from typing import Optional, List
from datetime import datetime
from fastapi import APIRouter, Depends, Query
from sqlalchemy.orm import Session

from app.core.database import SessionLocal
from app.core.auth import get_current_user, requires_role
from app.models.user import User
from app.models.audit_log import AuditLog
from app.schemas.audit_log import AuditLogOut

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

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()

def _ts_col():
    # vorhandene Zeitspalte wählen, sonst Fallback auf id
    return (
        getattr(AuditLog, "created_at", None)
        or getattr(AuditLog, "timestamp", None)
        or getattr(AuditLog, "created", None)
        or AuditLog.id
    )

@router.get("/", response_model=List[AuditLogOut], dependencies=[Depends(requires_role("admin"))])
def list_audit_logs(
    limit: int = Query(100, ge=1, le=1000),
    offset: int = Query(0, ge=0),
    user_id: Optional[int] = Query(None, ge=1),
    action: Optional[str] = Query(None),
    q: Optional[str] = Query(None),
    date_from: Optional[str] = Query(None),
    date_to: Optional[str] = Query(None),
    db: Session = Depends(get_db),
    _: User = Depends(get_current_user),
):
    qs = db.query(AuditLog)

    if user_id is not None:
        qs = qs.filter(AuditLog.user_id == user_id)
    if action:
        qs = qs.filter(AuditLog.action == action)

    if q and hasattr(AuditLog, "info"):
        like = f"%{q}%"
        qs = qs.filter(AuditLog.info.ilike(like))

    ts = _ts_col()

    # ISO-Zeiten robust parsen
    def _parse_iso(s: Optional[str]) -> Optional[datetime]:
        if not s:
            return None
        try:
            return datetime.fromisoformat(s.replace("Z", "+00:00"))
        except Exception:
            return None

    dtf = _parse_iso(date_from)
    dtt = _parse_iso(date_to)

    if dtf is not None and ts is not AuditLog.id:
        qs = qs.filter(ts >= dtf)
    if dtt is not None and ts is not AuditLog.id:
        qs = qs.filter(ts <= dtt)

    qs = qs.order_by(ts.desc(), AuditLog.id.desc()).limit(limit).offset(offset)
    return qs.all()