#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Name:        app/core/qdrant.py
Version:     v1.3.1 (2025-09-05)

Kurzbeschreibung:
  Qdrant-Client & Collection-Setup für mindnet.
  - Stellt sicher, dass {prefix}_notes / {prefix}_chunks / {prefix}_edges existieren.
  - Edges-Collection nutzt 1D Dummy-Vektor (Workaround für Python-Client).
  - **Nicht-destruktiv per Default**: ensure_collections(..., destructive=False).
  - **Abwärtskompatibel**: collection_names(prefix) wieder verfügbar.

Aufruf/Verwendung:
  from app.core.qdrant import QdrantConfig, get_client, ensure_collections, collection_names

Umgebungsvariablen (optional):
  QDRANT_URL | QDRANT_HOST/QDRANT_PORT, QDRANT_API_KEY,
  COLLECTION_PREFIX (Default "mindnet"), VECTOR_DIM (Default 384)

Änderungen:
  v1.3.1: Helper collection_names(prefix) wiederhergestellt (für reset_qdrant usw.).
  v1.3.0: ensure_collections(..., destructive=False) – keine stillen Drops im Dry-Run.
          Edges-Collection nur bei explicit destructive=True neu anlegen.
  ≤v1.2.x: Konnte {prefix}_edges bei fehlender VectorConfig automatisch neu erstellen (riskant).

Bezug/Quelle:
  Alte Core-Variante enthielt collection_names(prefix); diverse Scripts nutzen das weiterhin. :contentReference[oaicite:1]{index=1}
"""
from __future__ import annotations
import os
from dataclasses import dataclass
from typing import Optional, Tuple

from qdrant_client import QdrantClient
from qdrant_client.http import models as rest


# -------------------------------
# Konfiguration
# -------------------------------

@dataclass
class QdrantConfig:
    url: str
    api_key: Optional[str]
    prefix: str
    dim: int

    @staticmethod
    def from_env() -> "QdrantConfig":
        url = os.getenv("QDRANT_URL")
        if not url:
            host = os.getenv("QDRANT_HOST", "127.0.0.1")
            port = int(os.getenv("QDRANT_PORT", "6333"))
            url = f"http://{host}:{port}"
        api_key = os.getenv("QDRANT_API_KEY") or None
        prefix = os.getenv("COLLECTION_PREFIX", "mindnet")
        dim = int(os.getenv("VECTOR_DIM", "384"))
        return QdrantConfig(url=url, api_key=api_key, prefix=prefix, dim=dim)


# -------------------------------
# Client
# -------------------------------

def get_client(cfg: QdrantConfig) -> QdrantClient:
    return QdrantClient(url=cfg.url, api_key=cfg.api_key)


# -------------------------------
# Collection-Erzeuger (Hilfsfunktionen)
# -------------------------------

def _create_notes(client: QdrantClient, name: str, dim: int) -> None:
    if not client.collection_exists(name):
        client.create_collection(
            collection_name=name,
            vectors_config=rest.VectorParams(size=dim, distance=rest.Distance.COSINE),
        )

def _create_chunks(client: QdrantClient, name: str, dim: int) -> None:
    if not client.collection_exists(name):
        client.create_collection(
            collection_name=name,
            vectors_config=rest.VectorParams(size=dim, distance=rest.Distance.COSINE),
        )

def _create_edges(client: QdrantClient, name: str) -> None:
    if not client.collection_exists(name):
        client.create_collection(
            collection_name=name,
            vectors_config=rest.VectorParams(size=1, distance=rest.Distance.DOT),  # 1D-Dummy
        )


# -------------------------------
# Public API
# -------------------------------

def ensure_collections(client: QdrantClient, prefix: str, dim: int, destructive: bool = False) -> None:
    """
    Stellt sicher, dass die drei Collections existieren.
    - Default **nicht destruktiv**: vorhandene Collections bleiben unangetastet.
    - Nur wenn 'destructive=True', wird eine ungeeignete Edges-Collection gelöscht und neu angelegt.
    """
    notes = f"{prefix}_notes"
    chunks = f"{prefix}_chunks"
    edges = f"{prefix}_edges"

    _create_notes(client, notes, dim)
    _create_chunks(client, chunks, dim)

    if client.collection_exists(edges):
        # Prüfen, ob die Edges-Collection bereits eine Vektorkonfig hat
        try:
            info = client.get_collection(edges)
            vectors_cfg = getattr(getattr(info.result, "config", None), "params", None)
            has_vectors = getattr(vectors_cfg, "vectors", None) is not None
        except Exception:
            # konservativ: nichts anfassen, um Datenverlust zu vermeiden
            has_vectors = True

        if not has_vectors:
            if destructive:
                client.delete_collection(edges)
                _create_edges(client, edges)
            else:
                print(
                    f"[ensure_collections] WARN: '{edges}' ohne VectorConfig gefunden; "
                    f"keine destruktive Änderung (destructive=False).",
                    flush=True,
                )
    else:
        _create_edges(client, edges)


def collection_names(prefix: str) -> Tuple[str, str, str]:
    """
    Abwärtskompatibler Helper für Scripts:
      returns (f"{prefix}_notes", f"{prefix}_chunks", f"{prefix}_edges")
    """
    return (f"{prefix}_notes", f"{prefix}_chunks", f"{prefix}_edges")


def wipe_collections(client: QdrantClient, prefix: str) -> None:
    """
    Löscht alle drei Collections – nur verwenden, wenn bewusst ein Clean-Rebuild gewünscht ist.
    """
    for name in collection_names(prefix):
        if client.collection_exists(name):
            client.delete_collection(name)