from django.db import models
from django.contrib.auth import get_user_model
from django.utils import timezone
from django.core.validators import FileExtensionValidator
import uuid

User = get_user_model()


class EmailFolder(models.Model):
    """Email folders for organizing emails."""
    
    FOLDER_TYPES = [
        ('inbox', 'Inbox'),
        ('sent', 'Sent'),
        ('drafts', 'Drafts'),
        ('trash', 'Trash'),
        ('spam', 'Spam'),
        ('archive', 'Archive'),
        ('custom', 'Custom'),
    ]
    
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='folders')
    name = models.CharField(max_length=100)
    folder_type = models.CharField(max_length=20, choices=FOLDER_TYPES, default='custom')
    parent = models.ForeignKey('self', on_delete=models.CASCADE, null=True, blank=True, related_name='children')
    color = models.CharField(max_length=7, default='#007bff')  # Hex color
    is_system = models.BooleanField(default=False)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    
    class Meta:
        db_table = 'email_folders'
        unique_together = ['user', 'name']
        ordering = ['name']
    
    def __str__(self):
        return f"{self.user.email} - {self.name}"


class Email(models.Model):
    """Email model for storing email messages."""
    
    PRIORITY_CHOICES = [
        ('low', 'Low'),
        ('normal', 'Normal'),
        ('high', 'High'),
    ]
    
    STATUS_CHOICES = [
        ('draft', 'Draft'),
        ('sent', 'Sent'),
        ('received', 'Received'),
        ('failed', 'Failed'),
    ]
    
    # Basic email information
    uuid = models.UUIDField(default=uuid.uuid4, unique=True, editable=False)
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='emails')
    folder = models.ForeignKey(EmailFolder, on_delete=models.CASCADE, related_name='emails')
    
    # Email headers
    subject = models.CharField(max_length=500)
    from_email = models.EmailField()
    to_emails = models.JSONField(default=list)  # List of email addresses
    cc_emails = models.JSONField(default=list)  # List of email addresses
    bcc_emails = models.JSONField(default=list)  # List of email addresses
    reply_to = models.EmailField(null=True, blank=True)
    
    # Email content
    body_text = models.TextField(blank=True)
    body_html = models.TextField(blank=True)
    
    # Email metadata
    message_id = models.CharField(max_length=500, unique=True, null=True, blank=True)
    in_reply_to = models.CharField(max_length=500, null=True, blank=True)
    references = models.TextField(blank=True)
    priority = models.CharField(max_length=10, choices=PRIORITY_CHOICES, default='normal')
    status = models.CharField(max_length=20, choices=STATUS_CHOICES, default='draft')
    
    # Flags and status
    is_read = models.BooleanField(default=False)
    is_starred = models.BooleanField(default=False)
    is_important = models.BooleanField(default=False)
    is_encrypted = models.BooleanField(default=False)
    
    # Timestamps
    sent_at = models.DateTimeField(null=True, blank=True)
    received_at = models.DateTimeField(null=True, blank=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    
    # Size information
    size = models.BigIntegerField(default=0)  # Size in bytes
    
    class Meta:
        db_table = 'emails'
        ordering = ['-created_at']
        indexes = [
            models.Index(fields=['user', 'folder', '-created_at']),
            models.Index(fields=['user', 'is_read']),
            models.Index(fields=['user', 'is_starred']),
            models.Index(fields=['message_id']),
        ]
    
    def __str__(self):
        return f"{self.subject} - {self.from_email}"
    
    def mark_as_read(self):
        """Mark email as read."""
        self.is_read = True
        self.save(update_fields=['is_read', 'updated_at'])
    
    def mark_as_unread(self):
        """Mark email as unread."""
        self.is_read = False
        self.save(update_fields=['is_read', 'updated_at'])
    
    def move_to_folder(self, folder):
        """Move email to another folder."""
        self.folder = folder
        self.save(update_fields=['folder', 'updated_at'])
    
    def get_recipients(self):
        """Get all recipients (to, cc, bcc)."""
        return self.to_emails + self.cc_emails + self.bcc_emails


class EmailAttachment(models.Model):
    """Email attachments."""
    
    email = models.ForeignKey(Email, on_delete=models.CASCADE, related_name='attachments')
    filename = models.CharField(max_length=255)
    content_type = models.CharField(max_length=100)
    size = models.BigIntegerField()
    file = models.FileField(
        upload_to='email_attachments/',
        validators=[FileExtensionValidator(allowed_extensions=['pdf', 'doc', 'docx', 'txt', 'jpg', 'jpeg', 'png', 'gif', 'zip', 'rar'])]
    )
    is_inline = models.BooleanField(default=False)
    content_id = models.CharField(max_length=100, blank=True)  # For inline attachments
    created_at = models.DateTimeField(auto_now_add=True)
    
    class Meta:
        db_table = 'email_attachments'
        ordering = ['filename']
    
    def __str__(self):
        return f"{self.email.subject} - {self.filename}"


class EmailThread(models.Model):
    """Email threads for conversation view."""
    
    emails = models.ManyToManyField(Email, related_name='threads')
    subject = models.CharField(max_length=500)
    participants = models.JSONField(default=list)  # List of email addresses
    last_activity = models.DateTimeField(auto_now=True)
    created_at = models.DateTimeField(auto_now_add=True)
    
    class Meta:
        db_table = 'email_threads'
        ordering = ['-last_activity']
    
    def __str__(self):
        return f"Thread: {self.subject}"


class EmailTemplate(models.Model):
    """Email templates for quick composition."""
    
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='email_templates')
    name = models.CharField(max_length=100)
    subject = models.CharField(max_length=500)
    body_html = models.TextField()
    body_text = models.TextField(blank=True)
    is_public = models.BooleanField(default=False)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    
    class Meta:
        db_table = 'email_templates'
        unique_together = ['user', 'name']
        ordering = ['name']
    
    def __str__(self):
        return f"{self.user.email} - {self.name}"


class EmailSignature(models.Model):
    """Email signatures."""
    
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='email_signatures')
    name = models.CharField(max_length=100)
    content_html = models.TextField()
    content_text = models.TextField(blank=True)
    is_default = models.BooleanField(default=False)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    
    class Meta:
        db_table = 'email_signatures'
        ordering = ['name']
    
    def __str__(self):
        return f"{self.user.email} - {self.name}"
    
    def save(self, *args, **kwargs):
        if self.is_default:
            # Ensure only one default signature per user
            EmailSignature.objects.filter(user=self.user, is_default=True).update(is_default=False)
        super().save(*args, **kwargs)


class EmailRule(models.Model):
    """Email rules for automatic processing."""
    
    ACTION_CHOICES = [
        ('move', 'Move to folder'),
        ('mark_read', 'Mark as read'),
        ('mark_important', 'Mark as important'),
        ('forward', 'Forward to'),
        ('delete', 'Delete'),
        ('reply', 'Auto-reply'),
    ]
    
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='email_rules')
    name = models.CharField(max_length=100)
    is_active = models.BooleanField(default=True)
    
    # Conditions
    condition_field = models.CharField(max_length=50)  # from, to, subject, body, etc.
    condition_operator = models.CharField(max_length=20)  # contains, equals, starts_with, etc.
    condition_value = models.CharField(max_length=500)
    
    # Actions
    action = models.CharField(max_length=20, choices=ACTION_CHOICES)
    action_value = models.CharField(max_length=500, blank=True)  # Folder name, email address, etc.
    
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    
    class Meta:
        db_table = 'email_rules'
        ordering = ['name']
    
    def __str__(self):
        return f"{self.user.email} - {self.name}"


class EmailSearch(models.Model):
    """Saved email searches."""
    
    user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='email_searches')
    name = models.CharField(max_length=100)
    query = models.JSONField()  # Search parameters
    created_at = models.DateTimeField(auto_now_add=True)
    
    class Meta:
        db_table = 'email_searches'
        unique_together = ['user', 'name']
        ordering = ['name']
    
    def __str__(self):
        return f"{self.user.email} - {self.name}"