import json
from typing import Any

import asyncpg

JOBS_CHANGED_CHANNEL = "jobs_changed"


async def enqueue(
    pool: asyncpg.Pool, account_id: int, kind: str, params: dict[str, Any]
) -> int:
    params_json = json.dumps(params)
    existing = await pool.fetchval(
        "SELECT id FROM jobs WHERE account_id = $1 AND kind = $2 "
        "AND params = $3::jsonb AND status IN ('pending', 'running') LIMIT 1",
        account_id,
        kind,
        params_json,
    )
    if existing is not None:
        return existing
    job_id = await pool.fetchval(
        "INSERT INTO jobs (account_id, kind, params) "
        "VALUES ($1, $2, $3::jsonb) RETURNING id",
        account_id,
        kind,
        params_json,
    )
    await pool.execute(f"NOTIFY {JOBS_CHANGED_CHANNEL}")
    return job_id