter(user=user).exists()


class PostComment(models.Model):
    class Status(models.TextChoices):
        PENDING = 'pending', _('Pending Moderation')
        APPROVED = 'approved', _('Approved')
        SPAM = 'spam', _('Spam / Rejected')

    post = models.ForeignKey(
        Post,
        on_delete=models.CASCADE,
        related_name='comments',
        verbose_name=_('Post')
    )
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='post_comments',
        verbose_name=_('User')
    )
    author_name = models.CharField(
        max_length=255,
        blank=True,
        null=True,
        verbose_name=_('Author Name')
    )
    author_email = models.EmailField(
        blank=True,
        null=True,
        verbose_name=_('Author Email')
    )
    content = models.TextField(
        verbose_name=_('Comment Content')
    )
    status = models.CharField(
        max_length=20,
        choices=Status.choices,
        default=Status.APPROVED,
        verbose_name=_('Moderation Status')
    )
    created_at = models.DateTimeField(
        auto_now_add=True,
        verbose_name=_('Created At')
    )

    class Meta:
        ordering = ('-created_at',)
        verbose_name = _('Post Comment')
        verbose_name_plural = _('Post Comments')

    def __str__(self):
        author = self.author_name or (self.user.fullname if self.user else "Anonymous")
        return f"Comment by {author} on {self.post.title}"


class PostLike(models.Model):
    post = models.ForeignKey(
        Post,
        on_delete=models.CASCADE,
        related_name='likes',
        verbose_name=_('Post')
    )
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name='cms_post_likes',
        verbose_name=_('User')
    )
    created_at = models.DateTimeField(
        auto_now_add=True,
        verbose_name=_('Created At')
    )

    class Meta:
        unique_together = ('post', 'user')
        ordering = ('-created_at',)
        verbose_name = _('Post Like')
        verbose_name_plural = _('Post Likes')

    def __str__(self):
        return f"{self.user} likes {self.post.title}"


class MediaAsset(models.Model):
    class MediaType(models.TextChoices):
        IMAGE = 'image', _('Image')
        VIDEO = 'video', _('Video')
        AUDIO = 'audio', _('Audio')
        DOCUMENT = 'document', _('Document / PDF')

    file = models.FileField(
        upload_to='cms/media/%Y/%m/',
        verbose_name=_('Media File')
    )
    title = models.CharField(
        max_length=255,
        blank=True,
        null=True,
        verbose_name=_('Title / Description')
    )
    media_type = models.CharField(
        max_length=20,
        choices=MediaType.choices,
        default=MediaType.IMAGE,
        verbose_name=_('Media Type')
    )
    file_size = models.PositiveIntegerField(
        default=0,
        verbose_name=_('File Size (Bytes)')
    )
    dimensions = models.CharField(
        max_length=50,
        blank=True,
        null=True,
        verbose_name=_('Dimensions (WxH)')
    )
    uploaded_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='uploaded_cms_media',
        verbose_name=_('Uploaded By')
    )
    created_at = models.DateTimeField(
        auto_now_add=True,
        verbose_name=_('Created At')
    )

    class Meta:
        ordering = ('-created_at',)
        verbose_name = _('Media Asset')
        verbose_name_plural = _('Media Asset Library')

    def __str__(self):
        return self.title or f"Media Asset #{self.id}"

    def save(self, *args, **kwargs):
        if self.file and not self.file_size:
            try:
                self.file_size = self.file.size
            except Exception:
                pass
        super().save(*args, **kwargs)