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

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

import logging

from app.database import 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("/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"}