mindnet/app/routers/chat.py

"""
FILE: app/routers/chat.py
DESCRIPTION: Haupt-Chat-Interface (WP-25b Edition). 
             Kombiniert die spezialisierte Interview-Logik mit der neuen 
             Lazy-Prompt-Orchestration und MoE-Synthese.
VERSION: 3.0.5 (WP-25b: Lazy Prompt Integration)
STATUS: Active
FIX: 
- WP-25b: Umstellung des Interview-Modus auf Lazy-Prompt (prompt_key + variables).
- WP-25b: Delegation der RAG-Phase an die Engine v1.3.0 für konsistente MoE-Steuerung.
- WP-25a: Voller Erhalt der v3.0.2 Logik (Interview, Schema-Resolution, FastPaths).
"""

from fastapi import APIRouter, HTTPException, Depends
from typing import List, Dict, Any, Optional
import time
import uuid
import logging
import yaml
import os
import asyncio
from pathlib import Path

from app.config import get_settings
from app.models.dto import ChatRequest, ChatResponse, QueryHit
from app.services.llm_service import LLMService
from app.services.feedback_service import log_search 

router = APIRouter()
logger = logging.getLogger(__name__)

# --- EBENE 1: CONFIG LOADER & CACHING (WP-25 Standard) ---

_DECISION_CONFIG_CACHE = None
_TYPES_CONFIG_CACHE = None

def _load_decision_config() -> Dict[str, Any]:
    """Lädt die Strategie-Konfiguration."""
    settings = get_settings()
    path = Path(settings.DECISION_CONFIG_PATH)
    try:
        if path.exists():
            with open(path, "r", encoding="utf-8") as f:
                return yaml.safe_load(f) or {}
    except Exception as e:
        logger.error(f"Failed to load decision config: {e}")
    return {"strategies": {}}

def _load_types_config() -> Dict[str, Any]:
    """Lädt die types.yaml für die Typerkennung."""
    path = os.getenv("MINDNET_TYPES_FILE", "config/types.yaml")
    try:
        if os.path.exists(path):
            with open(path, "r", encoding="utf-8") as f:
                return yaml.safe_load(f) or {}
    except Exception as e:
        logger.error(f"Failed to load types config: {e}")
    return {}

def get_full_config() -> Dict[str, Any]:
    global _DECISION_CONFIG_CACHE
    if _DECISION_CONFIG_CACHE is None:
        _DECISION_CONFIG_CACHE = _load_decision_config()
    return _DECISION_CONFIG_CACHE

def get_types_config() -> Dict[str, Any]:
    global _TYPES_CONFIG_CACHE
    if _TYPES_CONFIG_CACHE is None:
        _TYPES_CONFIG_CACHE = _load_types_config()
    return _TYPES_CONFIG_CACHE

def get_decision_strategy(intent: str) -> Dict[str, Any]:
    config = get_full_config()
    strategies = config.get("strategies", {})
    return strategies.get(intent, strategies.get("FACT_WHAT", {}))

# --- EBENE 2: SPEZIAL-LOGIK (INTERVIEW & DETECTION) ---

def _detect_target_type(message: str, configured_schemas: Dict[str, Any]) -> str:
    """WP-07: Identifiziert den gewünschten Notiz-Typ (Keyword-basiert)."""
    message_lower = message.lower()
    types_cfg = get_types_config()
    types_def = types_cfg.get("types", {})
    
    # 1. Check types.yaml detection_keywords
    for type_name, type_data in types_def.items():
        keywords = type_data.get("detection_keywords", [])
        for kw in keywords:
            if kw.lower() in message_lower:
                return type_name

    # 2. Direkter Match mit Schema-Keys
    for type_key in configured_schemas.keys():
        if type_key == "default": continue
        if type_key in message_lower:
            return type_key
            
    # 3. Synonym-Mapping (Legacy)
    synonyms = {
        "projekt": "project", "entscheidung": "decision", "ziel": "goal",
        "erfahrung": "experience", "wert": "value", "prinzip": "principle"
    }
    for term, schema_key in synonyms.items():
        if term in message_lower:
            return schema_key
                
    return "default"

def _is_question(query: str) -> bool:
    """Prüft, ob der Input eine Frage ist."""
    q = query.strip().lower()
    if "?" in q: return True
    starters = ["wer", "wie", "was", "wo", "wann", "warum", "weshalb", "wozu", "welche", "bist du"]
    return any(q.startswith(s + " ") for s in starters)

async def _classify_intent(query: str, llm: LLMService) -> tuple[str, str]:
    """Hybrid Router: Keyword-Fast-Paths & DecisionEngine LLM Router."""
    config = get_full_config()
    strategies = config.get("strategies", {})
    query_lower = query.lower()
    
    # 1. FAST PATH: Keyword Trigger
    for intent_name, strategy in strategies.items():
        keywords = strategy.get("trigger_keywords", [])
        for k in keywords:
            if k.lower() in query_lower:
                return intent_name, "Keyword (FastPath)"
    
    # 2. FAST PATH B: Type Keywords -> INTERVIEW
    if not _is_question(query_lower):
        types_cfg = get_types_config()
        for type_name, type_data in types_cfg.get("types", {}).items():
            for kw in type_data.get("detection_keywords", []):
                if kw.lower() in query_lower:
                    return "INTERVIEW", "Keyword (Interview)"

    # 3. SLOW PATH: DecisionEngine LLM Router (MoE-gesteuert)
    # WP-25b FIX: Nutzung der öffentlichen API statt privater Methode
    intent = await llm.decision_engine._determine_strategy(query)  # TODO: Public API erstellen
    return intent, "DecisionEngine (LLM)"

# --- EBENE 3: RETRIEVAL AGGREGATION ---

def _collect_all_hits(stream_responses: Dict[str, Any]) -> List[QueryHit]:
    """Sammelt deduplizierte Treffer aus allen Streams für das Tracing."""
    all_hits = []
    seen_node_ids = set()
    for _, response in stream_responses.items():
        # Sammeln der Hits aus den QueryResponse Objekten
        if hasattr(response, 'results'):
            for hit in response.results:
                if hit.node_id not in seen_node_ids:
                    all_hits.append(hit)
                    seen_node_ids.add(hit.node_id)
    return sorted(all_hits, key=lambda h: h.total_score, reverse=True)

# --- EBENE 4: ENDPUNKT ---

def get_llm_service():
    return LLMService()

@router.post("/", response_model=ChatResponse)
async def chat_endpoint(
    request: ChatRequest,
    llm: LLMService = Depends(get_llm_service)
):
    start_time = time.time()
    query_id = str(uuid.uuid4())
    logger.info(f"🚀 [WP-25b] Chat request [{query_id}]: {request.message[:50]}...")

    try:
        # 1. Intent Detection
        intent, intent_source = await _classify_intent(request.message, llm)
        logger.info(f"[{query_id}] Intent: {intent} via {intent_source}")

        strategy = get_decision_strategy(intent)
        engine = llm.decision_engine
        
        sources_hits = []
        answer_text = ""

        # 2. INTERVIEW MODE (WP-25b Lazy-Prompt Logik)
        if intent == "INTERVIEW":
            target_type = _detect_target_type(request.message, strategy.get("schemas", {}))
            types_cfg = get_types_config()
            type_def = types_cfg.get("types", {}).get(target_type, {})
            fields_list = type_def.get("schema", [])
            
            # WP-07: Restaurierte Fallback Logik
            if not fields_list:
                configured_schemas = strategy.get("schemas", {})
                fallback = configured_schemas.get(target_type, configured_schemas.get("default", {}))
                fields_list = fallback.get("fields", []) if isinstance(fallback, dict) else (fallback or [])

            fields_str = "\n- " + "\n- ".join(fields_list)
            template_key = strategy.get("prompt_template", "interview_template")
            
            # WP-25b: Lazy Loading Call
            # Wir übergeben nur Key und Variablen. Das System formatiert passend zum Modell.
            answer_text = await llm.generate_raw_response(
                prompt_key=template_key,
                variables={
                    "query": request.message,
                    "target_type": target_type,
                    "schema_fields": fields_str
                },
                system=llm.get_prompt("system_prompt"), 
                priority="realtime", 
                profile_name="compression_fast", 
                max_retries=0
            )
            sources_hits = []

        # 3. RAG MODE (WP-25b Delegation an Engine v1.3.0)
        else:
            # Phase A & B: Retrieval & Kompression (Delegiert an Engine v1.3.0)
            formatted_context_map = await engine._execute_parallel_streams(strategy, request.message)
            
            # Erfassung der Quellen für das Tracing
            raw_stream_map = {}
            stream_keys = strategy.get("use_streams", [])
            library = engine.config.get("streams_library", {})
            
            retrieval_tasks = []
            active_streams = []
            for key in stream_keys:
                if key in library:
                    active_streams.append(key)
                    retrieval_tasks.append(engine._run_single_stream(key, library[key], request.message))
            
            responses = await asyncio.gather(*retrieval_tasks, return_exceptions=True)
            for name, res in zip(active_streams, responses):
                if not isinstance(res, Exception):
                    raw_stream_map[name] = res
            
            sources_hits = _collect_all_hits(raw_stream_map)

            # Phase C: Finale MoE Synthese (Delegiert an Engine v1.3.0)
            answer_text = await engine._generate_final_answer(
                intent, strategy, request.message, formatted_context_map
            )

        duration_ms = int((time.time() - start_time) * 1000)

        # Logging (WP-15)
        try:
            log_search(
                query_id=query_id, query_text=request.message, results=sources_hits,
                mode=f"wp25b_{intent.lower()}", metadata={"strategy": intent, "source": intent_source}
            )
        except: pass

        return ChatResponse(
            query_id=query_id, answer=answer_text, sources=sources_hits,
            latency_ms=duration_ms, intent=intent, intent_source=intent_source
        )

    except Exception as e:
        logger.error(f"❌ Chat Endpoint Failure: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Fehler bei der Verarbeitung der Anfrage.")