"""Worker RAR — proces propriu (NU task asyncio in uvicorn; plan.md sect. 4).

Bucla: heartbeat -> recupereaza orfane -> claim atomic -> login -> postPrezentare -> update.
Ruleaza ca proces separat sub `restart: always` (docker compose).

T2 implementat:
  - claim atomic anti-race (BEGIN IMMEDIATE), respecta next_attempt_at (backoff).
  - reconciliere anti-duplicat pe raspuns pierdut: pe eroare tranzitorie/timeout SAU pe
    rand 'sending' orfan (worker mort mid-POST), interogheaza finalizate si match pe
    vin+dataPrestatie+odometruFinal; daca exista -> 'sent' (NU re-trimite).
  - retry/backoff exponential pe erori tranzitorii; peste worker_max_retries -> 'error' (banner).
  - lease/timeout pe randuri 'sending' orfane.
  - re-login la token expirat (401 mid-sesiune) — JWT 30h, retry NU plafonat la 30h.

Creds per-cerere (plan sect. 5): fiecare submission poarta creds RAR CRIPTATE
(rar_creds_enc). Worker-ul face login per CONT cu acele creds, cache-uieste JWT
(30h) in memorie si STERGE creds-urile contului dupa primul login reusit. Token-ul
in memorie acopera restul trimiterilor; la restart token-ul se pierde si contul
re-loghează la urmatorul submission care aduce creds proaspete (degradare acceptata).
Dev: `worker_use_test_creds` foloseste creds <test> cand submission-ul nu are enc.

Ce NU e inca: criptare PII payload at-rest (P2), b64Image mare pe disc (P2).

Pornire:    python -m app.worker
"""

from __future__ import annotations

import json
import signal
import sys
import time
from datetime import datetime, timedelta, timezone

import httpx

from ..config import Settings, get_settings, load_test_credentials
from ..crypto import decrypt_creds
from ..db import get_connection, init_db, write_heartbeat
from ..mapping import DEFAULT_ACCOUNT_ID, upsert_nomenclator
from ..payload import build_rar_payload
from ..reconcile import match_finalizata
from ..rar_client import RarAuthError, RarClient, RarError

_running = True


def _stop(signum: int, frame: object) -> None:
    global _running
    _running = False


def _now() -> datetime:
    return datetime.now(timezone.utc)


def _iso(dt: datetime) -> str:
    return dt.isoformat(timespec="seconds")


def _backoff_seconds(settings: Settings, retry_count: int) -> int:
    return min(settings.worker_retry_base_s * (2 ** max(0, retry_count - 1)), settings.worker_retry_max_s)


def _is_transient(exc: Exception) -> bool:
    """Eroare in care POST-ul poate sa fi ajuns/sa nu fi ajuns la RAR -> reconciliere + retry."""
    if isinstance(exc, (httpx.TimeoutException, httpx.TransportError)):
        return True
    if isinstance(exc, RarError) and not isinstance(exc, RarAuthError):
        code = exc.status_code
        return code is None or code >= 500 or code in (408, 429)
    return False


# --- Operatii pe submissions ---

def mark(conn, submission_id: int, status: str, *, rar_status_code=None, rar_error=None, id_prezentare=None) -> None:
    if status == "sent":
        # T16: purge_after = sent + 90 zile (GDPR/L.142 retentie maxima).
        conn.execute(
            "UPDATE submissions SET status=?, rar_status_code=?, rar_error=?, id_prezentare=?, "
            "sending_since=NULL, updated_at=datetime('now'), "
            "purge_after=datetime('now', '+90 days') WHERE id=?",
            (status, rar_status_code, rar_error, id_prezentare, submission_id),
        )
    else:
        conn.execute(
            "UPDATE submissions SET status=?, rar_status_code=?, rar_error=?, id_prezentare=?, "
            "sending_since=NULL, updated_at=datetime('now') WHERE id=?",
            (status, rar_status_code, rar_error, id_prezentare, submission_id),
        )


# T16: purge interval in secunde (odata pe ora, nu prea agresiv)
_PURGE_INTERVAL_S = 3600


def purge_expired(conn) -> dict[str, int]:
    """Sterge randurile expirate (purge_after < now).

    T16/OV-5: purge_after era exportat dar setat de nimeni si niciun job nu exista.
    Acum: submissions sent + expirate, import_batches expirate (import_rows via CASCADE).
    Intoarce {submissions_purged, batches_purged}.
    """
    cur_sub = conn.execute(
        "DELETE FROM submissions WHERE purge_after IS NOT NULL AND purge_after < datetime('now') AND status='sent'"
    )
    cur_batch = conn.execute(
        "DELETE FROM import_batches WHERE purge_after IS NOT NULL AND purge_after < datetime('now')"
    )
    return {
        "submissions_purged": cur_sub.rowcount,
        "batches_purged": cur_batch.rowcount,
    }


def requeue_with_backoff(conn, settings: Settings, submission_id: int, *, reason: str) -> None:
    """Re-pune randul in coada cu retry++ si next_attempt_at = now + backoff."""
    row = conn.execute("SELECT retry_count FROM submissions WHERE id=?", (submission_id,)).fetchone()
    new_retry = int(row["retry_count"]) + 1 if row else 1
    if new_retry > settings.worker_max_retries:
        mark(conn, submission_id, "error", rar_error=f"esuat dupa {new_retry-1} reincercari: {reason}")
        print(f"[worker] submission {submission_id} -> error (max retries): {reason}", flush=True)
        return
    next_at = _iso(_now() + timedelta(seconds=_backoff_seconds(settings, new_retry)))
    conn.execute(
        "UPDATE submissions SET status='queued', retry_count=?, next_attempt_at=?, "
        "rar_error=?, sending_since=NULL, updated_at=datetime('now') WHERE id=?",
        (new_retry, next_at, reason, submission_id),
    )
    print(f"[worker] submission {submission_id} -> requeue (retry {new_retry}, next {next_at}): {reason}", flush=True)


def claim_one(conn) -> dict | None:
    """Claim atomic 'queued' -> 'sending', respectand next_attempt_at. Intoarce randul sau None.

    Randul include `account_id` si `rar_creds_enc` (creds RAR criptate) pentru
    login-ul per-cont din `run`.
    """
    conn.execute("BEGIN IMMEDIATE")
    try:
        row = conn.execute(
            "SELECT s.id, s.account_id, s.payload_json, s.rar_creds_enc "
            "FROM submissions s LEFT JOIN accounts a ON a.id = s.account_id "
            "WHERE s.status='queued' "
            "AND (s.next_attempt_at IS NULL OR s.next_attempt_at <= ?) "
            "AND COALESCE(a.active, 1) = 1 "
            "ORDER BY s.id LIMIT 1",
            (_iso(_now()),),
        ).fetchone()
        if not row:
            conn.execute("COMMIT")
            return None
        conn.execute(
            "UPDATE submissions SET status='sending', sending_since=datetime('now'), "
            "updated_at=datetime('now') WHERE id=?",
            (row["id"],),
        )
        conn.execute("COMMIT")
        return {
            "id": row["id"],
            "account_id": row["account_id"] if row["account_id"] is not None else DEFAULT_ACCOUNT_ID,
            "creds_enc": row["rar_creds_enc"],
            "content": json.loads(row["payload_json"]),
        }
    except Exception:
        conn.execute("ROLLBACK")
        raise


def reconcile_and_mark(conn, rar: RarClient, token: str, submission_id: int, content: dict) -> bool:
    """Cauta la RAR o prezentare deja inregistrata pentru acest continut. Marcheaza 'sent' daca exista.

    Intoarce True daca a gasit (si a marcat sent), False altfel.
    """
    finalizate = rar.get_finalizate(token)
    found_id = match_finalizata(
        finalizate,
        vin=content.get("vin", ""),
        data_prestatie=content.get("data_prestatie", ""),
        odometru_final=content.get("odometru_final"),
    )
    if found_id is not None:
        mark(conn, submission_id, "sent", rar_status_code=200, id_prezentare=found_id,
             rar_error="reconciliat (raspuns pierdut)")
        print(f"[worker] submission {submission_id} -> sent prin reconciliere (idPrezentare={found_id})", flush=True)
        return True
    return False


def process_one(conn, settings: Settings, rar: RarClient, token: str, claimed: dict) -> str:
    """Trimite o prezentare claimed. Intoarce starea finala (pentru teste/loguri)."""
    sid = claimed["id"]
    content = claimed["content"]
    payload = build_rar_payload(content)
    try:
        data = rar.post_prezentare(token, payload)
        mark(conn, sid, "sent", rar_status_code=200, id_prezentare=data.get("id"))
        print(f"[worker] submission {sid} -> sent (idPrezentare={data.get('id')})", flush=True)
        return "sent"
    except RarError as exc:
        if exc.status_code == 400:
            detail = json.dumps(exc.field_errors, ensure_ascii=False) if exc.field_errors else str(exc)
            mark(conn, sid, "needs_data", rar_status_code=400, rar_error=detail)
            print(f"[worker] submission {sid} -> needs_data: {detail}", flush=True)
            return "needs_data"
        if _is_transient(exc):
            return _handle_transient(conn, settings, rar, token, sid, content, str(exc))
        # 4xx nerecuperabil (nu 400/401/408/429) -> error.
        mark(conn, sid, "error", rar_status_code=exc.status_code, rar_error=str(exc))
        print(f"[worker] submission {sid} -> error: {exc}", flush=True)
        return "error"
    except (httpx.TimeoutException, httpx.TransportError) as exc:
        return _handle_transient(conn, settings, rar, token, sid, content, f"retea: {exc}")


def _handle_transient(conn, settings: Settings, rar: RarClient, token: str, sid: int, content: dict, reason: str) -> str:
    """Eroare ambigua: POST-ul poate sa fi ajuns la RAR. Reconciliaza intai; altfel retry/backoff."""
    try:
        if reconcile_and_mark(conn, rar, token, sid, content):
            return "sent"
    except RarError as exc:
        # Reconcilierea insasi a esuat -> nu putem confirma; tratam ca tranzitoriu si retry.
        reason = f"{reason}; reconciliere esuata: {exc}"
    requeue_with_backoff(conn, settings, sid, reason=reason)
    return "requeued"


def recover_orphans(conn, settings: Settings, rar: RarClient, token: str, account_id: int | None = None) -> int:
    """Randuri 'sending' mai vechi de lease (worker mort mid-POST). Reconciliaza; altfel requeue.

    `account_id` filtreaza la orfanii unui cont (login-ul e per-cont); None = toti
    (compat teste / single-account).
    """
    cutoff = _iso(_now() - timedelta(seconds=settings.worker_sending_lease_s))
    if account_id is not None:
        orphans = conn.execute(
            "SELECT id, payload_json FROM submissions WHERE status='sending' "
            "AND (sending_since IS NULL OR sending_since <= ?) AND account_id=?",
            (cutoff, account_id),
        ).fetchall()
    else:
        orphans = conn.execute(
            "SELECT id, payload_json FROM submissions WHERE status='sending' "
            "AND (sending_since IS NULL OR sending_since <= ?)",
            (cutoff,),
        ).fetchall()
    recovered = 0
    for row in orphans:
        sid = row["id"]
        content = json.loads(row["payload_json"])
        try:
            if reconcile_and_mark(conn, rar, token, sid, content):
                recovered += 1
            else:
                # Nu e la RAR -> sigur de re-trimis.
                requeue_with_backoff(conn, settings, sid, reason="orfan recuperat (nu exista la RAR)")
                recovered += 1
        except RarError as exc:
            print(f"[worker] orfan {sid}: reconciliere esuata ({exc}); il las pentru data viitoare", flush=True)
    return recovered


def _queue_depth(conn) -> int:
    row = conn.execute("SELECT COUNT(*) AS n FROM submissions WHERE status='queued'").fetchone()
    return int(row["n"]) if row else 0


def _refresh_nomenclator(conn, rar: RarClient, token: str) -> None:
    """Ia nomenclatorul live din RAR si il upsert-eaza local. Erorile NU opresc worker-ul."""
    try:
        items = rar.get_nomenclator(token)
        n = upsert_nomenclator(conn, items)
        print(f"[worker] nomenclator refresh: {n} coduri", flush=True)
    except Exception as exc:  # noqa: BLE001 — refresh best-effort, nu blocheaza trimiterea
        print(f"[worker] nomenclator refresh esuat (continui): {exc}", flush=True)


class AccountSessions:
    """Sesiuni RAR per cont: login lazy cu creds din submission + cache JWT (30h).

    La primul login reusit pentru un cont sterge creds-urile criptate ale contului
    (token-ul in memorie acopera restul). Pe 401 mid-sesiune se invalideaza sesiunea
    -> re-login la urmatorul submission cu creds.
    """

    def __init__(self, settings: Settings):
        self.settings = settings
        self._sessions: dict[int, tuple[RarClient, str]] = {}

    def get_token(self, conn, account_id: int, creds: dict | None) -> str | None:
        """Token valid pentru cont. Login daca lipseste din cache si avem creds; altfel None."""
        sess = self._sessions.get(account_id)
        if sess is not None:
            return sess[1]
        if not creds or not creds.get("email") or not creds.get("password"):
            return None
        rar = RarClient(self.settings)
        try:
            token = rar.login(creds["email"], creds["password"])
        except Exception:
            rar.close()
            raise
        self._sessions[account_id] = (rar, token)
        write_heartbeat(conn, rar_login_ok=True, detail=f"login RAR ok (cont {account_id})")
        # Creds efemere pe submissions nu mai sunt necesare: JWT acopera retry-urile -> sterge.
        # GATE PURJARE (T1/Voce#5): sterge DOAR submissions.rar_creds_enc, NU accounts.rar_creds_enc.
        # Canal web: fallback exista in accounts -> purjarea e inofensiva (re-login dupa restart).
        # Canal API pur: purjarea e identica cu Treapta 1 (neatinsa).
        conn.execute(
            "UPDATE submissions SET rar_creds_enc=NULL WHERE account_id=? AND rar_creds_enc IS NOT NULL",
            (account_id,),
        )
        # Nomenclator live (autoritativ) la fiecare login proaspat.
        _refresh_nomenclator(conn, rar, token)
        return token

    def rar(self, account_id: int) -> RarClient:
        return self._sessions[account_id][0]

    def active(self) -> list[tuple[int, RarClient, str]]:
        return [(acct, rar, tok) for acct, (rar, tok) in self._sessions.items()]

    def invalidate(self, account_id: int) -> None:
        sess = self._sessions.pop(account_id, None)
        if sess is not None:
            sess[0].close()

    def close_all(self) -> None:
        for rar, _tok in self._sessions.values():
            rar.close()
        self._sessions.clear()


def _creds_for(claimed: dict, settings: Settings) -> dict | None:
    """Creds pentru un submission: decripteaza enc-ul lipit; altfel creds <test> (dev)."""
    creds = decrypt_creds(claimed.get("creds_enc"))
    if creds:
        return creds
    if settings.worker_use_test_creds:
        return load_test_credentials()
    return None


def _creds_from_account(conn, account_id: int) -> dict | None:
    """Fallback T1/D4: crede RAR durabile per-cont din accounts.rar_creds_enc.

    Canal web nu are re-pusher. Cand submission n-are creds (sterse dupa primul login
    sau upload web fara creds), worker-ul re-citeste din cont si poate re-login oricand.
    """
    row = conn.execute(
        "SELECT rar_creds_enc FROM accounts WHERE id=?", (account_id,)
    ).fetchone()
    if row and row["rar_creds_enc"]:
        return decrypt_creds(row["rar_creds_enc"])
    return None


def run() -> int:
    signal.signal(signal.SIGTERM, _stop)
    signal.signal(signal.SIGINT, _stop)

    settings = get_settings()
    init_db()
    conn = get_connection()
    print(f"[worker] pornit (send_enabled={settings.worker_send_enabled}, env={settings.rar_env})", flush=True)

    sessions = AccountSessions(settings)
    _last_purge_time: float = 0.0

    while _running:
        try:
            write_heartbeat(conn, detail=f"poll (queue={_queue_depth(conn)})")

            # T16: purjare periodica (odata pe ora) — NU mai frecvent.
            now_ts = time.time()
            if now_ts - _last_purge_time >= _PURGE_INTERVAL_S:
                stats = purge_expired(conn)
                if stats["submissions_purged"] or stats["batches_purged"]:
                    print(
                        f"[worker] purjare: {stats['submissions_purged']} submissions, "
                        f"{stats['batches_purged']} batches sterse",
                        flush=True,
                    )
                _last_purge_time = now_ts

            if not settings.worker_send_enabled:
                time.sleep(settings.worker_poll_interval_s)
                continue

            claimed = claim_one(conn)
            if claimed is None:
                # Nimic de trimis: recupereaza orfanii conturilor deja logate.
                for acct, rar, tok in sessions.active():
                    recover_orphans(conn, settings, rar, tok, account_id=acct)
                time.sleep(settings.worker_poll_interval_s)
                continue

            sid = claimed["id"]
            account_id = claimed["account_id"]
            # T1/D4: incearca creds din submission (canal API efemer), cu fallback la
            # accounts.rar_creds_enc (canal web durabil). Canal web n-are re-pusher.
            creds = _creds_for(claimed, settings) or _creds_from_account(conn, account_id)

            try:
                token = sessions.get_token(conn, account_id, creds)
            except RarAuthError as exc:
                # Creds gresite (login 401): NU se face retry (plan, failure registry).
                mark(conn, sid, "error", rar_status_code=401, rar_error="credentiale RAR invalide")
                print(f"[worker] submission {sid} (cont {account_id}) -> error: {exc}", flush=True)
                continue

            if token is None:
                # Fara creds disponibile (token pierdut la restart + creds sterse).
                # Re-pune in coada cu backoff; ROAAUTO re-trimite creds proaspete.
                requeue_with_backoff(conn, settings, sid, reason="creds RAR indisponibile (astept re-trimitere)")
                continue

            rar = sessions.rar(account_id)
            # Recupereaza orfanii contului inainte de trimitere (acelasi token).
            recover_orphans(conn, settings, rar, token, account_id=account_id)
            try:
                process_one(conn, settings, rar, token, claimed)
            except RarAuthError as exc:
                # Token expirat mid-sesiune: invalideaza sesiunea, re-pune randul.
                print(f"[worker] cont {account_id} token expirat: {exc}; re-login data viitoare", flush=True)
                sessions.invalidate(account_id)
                requeue_with_backoff(conn, settings, sid, reason="token RAR expirat")

        except Exception as exc:  # noqa: BLE001 — loop top-level: o eroare punctuala nu opreste worker-ul
            print(f"[worker] eroare neasteptata: {exc}", flush=True)
            time.sleep(settings.worker_poll_interval_s)

    sessions.close_all()
    conn.close()
    print("[worker] oprit curat", flush=True)
    return 0


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