imap-mail-filter-service/app/routers/logs.py

import logging
from datetime import datetime

from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy import or_, text
from sqlalchemy.orm import Session

from app.database import engine, get_db
from app.models.db_models import FilterLog, LogLevel

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/logs", tags=["logs"])

# Obergrenze fürs Zählen: exakte Zahlen über Millionen Zeilen kosten Sekunden,
# für die Anzeige reicht "mehr als 1.000".
COUNT_CAP = 1000


def _like(value: str) -> str:
    escaped = value.replace("\\", "\\\\").replace("%", "\\%").replace("_", "\\_")
    return f"%{escaped}%"


def _parse_ts(value: str | None) -> datetime | None:
    if not value:
        return None
    try:
        # Browser schickt ISO mit 'Z' (UTC) — DB speichert naive UTC
        return datetime.fromisoformat(value.replace("Z", "+00:00")).replace(tzinfo=None)
    except ValueError:
        raise HTTPException(400, f"Ungültiges Datum: {value}")


@router.get("/")
def get_logs(
    account_id: int | None = None,
    level: str | None = Query(default=None, description="Kommagetrennt: success,info,warning,error"),
    q: str | None = Query(default=None, description="Freitext über alle Felder"),
    sender: str | None = None,
    subject: str | None = None,
    rule: str | None = None,
    folder: str | None = None,
    message: str | None = None,
    since: str | None = None,
    until: str | None = None,
    before_id: int | None = Query(default=None, description="Für 'Mehr laden': nur Einträge älter als diese ID"),
    limit: int = Query(default=100, ge=1, le=500),
    db: Session = Depends(get_db),
):
    """Neueste zuerst, geblättert per before_id (Keyset) statt OFFSET: jede Seite
    ist gleich schnell, egal wie weit man zurückblättert."""
    query = db.query(FilterLog)
    if account_id:
        query = query.filter(FilterLog.account_id == account_id)
    if level:
        levels = []
        for part in level.split(","):
            try:
                levels.append(LogLevel(part.strip()))
            except ValueError:
                raise HTTPException(400, f"Unbekanntes Level: {part}")
        query = query.filter(FilterLog.level.in_(levels))
    ts_since, ts_until = _parse_ts(since), _parse_ts(until)
    if ts_since:
        query = query.filter(FilterLog.created_at >= ts_since)
    if ts_until:
        query = query.filter(FilterLog.created_at < ts_until)

    # Freitext: jedes Wort muss in irgendeinem Feld vorkommen
    if q:
        for word in q.split():
            pat = _like(word)
            query = query.filter(or_(
                FilterLog.message.ilike(pat, escape="\\"),
                FilterLog.mail_subject.ilike(pat, escape="\\"),
                FilterLog.mail_from.ilike(pat, escape="\\"),
                FilterLog.rule_name.ilike(pat, escape="\\"),
                FilterLog.details.ilike(pat, escape="\\"),
                FilterLog.folder.ilike(pat, escape="\\"),
            ))
    for column, value in (
        (FilterLog.mail_from, sender),
        (FilterLog.mail_subject, subject),
        (FilterLog.rule_name, rule),
        (FilterLog.message, message),
    ):
        if value:
            query = query.filter(column.ilike(_like(value), escape="\\"))
    if folder:
        # Quellordner steht in folder, das Ziel einer Verschiebe-Aktion in details
        pat = _like(folder)
        query = query.filter(or_(
            FilterLog.folder.ilike(pat, escape="\\"),
            (FilterLog.action_type == "move") & FilterLog.details.ilike(pat, escape="\\"),
        ))

    count_query = query
    if before_id:
        query = query.filter(FilterLog.id < before_id)

    rows = query.order_by(FilterLog.id.desc()).limit(limit + 1).all()
    has_more = len(rows) > limit
    rows = rows[:limit]

    # Treffermenge nur bis COUNT_CAP zählen (und nur für die erste Seite)
    total = None
    if before_id is None:
        total = count_query.with_entities(FilterLog.id).limit(COUNT_CAP + 1).count()

    return {
        "total": total,
        "total_capped": total is not None and total > COUNT_CAP,
        "has_more": has_more,
        "next_before_id": rows[-1].id if rows and has_more else None,
        "logs": [
            {
                "id": log.id,
                "account_id": log.account_id,
                "account_name": log.account_name,
                "level": log.level.value if log.level else "info",
                "message": log.message,
                "rule_name": log.rule_name,
                "action_type": log.action_type,
                "mail_uid": log.mail_uid,
                "mail_subject": log.mail_subject,
                "mail_from": log.mail_from,
                "folder": log.folder,
                "details": log.details,
                "created_at": log.created_at.isoformat() if log.created_at else None,
            }
            for log in rows
        ],
    }


@router.delete("/")
def clear_logs(account_id: int | None = None, db: Session = Depends(get_db)):
    """Löscht Logs. Ohne account_id: schnelles Drop+Recreate der Tabelle
    (sekundenschnell auch bei Millionen Zeilen). Mit account_id: normales DELETE."""
    try:
        if account_id is None:
            # Vollständiges Leeren: DROP+CREATE statt DELETE.
            # DELETE FROM filter_logs würde jede Zeile einzeln ins WAL schreiben,
            # bei Millionen Einträgen dauert das ewig und blockiert die DB.
            db.close()  # Sitzung freigeben, sonst holds sie noch Locks
            row_count = 0
            with engine.begin() as conn:
                row_count = conn.execute(text("SELECT COUNT(*) FROM filter_logs")).scalar() or 0
                FilterLog.__table__.drop(conn, checkfirst=True)
                FilterLog.__table__.create(conn, checkfirst=True)
                # PRAGMA wal_checkpoint(TRUNCATE) räumt die WAL-Datei auf
                conn.execute(text("PRAGMA wal_checkpoint(TRUNCATE)"))
            logger.info("Log vollständig geleert (%d Einträge, Tabelle neu angelegt)", row_count)
            return {"deleted": row_count}

        count = db.query(FilterLog).filter(FilterLog.account_id == account_id).delete()
        db.commit()
        return {"deleted": count}
    except Exception as e:
        logger.exception("clear_logs fehlgeschlagen")
        raise HTTPException(500, f"Fehler beim Leeren des Logs: {e}")