"""
Notification models and Pydantic schemas.
"""
import uuid
from datetime import datetime
from typing import Optional, List, Dict, Any
from enum import Enum
from pydantic import BaseModel, Field


class NotificationChannel(str, Enum):
    WHATSAPP = "whatsapp"
    EMAIL = "email"
    SMS = "sms"
    PUSH = "push"


class NotificationStatus(str, Enum):
    PENDING = "pending"
    QUEUED = "queued"
    SENDING = "sending"
    SENT = "sent"
    DELIVERED = "delivered"
    FAILED = "failed"


class NotificationPriority(str, Enum):
    LOW = "low"
    NORMAL = "normal"
    HIGH = "high"
    CRITICAL = "critical"


# --- Request Schemas ---

class SendNotificationRequest(BaseModel):
    """Send a notification via one or more channels."""
    recipient: str = Field(..., description="Phone number (with country code) or email")
    channels: List[NotificationChannel] = Field(
        default=[NotificationChannel.WHATSAPP],
        description="Delivery channels"
    )
    template_name: str = Field(..., description="Template identifier")
    template_data: Dict[str, Any] = Field(default_factory=dict)
    priority: NotificationPriority = Field(default=NotificationPriority.NORMAL)
    source: Optional[str] = Field(None, description="Originating microservice")
    merchant_id: str = Field(..., description="Merchant ID (required for credential lookup)")
    merchant_name: Optional[str] = Field("", description="Merchant name (injected into template variables at dispatch)")
    metadata: Optional[Dict[str, Any]] = None


class SendBatchRequest(BaseModel):
    """Send notifications to multiple recipients."""
    notifications: List[SendNotificationRequest] = Field(
        ..., min_length=1, max_length=100
    )


class ListNotificationsRequest(BaseModel):
    """List notifications with filters and projection support."""
    filters: Optional[Dict[str, Any]] = Field(default_factory=dict)
    skip: int = Field(default=0, ge=0)
    limit: int = Field(default=50, ge=1, le=200)
    projection_list: Optional[List[str]] = Field(
        None, description="List of fields to include in response"
    )


# --- Response Schemas ---

class SendNotificationResponse(BaseModel):
    success: bool
    notification_id: str
    message: str
    channels: List[str]


class SendBatchResponse(BaseModel):
    success: bool
    total: int
    queued: int
    failed: int
    results: List[SendNotificationResponse]


class NotificationDetail(BaseModel):
    notification_id: str
    recipient: str
    channels: List[str]
    template_name: str
    template_data: Dict[str, Any] = {}
    status: str
    priority: str = "normal"
    source: Optional[str] = None
    merchant_id: Optional[str] = None
    merchant_name: Optional[str] = None
    channel_results: Dict[str, Any] = {}
    retry_count: int = 0
    created_at: Optional[datetime] = None
    updated_at: Optional[datetime] = None
    sent_at: Optional[datetime] = None


class ListNotificationsResponse(BaseModel):
    success: bool = True
    total: int
    skip: int
    limit: int
    data: List[Any]


# --- MongoDB Document Shape ---

def new_notification_doc(req: SendNotificationRequest) -> Dict[str, Any]:
    now = datetime.utcnow()
    return {
        "notification_id": str(uuid.uuid4()),
        "recipient": req.recipient,
        "channels": [ch.value for ch in req.channels],
        "template_name": req.template_name,
        "template_data": req.template_data,
        "priority": req.priority.value,
        "status": NotificationStatus.QUEUED.value,
        "source": req.source,
        "merchant_id": req.merchant_id,
        "merchant_name": req.merchant_name or "",
        "metadata": req.metadata or {},
        "channel_results": {},
        "retry_count": 0,
        "created_at": now,
        "updated_at": now,
        "sent_at": None,
    }