"""
FILE: app/services/edge_registry.py
DESCRIPTION: Single Source of Truth für Kanten-Typen. Parst '01_edge_vocabulary.md'.
             WP-22 Teil B: Registry & Validation.
             FIX: Beachtet MINDNET_VOCAB_PATH und MINDNET_VAULT_ROOT aus .env sicher.
VERSION: 0.6.5 (Path Stability Update)
"""
import re
import os
import json
import logging
from typing import Dict, Optional, Set

from app.config import get_settings

logger = logging.getLogger(__name__)

class EdgeRegistry:
    _instance = None

    def __new__(cls, vault_root: Optional[str] = None):
        if cls._instance is None:
            cls._instance = super(EdgeRegistry, cls).__new__(cls)
            cls._instance.initialized = False
        return cls._instance

    def __init__(self, vault_root: Optional[str] = None):
        if self.initialized: 
            return
            
        settings = get_settings()
        
        # --- WP-22 Pfad-Priorisierung ---
        # 1. Expliziter Vokabular-Pfad (höchste Prio)
        vocab_env = os.getenv("MINDNET_VOCAB_PATH")
        
        # 2. Vault Root Auflösung
        # Wir prüfen os.getenv direkt, falls Pydantic Settings (settings.MINDNET_VAULT_ROOT) 
        # das Feld nicht definiert haben.
        self.vault_root = (
            vault_root or 
            vocab_env or 
            os.getenv("MINDNET_VAULT_ROOT") or 
            getattr(settings, "MINDNET_VAULT_ROOT", "./vault")
        )
        
        # Falls vocab_env eine komplette Datei ist, nutzen wir sie direkt, 
        # ansonsten bauen wir den Pfad relativ zur vault_root.
        if vocab_env and vocab_env.endswith(".md"):
            self.full_vocab_path = os.path.abspath(vocab_env)
        else:
            self.full_vocab_path = os.path.abspath(
                os.path.join(self.vault_root, "01_User_Manual", "01_edge_vocabulary.md")
            )
        
        self.unknown_log_path = "data/logs/unknown_edges.jsonl"
        self.canonical_map: Dict[str, str] = {} 
        self.valid_types: Set[str] = set()
        
        self._load_vocabulary()
        self.initialized = True

    def _load_vocabulary(self):
        """Parst die Markdown-Tabelle im Vault."""
        if not os.path.exists(self.full_vocab_path):
            logger.warning(f"Edge Vocabulary NOT found at: {self.full_vocab_path}. Registry is empty.")
            return

        # Regex für Markdown Tabellen: | **canonical** | Aliases | ...
        pattern = re.compile(r"\|\s*\*\*([a-z_]+)\*\*\s*\|\s*([^|]+)\|")

        try:
            with open(self.full_vocab_path, "r", encoding="utf-8") as f:
                count_types = 0
                count_aliases = 0
                for line in f:
                    match = pattern.search(line)
                    if match:
                        canonical = match.group(1).strip()
                        aliases_str = match.group(2).strip()
                        
                        self.valid_types.add(canonical)
                        self.canonical_map[canonical] = canonical
                        count_types += 1
                        
                        if aliases_str and "Kein Alias" not in aliases_str:
                            # Aliase säubern und mappen
                            aliases = [a.strip() for a in aliases_str.split(",") if a.strip()]
                            for alias in aliases:
                                clean_alias = alias.replace("`", "").lower().strip()
                                self.canonical_map[clean_alias] = canonical
                                count_aliases += 1
            
            logger.info(f"EdgeRegistry: Loaded {count_types} types and {count_aliases} aliases from {self.full_vocab_path}.")

        except Exception as e:
            logger.error(f"Failed to parse Edge Vocabulary at {self.full_vocab_path}: {e}")

    def resolve(self, edge_type: str) -> str:
        """Normalisiert Kanten-Typen via Registry oder loggt Unbekannte."""
        if not edge_type: 
            return "related_to"
            
        # Normalisierung: Kleinschreibung und Unterstriche statt Leerzeichen
        clean_type = edge_type.lower().strip().replace(" ", "_")
        
        # 1. Direkter Match (Kanonisch oder Alias)
        if clean_type in self.canonical_map:
            return self.canonical_map[clean_type]
        
        # 2. Unbekannt -> Logging & Fallback
        self._log_unknown(clean_type)
        return clean_type 

    def _log_unknown(self, edge_type: str):
        """Schreibt unbekannte Typen für Review in ein Log."""
        try:
            os.makedirs(os.path.dirname(self.unknown_log_path), exist_ok=True)
            entry = {"unknown_type": edge_type, "status": "new"}
            with open(self.unknown_log_path, "a", encoding="utf-8") as f:
                f.write(json.dumps(entry) + "\n")
        except Exception:
            pass

# Singleton Instanz
registry = EdgeRegistry()