"""
app/services/discovery.py
Service für Link-Vorschläge und Knowledge-Discovery (WP-11).
Adaptiert für Async-Architecture (v2.4).
"""
import logging
import os
from typing import List, Dict, Any
import yaml

# Wir nutzen hier weiterhin die Low-Level Funktionen, da diese stabil sind
from app.core.qdrant import QdrantConfig, get_client
from app.models.dto import QueryRequest
from app.core.retriever import hybrid_retrieve

logger = logging.getLogger(__name__)

class DiscoveryService:
    def __init__(self, collection_prefix: str = None):
        self.cfg = QdrantConfig.from_env()
        self.prefix = collection_prefix or self.cfg.prefix or "mindnet"
        self.client = get_client(self.cfg)
        self.registry = self._load_type_registry()

    async def analyze_draft(self, text: str, current_type: str) -> Dict[str, Any]:
        """
        Analysiert einen Draft-Text und schlägt Verlinkungen vor.
        Kombiniert Exact Match (Titel/Alias) und Semantic Match.
        """
        suggestions = []
        default_edge_type = self._get_default_edge_type(current_type)

        # 1. Exact Match: Finde Begriffe im Text, die als Notiz-Titel existieren
        # (Dies läuft synchron, ist aber sehr schnell durch Qdrant Scroll)
        known_entities = self._fetch_all_titles_and_aliases()
        found_entities = self._find_entities_in_text(text, known_entities)
        
        existing_target_ids = set()

        for entity in found_entities:
            existing_target_ids.add(entity["id"])
            target_title = entity["title"]
            suggested_md = f"[[rel:{default_edge_type} {target_title}]]"
            
            suggestions.append({
                "type": "exact_match",
                "text_found": entity["match"],
                "target_title": target_title,
                "target_id": entity["id"],
                "suggested_edge_type": default_edge_type,
                "suggested_markdown": suggested_md,
                "confidence": 1.0,
                "reason": f"Exakter Treffer (Default für '{current_type}': {default_edge_type})"
            })

        # 2. Semantic Match: Finde inhaltlich ähnliche Notizen
        # Wir filtern Ergebnisse heraus, die wir schon per Exact Match gefunden haben.
        semantic_hits = await self._get_semantic_suggestions_async(text)
        
        for hit in semantic_hits:
            if hit.node_id in existing_target_ids:
                continue
            
            if hit.total_score > 0.65:
                # FIX: Titel aus Payload lesen, nicht ID!
                target_title = hit.payload.get("title") or hit.node_id
                
                suggested_md = f"[[rel:{default_edge_type} {target_title}]]"
                
                suggestions.append({
                    "type": "semantic_match",
                    "text_found": (hit.source.get("text") or "")[:50] + "...",
                    "target_title": target_title,
                    "target_id": hit.node_id,
                    "suggested_edge_type": default_edge_type,
                    "suggested_markdown": suggested_md,
                    "confidence": round(hit.total_score, 2),
                    "reason": f"Semantische Ähnlichkeit ({hit.total_score:.2f})"
                })

        return {
            "draft_length": len(text),
            "suggestions_count": len(suggestions),
            "suggestions": suggestions
        }

    # --- Helpers ---

    async def _get_semantic_suggestions_async(self, text: str):
        """Async Wrapper um den Hybrid Retriever."""
        req = QueryRequest(query=text, top_k=5, explain=False)
        try:
            # Da hybrid_retrieve (noch) sync ist, rufen wir es direkt auf.
            # In einer voll-async Umgebung würde man dies in einen Thread-Pool auslagern,
            # aber da Qdrant-Client sync ist, ist das hier okay.
            res = hybrid_retrieve(req)
            return res.results
        except Exception as e:
            logger.error(f"Semantic suggestion failed: {e}")
            return []

    def _load_type_registry(self) -> dict:
        path = os.getenv("MINDNET_TYPES_FILE", "config/types.yaml")
        if not os.path.exists(path):
            if os.path.exists("types.yaml"): path = "types.yaml"
            else: return {}
        try:
            with open(path, "r", encoding="utf-8") as f: return yaml.safe_load(f) or {}
        except Exception: return {}

    def _get_default_edge_type(self, note_type: str) -> str:
        types_cfg = self.registry.get("types", {})
        type_def = types_cfg.get(note_type, {})
        defaults = type_def.get("edge_defaults")
        if defaults and isinstance(defaults, list) and len(defaults) > 0:
            return defaults[0]
        return "related_to"

    def _fetch_all_titles_and_aliases(self) -> List[Dict]:
        notes = []
        next_page = None
        col_name = f"{self.prefix}_notes"
        try:
            while True:
                res, next_page = self.client.scroll(collection_name=col_name, limit=1000, offset=next_page, with_payload=True, with_vectors=False)
                for point in res:
                    pl = point.payload or {}
                    aliases = pl.get("aliases") or []
                    if isinstance(aliases, str): aliases = [aliases]
                    notes.append({"id": pl.get("note_id"), "title": pl.get("title"), "aliases": aliases})
                if next_page is None: break
        except Exception: return []
        return notes

    def _find_entities_in_text(self, text: str, entities: List[Dict]) -> List[Dict]:
        found = []
        text_lower = text.lower()
        for entity in entities:
            title = entity.get("title")
            if title and title.lower() in text_lower:
                found.append({"match": title, "title": title, "id": entity["id"]})
                continue
            aliases = entity.get("aliases", [])
            for alias in aliases:
                if alias and str(alias).lower() in text_lower:
                    found.append({"match": alias, "title": title, "id": entity["id"]})
                    break
        return found