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

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

import logging

from app.database import engine, get_db
from app.models.db_models import (
    Account,
    FilterAction,
    FilterCondition,
    FilterLog,
    FilterRule,
    LogLevel,
    ProcessedMail,
)
from app.schemas.schemas import FilterRuleCreate, FilterRuleResponse, FilterRuleUpdate

logger = logging.getLogger(__name__)


def _reset_processed_for_rule(db: Session, rule_id: int) -> int:
    """Reset processed mails for a specific rule so they get re-evaluated."""
    count = (
        db.query(ProcessedMail)
        .filter(ProcessedMail.rule_id == rule_id)
        .delete()
    )
    if count:
        logger.info("Filter geändert: %d verarbeitete Mails für Regel %d zurückgesetzt", count, rule_id)
    return count

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


@router.post("/reset-all-processed")
def reset_all_processed(db: Session = Depends(get_db)):
    """Setzt den 'verarbeitet'-Status ALLER Mails zurück — alle Regeln bewerten
    beim nächsten Poll wieder jede Mail im Ordner neu. Sicher, weil schon
    verschobene Mails nicht mehr in der Quelle liegen und daher nicht erneut
    verschoben werden können. Nutzt DROP+CREATE statt DELETE, damit auch
    bei Millionen Zeilen sekundenschnell."""
    try:
        row_count = db.query(ProcessedMail).count()
        db.close()  # Sitzung freigeben, damit DDL nicht am Lock hängt
        with engine.begin() as conn:
            ProcessedMail.__table__.drop(conn, checkfirst=True)
            ProcessedMail.__table__.create(conn, checkfirst=True)
            conn.execute(text("PRAGMA wal_checkpoint(TRUNCATE)"))
        logger.info("ProcessedMail vollständig zurückgesetzt (%d Einträge entfernt)", row_count)
        return {"reset": row_count}
    except Exception as e:
        logger.exception("reset-all-processed fehlgeschlagen")
        raise HTTPException(500, f"Fehler beim Zurücksetzen: {e}")


@router.post("/retry-failed")
def retry_failed_fetches(account_id: int | None = None, db: Session = Depends(get_db)):
    """Löscht ProcessedMail-Einträge für UIDs, für die es einen ERROR-Log
    mit 'Fehler beim Abrufen' gibt — damit der Scheduler sie beim nächsten
    Poll neu versucht (z.B. nach einem Codec-Fix)."""
    try:
        log_q = db.query(FilterLog.mail_uid, FilterLog.account_id).filter(
            FilterLog.level == LogLevel.ERROR,
            FilterLog.message.like("Fehler beim Abrufen%"),
            FilterLog.mail_uid.isnot(None),
        )
        if account_id is not None:
            log_q = log_q.filter(FilterLog.account_id == account_id)

        pairs = log_q.distinct().all()
        if not pairs:
            return {"reset": 0, "unique_uids": 0}

        # Bulk-Delete pro Account: alle UIDs in einem Query
        by_account: dict[int | None, set[str]] = {}
        for uid, acc_id in pairs:
            by_account.setdefault(acc_id, set()).add(uid)

        total = 0
        for acc_id, uids in by_account.items():
            q = db.query(ProcessedMail).filter(ProcessedMail.mail_uid.in_(list(uids)))
            if acc_id is not None:
                q = q.filter(ProcessedMail.account_id == acc_id)
            total += q.delete(synchronize_session=False)
        db.commit()
        unique_uids = sum(len(v) for v in by_account.values())
        logger.info(
            "Retry-Failed: %d ProcessedMail-Einträge für %d UIDs entfernt", total, unique_uids
        )
        return {"reset": total, "unique_uids": unique_uids}
    except Exception as e:
        logger.exception("retry-failed fehlgeschlagen")
        raise HTTPException(500, f"Fehler bei retry-failed: {e}")


@router.get("/account/{account_id}", response_model=list[FilterRuleResponse])
def list_filters(account_id: int, db: Session = Depends(get_db)):
    account = db.get(Account, account_id)
    if not account:
        raise HTTPException(404, "Konto nicht gefunden")
    rules = (
        db.query(FilterRule)
        .filter(FilterRule.account_id == account_id)
        .order_by(FilterRule.priority)
        .all()
    )
    return rules


@router.get("/{rule_id}", response_model=FilterRuleResponse)
def get_filter(rule_id: int, db: Session = Depends(get_db)):
    rule = db.get(FilterRule, rule_id)
    if not rule:
        raise HTTPException(404, "Filterregel nicht gefunden")
    return rule


@router.post("/", response_model=FilterRuleResponse, status_code=201)
def create_filter(data: FilterRuleCreate, db: Session = Depends(get_db)):
    account = db.get(Account, data.account_id)
    if not account:
        raise HTTPException(404, "Konto nicht gefunden")

    if data.priority is None:
        # Ans Ende einsortieren: max(priority) + 10 für dieses Konto. Falls noch
        # keine Regel existiert, starten wir bei 10.
        current_max = db.query(func.max(FilterRule.priority)).filter(
            FilterRule.account_id == data.account_id
        ).scalar()
        priority = (current_max + 10) if current_max is not None else 10
    else:
        priority = data.priority

    rule = FilterRule(
        account_id=data.account_id,
        name=data.name,
        priority=priority,
        enabled=data.enabled,
        stop_processing=data.stop_processing,
        source_folder=data.source_folder,
    )
    db.add(rule)
    db.flush()

    for cond_data in data.conditions:
        cond = FilterCondition(rule_id=rule.id, **cond_data.model_dump())
        db.add(cond)
    for action_data in data.actions:
        action = FilterAction(rule_id=rule.id, **action_data.model_dump())
        db.add(action)

    # Neue Regel → hat noch keinen processed-Status, wird automatisch alle Mails prüfen

    db.commit()
    db.refresh(rule)
    return rule


@router.put("/{rule_id}", response_model=FilterRuleResponse)
def update_filter(rule_id: int, data: FilterRuleUpdate, db: Session = Depends(get_db)):
    rule = db.get(FilterRule, rule_id)
    if not rule:
        raise HTTPException(404, "Filterregel nicht gefunden")

    update_data = data.model_dump(exclude_unset=True)

    # Update conditions if provided
    if "conditions" in update_data:
        for cond in rule.conditions:
            db.delete(cond)
        for cond_data in data.conditions:
            cond = FilterCondition(rule_id=rule.id, **cond_data.model_dump())
            db.add(cond)
        del update_data["conditions"]

    # Update actions if provided
    if "actions" in update_data:
        for action in rule.actions:
            db.delete(action)
        for action_data in data.actions:
            action = FilterAction(rule_id=rule.id, **action_data.model_dump())
            db.add(action)
        del update_data["actions"]

    for key, value in update_data.items():
        setattr(rule, key, value)

    # Regel geändert → nur diese Regel zurücksetzen
    _reset_processed_for_rule(db, rule.id)

    db.commit()
    db.refresh(rule)
    return rule


@router.delete("/{rule_id}", status_code=204)
def delete_filter(rule_id: int, db: Session = Depends(get_db)):
    rule = db.get(FilterRule, rule_id)
    if not rule:
        raise HTTPException(404, "Filterregel nicht gefunden")
    # processed-Einträge werden per CASCADE gelöscht
    db.delete(rule)
    db.commit()


@router.put("/reorder/{account_id}")
def reorder_filters(account_id: int, rule_ids: list[int], db: Session = Depends(get_db)):
    for priority, rule_id in enumerate(rule_ids):
        rule = db.get(FilterRule, rule_id)
        if rule and rule.account_id == account_id:
            rule.priority = priority
    db.commit()
    return {"message": "Reihenfolge aktualisiert"}