#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Name:        app/core/qdrant.py
Version:     v1.7.0 (2025-11-08)

Kurzbeschreibung
  Qdrant-Client & Collection-Setup für mindnet.
  - Stellt sicher, dass {prefix}_notes / {prefix}_chunks / {prefix}_edges existieren.
  - Edges-Collection nutzt 1D Dummy-Vektor (kein Such-Usecase).
  - Legt sinnvolle Payload-Indizes an.
  - Liefert zähl-/list-/fetch-Helfer, die von Importer/Exporter/Tests genutzt werden.

Änderungsverlauf (Relevantes)
  v1.5.0:
    * ensure_collections_for_prefix(...)  → Wrapper für legacy-Importer
    * count_points(client, collection)    → stabile Zählfunktion (mit Fallback)
    * get_counts_for_prefix(...)          → Summary über alle drei Collections
    * truncate_collections(...)           → alle Punkte löschen (Collections bleiben)
  v1.6.0:
    * list_note_ids(client, notes_collection) → alle payload.note_id (unique)
  v1.7.0:
    * fetch_one_note(client, notes_collection, note_id, with_vectors=False)
      → von import_markdown v3.9.0 erwartet; liefert (point_id, payload, vector?)

Öffentliche API
  from app.core.qdrant import (
      QdrantConfig, get_client,
      ensure_collections, ensure_payload_indexes,
      ensure_collections_for_prefix, collection_names,
      count_points, get_counts_for_prefix, truncate_collections,
      list_note_ids, fetch_one_note,
  )
"""
from __future__ import annotations

import os
from dataclasses import dataclass
from typing import Optional, Tuple, Dict, List, Any

from qdrant_client import QdrantClient
from qdrant_client.http import models as rest
from app.core.env_vars import get_collection_prefix


# ---------------------------------------------------------
# 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)


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


# ---------------------------------------------------------
# Collection-Erstellung
# ---------------------------------------------------------
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
        )


def ensure_collections(client: QdrantClient, prefix: str, dim: int, destructive: bool = False) -> None:
    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):
        # Robustheit: Prüfen, ob eine VectorConfig existiert; falls nicht → optional neu erstellen
        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:
            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; destructive=False.", flush=True)
    else:
        _create_edges(client, edges)


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


# ---------------------------------------------------------
# Payload-Indizes
# ---------------------------------------------------------
def _safe_create_index(client: QdrantClient, col: str, field: str, schema: rest.PayloadSchemaType) -> None:
    try:
        client.create_payload_index(collection_name=col, field_name=field, field_schema=schema)
    except Exception:
        # bereits vorhanden oder Schema nicht unterstützt → ignorieren
        pass


def ensure_payload_indexes(client: QdrantClient, prefix: str) -> None:
    notes, chunks, edges = collection_names(prefix)
    # Notes
    _safe_create_index(client, notes, "note_id", rest.PayloadSchemaType.KEYWORD)
    # Chunks
    _safe_create_index(client, chunks, "note_id", rest.PayloadSchemaType.KEYWORD)
    _safe_create_index(client, chunks, "chunk_index", rest.PayloadSchemaType.INTEGER)
    _safe_create_index(client, chunks, "chunk_id", rest.PayloadSchemaType.KEYWORD)
    # Edges
    for f in ("kind", "scope", "source_id", "target_id", "note_id", "edge_id"):
        _safe_create_index(client, edges, f, rest.PayloadSchemaType.KEYWORD)


# ---------------------------------------------------------
# Zähl-/Listen-/Maintenance-Helfer
# ---------------------------------------------------------
def ensure_collections_for_prefix(
    client: QdrantClient, prefix: str, dim: int, destructive: bool = False
) -> Tuple[str, str, str]:
    """
    Legacy-Wrapper (Kompatibilität zu älteren Skripten).
    """
    ensure_collections(client, prefix, dim, destructive=destructive)
    ensure_payload_indexes(client, prefix)
    return collection_names(prefix)


def count_points(client: QdrantClient, collection: str) -> int:
    """
    Zähle Punkte robust:
      1) bevorzugt count(exact=True)
      2) Fallback via Scroll
    """
    try:
        res = client.count(collection_name=collection, count_filter=None, exact=True)
        cnt = getattr(res, "count", None)
        if isinstance(cnt, int):
            return cnt
        if isinstance(res, dict) and "count" in res:
            return int(res["count"])
    except Exception:
        pass

    total = 0
    next_page = None
    while True:
        points, next_page = client.scroll(
            collection_name=collection,
            limit=2048,
            with_payload=False,
            with_vectors=False,
            offset=next_page,
        )
        total += len(points)
        if next_page is None or not points:
            break
    return total


def get_counts_for_prefix(client: QdrantClient, prefix: str) -> Dict[str, int]:
    notes, chunks, edges = collection_names(prefix)
    return {
        "notes": count_points(client, notes),
        "chunks": count_points(client, chunks),
        "edges": count_points(client, edges),
    }


def truncate_collections(client: QdrantClient, prefix: str) -> None:
    """
    Löscht alle Punkte (Collections bleiben bestehen).
    """
    for col in collection_names(prefix):
        try:
            client.delete(
                collection_name=col,
                points_selector=rest.FilterSelector(filter=rest.Filter(must=[])),
                wait=True,
            )
        except Exception:
            pass


def list_note_ids(client: QdrantClient, notes_collection: str, limit: int = 100000) -> List[str]:
    """
    Liste aller payload.note_id (unique) aus der Notes-Collection.
    """
    out: List[str] = []
    seen = set()
    next_page = None
    fetched = 0
    while True:
        points, next_page = client.scroll(
            collection_name=notes_collection,
            scroll_filter=None,
            limit=min(512, max(1, limit - fetched)),
            with_payload=True,
            with_vectors=False,
            offset=next_page,
        )
        if not points:
            break
        for p in points:
            pl = p.payload or {}
            nid = pl.get("note_id")
            if isinstance(nid, str) and nid not in seen:
                seen.add(nid)
                out.append(nid)
                fetched += 1
                if fetched >= limit:
                    return out
        if next_page is None:
            break
    return out


# ---------------------------------------------------------
# Fetch-Helfer (NEU für Importer v3.9.0)
# ---------------------------------------------------------
def _match_value(value: Any):
    """
    Qdrant HTTP-Models haben je nach Version unterschiedliche Konstruktoren.
    Wir versuchen zuerst MatchValue(value=...), dann MatchValue(...) als Fallback.
    """
    try:
        return rest.MatchValue(value=value)
    except TypeError:
        return rest.MatchValue(value)  # ältere Signatur


def fetch_one_note(
    client: QdrantClient,
    notes_collection: str,
    note_id: str,
    with_vectors: bool = False,
) -> Optional[Tuple[str, Dict[str, Any], Optional[Any]]]:
    """
    Liefert genau eine Note anhand payload.note_id.
    Rückgabe:
      (point_id, payload_dict, vector_or_None) oder None, falls nicht gefunden.

    Bruchsicher ggü. unterschiedlichen Client-Versionen.
    """
    cond = rest.FieldCondition(key="note_id", match=_match_value(note_id))
    flt = rest.Filter(must=[cond])

    points, _ = client.scroll(
        collection_name=notes_collection,
        scroll_filter=flt,
        limit=1,
        with_payload=True,
        with_vectors=with_vectors,
    )
    if not points:
        return None

    p = points[0]
    pid = str(getattr(p, "id", "")) if getattr(p, "id", None) is not None else ""
    payload = p.payload or {}
    vec = None
    if with_vectors:
        # Vektoren-Struktur ist je nach Clientversion leicht anders
        vec = getattr(p, "vector", None)
        if vec is None:
            vec = payload.get("_vector")  # selten als Payload-Schatten
    return (pid, payload, vec)