"""
Notification API endpoints.
POST /send          — Send single notification
POST /send/batch    — Send batch notifications
POST /list          — List notifications (with projection_list support)
GET  /{id}          — Get notification by ID
POST /{id}/retry    — Retry a failed notification
GET  /channels/status — Channel configuration status (per-merchant)
"""
from fastapi import APIRouter, HTTPException, Query, status
from app.models.notification import (
    SendNotificationRequest,
    SendNotificationResponse,
    SendBatchRequest,
    SendBatchResponse,
    ListNotificationsRequest,
    ListNotificationsResponse,
)
from app.services.notification_service import NotificationService
from app.services.dispatcher import NotificationDispatcher
from app.core.logging import get_logger

logger = get_logger(__name__)

router = APIRouter(tags=["Notifications"])


@router.post("/send", response_model=SendNotificationResponse)
async def send_notification(payload: SendNotificationRequest):
    """
    Queue a notification for delivery via one or more channels.
    merchant_id is required — credentials are fetched from merchant settings.
    """
    try:
        doc = await NotificationService.create_and_queue(payload)
        return SendNotificationResponse(
            success=True,
            notification_id=doc["notification_id"],
            message="Notification queued for delivery",
            channels=doc["channels"],
        )
    except Exception as e:
        logger.error(
            "Send notification failed",
            exc_info=True,
            extra={
                "event": "notification_create_failure",
                "merchant_id": payload.merchant_id,
                "template_name": payload.template_name,
            },
        )
        raise HTTPException(status.HTTP_500_INTERNAL_SERVER_ERROR, detail=str(e))


@router.post("/send/batch", response_model=SendBatchResponse)
async def send_batch(payload: SendBatchRequest):
    """Queue multiple notifications in one call."""
    queued, failed, results = await NotificationService.create_and_queue_batch(
        payload.notifications
    )
    return SendBatchResponse(
        success=failed == 0,
        total=len(payload.notifications),
        queued=queued,
        failed=failed,
        results=[
            SendNotificationResponse(
                success="error" not in r,
                notification_id=r.get("notification_id", ""),
                message=r.get("error", "Queued"),
                channels=r.get("channels", []),
            )
            for r in results
        ],
    )


@router.post("/list", response_model=ListNotificationsResponse)
async def list_notifications(payload: ListNotificationsRequest):
    """
    List notifications with filters and projection_list support.
    Follows the mandatory POST /list pattern with MongoDB projection.
    """
    docs, total = await NotificationService.list_notifications(
        filters=payload.filters,
        skip=payload.skip,
        limit=payload.limit,
        projection_list=payload.projection_list,
    )
    return ListNotificationsResponse(
        success=True,
        total=total,
        skip=payload.skip,
        limit=payload.limit,
        data=docs,
    )


@router.get("/{notification_id}")
async def get_notification(notification_id: str):
    """Get a single notification by ID."""
    doc = await NotificationService.get_notification(notification_id)
    if not doc:
        raise HTTPException(status.HTTP_404_NOT_FOUND, detail="Notification not found")
    return {"success": True, "data": doc}


@router.post("/{notification_id}/retry")
async def retry_notification(notification_id: str):
    """Re-queue a failed notification for retry."""
    doc = await NotificationService.retry_notification(notification_id)
    if not doc:
        raise HTTPException(
            status.HTTP_400_BAD_REQUEST,
            detail="Notification not found or not in failed state",
        )
    return {"success": True, "message": "Notification re-queued", "data": doc}


@router.get("/channels/status")
async def channel_status(
    merchant_id: str = Query(..., description="Merchant ID to check channel availability"),
):
    """
    Return which notification channels are configured for a specific merchant.
    Credentials are per-merchant, so merchant_id is required.
    """
    channels = await NotificationDispatcher.get_channel_status(merchant_id)
    return {"success": True, "merchant_id": merchant_id, "channels": channels}