"""sortof download_jobs drainer.

Long-running asyncio loop that claims queued jobs from download_jobs,
calls worker.process_one() to materialize mod_parsed rows via
DepotDownloader, and updates job status. Single connection per process;
multiple instances are safe because claims use FOR UPDATE SKIP LOCKED.

Manual requeue (after a transient failure):
    UPDATE download_jobs
    SET status='queued', attempts=0, error=NULL
    WHERE id='<uuid>';

Bulk requeue everything that hit MAX_ATTEMPTS:
    UPDATE download_jobs
    SET status='queued', attempts=0, error=NULL
    WHERE status='failed';
"""

from __future__ import annotations

import asyncio
import logging
import os
import signal
import sys
import time
import urllib.parse
from pathlib import Path

import asyncpg
from dotenv import load_dotenv

from worker import (
    DEFAULT_DD_PATH,
    fetch_workshop_details,
    process_one,
)

ENV_PATH = Path(__file__).resolve().parent.parent / ".env"

IDLE_SLEEP_S = 5
HEARTBEAT_S = 60
BATCH_SIZE = 1
MAX_ATTEMPTS = 5
STALE_RECLAIM_MIN = 30

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s %(levelname)s %(name)s %(message)s",
)
log = logging.getLogger("sortof.drain")


CLAIM_SQL = """
UPDATE download_jobs
SET status='downloading', attempts=attempts+1, updated_at=now()
WHERE id IN (
    SELECT id FROM download_jobs
    WHERE status='queued' AND attempts < $1
    ORDER BY priority DESC, created_at ASC
    LIMIT $2
    FOR UPDATE SKIP LOCKED
)
RETURNING id, workshop_id, attempts
"""

RECLAIM_SQL = f"""
UPDATE download_jobs
SET status='queued', updated_at=now()
WHERE status='downloading'
  AND updated_at < now() - interval '{STALE_RECLAIM_MIN} minutes'
RETURNING id
"""

DEPTH_SQL = """
SELECT COUNT(*) FROM download_jobs
WHERE status='queued' AND attempts < $1
"""

DONE_SQL = """
UPDATE download_jobs
SET status='done', completed_at=now(), updated_at=now(), error=NULL
WHERE id=$1
"""

FAIL_SQL = """
UPDATE download_jobs
SET status='failed', updated_at=now(), error=$2
WHERE id=$1
"""


def build_dsn() -> str:
    load_dotenv(ENV_PATH)
    explicit = os.environ.get("DATABASE_URL")
    if explicit:
        return explicit
    user = os.environ["POSTGRES_USER"]
    pw = urllib.parse.quote(os.environ["POSTGRES_PASSWORD"], safe="")
    name = os.environ["POSTGRES_DB"]
    host = os.environ.get("POSTGRES_HOST", "127.0.0.1")
    port = os.environ.get("POSTGRES_PORT", "5439")
    return f"postgresql://{user}:{pw}@{host}:{port}/{name}"


def resolve_dd_path() -> Path:
    """Resolve the DepotDownloader binary or fail loudly.

    Order of precedence: $DD_PATH env var, then worker.py's argparse
    default (DEFAULT_DD_PATH).
    """
    candidates: list[Path] = []
    env_dd = os.environ.get("DD_PATH")
    if env_dd:
        candidates.append(Path(env_dd))
    candidates.append(Path(DEFAULT_DD_PATH))
    for p in candidates:
        if p.is_file():
            return p
    raise RuntimeError(
        "DepotDownloader not found. Tried: "
        + ", ".join(str(c) for c in candidates)
        + ". Set DD_PATH or place the binary at the default path."
    )


async def reclaim_stale(conn: asyncpg.Connection) -> int:
    rows = await conn.fetch(RECLAIM_SQL)
    return len(rows)


async def claim_batch(conn: asyncpg.Connection, n: int):
    return await conn.fetch(CLAIM_SQL, MAX_ATTEMPTS, n)


async def queue_depth(conn: asyncpg.Connection) -> int:
    return await conn.fetchval(DEPTH_SQL, MAX_ATTEMPTS)


async def mark_done(conn: asyncpg.Connection, job_id) -> None:
    await conn.execute(DONE_SQL, job_id)


async def mark_failed(conn: asyncpg.Connection, job_id, msg: str) -> None:
    await conn.execute(FAIL_SQL, job_id, msg[:500])


async def run() -> int:
    dd_path = resolve_dd_path()  # raises before opening DB if missing

    dsn = build_dsn()
    conn = await asyncpg.connect(dsn=dsn)

    stop = asyncio.Event()
    loop = asyncio.get_running_loop()

    def _handle(sig: signal.Signals):
        log.info("drain shutting down (signal=%s)", sig.name)
        stop.set()

    for s in (signal.SIGTERM, signal.SIGINT):
        loop.add_signal_handler(s, _handle, s)

    try:
        n_reclaimed = await reclaim_stale(conn)
        log.info(
            "drain starting, reclaimed %d stale, dd_path=%s",
            n_reclaimed, dd_path,
        )

        last_heartbeat = 0.0
        while not stop.is_set():
            rows = await claim_batch(conn, BATCH_SIZE)

            if not rows:
                now = time.monotonic()
                if now - last_heartbeat >= HEARTBEAT_S:
                    depth = await queue_depth(conn)
                    log.info("idle, queue depth=%d", depth)
                    last_heartbeat = now
                try:
                    await asyncio.wait_for(stop.wait(), timeout=IDLE_SLEEP_S)
                except asyncio.TimeoutError:
                    pass
                continue

            ids = [r["workshop_id"] for r in rows]
            try:
                details = await asyncio.to_thread(fetch_workshop_details, ids)
            except Exception as e:
                log.warning("steam fetch failed: %s", e)
                for r in rows:
                    await mark_failed(conn, r["id"], "steam fetch error")
                continue

            for r in rows:
                wid = r["workshop_id"]
                attempt = r["attempts"]
                log.info("claimed wsid=%s attempt=%d", wid, attempt)
                detail = details.get(wid)
                if not detail or detail.get("result") != 1:
                    reason = (
                        f"steam result={detail.get('result') if detail else 'none'}"
                    )
                    log.info("failed wsid=%s reason=%s", wid, reason)
                    await mark_failed(conn, r["id"], reason)
                    continue
                try:
                    outcome = await process_one(conn, wid, detail, dd_path, False)
                except Exception as e:
                    log.exception("drain exception wsid=%s", wid)
                    await mark_failed(conn, r["id"], str(e)[:500])
                    continue
                if outcome in ("hit", "refreshed"):
                    log.info("done wsid=%s outcome=%s", wid, outcome)
                    await mark_done(conn, r["id"])
                else:
                    reason = f"process_one={outcome}"
                    log.info("failed wsid=%s reason=%s", wid, reason)
                    await mark_failed(conn, r["id"], reason)
    finally:
        await conn.close()
        log.info("drain stopped")

    return 0


if __name__ == "__main__":
    sys.exit(asyncio.run(run()))