# -*- coding: utf-8 -*-
"""
plan_router.py – v0.10.0 (WP-15)

Minimal-CRUD für Plan-Templates & Pläne (POST/GET) + Idempotenz via Fingerprint.
Erweiterung ggü. v0.9.0: optionale Section-Felder ideal/supplement + materialisierte
Facettenfelder für Qdrant-Indizes; robustere Payload→Model-Konvertierung.
"""
from fastapi import APIRouter, HTTPException
from pydantic import BaseModel, Field
from typing import List, Optional, Dict, Any
from uuid import uuid4
from datetime import datetime, timezone
import hashlib
import json
import os

from clients import model, qdrant
from qdrant_client.models import PointStruct, Filter, FieldCondition, MatchValue, VectorParams, Distance

router = APIRouter(tags=["plans"])

# -----------------
# Konfiguration
# -----------------
PLAN_COLLECTION = os.getenv("PLAN_COLLECTION") or os.getenv("QDRANT_COLLECTION_PLANS", "plans")
PLAN_TEMPLATE_COLLECTION = os.getenv("PLAN_TEMPLATE_COLLECTION", "plan_templates")
PLAN_SESSION_COLLECTION = os.getenv("PLAN_SESSION_COLLECTION", "plan_sessions")

# -----------------
# Modelle
# -----------------
class TemplateSection(BaseModel):
    name: str
    target_minutes: int
    must_keywords: List[str] = []
    ideal_keywords: List[str] = []          # NEU
    supplement_keywords: List[str] = []     # NEU
    forbid_keywords: List[str] = []
    capability_targets: Dict[str, int] = {}

class PlanTemplate(BaseModel):
    id: str = Field(default_factory=lambda: str(uuid4()))
    name: str
    discipline: str
    age_group: str
    target_group: str
    total_minutes: int
    sections: List[TemplateSection] = []
    goals: List[str] = []
    equipment_allowed: List[str] = []
    created_by: str
    version: str

class PlanItem(BaseModel):
    exercise_external_id: str
    duration: int
    why: str

class PlanSection(BaseModel):
    name: str
    items: List[PlanItem] = []
    minutes: int

class Plan(BaseModel):
    id: str = Field(default_factory=lambda: str(uuid4()))
    template_id: Optional[str] = None
    title: str
    discipline: str
    age_group: str
    target_group: str
    total_minutes: int
    sections: List[PlanSection] = []
    goals: List[str] = []
    capability_summary: Dict[str, int] = {}
    novelty_against_last_n: Optional[float] = None
    fingerprint: Optional[str] = None
    created_by: str
    created_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
    source: str = "API"

# -----------------
# Helpers
# -----------------

def _ensure_collection(name: str):
    # Legt Collection an, wenn sie fehlt (analog exercise_router)
    if not qdrant.collection_exists(name):
        qdrant.recreate_collection(
            collection_name=name,
            vectors_config=VectorParams(size=model.get_sentence_embedding_dimension(), distance=Distance.COSINE),
        )


def _norm_list(xs: List[str]) -> List[str]:
    seen, out = set(), []
    for x in xs or []:
        s = str(x).strip()
        k = s.casefold()
        if s and k not in seen:
            seen.add(k)
            out.append(s)
    return sorted(out, key=str.casefold)


def _template_embed_text(tpl: PlanTemplate) -> str:
    parts = [tpl.name, tpl.discipline, tpl.age_group, tpl.target_group]
    parts += tpl.goals
    parts += [s.name for s in tpl.sections]
    return ". ".join([p for p in parts if p])


def _plan_embed_text(p: Plan) -> str:
    parts = [p.title, p.discipline, p.age_group, p.target_group]
    parts += p.goals
    parts += [s.name for s in p.sections]
    return ". ".join([p for p in parts if p])


def _embed(text: str):
    return model.encode(text or "").tolist()


def _fingerprint_for_plan(p: Plan) -> str:
    """sha256(title, total_minutes, sections.items.exercise_external_id, sections.items.duration)"""
    core = {
        "title": p.title,
        "total_minutes": int(p.total_minutes),
        "items": [
            {
                "exercise_external_id": it.exercise_external_id,
                "duration": int(it.duration),
            }
            for sec in p.sections
            for it in (sec.items or [])
        ],
    }
    raw = json.dumps(core, sort_keys=True, ensure_ascii=False)
    return hashlib.sha256(raw.encode("utf-8")).hexdigest()


def _get_by_field(collection: str, key: str, value: Any) -> Optional[Dict[str, Any]]:
    flt = Filter(must=[FieldCondition(key=key, match=MatchValue(value=value))])
    pts, _ = qdrant.scroll(collection_name=collection, scroll_filter=flt, limit=1, with_payload=True)
    if not pts:
        return None
    payload = dict(pts[0].payload or {})
    payload.setdefault("id", str(pts[0].id))
    return payload


def _as_model(model_cls, payload: Dict[str, Any]):
    """Filtert unbekannte Felder heraus (Pydantic v1/v2 kompatibel)."""
    fields = getattr(model_cls, "model_fields", None) or getattr(model_cls, "__fields__", {})
    allowed = set(fields.keys())
    data = {k: payload[k] for k in payload.keys() if k in allowed}
    return model_cls(**data)

# -----------------
# Endpoints
# -----------------
@router.post("/plan_templates", response_model=PlanTemplate)
def create_plan_template(t: PlanTemplate):
    _ensure_collection(PLAN_TEMPLATE_COLLECTION)
    payload = t.model_dump()
    # Normalisierung
    payload["goals"] = _norm_list(payload.get("goals"))
    sections = payload.get("sections", []) or []
    for s in sections:
        s["must_keywords"] = _norm_list(s.get("must_keywords") or [])
        s["ideal_keywords"] = _norm_list(s.get("ideal_keywords") or [])            # NEU
        s["supplement_keywords"] = _norm_list(s.get("supplement_keywords") or [])  # NEU
        s["forbid_keywords"] = _norm_list(s.get("forbid_keywords") or [])

    # Materialisierte Facettenfelder (stabile KEYWORD-Indizes in Qdrant)
    payload["section_names"] = _norm_list([s.get("name", "") for s in sections])
    payload["section_must_keywords"] = _norm_list([kw for s in sections for kw in (s.get("must_keywords") or [])])
    payload["section_ideal_keywords"] = _norm_list([kw for s in sections for kw in (s.get("ideal_keywords") or [])])
    payload["section_supplement_keywords"] = _norm_list([kw for s in sections for kw in (s.get("supplement_keywords") or [])])
    payload["section_forbid_keywords"] = _norm_list([kw for s in sections for kw in (s.get("forbid_keywords") or [])])

    vec = _embed(_template_embed_text(t))
    qdrant.upsert(collection_name=PLAN_TEMPLATE_COLLECTION, points=[PointStruct(id=str(t.id), vector=vec, payload=payload)])
    return t


@router.get("/plan_templates/{tpl_id}", response_model=PlanTemplate)
def get_plan_template(tpl_id: str):
    _ensure_collection(PLAN_TEMPLATE_COLLECTION)
    found = _get_by_field(PLAN_TEMPLATE_COLLECTION, "id", tpl_id)
    if not found:
        raise HTTPException(status_code=404, detail="not found")
    return _as_model(PlanTemplate, found)


@router.post("/plan", response_model=Plan)
def create_plan(p: Plan):
    _ensure_collection(PLAN_COLLECTION)
    # Fingerprint
    fp = _fingerprint_for_plan(p)
    p.fingerprint = p.fingerprint or fp

    # Idempotenz
    existing = _get_by_field(PLAN_COLLECTION, "fingerprint", p.fingerprint)
    if existing:
        return _as_model(Plan, existing)

    # Normalisieren
    p.goals = _norm_list(p.goals)
    payload = p.model_dump()
    # ISO8601 sicherstellen
    if isinstance(payload.get("created_at"), datetime):
        payload["created_at"] = payload["created_at"].astimezone(timezone.utc).isoformat()

    vec = _embed(_plan_embed_text(p))
    qdrant.upsert(collection_name=PLAN_COLLECTION, points=[PointStruct(id=str(p.id), vector=vec, payload=payload)])
    return p


@router.get("/plan/{plan_id}", response_model=Plan)
def get_plan(plan_id: str):
    _ensure_collection(PLAN_COLLECTION)
    found = _get_by_field(PLAN_COLLECTION, "id", plan_id)
    if not found:
        raise HTTPException(status_code=404, detail="not found")
    # created_at zurück in datetime (ISO)
    if isinstance(found.get("created_at"), str):
        try:
            found["created_at"] = datetime.fromisoformat(found["created_at"])
        except Exception:
            pass
    return _as_model(Plan, found)