"""
Chat Models für Live-Chat System
"""

from django.db import models
from django.contrib.auth.models import User
from django.utils import timezone
from django.conf import settings
import uuid


class ChatRoom(models.Model):
    """Chat-Raum für Kunde-Admin Kommunikation"""
    
    ROOM_STATUS_CHOICES = [
        ('active', 'Aktiv'),
        ('waiting', 'Wartend'),
        ('closed', 'Geschlossen'),
        ('archived', 'Archiviert'),
    ]
    
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    customer = models.ForeignKey(User, on_delete=models.CASCADE, related_name='customer_chats')
    admin = models.ForeignKey(User, on_delete=models.SET_NULL, null=True, blank=True, related_name='admin_chats')
    status = models.CharField(max_length=20, choices=ROOM_STATUS_CHOICES, default='waiting')
    subject = models.CharField(max_length=200, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    last_message_at = models.DateTimeField(null=True, blank=True)
    
    class Meta:
        ordering = ['-last_message_at', '-created_at']
        verbose_name = 'Chat-Raum'
        verbose_name_plural = 'Chat-Räume'
    
    def __str__(self):
        return f"Chat {self.id} - {self.customer.username}"
    
    def get_unread_count(self, user):
        """Anzahl ungelesener Nachrichten für User"""
        return self.messages.filter(
            sender__in=self.get_other_users(user),
            read_at__isnull=True
        ).count()
    
    def get_other_users(self, user):
        """Andere User im Chat"""
        if user == self.customer:
            return [self.admin] if self.admin else []
        elif user == self.admin:
            return [self.customer]
        return []
    
    def mark_messages_as_read(self, user):
        """Nachrichten als gelesen markieren"""
        other_users = self.get_other_users(user)
        self.messages.filter(
            sender__in=other_users,
            read_at__isnull=True
        ).update(read_at=timezone.now())


class ChatMessage(models.Model):
    """Chat-Nachricht"""
    
    MESSAGE_TYPE_CHOICES = [
        ('text', 'Text'),
        ('image', 'Bild'),
        ('file', 'Datei'),
        ('system', 'System'),
    ]
    
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    room = models.ForeignKey(ChatRoom, on_delete=models.CASCADE, related_name='messages')
    sender = models.ForeignKey(User, on_delete=models.CASCADE, related_name='sent_messages')
    message_type = models.CharField(max_length=20, choices=MESSAGE_TYPE_CHOICES, default='text')
    content = models.TextField()
    file = models.FileField(upload_to='chat_files/', null=True, blank=True)
    image = models.ImageField(upload_to='chat_images/', null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    read_at = models.DateTimeField(null=True, blank=True)
    is_system_message = models.BooleanField(default=False)
    
    class Meta:
        ordering = ['created_at']
        verbose_name = 'Chat-Nachricht'
        verbose_name_plural = 'Chat-Nachrichten'
    
    def __str__(self):
        return f"{self.sender.username}: {self.content[:50]}"
    
    def save(self, *args, **kwargs):
        """Nachricht speichern und Room aktualisieren"""
        is_new = self.pk is None
        super().save(*args, **kwargs)
        
        if is_new:
            # Room last_message_at aktualisieren
            self.room.last_message_at = self.created_at
            self.room.save(update_fields=['last_message_at'])


class ChatNotification(models.Model):
    """Chat-Benachrichtigungen"""
    
    NOTIFICATION_TYPE_CHOICES = [
        ('new_message', 'Neue Nachricht'),
        ('room_assigned', 'Raum zugewiesen'),
        ('room_closed', 'Raum geschlossen'),
        ('customer_online', 'Kunde online'),
        ('customer_offline', 'Kunde offline'),
    ]
    
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='chat_notifications')
    room = models.ForeignKey(ChatRoom, on_delete=models.CASCADE, related_name='notifications')
    notification_type = models.CharField(max_length=20, choices=NOTIFICATION_TYPE_CHOICES)
    title = models.CharField(max_length=200)
    message = models.TextField()
    created_at = models.DateTimeField(auto_now_add=True)
    read_at = models.DateTimeField(null=True, blank=True)
    sent_via_email = models.BooleanField(default=False)
    sent_via_push = models.BooleanField(default=False)
    
    class Meta:
        ordering = ['-created_at']
        verbose_name = 'Chat-Benachrichtigung'
        verbose_name_plural = 'Chat-Benachrichtigungen'
    
    def __str__(self):
        return f"{self.notification_type}: {self.title}"


class UserOnlineStatus(models.Model):
    """Online-Status von Benutzern"""
    
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name='online_status')
    is_online = models.BooleanField(default=False)
    last_seen = models.DateTimeField(auto_now=True)
    current_room = models.ForeignKey(ChatRoom, on_delete=models.SET_NULL, null=True, blank=True)
    
    class Meta:
        verbose_name = 'Online-Status'
        verbose_name_plural = 'Online-Status'
    
    def __str__(self):
        status = "Online" if self.is_online else "Offline"
        return f"{self.user.username} - {status}"


class QuickResponse(models.Model):
    """Schnelle Antworten für Admins"""
    
    category = models.CharField(max_length=50, choices=[
        ('greeting', 'Begrüßung'),
        ('pricing', 'Preise'),
        ('shipping', 'Versand'),
        ('custom_order', 'Custom Order'),
        ('technical', 'Technische Fragen'),
        ('general', 'Allgemein'),
    ])
    title = models.CharField(max_length=100)
    content = models.TextField()
    created_by = models.ForeignKey(User, on_delete=models.CASCADE, related_name='quick_responses')
    created_at = models.DateTimeField(auto_now_add=True)
    is_active = models.BooleanField(default=True)
    use_count = models.IntegerField(default=0)
    
    class Meta:
        ordering = ['category', 'title']
        verbose_name = 'Schnelle Antwort'
        verbose_name_plural = 'Schnelle Antworten'
    
    def __str__(self):
        return f"{self.category}: {self.title}"
    
    def increment_use_count(self):
        """Verwendungszähler erhöhen"""
        self.use_count += 1
        self.save(update_fields=['use_count'])


class ChatAnalytics(models.Model):
    """Chat-Analytics für Performance-Tracking"""
    
    date = models.DateField()
    total_messages = models.IntegerField(default=0)
    total_rooms = models.IntegerField(default=0)
    active_rooms = models.IntegerField(default=0)
    avg_response_time = models.FloatField(default=0)  # in Sekunden
    customer_satisfaction = models.FloatField(default=0)  # 0-5 Sterne
    total_duration = models.FloatField(default=0)  # in Minuten
    
    class Meta:
        unique_together = ['date']
        verbose_name = 'Chat-Analytics'
        verbose_name_plural = 'Chat-Analytics'
    
    def __str__(self):
        return f"Chat Analytics - {self.date}"
    
    @classmethod
    def get_or_create_today(cls):
        """Heutige Analytics erstellen oder abrufen"""
        today = timezone.now().date()
        analytics, created = cls.objects.get_or_create(date=today)
        return analytics