import asyncio
import json
import shutil
import uuid
from datetime import datetime, timedelta, timezone

from fastapi import APIRouter, HTTPException
from fastapi.responses import Response

from agents import active_agents, provider_available
from config import PROJECTS_DIR, UNI_DIR, PROVIDERS
from database import (
    create_guide, delete_guide, get_guide, list_guides,
    create_topic, list_topics as db_list_topics, delete_topic,
    list_block_progress, get_block_progress, set_open_question,
    set_block_score_and_streak,
    delete_block_data, delete_block_progress, subs_per_level, subs_per_level_raw,
    delete_topic_pipeline, delete_source, get_guide_content, delete_guide_content,
    get_sub_artefakte, kanban_reset, delete_guide_board,
    get_practice_progress, upsert_practice_progress, sub_levels_norm, subs_per_level_norm,
)
from textkit import _norm_title
from blocks import generate_blocks, cancel_blocks, blocks_status, active_blocks, reset_blocks, load_source, load_overview, subblocks_title, subblocks_frei, load_question_pattern, load_question_pattern_free, _blocks_files
from board_inventory import add_research_agent, board_snapshot, requeue_dead, reset_board_from_stage, restart_artefact_card
from learning import block_chat, block_discussion, exam_rating, exam_rating_fast, exam_question, exam_question_variant, generate_quiz, generate_gapchoice, generate_gaptext, check_gaptext, hurdles_distractor_block, compute_score, floor_from_score, level_from_score, cap_final, cap_aktuell, freie_level, thresholds, points_delta, cap_followup, leitner_step, PRACTICE_NEW_PER_SESSION
from guide import chat_with_guide, generate_guide, guide_slot_files, block_pruefen, block_adopt, content_fuer_level
from pipeline import cancel_guide
from rules import FORMATE, formats_stats, guide_lock, ist_completed, load_learnstate, topic_completed
from models import (
    GuideCreateRequest, GuideResponse,
    TopicCreateRequest,
    BlocksCreateRequest, BlocksResetStageRequest, BlocksCardRestartRequest, BlocksStatusResponse, QaRunRequest, RepairRequest,
    GuideCardResetRequest, GuideFormatRequest,
    GuideBoardResetRequest, GuideChatRequest, GuideChatResponse,
    ProviderInfo,
    FolderResponse, BlocksSourceUpdate, BlocksSourceResponse, BlockOverview,
    BlockChatRequest, BlockChatResponse,
    BlockExamRequest, BlockExamResponse, BlockLearnStateResponse,
    BlockPruefenRequest, BlockPruefenResponse, BlockUebernehmenRequest, BlockUebernehmenResponse,
    PracticeAnswerRequest,
)
from paths import blocks_topics, guide_content_path, project_dir, topic_dir, source_path, safe_folder
from fsutil import atomic_write_json

router = APIRouter(prefix="/api")


@router.get("/providers", response_model=list[ProviderInfo])
async def get_providers():
    return [{"id": pid, "available": provider_available(pid)} for pid in PROVIDERS]


@router.get("/topics")
async def get_topics():
    db_topics = await db_list_topics()
    guides = await list_guides()
    derived = {g["topic"] for g in guides}
    derived.update(blocks_topics())
    derived.update(job["topic"] for job in active_blocks())
    # DB is authoritative (order: newest first); append derived entries without a DB row at the end
    return db_topics + sorted(derived - set(db_topics))


@router.get("/stats")
async def get_stats():
    """Tracker: number of topics + per format created/completed."""
    guides, levels = await load_learnstate()
    topics = set(await db_list_topics()) | {g["topic"] for g in guides} | set(blocks_topics())
    if PROJECTS_DIR.is_dir():
        topics |= {e.name for e in PROJECTS_DIR.iterdir() if e.is_dir()}
    return {"topics": len(topics), "formats": formats_stats(guides, levels)}


@router.get("/topics/progress")
async def topic_progress(topic: str):
    """Completion status per format + topic completion — for unlocking the next expansion stage."""
    guides, levels = await load_learnstate()
    status = {fmt: ist_completed(topic, fmt, guides, levels) for fmt in FORMATE}
    status["completed"] = topic_completed(topic, guides, levels)
    return status


@router.post("/topics")
async def add_topic(req: TopicCreateRequest):
    await create_topic(req.name.strip())
    return {"ok": True}


@router.delete("/topics")
async def remove_topic(topic: str):
    await delete_topic(topic)
    await delete_block_data(topic)
    await delete_topic_pipeline(topic)
    await delete_source(topic)          # topic config (DB) — removed together with the topic
    await delete_guide_content(topic)
    shutil.rmtree(topic_dir(topic), ignore_errors=True)
    return {"ok": True}


@router.get("/folders", response_model=list[FolderResponse])
async def list_folders(kind: str):
    """Folders for the source selection: kind=projekt → projects/, kind=uni → uni/."""
    base = {"projekt": (PROJECTS_DIR, "projects"), "uni": (UNI_DIR, "uni")}.get(kind)
    if base is None:
        raise HTTPException(400, "kind must be 'projekt' or 'uni'")
    root, prefix = base
    if not root.is_dir():
        return []
    return [{"name": e.name, "location": f"{prefix}/{e.name}"} for e in sorted(root.iterdir()) if e.is_dir()]


# --- Blocks ---

@router.get("/blocks/status", response_model=BlocksStatusResponse)
async def get_blocks_status(topic: str):
    return await blocks_status(topic)


@router.get("/blocks/active")
async def get_active_blocks():
    return active_blocks()


@router.post("/blocks")
async def create_blocks(req: BlocksCreateRequest):
    topic = req.topic.strip()
    if (await blocks_status(topic))["generating"]:
        return {"ok": True, "status": "already_generating"}
    await create_topic(topic)
    qp = source_path(topic)
    # Persist the source only the FIRST time; ▶/Resume keeps the existing choice.
    if not qp.exists():
        type, location = req.source_type, req.source_location.strip()
        if type in ("projekt", "uni"):
            folder = safe_folder(location)
            if folder is None or not folder.is_dir():
                raise HTTPException(400, "Folder invalid or not found (path relative to the project root, no ../).")
        elif type == "link":
            if not location.lower().startswith(("http://", "https://")):
                raise HTTPException(400, "Link must start with http:// or https://.")
        qp.parent.mkdir(parents=True, exist_ok=True)
        atomic_write_json(qp, {"type": type, "location": location, "spec": req.instructions.strip()})
    asyncio.create_task(generate_blocks(topic, req.instructions.strip(), req.provider,
                                        research=req.research, qa_force=req.qa_force))
    return {"ok": True}


@router.get("/blocks/board")
async def get_blocks_board(topic: str):
    """Live kanban board: columns with counts + newest cards, dead-letter, agents."""
    snap = await board_snapshot(topic)
    status = await blocks_status(topic)
    snap["generating"] = status["generating"]
    snap["progress"] = status["progress"]
    snap["error"] = status["error"]
    snap["agents"] = [{"key": a["key"], "label": a["label"] or a["key"].removeprefix(f"blocks-{topic}-"), "runtime": a["runtime"]}
                      for a in active_agents(f"blocks-{topic}-")]
    return snap


_qa_laeuft: set[str] = set()


@router.post("/blocks/qa")
async def run_qa_route(req: QaRunRequest):
    """Manual QA run (like the gate: incl. LLM samples); the badge reads the written report."""
    if req.topic in _qa_laeuft:
        return {"status": "läuft bereits"}
    _qa_laeuft.add(req.topic)
    try:
        import qa
        report = await qa.qa_report(req.topic, llm=req.llm)
        if report is None:
            raise HTTPException(status_code=404, detail="keine fertigen Bausteine")
        await asyncio.to_thread(qa._write_report, report)
        return {"note": report["note"], "note_artefakte": report["note_artefakte"]}
    finally:
        _qa_laeuft.discard(req.topic)


_repair_laeuft: set[str] = set()


@router.post("/blocks/repair")
async def run_repair_route(req: RepairRequest):
    """Fix the latest QA findings in place: hygiene, confirmed duplicates, foreign/unreal blocks."""
    topic = req.topic.strip()
    if (await blocks_status(topic))["generating"]:
        return {"status": "generating"}
    if topic in _repair_laeuft:
        return {"status": "läuft bereits"}
    _repair_laeuft.add(topic)
    try:
        import repair
        res = await repair.repair_befunde(topic)
        if "fehler" in res:
            raise HTTPException(status_code=404, detail=res["fehler"])
        return res
    finally:
        _repair_laeuft.discard(topic)


@router.post("/blocks/research")
async def add_blocks_research(topic: str, provider: str = "claude"):
    """Attach one more research agent — to the live flow, or attach-or-start."""
    if add_research_agent(topic):
        return {"ok": True, "attached": True}
    if (await blocks_status(topic))["generating"]:
        return {"ok": False, "status": "starting"}  # flow is booting, try again shortly
    asyncio.create_task(generate_blocks(topic, "", provider, research=True))
    return {"ok": True, "attached": False}


@router.post("/blocks/reset-stage")
async def reset_blocks_stage(req: BlocksResetStageRequest):
    """Reset cards from a column onward back to that column (no regeneration)."""
    topic = req.topic.strip()
    if (await blocks_status(topic))["generating"]:
        return {"ok": True, "status": "generating"}  # don't interfere with a running generation
    moved = await reset_board_from_stage(topic, req.board, req.stage, _blocks_files(topic))
    return {"ok": True, "moved": moved}


@router.post("/blocks/requeue-dead")
async def requeue_blocks_dead(topic: str):
    return {"ok": True, "requeued": await requeue_dead(topic)}


@router.post("/blocks/card-restart")
async def blocks_card_restart(req: BlocksCardRestartRequest):
    if (await blocks_status(req.topic))["generating"]:
        return {"ok": True, "status": "generating"}
    if not await restart_artefact_card(req.topic, req.card_id):
        raise HTTPException(404, "Card not found")
    return {"ok": True}


@router.post("/guides/board/card-reset")
async def guide_card_reset(req: GuideCardResetRequest):
    running = [g for g in await list_guides()
               if g["topic"] == req.topic and g["format"] == req.format
               and g["status"] in ("queued", "generating")]
    if running:
        return {"ok": True, "status": "generating"}
    from guide_board import reset_card
    if not await reset_card(req.topic, req.format, req.block_norm, req.ab_stage):
        raise HTTPException(404, "Card not found")
    return {"ok": True}


@router.post("/blocks/cancel")
async def cancel_blocks_route(topic: str):
    if not cancel_blocks(topic):
        raise HTTPException(404, "No running generation")
    return {"ok": True}


@router.delete("/blocks")
async def remove_blocks(topic: str):
    reset_blocks(topic)              # Files: crawl + triage + inventory…questions gone; source.json stays
    await delete_topic_pipeline(topic)  # DB: blocks area gone; topic config (source) stays
    await kanban_reset(topic)        # kanban cards + cluster membership gone
    return {"ok": True}


@router.delete("/blocks/progress")
async def reset_block_progress(topic: str, block: str):
    """Reset learning progress of ONE block to zero (score/streak/flags/open question)."""
    await delete_block_progress(topic, block)
    return {"ok": True}


def _validate_source(type: str, location: str) -> None:
    """Check source input (same rules as on creation)."""
    if type in ("projekt", "uni"):
        folder = safe_folder(location)
        if folder is None or not folder.is_dir():
            raise HTTPException(400, "Folder invalid or not found (path relative to the project root, no ../).")
    elif type == "link":
        if not location.lower().startswith(("http://", "https://")):
            raise HTTPException(400, "Link must start with http:// or https://.")


@router.get("/blocks/source", response_model=BlocksSourceResponse)
async def get_blocks_source(topic: str):
    return load_source(topic)


@router.put("/blocks/source", response_model=BlocksSourceResponse)
async def update_blocks_source(req: BlocksSourceUpdate):
    """Only save — NO regeneration. Overwrite the source/spec choice."""
    topic, type, location = req.topic.strip(), req.type, req.location.strip()
    _validate_source(type, location)
    qp = source_path(topic)
    qp.parent.mkdir(parents=True, exist_ok=True)
    data = {"type": type, "location": location, "spec": req.spec.strip()}
    atomic_write_json(qp, data)
    return data


@router.get("/blocks/completeness")
async def blocks_completeness(topic: str):
    """Beleg der Themen-Zerlegung: Bestand, Filter-Bilanz, Lernziele, Artefakte, Laufzeit."""
    import glob as _glob
    from pathlib import Path as _Path
    from paths import arbeit_dir
    from database import (kanban_stage_counts, list_blocks, list_subblocks, list_lernziele,
                          count_question_pattern_blocks, count_sub_artefakte, event_span)
    counts = await kanban_stage_counts(topic)
    inv = counts.get("inventory", {})
    blocks = await list_blocks(topic, status="consensus")
    subs = 0
    for b in blocks:
        subs += sum(1 for s in await list_subblocks(topic, b["title_norm"]) if s["status"] == "consensus")
    ziele = await list_lernziele(topic)
    dead = sum(v for board in counts.values() for s, v in board.items() if s == "dead")
    degradiert = ueberstimmt = 0
    for p in _glob.glob(str(arbeit_dir(topic) / "inventar-filter*.json")):
        try:
            d = json.loads(_Path(p).read_text(encoding="utf-8"))
            degradiert += d.get("degradiert", 0)
            ueberstimmt += len(d.get("ueberstimmt", []))
        except Exception:
            continue
    status = await blocks_status(topic)
    return {
        "bloecke": len(blocks), "subs": subs,
        "verworfen": inv.get("rejected", 0), "zusammengelegt": inv.get("grouped", 0),
        "degradiert_geprueft": degradiert, "panel_gerettet": ueberstimmt,
        "ziele_total": len(ziele), "ziele_covered": sum(1 for z in ziele if z["covered"]),
        "frage_bloecke": await count_question_pattern_blocks(topic),
        "lernkarten": await count_sub_artefakte(topic),
        "dead": dead, "lauf_minuten": await event_span(topic),
        "vollstaendig": bool(status.get("ready")) and dead == 0,
    }


@router.get("/blocks/overview", response_model=list[BlockOverview])
async def get_blocks_uebersicht(topic: str):
    return await load_overview(topic)


@router.get("/blocks/question-pattern")
async def get_question_pattern(topic: str, block: str):
    """Unlocked question patterns of a block (up to the current level; empty = live)."""
    state = await get_block_progress(topic, block)
    fe = freie_level(state["good_answers"], await subs_per_level(topic, block))
    return {"pattern": await load_question_pattern_free(topic, block, fe)}


# --- Practice deck: Leitner flashcard pool per topic ---

async def build_practice_deck(topic: str) -> dict:
    """ONE stack per topic (spacing beats per-block mini-stacks): due cards first
    (oldest due_at), then up to PRACTICE_NEW_PER_SESSION new ones. Level gate via the
    block's exam score (freie_level) — locked cards are counted for transparency."""
    cards = await get_sub_artefakte(topic, "flashcard")
    levels = await sub_levels_norm(topic)
    n_je = await subs_per_level_norm(topic)
    progress = {_norm_title(p["block"]): p["good_answers"] for p in await list_block_progress(topic)}
    pp = {(p["block_norm"], p["sub_norm"]): p for p in await get_practice_progress(topic)}
    now = datetime.now(timezone.utc).isoformat()
    due, new, future, gesperrt = [], [], [], 0
    for r in cards:
        bn, sn = r["block_norm"], r["sub_norm"]
        n_block = n_je.get(bn)
        if n_block is not None:  # legacy blocks without level data pass unfiltered
            if levels.get((bn, sn), 1) > freie_level(progress.get(bn, 0), n_block):
                gesperrt += 1
                continue
        try:
            data = json.loads(r["data"])
        except (ValueError, TypeError):
            continue
        card = {"block": r["block"], "block_norm": bn, "sub_norm": sn,
                "subblock": r["sub_title"], "question": data.get("question", ""),
                "answer": data.get("answer", "")}
        p = pp.get((bn, sn))
        if p is None:
            card.update(box=None, status="new")
            new.append(card)
        elif p["due_at"] <= now:
            card.update(box=p["box"], status="due", due_at=p["due_at"])
            due.append(card)
        else:
            future.append(p["due_at"])
    due.sort(key=lambda c: c["due_at"])
    new_total = len(new)
    new = new[:PRACTICE_NEW_PER_SESSION]
    return {"cards": due + new,
            "counts": {"due": len(due), "new": len(new), "new_total": new_total,
                       "gesperrt": gesperrt},
            "next_due_at": min(future) if future else None}


@router.get("/practice/deck")
async def practice_deck(topic: str):
    return await build_practice_deck(topic)


@router.post("/practice/answer")
async def practice_answer(req: PracticeAnswerRequest):
    """Book a Leitner step. Deliberately NO existence check against sub_artefakte:
    an answer during regeneration books instead of failing (worst case an orphan row)."""
    pp = {(p["block_norm"], p["sub_norm"]): p for p in await get_practice_progress(req.topic)}
    prev = pp.get((req.block_norm, req.sub_norm))
    box, days = leitner_step(prev["box"] if prev else None, req.correct)
    due_at = (datetime.now(timezone.utc) + timedelta(days=days)).isoformat()
    await upsert_practice_progress(req.topic, req.block_norm, req.sub_norm, box, due_at)
    return {"box": box, "due_at": due_at}


# --- Block learning: chat, exam ---

@router.get("/blocks/learnstate", response_model=BlockLearnStateResponse)
async def block_learnstate(topic: str):
    """Exam state per block (raw title as key). cap_final = all subs × 25;
    cap_aktuell + freie_level from the score — for ALL blocks (even unexamined)."""
    progress = {p["block"]: p for p in await list_block_progress(topic)}
    levels = await subs_per_level_raw(topic)

    def _state(score: int, streak: int, n_je_level: dict[int, int]) -> dict:
        return {
            "good_answers": score, "streak": streak,
            "cap": cap_final(n_je_level),
            "cap_aktuell": cap_aktuell(score, n_je_level),
            "freie_level": freie_level(score, n_je_level),
        }

    blocks = {
        b: _state(progress[b]["good_answers"] if b in progress else 0,
                  progress[b]["streak"] if b in progress else 0, n)
        for b, n in levels.items()
    }
    # Legacy blocks with an exam but without subs → empty levels (cap 0).
    for b, p in progress.items():
        if b not in blocks:
            blocks[b] = _state(p["good_answers"], p["streak"], {})
    return {"blocks": blocks}


@router.post("/blocks/chat", response_model=BlockChatResponse)
async def block_chat_route(req: BlockChatRequest):
    reply = await block_chat(
        req.topic, req.block, req.section, req.section_compact,
        [m.model_dump() for m in req.messages], provider=req.provider,
    )
    return {"reply": reply}


# Serialize ratings per (topic, block) — otherwise two simultaneous ratings would
# overwrite the absolute score with a stale base (race).
_check_locks: dict[tuple[str, str], asyncio.Lock] = {}


def _check_lock(topic: str, block: str) -> asyncio.Lock:
    key = (topic, block)
    lock = _check_locks.get(key)
    if lock is None:
        lock = _check_locks[key] = asyncio.Lock()
    return lock


def _basis(state: dict, question: str) -> tuple[int, bool]:
    """Score base BEFORE the question. Same open question → re-rating on the same base
    (idempotent); otherwise a new question on the current state. → (basis, re_rating)."""
    re_rating = state["offene_question"] == question and state["offene_basis"] is not None
    return (state["offene_basis"] if re_rating else state["good_answers"]), re_rating


def _color(points: int) -> str:
    """Points delta → rough bubble coloring."""
    return "gut" if points > 0 else ("neutral" if points == 0 else "schlecht")


async def _book_score(req, question: str, tier: str, n_je_level: dict[int, int]) -> dict:
    """Book score+streak drift-free (lock + open-question/open-streak anchor). Tier →
    points delta (streak-modulated) or progressive malus on error. cap_aktuell is derived
    from the base (delayed unlock at the level threshold).
    Re-rating of the same question uses the open streak anchor → idempotent."""
    async with _check_lock(req.topic, req.block):
        state = await get_block_progress(req.topic, req.block)
        basis, re_rating = _basis(state, question)
        streak_basis = state["offene_streak"] if re_rating else state["streak"]
        if not re_rating:
            await set_open_question(req.topic, req.block, question, basis, state["streak"])
        s = thresholds(n_je_level)
        cf = s[-1]
        ca = cap_aktuell(basis, n_je_level)
        floor = floor_from_score(basis, cf, s)
        d, new_streak = points_delta(tier, streak_basis, basis, ca)
        score = compute_score(basis, d, floor, ca, cf)
        points = score - basis
        good, streak = await set_block_score_and_streak(req.topic, req.block, score, new_streak)
        return {"points": points, "rating": _color(points), "good_answers": good, "streak": streak, "cap": cf}


@router.post("/blocks/exam", response_model=BlockExamResponse)
async def block_exam_route(req: BlockExamRequest):
    state = await get_block_progress(req.topic, req.block)
    good = state["good_answers"]
    n_je_level = await subs_per_level(req.topic, req.block)
    cap = cap_final(n_je_level)
    tier = level_from_score(good, cap) or "beginner"  # addressee role of the question
    fe = freie_level(good, n_je_level)                  # only check unlocked subs
    compact = req.section_compact
    msgs = [m.model_dump() for m in req.messages]

    if req.action == "question":
        if req.pattern.strip():
            # From a drawn pattern, phrase a concrete question at the tier (no dedup needed).
            question = await exam_question_variant(req.topic, req.block, req.section, compact, req.pattern, tier=tier, provider=req.provider)
        else:
            # Fallback (no pattern sidecar): live generation, focus only on unlocked subs.
            subs = await subblocks_frei(req.topic, req.block, fe)
            question = await exam_question(req.topic, req.block, req.section, compact, msgs, subblocks=subs, avoid=req.avoid, tier=tier, provider=req.provider)
        if question is None:
            raise HTTPException(502, "Question failed — please try again")
        return {"question": question, "good_answers": good, "cap": cap}

    if req.action == "discussion":
        if not req.question.strip():
            raise HTTPException(400, "Discussion needs an active question")
        reply = await block_discussion(
            req.topic, req.block, req.section, compact,
            req.question, req.last_rating or None, msgs, provider=req.provider,
        )
        if reply is None:
            raise HTTPException(502, "Discussion failed — please try again")
        return {"reply": reply, "good_answers": good, "cap": cap}

    # --- Quiz: easy (1 of 4) +1/−1 · hard (x of 4) +3/−1 — deterministic ---
    if req.action == "quiz_question":
        if not req.pattern.strip():
            raise HTTPException(400, "Quiz needs a pattern")
        distractors = await hurdles_distractor_block(req.topic, req.block)
        quiz = await generate_quiz(req.topic, req.block, req.section, compact, req.pattern, tier=tier, provider=req.provider, distractor_block=distractors)
        if quiz is None:
            raise HTTPException(502, "Quiz question failed — please try again")
        return {"question": quiz["question"], "options": quiz["options"],
                "good_answers": good, "cap": cap}

    if req.action == "quiz_answer":
        if not req.question.strip():
            raise HTTPException(400, "Quiz answer needs a question")
        hit = set(req.selection) == set(req.correct)  # exactly the correct set
        res = await _book_score(req, req.question, "strong" if hit else "barely", n_je_level)
        res["feedback"] = "Correct — all correct ones hit." if hit else "Not quite — the marked ones were correct."
        return res

    # --- Gap text: easy (term from 4) +1/−1 · hard (free typing) +3/−1 ---
    if req.action == "gap_question":
        if not req.pattern.strip():
            raise HTTPException(400, "Gap text needs a pattern")
        if req.schwer:
            lt = await generate_gaptext(req.topic, req.block, req.section, compact, req.pattern, tier=tier, provider=req.provider)
            if lt is None:
                raise HTTPException(502, "Gap text failed — please try again")
            return {"sentence": lt["sentence"], "solution": lt["solution"], "alternatives": lt["alternatives"],
                    "good_answers": good, "cap": cap}
        distractors = await hurdles_distractor_block(req.topic, req.block)
        lw = await generate_gapchoice(req.topic, req.block, req.section, compact, req.pattern, tier=tier, provider=req.provider, distractor_block=distractors)
        if lw is None:
            raise HTTPException(502, "Gap text failed — please try again")
        return {"sentence": lw["sentence"], "options": lw["options"],
                "good_answers": good, "cap": cap}

    if req.action == "gap_answer":
        if not req.question.strip():
            raise HTTPException(400, "Gap-text answer needs a sentence")
        if req.schwer:  # free typed → synonym-tolerant AI check
            ok = await check_gaptext(req.topic, req.block, req.question, req.solution, req.alternatives, req.input, provider=req.provider)
            feedback = "Correct!" if ok else f"Not quite — expected „{req.solution}“."
        else:  # term chosen from 4 → deterministic
            ok = set(req.selection) == set(req.correct)
            feedback = "Correct!" if ok else "Not quite — the marked term was correct."
        res = await _book_score(req, req.question, "strong" if ok else "barely", n_je_level)
        res["feedback"] = feedback
        return res

    # action "answer" (Agent 1 fast) / "answer_check" (Agent 2 thorough).
    if not any(m.get("role") == "user" for m in msgs):
        raise HTTPException(400, "Answer needs a user answer")
    if not req.question.strip():
        raise HTTPException(400, "Answer needs an active question")

    if req.action == "answer":
        # Agent 1: preview only — tier + expected points, persist NOTHING, no anchor.
        data = await exam_rating_fast(
            req.topic, req.block, req.section, compact, req.question, msgs, provider=req.provider,
        )
        if data is None:
            raise HTTPException(502, "Rating failed — please try again")
        basis, re_rating = _basis(state, req.question)
        streak_basis = state["offene_streak"] if re_rating else state["streak"]
        s = thresholds(n_je_level)
        ca = cap_aktuell(basis, n_je_level)
        floor = floor_from_score(basis, s[-1], s)
        tier = cap_followup(data["tier"], req.asked_again)
        d, _ = points_delta(tier, streak_basis, basis, ca)
        score = compute_score(basis, d, floor, ca, s[-1])
        points = score - basis
        return {"feedback": data["feedback"], "points": points, "rating": _color(points),
                "good_answers": good, "cap": cap}

    # action "answer_check" (Agent 2 thorough): binding, persisted. ONLY here does the score change.
    # The LLM runs WITHOUT a lock; booking is done briefly via _book_score (anchor + score), as with quiz/gap.
    # This way the long AI rating doesn't block a following (deterministic) answer of the same block.
    data = await exam_rating(
        req.topic, req.block, req.section, compact, req.question, msgs, provider=req.provider,
        role="guide" if req.thorough else "judge", reason=req.reason,
    )
    if data is None:
        raise HTTPException(502, "Rating failed — please try again")
    tier = cap_followup(data["tier"], req.asked_again)
    res = await _book_score(req, req.question, tier, n_je_level)  # short lock: drift-free base via anchor
    res["feedback"] = data["feedback"]
    return res


# --- Guides ---

@router.post("/guides", response_model=GuideResponse)
async def create(req: GuideCreateRequest):
    guides, levels = await load_learnstate()
    reason = guide_lock(req.topic.strip(), req.format, guides, levels)
    if reason:
        raise HTTPException(400 if reason == "Erst Blocks erstellen" else 409, reason)  # string matches rules.py contract
    await create_topic(req.topic.strip())
    now = datetime.now(timezone.utc).isoformat()
    guide = {
        "id": str(uuid.uuid4()),
        "topic": req.topic.strip(),
        "format": req.format,
        "instructions": req.instructions.strip(),
        "status": "queued",
        "progress": None,
        "created_at": now,
        "updated_at": now,
    }
    await create_guide(guide)
    asyncio.create_task(generate_guide(guide["id"], guide["topic"], guide["format"], guide["instructions"], req.provider, ab_step=req.ab_step))
    return guide


@router.get("/guides", response_model=list[GuideResponse])
async def list_all():
    return await list_guides()


@router.get("/guides/board")
async def get_guide_board(topic: str, format: str = "Guide"):
    """Live guide board: columns with counts + cards (rounds, covered objectives), agents."""
    import guide_board
    snap = await guide_board.board_snapshot(topic, format)
    guide = next((g for g in await list_guides()
                  if g["topic"] == topic and g["format"] == format), None)
    snap["generating"] = bool(guide and guide["status"] in ("queued", "generating"))
    snap["guide_id"] = guide["id"] if guide else None
    snap["progress"] = guide.get("progress") if guide else None
    snap["error"] = guide.get("error_msg") if guide else None
    prefix = f"{guide['id']}-" if guide else "-"
    snap["agents"] = [{"key": a["key"], "label": a["label"] or a["key"].removeprefix(prefix), "runtime": a["runtime"]}
                      for a in active_agents(prefix)]
    return snap


@router.post("/guides/board/reset")
async def reset_guide_board(req: GuideBoardResetRequest):
    """Reset cards from a stage onward — without generation (pendant to blocks reset-stage)."""
    import guide_board
    topic = req.topic.strip()
    guide = next((g for g in await list_guides()
                  if g["topic"] == topic and g["format"] == req.format), None)
    if guide and guide["status"] in ("queued", "generating"):
        return {"ok": True, "status": "generating"}
    moved = await guide_board.reset_from_stage(topic, req.format, req.ab_stage)
    return {"ok": True, "moved": moved}


@router.get("/guides/{guide_id}/content")
async def guide_content(guide_id: str, level: int = 4):
    """Guide content. `level` (1=A · 2=F · 3=E · 4=V) filters to subblocks up to this
    level; 4 = full version (raw, unchanged)."""
    guide = await get_guide(guide_id)
    if guide is None:
        raise HTTPException(404, "Guide not found")
    if guide["status"] != "done":
        raise HTTPException(404, "Content not available")
    stored = await get_guide_content(guide["topic"], guide["format"])  # DB-first
    if stored is None:
        path = guide_content_path(guide["topic"], guide["format"])  # fallback: file (legacy topics)
        if not path.exists():
            raise HTTPException(404, "File not found")
        stored = path.read_text(encoding="utf-8")
    if level >= 4:
        return Response(content=stored, media_type="application/json")  # full version, raw
    try:
        return content_fuer_level(json.loads(stored), level)
    except ValueError:
        return Response(content=stored, media_type="application/json")


@router.post("/guides/{guide_id}/chat", response_model=GuideChatResponse)
async def guide_chat(guide_id: str, req: GuideChatRequest):
    guide = await get_guide(guide_id)
    if guide is None:
        raise HTTPException(404, "Guide not found")
    reply = await chat_with_guide(
        guide["topic"], guide["format"], req.section, req.outline,
        [m.model_dump() for m in req.messages],
        provider=req.provider,
    )
    return {"reply": reply}


async def _guide_tf(guide_id: str) -> tuple[str, str]:
    guide = await get_guide(guide_id)
    if guide is None:
        raise HTTPException(404, "Guide not found")
    return guide["topic"], guide["format"]


@router.post("/guides/{guide_id}/block/pruefen", response_model=BlockPruefenResponse)
async def block_pruefen_route(guide_id: str, req: BlockPruefenRequest):
    topic, fmt = await _guide_tf(guide_id)
    new = await block_pruefen(topic, fmt, req.block, req.spot, req.snippet, req.hint, provider=req.provider)
    if new is None:
        raise HTTPException(502, "Check failed — please try again")
    return {"revised": new}


@router.post("/guides/{guide_id}/block/uebernehmen", response_model=BlockUebernehmenResponse)
async def block_adopt_route(guide_id: str, req: BlockUebernehmenRequest):
    topic, fmt = await _guide_tf(guide_id)
    res = await block_adopt(topic, fmt, req.block, req.spot, req.alt, req.revised)
    if res is None:
        raise HTTPException(404, "Section not found")
    return res


@router.post("/guides/{guide_id}/cancel")
async def cancel(guide_id: str):
    cancelled = await cancel_guide(guide_id)
    if not cancelled:
        raise HTTPException(404, "No active process found")
    return {"ok": True}


@router.post("/guides/board/remove")
async def remove_guide_format(req: GuideFormatRequest):
    """Board-Remove: discard ALL runs of topic+format — old error rows pile up, and the
    per-guide delete keeps the board cards until the LAST row is gone (measured: 8 rows)."""
    doomed = [g for g in await list_guides() if g["topic"] == req.topic and g["format"] == req.format]
    if any(g["status"] in ("queued", "generating") for g in doomed):
        return {"ok": True, "status": "generating"}
    for g in doomed:
        await delete_guide(g["id"])
    await delete_guide_content(req.topic, req.format)
    await delete_guide_board(req.topic, req.format)
    content = guide_content_path(req.topic, req.format)
    for p in guide_slot_files(content):
        p.unlink(missing_ok=True)
    content.unlink(missing_ok=True)
    return {"ok": True, "removed": len(doomed)}


@router.delete("/guides/{guide_id}")
async def remove(guide_id: str, slots: bool = False):
    guide = await get_guide(guide_id)
    if guide is None:
        raise HTTPException(404, "Guide not found")
    await delete_guide(guide_id)
    # Content/step files are shared by all runs of a topic+format — only delete them
    # once no entry needs them anymore. Partial progress (step files without finished
    # content) is kept for resume, unless explicitly requested (slots=1).
    rest = [g for g in await list_guides() if g["topic"] == guide["topic"] and g["format"] == guide["format"]]
    if not rest:
        await delete_guide_content(guide["topic"], guide["format"])
        await delete_guide_board(guide["topic"], guide["format"])  # board cards + lernziele
        content = guide_content_path(guide["topic"], guide["format"])
        if slots or content.exists():
            for p in guide_slot_files(content):
                p.unlink(missing_ok=True)
            content.unlink(missing_ok=True)
    return {"ok": True}