"""Notification endpoints.

Endpoints
---------
GET    /notifications              — list user notifications (paginated)
GET    /notifications/unread-count — count of unread notifications
PATCH  /notifications/{id}/read   — mark one notification as read
POST   /notifications/read-all    — mark all as read
"""

# Import uuid
import uuid

# Import APIRouter, Depends, Query from fastapi
from fastapi import APIRouter, Depends, Query

# Import Session from sqlalchemy.orm
from sqlalchemy.orm import Session

# Import get_db from app.database
from app.database import get_db

# Import get_current_user from app.dependencies.auth
from app.dependencies.auth import get_current_user

# Import UnitOfWork from app.domain.unit_of_work
from app.domain.unit_of_work import UnitOfWork

# Import User from app.models.user
from app.models.user import User

# Import NotificationOut, UnreadCountOut from app.schemas.notification
from app.schemas.notification import NotificationOut, UnreadCountOut

# Import  from app.services.notification_service
from app.services.notification_service import (
    get_unread_count,
    list_notifications,
    mark_all_as_read,
    mark_as_read,
)

# Assign router = APIRouter(prefix="/notifications", tags=["notifications"])
router = APIRouter(prefix="/notifications", tags=["notifications"])


# ---------------------------------------------------------------------------
# GET /notifications  —  list (paginated)
# ---------------------------------------------------------------------------


@router.get("", response_model=list[NotificationOut])
# Define function list_notifications_endpoint
def list_notifications_endpoint(
    # Entry: offset
    offset: int = Query(0, ge=0),
    # Entry: limit
    limit: int = Query(20, ge=1, le=100),
    # Entry: db
    db: Session = Depends(get_db),
    # Entry: current_user
    current_user: User = Depends(get_current_user),
) -> list[NotificationOut]:
    """Return paginated notifications for the current user, newest first."""
    # Return list_notifications(db, current_user.id, offset=offset, limit=limit)
    return list_notifications(db, current_user.id, offset=offset, limit=limit)


# ---------------------------------------------------------------------------
# GET /notifications/unread-count
# ---------------------------------------------------------------------------


@router.get("/unread-count", response_model=UnreadCountOut)
# Define function unread_count
def unread_count(
    # Entry: db
    db: Session = Depends(get_db),
    # Entry: current_user
    current_user: User = Depends(get_current_user),
) -> UnreadCountOut:
    """Return the number of unread notifications for the current user."""
    # Assign count = get_unread_count(db, current_user.id)
    count = get_unread_count(db, current_user.id)
    # Return UnreadCountOut(unread_count=count)
    return UnreadCountOut(unread_count=count)


# ---------------------------------------------------------------------------
# PATCH /notifications/{id}/read
# ---------------------------------------------------------------------------


@router.patch("/{notification_id}/read", response_model=NotificationOut)
# Define function read_notification
def read_notification(
    # Entry: notification_id
    notification_id: uuid.UUID,
    # Entry: db
    db: Session = Depends(get_db),
    # Entry: current_user
    current_user: User = Depends(get_current_user),
) -> NotificationOut:
    """Mark a single notification as read."""
    # Open context manager
    with UnitOfWork(db) as uow:
        # Assign notif = mark_as_read(db, notification_id, current_user.id)
        notif = mark_as_read(db, notification_id, current_user.id)
        # Call uow.commit()
        uow.commit()
    # Return notif
    return notif


# ---------------------------------------------------------------------------
# POST /notifications/read-all
# ---------------------------------------------------------------------------


@router.post("/read-all")
# Define function read_all_notifications
def read_all_notifications(
    # Entry: db
    db: Session = Depends(get_db),
    # Entry: current_user
    current_user: User = Depends(get_current_user),
) -> dict:
    """Mark all notifications for the current user as read."""
    # Open context manager
    with UnitOfWork(db) as uow:
        # Assign count = mark_all_as_read(db, current_user.id)
        count = mark_all_as_read(db, current_user.id)
        # Call uow.commit()
        uow.commit()
    # Return {"detail": f"Marked {count} notifications as read"}
    return {"detail": f"Marked {count} notifications as read"}