"""
In-app varslingssenter (FEATURE_BACKLOG.md "Varsler"-runden, 2026-07-25).

Eid av BRUKER (mottaker), ikke organisasjon -- plain_connection(), samme
mønster som personlig profil/HCP-historikk/venner. `create_notification()`
er den eneste skrivevegen inn -- kalt fra andre routere (i dag kun
friends.py) ved konkrete hendelser, ikke noe generisk event-system.
"""

from __future__ import annotations

from typing import Literal

from fastapi import APIRouter, Depends
from pydantic import BaseModel

from ..auth import CurrentUser, get_current_user
from ..db import plain_connection

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

NotificationType = Literal["friend", "tournament", "round", "result"]


async def create_notification(conn, *, user_id: str, type: NotificationType, message: str, link_path: str) -> None:
    """Kalles fra andre routere sin egen `plain_connection()`/transaksjon --
    tar en allerede-åpen `conn`, åpner ikke en egen."""
    await conn.execute(
        "INSERT INTO notification (user_id, type, message, link_path) VALUES ($1, $2, $3, $4)",
        user_id,
        type,
        message,
        link_path,
    )


class NotificationOut(BaseModel):
    id: str
    type: str
    message: str
    link_path: str
    created_at: str
    read_at: str | None


@router.get("/notifications", response_model=list[NotificationOut])
async def list_notifications(user: CurrentUser = Depends(get_current_user)) -> list[NotificationOut]:
    async with plain_connection() as conn:
        rows = await conn.fetch(
            """
            SELECT id::text AS id, type, message, link_path, created_at, read_at
            FROM notification WHERE user_id = $1
            ORDER BY created_at DESC
            LIMIT 100
            """,
            user.user_id,
        )
    return [
        NotificationOut(
            id=r["id"],
            type=r["type"],
            message=r["message"],
            link_path=r["link_path"],
            created_at=r["created_at"].isoformat(),
            read_at=r["read_at"].isoformat() if r["read_at"] else None,
        )
        for r in rows
    ]


@router.get("/notifications/unread-count")
async def unread_count(user: CurrentUser = Depends(get_current_user)) -> dict[str, int]:
    async with plain_connection() as conn:
        count = await conn.fetchval(
            "SELECT COUNT(*) FROM notification WHERE user_id = $1 AND read_at IS NULL",
            user.user_id,
        )
    return {"count": count}


@router.post("/notifications/{notification_id}/read")
async def mark_read(notification_id: str, user: CurrentUser = Depends(get_current_user)) -> dict[str, bool]:
    async with plain_connection() as conn:
        await conn.execute(
            "UPDATE notification SET read_at = now() WHERE id = $1 AND user_id = $2 AND read_at IS NULL",
            notification_id,
            user.user_id,
        )
    return {"ok": True}


@router.post("/notifications/read-all")
async def mark_all_read(user: CurrentUser = Depends(get_current_user)) -> dict[str, bool]:
    async with plain_connection() as conn:
        await conn.execute(
            "UPDATE notification SET read_at = now() WHERE user_id = $1 AND read_at IS NULL",
            user.user_id,
        )
    return {"ok": True}