from __future__ import annotations

import json
from typing import Any

import aiosqlite
from pywebpush import WebPushException, webpush

from server.db import utc_now_iso
from server.settings import settings


async def save_subscription(db: aiosqlite.Connection, sub: dict[str, Any]) -> None:
    keys = sub.get("keys", {})
    await db.execute(
        """
        INSERT INTO push_subscription (endpoint, p256dh, auth, created_at)
        VALUES (?, ?, ?, ?)
        ON CONFLICT(endpoint) DO UPDATE SET p256dh=excluded.p256dh, auth=excluded.auth
        """,
        (sub["endpoint"], keys.get("p256dh", ""), keys.get("auth", ""), utc_now_iso()),
    )
    await db.commit()


async def get_subscriptions(db: aiosqlite.Connection) -> list[dict[str, str]]:
    cur = await db.execute("SELECT endpoint, p256dh, auth FROM push_subscription")
    rows = await cur.fetchall()
    await cur.close()
    return [{"endpoint": r[0], "p256dh": r[1], "auth": r[2]} for r in rows]


def _vapid_claims() -> dict[str, str]:
    return {"sub": settings.vapid_claims_email}


async def send_push(
    db: aiosqlite.Connection,
    payload: dict[str, Any],
) -> int:
    if not settings.vapid_private_key or not settings.vapid_public_key:
        return 0

    subs = await get_subscriptions(db)
    sent = 0
    dead: list[str] = []

    for sub in subs:
        subscription = {
            "endpoint": sub["endpoint"],
            "keys": {"p256dh": sub["p256dh"], "auth": sub["auth"]},
        }
        try:
            webpush(
                subscription_info=subscription,
                data=json.dumps(payload),
                vapid_private_key=settings.vapid_private_key,
                vapid_claims=_vapid_claims(),
            )
            sent += 1
        except WebPushException as exc:
            if exc.response and exc.response.status_code in (404, 410):
                dead.append(sub["endpoint"])

    for endpoint in dead:
        await db.execute("DELETE FROM push_subscription WHERE endpoint = ?", (endpoint,))
    if dead:
        await db.commit()

    return sent


async def send_slot_reminder(
    db: aiosqlite.Connection,
    slot_id: str,
    title: str,
    body: str,
    *,
    silent: bool = True,
) -> int:
    payload = {
        "title": title,
        "body": body,
        "slot_id": slot_id,
        "silent": silent,
        "tag": f"med-{slot_id}",
    }
    return await send_push(db, payload)