from datetime import datetime, timezone
from enum import Enum

from sqlalchemy import Column, String, ForeignKey, Enum as SQLEnum, Text, DateTime, Integer
from sqlalchemy.dialects.postgresql import UUID, JSONB
from sqlalchemy.orm import relationship

from .base import Base, TimestampMixin, UUIDMixin


class NotificationType(str, Enum):
    EMAIL = "email"
    SMS = "sms"
    PUSH = "push"
    IN_APP = "in_app"


class NotificationStatus(str, Enum):
    QUEUED = "queued"
    SENT = "sent"
    DELIVERED = "delivered"
    FAILED = "failed"
    OPENED = "opened"
    CLICKED = "clicked"


class NotificationLog(Base, UUIDMixin, TimestampMixin):
    __tablename__ = 'notification_logs'

    # Notification Details
    notification_type = Column(SQLEnum(NotificationType), nullable=False)
    status = Column(SQLEnum(NotificationStatus), nullable=False, default=NotificationStatus.QUEUED)

    # Content
    subject = Column(String)
    content_preview = Column(String(255))  # Short preview of content
    template_id = Column(UUID(as_uuid=True), ForeignKey('email_templates.id'))

    # Recipient Information
    event_id = Column(UUID(as_uuid=True), ForeignKey('events.id'), nullable=False)
    guest_id = Column(UUID(as_uuid=True), ForeignKey('guests.id'))  # Optional, if sent to a specific guest
    recipient = Column(String, nullable=False)  # Email address or phone number

    # Tracking
    sent_at = Column(DateTime(timezone=True))
    delivered_at = Column(DateTime(timezone=True))
    opened_at = Column(DateTime(timezone=True))
    error_message = Column(Text)
    retry_count = Column(Integer, default=0)
    external_id = Column(String)  # ID from external provider (SendGrid, Twilio, etc.)

    # Additional Data
    notification_metadata = Column(JSONB, default=dict)

    # Relationships
    event = relationship("Event")
    guest = relationship("Guest")
    template = relationship("EmailTemplate")

    def __repr__(self):
        return f"<NotificationLog {self.notification_type.value} to {self.recipient} status={self.status.value}>"

    def mark_sent(self):
        """Mark notification as sent"""
        self.status = NotificationStatus.SENT
        self.sent_at = datetime.now(timezone.utc)

    def mark_delivered(self):
        """Mark notification as delivered"""
        self.status = NotificationStatus.DELIVERED
        self.delivered_at = datetime.now(timezone.utc)

    def mark_opened(self):
        """Mark notification as opened"""
        self.status = NotificationStatus.OPENED
        self.opened_at = datetime.now(timezone.utc)

    def mark_failed(self, error: str):
        """Mark notification as failed with error message"""
        self.status = NotificationStatus.FAILED
        self.error_message = error
        self.retry_count += 1

    @property
    def can_retry(self):
        """Check if notification can be retried (fewer than 3 attempts)"""
        return self.status == NotificationStatus.FAILED and self.retry_count < 3