from django.db import models
from django.utils import timezone
from django.utils.text import slugify


class CaseStudyCategory(models.Model):
    """Model for case study categories"""
    name = models.CharField(max_length=100)
    slug = models.SlugField(max_length=100, unique=True)
    description = models.TextField(blank=True)
    display_order = models.PositiveIntegerField(default=0)
    is_active = models.BooleanField(default=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        verbose_name = "Case Study Category"
        verbose_name_plural = "Case Study Categories"
        ordering = ['display_order', 'name']

    def __str__(self):
        return self.name

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.name)
        super().save(*args, **kwargs)


class Client(models.Model):
    """Model for clients"""
    name = models.CharField(max_length=200)
    slug = models.SlugField(max_length=200, unique=True)
    logo = models.ImageField(upload_to='case_studies/clients/', blank=True, null=True)
    logo_url = models.CharField(max_length=500, blank=True, help_text="External logo URL")
    description = models.TextField(blank=True)
    website = models.URLField(blank=True)
    is_active = models.BooleanField(default=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        verbose_name = "Client"
        verbose_name_plural = "Clients"
        ordering = ['name']

    def __str__(self):
        return self.name

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.name)
        super().save(*args, **kwargs)

    @property
    def get_logo_url(self):
        """Return the logo URL (uploaded image or external URL)"""
        if self.logo and hasattr(self.logo, 'url'):
            return self.logo.url
        elif self.logo_url:
            return self.logo_url
        return None


class CaseStudy(models.Model):
    """Model for case studies"""
    title = models.CharField(max_length=300)
    slug = models.SlugField(max_length=300, unique=True)
    subtitle = models.CharField(max_length=300, blank=True)
    description = models.TextField()
    excerpt = models.TextField(blank=True, help_text="Short excerpt for preview")
    
    # Images
    thumbnail = models.ImageField(upload_to='case_studies/thumbnails/', blank=True, null=True)
    thumbnail_url = models.CharField(max_length=500, blank=True, help_text="External thumbnail URL")
    featured_image = models.ImageField(upload_to='case_studies/featured/', blank=True, null=True)
    featured_image_url = models.CharField(max_length=500, blank=True, help_text="External featured image URL")
    poster_image = models.ImageField(upload_to='case_studies/posters/', blank=True, null=True)
    poster_image_url = models.CharField(max_length=500, blank=True, help_text="External poster image URL")
    project_image = models.ImageField(upload_to='case_studies/projects/', blank=True, null=True)
    project_image_url = models.CharField(max_length=500, blank=True, help_text="External project image URL")
    
    # Content sections
    project_overview = models.TextField(blank=True, help_text="Project overview content")
    site_map_content = models.TextField(blank=True, help_text="Site map / process content")
    
    # Relations
    category = models.ForeignKey(
        CaseStudyCategory,
        on_delete=models.SET_NULL,
        null=True,
        related_name='case_studies'
    )
    client = models.ForeignKey(
        Client,
        on_delete=models.SET_NULL,
        null=True,
        blank=True,
        related_name='case_studies'
    )
    
    # SEO and metadata
    meta_description = models.CharField(max_length=160, blank=True)
    meta_keywords = models.CharField(max_length=255, blank=True)
    
    # Status and visibility
    published = models.BooleanField(default=True)
    featured = models.BooleanField(default=False, help_text="Featured case study")
    views_count = models.PositiveIntegerField(default=0)
    display_order = models.PositiveIntegerField(default=0)
    
    # Timestamps
    published_at = models.DateTimeField(default=timezone.now)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        verbose_name = "Case Study"
        verbose_name_plural = "Case Studies"
        ordering = ['display_order', '-published_at', '-created_at']
        indexes = [
            models.Index(fields=['-published_at']),
            models.Index(fields=['slug']),
            models.Index(fields=['published']),
        ]

    def __str__(self):
        return self.title

    def save(self, *args, **kwargs):
        if not self.slug:
            self.slug = slugify(self.title)
        if not self.excerpt and self.description:
            # Generate excerpt from description (first 200 characters)
            self.excerpt = self.description[:200] + '...' if len(self.description) > 200 else self.description
        super().save(*args, **kwargs)

    @property
    def get_thumbnail_url(self):
        """Return the thumbnail URL (uploaded image or external URL)"""
        if self.thumbnail and hasattr(self.thumbnail, 'url'):
            return self.thumbnail.url
        elif self.thumbnail_url:
            return self.thumbnail_url
        return None

    @property
    def get_featured_image_url(self):
        """Return the featured image URL (uploaded image or external URL)"""
        if self.featured_image and hasattr(self.featured_image, 'url'):
            return self.featured_image.url
        elif self.featured_image_url:
            return self.featured_image_url
        return None

    @property
    def get_poster_image_url(self):
        """Return the poster image URL (uploaded image or external URL)"""
        if self.poster_image and hasattr(self.poster_image, 'url'):
            return self.poster_image.url
        elif self.poster_image_url:
            return self.poster_image_url
        return None

    @property
    def get_project_image_url(self):
        """Return the project image URL (uploaded image or external URL)"""
        if self.project_image and hasattr(self.project_image, 'url'):
            return self.project_image.url
        elif self.project_image_url:
            return self.project_image_url
        return None

    def increment_views(self):
        """Increment the view count"""
        self.views_count += 1
        self.save(update_fields=['views_count'])


class CaseStudyImage(models.Model):
    """Model for additional case study images (gallery)"""
    case_study = models.ForeignKey(CaseStudy, on_delete=models.CASCADE, related_name='gallery_images')
    image = models.ImageField(upload_to='case_studies/gallery/')
    image_url = models.CharField(max_length=500, blank=True, help_text="External image URL")
    caption = models.CharField(max_length=200, blank=True)
    display_order = models.PositiveIntegerField(default=0)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name = "Case Study Image"
        verbose_name_plural = "Case Study Images"
        ordering = ['display_order', 'created_at']

    def __str__(self):
        return f"{self.case_study.title} - Image {self.display_order}"

    @property
    def get_image_url(self):
        """Return the image URL (uploaded image or external URL)"""
        if self.image and hasattr(self.image, 'url'):
            return self.image.url
        elif self.image_url:
            return self.image_url
        return None


class CaseStudyProcess(models.Model):
    """Model for case study process steps"""
    case_study = models.ForeignKey(CaseStudy, on_delete=models.CASCADE, related_name='process_steps')
    title = models.CharField(max_length=200)
    description = models.TextField()
    step_number = models.PositiveIntegerField()
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        verbose_name = "Case Study Process"
        verbose_name_plural = "Case Study Processes"
        ordering = ['step_number']

    def __str__(self):
        return f"{self.case_study.title} - Step {self.step_number}: {self.title}"