from django.db import models
from django.utils.translation import gettext_lazy as _
from django.utils.text import slugify
from django.conf import settings
from typing import Optional

class BookSubjectArea(models.Model):
    title =  models.JSONField(default = list  , verbose_name=_('Title'))
    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_('created at'))
    updated_at = models.DateTimeField(auto_now=True, verbose_name=_('updated at'))
    
    def __str__(self):
        return self.title[0]['text'] if self.title else str(self.id)

    def get_title(self,lang):
        """
            Get title for a specific language
        """

        if not self.title or not isinstance(self.title, list):
            return None

        for tr in self.title:
            if isinstance(tr, dict) and tr.get('language_code') == lang:
                return tr.get('text', '')

        for tr in self.title:
            if isinstance(tr, dict) and tr.get('language_code') == 'en':
                return tr.get('text', '')
        return None


class BookType(models.Model):
    title =  models.JSONField(default = list  , verbose_name=_('Title'))
    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_('created at'))
    updated_at = models.DateTimeField(auto_now=True, verbose_name=_('updated at'))
    
    def __str__(self):
        return self.title[0]['text'] if self.title else str(self.id)

    def get_title(self,lang):
        """
            Get title for a specific language
        """

        if not self.title or not isinstance(self.title, list):
            return None

        for tr in self.title:
            if isinstance(tr, dict) and tr.get('language_code') == lang:
                return tr.get('text', '')

        for tr in self.title:
            if isinstance(tr, dict) and tr.get('language_code') == 'en':
                return tr.get('text', '')
        return None

class BookReference(models.Model):
    """
    Model for hadis book references with detailed information
    This is different from library books - these are reference books for hadis
    """
    legacy_id = models.CharField(max_length=255, unique=True, null=True, blank=True, db_index=True)
    source_url = models.URLField(max_length=1000, null=True, blank=True, verbose_name=_('Source URL'))
    title =  models.JSONField(default = list  , verbose_name=_('Title'))
    description =  models.JSONField(default = list  , verbose_name=_('Description'))
    language =  models.JSONField(default = list  , verbose_name=_('Language'))
    isbn = models.CharField(max_length=100, verbose_name=_('ISBN'), blank=True, null=True)
    volume = models.CharField(max_length=100, verbose_name=_('volume'), blank=True, null=True)
    number_of_volumes = models.PositiveIntegerField(verbose_name=_('Total Number of Volumes'), null=True, blank=True)
    year_of_publication = models.CharField(max_length=50, verbose_name=_('year of publication'), blank=True, null=True)
    number_page = models.PositiveIntegerField(verbose_name=_('number of pages'), blank=True, null=True)
    slug = models.SlugField(max_length=255, verbose_name=_('slug'), blank=True,unique=True)
    publisher =  models.JSONField(default = list  , verbose_name=_('Publisher'))
    subject_area = models.ManyToManyField(BookSubjectArea, related_name="book_subjects", verbose_name=_('subject area'), blank=True)
    type = models.ForeignKey(BookType, on_delete=models.SET_NULL, null=True, blank=True, verbose_name=_('type'))
    order = models.IntegerField(default=0, verbose_name=_('Order'))
    researcher = models.JSONField(default=list, blank=True, verbose_name=_('Researcher'))
    city_of_publication = models.JSONField(default=list, blank=True, verbose_name=_('City of Publication'))
    country_of_publication = models.JSONField(default=list, blank=True, verbose_name=_('Country of Publication'))
    edition_number = models.CharField(max_length=100, blank=True, null=True, verbose_name=_('Edition Number'))
    rate = models.DecimalField(
        max_digits=3,
        decimal_places=2,
        verbose_name=_('rate'),
        blank=True,
        null=True,
        help_text=_('Rating from 0 to 5')
    )

    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:
        indexes = [
            models.Index(fields=['id']),  # Already indexed (PK)
        ]
        verbose_name = _('Book Reference')
        verbose_name_plural = _('Book References')
        ordering = ('-created_at',)

    def __str__(self):
        return self.title[0]['text'] if self.title else "Untitled Reference"

    def _get_json_field(self, field_name: str, lang: Optional[str]=None , fallback: str = "en"):
        """
        Generic getter for JSONField in our [{text, language_code}] format.
        Usage: self._get_json_field('title', 'fa')
        """
        if lang is None:
            lang = fallback

        value = getattr(self, field_name, None)
        if not value or not isinstance(value, list):
            return None

        # 1) exact language
        for item in value:
            if isinstance(item, dict) and item.get("language_code") == lang:
                return item.get("text", "")

        # 2) fallback language
        if fallback and fallback != lang:
            for item in value:
                if isinstance(item, dict) and item.get("language_code") == fallback:
                    return item.get("text", "")

        # 3) first available
        item = value[0]
        print(item)
        return item.get("text", "") if isinstance(item, dict) else None

    @property
    def share_link(self):
        if self.slug:
            return f"{settings.DOVODI_DOMAIN}/arguments/sources/{self.slug}"
        return None

    def get_title(self,lang):
        return self._get_json_field("title" , lang)

    def get_description(self, lang):
        return self._get_json_field("description" , lang)

    
    def get_publisher(self, lang):
        return self._get_json_field("publisher" , lang)

    def get_language(self, lang):
        return self._get_json_field("language" , lang)


    def save(self, *args, **kwargs):
        if not self.slug or (isinstance(self.slug, str) and self.slug.strip() == ''):
            # Try to get text from title field with robust error handling
            try:
                if self.title and isinstance(self.title, list) and len(self.title) > 0:
                    first_item = self.title[0]
                    if isinstance(first_item, dict):
                        title_text = first_item.get('text', '').strip()
                        if title_text:
                            base_slug = slugify(title_text, allow_unicode=True)
                            slug = base_slug
                            counter = 1
                            while BookReference.objects.filter(slug=slug).exclude(pk=self.pk).exists():
                                slug = f"{base_slug}-{counter}"
                                counter += 1
                            self.slug = slug
                        else:
                            # Fallback if text is empty
                            import time
                            suffix = int(time.time() * 1000) % 1000000
                            base_slug = f"book-{suffix}"
                            counter = 1
                            while BookReference.objects.filter(slug=base_slug).exclude(pk=self.pk).exists():
                                base_slug = f"book-{suffix}-{counter}"
                                counter += 1
                            self.slug = base_slug
                    else:
                        # Fallback if structure is invalid
                        import time
                        suffix = int(time.time() * 1000) % 1000000
                        base_slug = f"book-{suffix}"
                        counter = 1
                        while BookReference.objects.filter(slug=base_slug).exclude(pk=self.pk).exists():
                            base_slug = f"book-{suffix}-{counter}"
                            counter += 1
                        self.slug = base_slug
                else:
                    # Fallback if title is empty or invalid
                    import time
                    suffix = int(time.time() * 1000) % 1000000
                    base_slug = f"book-{suffix}"
                    counter = 1
                    while BookReference.objects.filter(slug=base_slug).exclude(pk=self.pk).exists():
                        base_slug = f"book-{suffix}-{counter}"
                        counter += 1
                    self.slug = base_slug
            except (IndexError, KeyError, AttributeError, TypeError):
                # Fallback on any error
                import time
                suffix = int(time.time() * 1000) % 1000000
                base_slug = f"book-{suffix}"
                counter = 1
                while BookReference.objects.filter(slug=base_slug).exclude(pk=self.pk).exists():
                    base_slug = f"book-{suffix}-{counter}"
                    counter += 1
                self.slug = base_slug
        super().save(*args, **kwargs)

class BookReferenceImage(models.Model):
    """
    Model for book reference images - multiple images per book reference
    """
    book_reference = models.ForeignKey(
        BookReference,
        on_delete=models.CASCADE,
        related_name='images',
        verbose_name=_('book reference')
    )
    image = models.ImageField(upload_to='hadis/book_reference_images/', verbose_name=_('image'))
    volume = models.CharField(max_length=50, null=True, blank=True, verbose_name=_('Volume'))
    order = models.PositiveIntegerField(default=0, verbose_name=_('order'))
    description =  models.JSONField(default = list  , verbose_name=_('Description'))

    created_at = models.DateTimeField(auto_now_add=True, verbose_name=_('created at'))

    class Meta:
        verbose_name = _('Book Reference Image')
        verbose_name_plural = _('Book Reference Images')
        ordering = ['order', '-created_at']

    def get_description(self,lang):
        """
            Get title for a specific language
        """

        if not self.description or not isinstance(self.description, list):
            return None

        for tr in self.description:
            if isinstance(tr, dict) and tr.get('language_code') == lang:
                return tr.get('text', '')

        for tr in self.description:
            if isinstance(tr, dict) and tr.get('language_code') == 'en':
                return tr.get('text', '')
        return None

    def __str__(self):
        return f"{self.book_reference} - Image {self.order}"

class BookReferenceDocument(models.Model):
    """
    Model for handling multiple PDF files per book (e.g., different volumes).
    """
    book_reference = models.ForeignKey(
        BookReference, 
        on_delete=models.CASCADE, 
        related_name='documents',
        verbose_name=_('book reference')
    )
    file = models.FileField(upload_to='hadis/book_reference_documents/', verbose_name=_('Document File'))
    volume = models.CharField(max_length=50, null=True, blank=True, verbose_name=_('Volume'))
    title = models.CharField(max_length=255, blank=True, null=True, help_text=_('e.g., Volume 1, 01.pdf'))
    order = models.PositiveIntegerField(default=0, verbose_name=_('order'))
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name = _('Book Reference Document')
        verbose_name_plural = _('Book Reference Documents')
        ordering = ['order', '-created_at']

    def __str__(self):
        return f"{self.book_reference} - {self.title or 'Doc ' + str(self.id)}"


class BookAuthor(models.Model):
    """
    Model for book reference authors
    """
    name =  models.JSONField(default = list  , verbose_name=_('Name'))
    birth_year_hijri = models.IntegerField(verbose_name=_("Birth Year (Hijri)"), null=True, blank=True)
    death_year_hijri = models.IntegerField(verbose_name=_("Death Year (Hijri)"), null=True, blank=True)
    birth_year_miladi = models.IntegerField(verbose_name=_("Birth Year (Miladi)"), null=True, blank=True)
    death_year_miladi = models.IntegerField(verbose_name=_("Death Year (Miladi)"), null=True, blank=True)
    book_references = models.ManyToManyField(
        BookReference,
        related_name='authors',
        verbose_name=_('book references'),
        blank=True
    )

    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:
        verbose_name = _('Book Author')
        verbose_name_plural = _('Book Authors')
        ordering = ['name']

    def __str__(self):
        return self.name[0]['text'] if self.name else "Unknown Author"

    def get_name(self,lang):
        """
            Get title for a specific language
        """

        if not self.name or not isinstance(self.name, list):
            return None

        for tr in self.name:
            if isinstance(tr, dict) and tr.get('language_code') == lang:
                return tr.get('text', '')

        for tr in self.name:
            if isinstance(tr, dict) and tr.get('language_code') == 'en':
                return tr.get('text', '')
        return None


class BookAttribute(models.Model):
    """
    Model for book reference attributes - custom key-value pairs
    """
    title =  models.JSONField(default = list  , verbose_name=_('Title'))
    value =  models.JSONField(default = list  , verbose_name=_('Value'))
    book_reference = models.ForeignKey(
        BookReference,
        on_delete=models.CASCADE,
        related_name='attributes',
        verbose_name=_('book attribute'),
        default = None,
        null = True
    )
    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:
        verbose_name = _('Book Attribute')
        verbose_name_plural = _('Book Attributes')
        ordering = ['title']

    def __str__(self):
        title = self.title[0]['text'] if self.title else "No Title"
        value = self.value[0]['text'] if self.value else "No Value"
        return f"{title}: {value}"

    def get_title(self,lang):
        """
            Get title for a specific language
        """

        if not self.title or not isinstance(self.title, list):
            return None

        for tr in self.title:
            if isinstance(tr, dict) and tr.get('language_code') == lang:
                return tr.get('text', '')

        for tr in self.title:
            if isinstance(tr, dict) and tr.get('language_code') == 'en':
                return tr.get('text', '')
        return None

    def get_value(self,lang):
        """
            Get title for a specific language
        """

        if not self.value or not isinstance(self.value, list):
            return None

        for tr in self.value:
            if isinstance(tr, dict) and tr.get('language_code') == lang:
                return tr.get('text', '')

        for tr in self.value:
            if isinstance(tr, dict) and tr.get('language_code') == 'en':
                return tr.get('text', '')
        return None