"""
User models for the Dubai Analytics Platform.
"""
from django.db import models
from django.contrib.auth.models import AbstractUser
from django.utils import timezone
import uuid
import secrets


class User(AbstractUser):
    """Custom user model with additional fields for the platform."""
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    email = models.EmailField(unique=True)
    subscription_type = models.CharField(
        max_length=20,
        choices=[
            ('free', 'Free'),
            ('paid', 'Paid'),
            ('premium', 'Premium'),
        ],
        default='free'
    )
    api_key = models.CharField(max_length=64, unique=True, blank=True, null=True)
    is_api_enabled = models.BooleanField(default=False)
    last_api_usage = models.DateTimeField(null=True, blank=True)
    company_name = models.CharField(max_length=255, blank=True)
    phone_number = models.CharField(max_length=20, blank=True)
    is_verified = models.BooleanField(default=False)
    
    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['username']

    class Meta:
        db_table = 'users'

    def __str__(self):
        return f"{self.email} ({self.subscription_type})"

    def save(self, *args, **kwargs):
        # Generate API key if not exists and API is enabled
        if self.is_api_enabled and not self.api_key:
            self.api_key = self.generate_api_key()
        super().save(*args, **kwargs)

    def generate_api_key(self):
        """Generate a secure API key."""
        return secrets.token_urlsafe(32)

    def get_usage_limits(self):
        """Get usage limits based on subscription type."""
        from django.conf import settings
        return settings.BILLING_SETTINGS.get(f'{self.subscription_type.upper()}_TIER_LIMITS', {})

    def can_make_api_call(self):
        """Check if user can make an API call based on their limits."""
        if not self.is_api_enabled:
            return False
        
        limits = self.get_usage_limits()
        if not limits:
            return False
            
        # This would need to be implemented with actual usage tracking
        # For now, return True if user has API enabled
        return True


class UserProfile(models.Model):
    """Extended user profile information."""
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='profile')
    avatar = models.ImageField(upload_to='avatars/', blank=True, null=True)
    bio = models.TextField(blank=True)
    website = models.URLField(blank=True)
    location = models.CharField(max_length=255, blank=True)
    timezone = models.CharField(max_length=50, default='Asia/Dubai')
    language = models.CharField(max_length=10, default='en')
    notification_preferences = models.JSONField(default=dict)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        db_table = 'user_profiles'

    def __str__(self):
        return f"{self.user.email} Profile"


class UserSession(models.Model):
    """Track user sessions for security."""
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='sessions')
    session_key = models.CharField(max_length=40, unique=True)
    ip_address = models.GenericIPAddressField()
    user_agent = models.TextField()
    created_at = models.DateTimeField(auto_now_add=True)
    last_activity = models.DateTimeField(auto_now=True)
    is_active = models.BooleanField(default=True)

    class Meta:
        db_table = 'user_sessions'
        indexes = [
            models.Index(fields=['user', 'is_active']),
            models.Index(fields=['session_key']),
        ]

    def __str__(self):
        return f"{self.user.email} - {self.session_key[:8]}..."


class APIKey(models.Model):
    """API keys for programmatic access."""
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='api_keys')
    name = models.CharField(max_length=100)
    key = models.CharField(max_length=64, unique=True)
    is_active = models.BooleanField(default=True)
    last_used = models.DateTimeField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    expires_at = models.DateTimeField(null=True, blank=True)

    class Meta:
        db_table = 'api_keys'
        indexes = [
            models.Index(fields=['user', 'is_active']),
            models.Index(fields=['key']),
        ]

    def __str__(self):
        return f"{self.user.email} - {self.name}"

    def is_expired(self):
        """Check if API key is expired."""
        if not self.expires_at:
            return False
        return timezone.now() > self.expires_at

    def is_valid(self):
        """Check if API key is valid."""
        return self.is_active and not self.is_expired()