"""
Planungs-KI P0: Kontext-Pack + Hybrid-Retrieval für Übungssuche in der Trainingsplanung.

Siehe .claude/docs/working/PLANNING_EXERCISE_SUGGEST_CONTEXT.md
"""
from __future__ import annotations

import re
from typing import Any, Dict, List, Optional, Sequence, Set, Tuple

from fastapi import HTTPException
from pydantic import BaseModel, Field

from tenant_context import TenantContext, library_content_visibility_sql
from planning_exercise_retrieval import run_multistage_planning_retrieval
from planning_exercise_llm_rank import try_llm_rerank_planning_hits
from planning_exercise_target_pipeline import (
    build_planning_target_with_query_pipeline,
    compose_retrieval_phase,
    should_run_llm_rank_pipeline,
)

# Planungs-Berechtigung + Sektionen (bestehende Implementierung)
from routers.training_planning import (
    _assert_training_unit_permission,
    _fetch_sections,
    _has_planning_role,
)

INTENT_SUGGEST_NEXT = "suggest_next"
INTENT_PROGRESSION_NEXT = "progression_next"
INTENT_DEEPEN_EXERCISE = "deepen_exercise"
INTENT_CONTINUE_PLAN = "continue_plan_goal"
INTENT_FREE_SEARCH = "free_search"

VALID_INTENTS = {
    INTENT_SUGGEST_NEXT,
    INTENT_PROGRESSION_NEXT,
    INTENT_DEEPEN_EXERCISE,
    INTENT_CONTINUE_PLAN,
    INTENT_FREE_SEARCH,
}


_LLM_RERANK_PRE_LIMIT = 32


class PlanningExerciseSuggestRequest(BaseModel):
    unit_id: Optional[int] = Field(default=None, ge=1)
    group_id: Optional[int] = Field(default=None, ge=1)
    section_order_index: Optional[int] = Field(default=None, ge=0)
    phase_order_index: Optional[int] = Field(default=None, ge=0)
    parallel_stream_order_index: Optional[int] = Field(default=None, ge=0)
    anchor_exercise_id: Optional[int] = Field(default=None, ge=1)
    progression_graph_id: Optional[int] = Field(default=None, ge=1)
    query: Optional[str] = ""
    intent_hint: Optional[str] = None
    planned_exercise_ids: Optional[List[int]] = None
    include_llm_intent: bool = True
    include_llm_rank: bool = False
    limit: int = Field(default=20, ge=1, le=50)
    exercise_kind_any: Optional[List[str]] = None


def resolve_planning_exercise_intent(query: Optional[str], intent_hint: Optional[str]) -> str:
    hint = (intent_hint or "").strip().lower()
    if hint in VALID_INTENTS:
        return hint
    q = (query or "").strip().lower()
    if not q:
        return INTENT_SUGGEST_NEXT
    if any(w in q for w in ("nächste", "naechste", "vorschlag", "vorschlagen", "empfehl")):
        return INTENT_SUGGEST_NEXT
    if "vertief" in q:
        return INTENT_DEEPEN_EXERCISE
    if "progression" in q or "graph" in q or "pfad" in q:
        return INTENT_PROGRESSION_NEXT
    if "aufbau" in q or "planung" in q or "bisher" in q:
        return INTENT_CONTINUE_PLAN
    return INTENT_FREE_SEARCH


def _intent_weights(intent: str) -> Dict[str, float]:
    base = {
        "fulltext": 0.18,
        "progression": 0.18,
        "skill": 0.12,
        "plan": 0.08,
        "profile": 0.22,
        "repeat_unit": -0.30,
        "repeat_group": -0.15,
    }
    if intent == INTENT_SUGGEST_NEXT:
        return {
            **base,
            "progression": 0.28,
            "skill": 0.12,
            "plan": 0.10,
            "profile": 0.25,
            "fulltext": 0.08,
        }
    if intent == INTENT_PROGRESSION_NEXT:
        return {**base, "progression": 0.42, "fulltext": 0.12, "skill": 0.10, "profile": 0.20}
    if intent == INTENT_DEEPEN_EXERCISE:
        return {**base, "skill": 0.15, "profile": 0.35, "fulltext": 0.15, "progression": 0.10}
    if intent == INTENT_CONTINUE_PLAN:
        return {**base, "plan": 0.12, "skill": 0.10, "profile": 0.30, "fulltext": 0.10, "progression": 0.08}
    if intent == INTENT_FREE_SEARCH:
        return {**base, "fulltext": 0.45, "progression": 0.08, "skill": 0.08, "profile": 0.15}
    return base


def _collect_planned_exercise_ids(sections: Sequence[Dict[str, Any]]) -> List[int]:
    out: List[int] = []
    seen: Set[int] = set()
    for sec in sorted(sections, key=lambda s: int(s.get("order_index") or 0)):
        items = sec.get("items") or []
        for it in sorted(items, key=lambda x: int(x.get("order_index") or 0)):
            if str(it.get("item_type") or "").strip().lower() == "note":
                continue
            raw = it.get("exercise_id")
            if raw is None:
                continue
            try:
                eid = int(raw)
            except (TypeError, ValueError):
                continue
            if eid < 1 or eid in seen:
                continue
            seen.add(eid)
            out.append(eid)
    return out


def _resolve_anchor_from_plan(
    planned_ids: Sequence[int],
    anchor_exercise_id: Optional[int],
) -> Optional[int]:
    if anchor_exercise_id and int(anchor_exercise_id) > 0:
        return int(anchor_exercise_id)
    if planned_ids:
        return int(planned_ids[-1])
    return None


def _load_exercise_titles(cur, exercise_ids: Sequence[int]) -> Dict[int, str]:
    if not exercise_ids:
        return {}
    ids = list(dict.fromkeys(int(x) for x in exercise_ids if int(x) > 0))
    ph = ",".join(["%s"] * len(ids))
    cur.execute(
        f"SELECT id, title FROM exercises WHERE id IN ({ph})",
        ids,
    )
    return {int(r["id"]): str(r["title"] or "").strip() for r in cur.fetchall()}


def _load_skill_ids_for_exercise(cur, exercise_id: Optional[int]) -> Set[int]:
    if not exercise_id:
        return set()
    cur.execute(
        "SELECT skill_id FROM exercise_skills WHERE exercise_id = %s",
        (int(exercise_id),),
    )
    return {int(r["skill_id"]) for r in cur.fetchall() if r.get("skill_id")}


def _load_progression_successors(
    cur,
    graph_id: Optional[int],
    from_exercise_id: Optional[int],
) -> Tuple[Set[int], Dict[int, str]]:
    if not graph_id or not from_exercise_id:
        return set(), {}
    cur.execute(
        """
        SELECT to_exercise_id, notes
        FROM exercise_progression_edges
        WHERE graph_id = %s AND from_exercise_id = %s
          AND LOWER(TRIM(edge_type)) = 'next_exercise'
        """,
        (int(graph_id), int(from_exercise_id)),
    )
    ids: Set[int] = set()
    notes: Dict[int, str] = {}
    for row in cur.fetchall():
        tid = int(row["to_exercise_id"])
        ids.add(tid)
        n = (row.get("notes") or "").strip()
        if n:
            notes[tid] = n
    return ids, notes


def _load_group_recent_exercise_ids(
    cur,
    group_id: Optional[int],
    exclude_unit_id: Optional[int] = None,
    limit: int = 40,
) -> Set[int]:
    if not group_id:
        return set()
    if exclude_unit_id is not None:
        cur.execute(
            """
            SELECT tusi.exercise_id AS eid
            FROM training_units tu
            INNER JOIN training_unit_sections tus ON tus.training_unit_id = tu.id
            INNER JOIN training_unit_section_items tusi ON tusi.section_id = tus.id
            WHERE tu.group_id = %s
              AND tu.id <> %s
              AND tusi.exercise_id IS NOT NULL
              AND COALESCE(tu.status, '') <> 'cancelled'
            ORDER BY tu.planned_date DESC NULLS LAST, tu.id DESC, tusi.order_index DESC
            LIMIT 200
            """,
            (int(group_id), int(exclude_unit_id)),
        )
    else:
        cur.execute(
            """
            SELECT tusi.exercise_id AS eid
            FROM training_units tu
            INNER JOIN training_unit_sections tus ON tus.training_unit_id = tu.id
            INNER JOIN training_unit_section_items tusi ON tusi.section_id = tus.id
            WHERE tu.group_id = %s
              AND tusi.exercise_id IS NOT NULL
              AND COALESCE(tu.status, '') <> 'cancelled'
            ORDER BY tu.planned_date DESC NULLS LAST, tu.id DESC, tusi.order_index DESC
            LIMIT 200
            """,
            (int(group_id),),
        )
    out: Set[int] = set()
    for r in cur.fetchall():
        if r.get("eid") is None:
            continue
        out.add(int(r["eid"]))
        if len(out) >= limit:
            break
    return out


def _section_title_for_index(sections: Sequence[Dict[str, Any]], section_order_index: Optional[int]) -> Optional[str]:
    if section_order_index is None:
        return None
    for sec in sections:
        if int(sec.get("order_index") or -1) == int(section_order_index):
            t = (sec.get("title") or "").strip()
            return t or None
    return None


def _normalize_query(query: Optional[str]) -> str:
    return re.sub(r"\s+", " ", (query or "").strip())


def _apply_client_planned_override(
    cur,
    pack: Dict[str, Any],
    body: PlanningExerciseSuggestRequest,
) -> Dict[str, Any]:
    """Client-Plan (ungespeichertes Formular) überschreibt DB-Stand."""
    if not body.planned_exercise_ids:
        return pack
    planned_ids: List[int] = []
    seen: Set[int] = set()
    for raw in body.planned_exercise_ids:
        try:
            eid = int(raw)
        except (TypeError, ValueError):
            continue
        if eid < 1 or eid in seen:
            continue
        seen.add(eid)
        planned_ids.append(eid)
    if not planned_ids:
        return pack

    pack["planned_exercise_ids"] = planned_ids
    if not body.anchor_exercise_id:
        anchor_id = _resolve_anchor_from_plan(planned_ids, None)
        pack["anchor_exercise_id"] = anchor_id
        if anchor_id:
            titles = _load_exercise_titles(cur, [anchor_id])
            pack["anchor_title"] = titles.get(anchor_id)
            pack["anchor_skill_ids"] = sorted(_load_skill_ids_for_exercise(cur, anchor_id))
        else:
            pack["anchor_title"] = None
            pack["anchor_skill_ids"] = []
    return pack


def build_planning_exercise_context_pack(
    cur,
    *,
    tenant: TenantContext,
    body: PlanningExerciseSuggestRequest,
) -> Dict[str, Any]:
    profile_id = tenant.profile_id
    role = tenant.global_role

    if not _has_planning_role(role):
        raise HTTPException(status_code=403, detail="Nur Trainer dürfen Planungs-Vorschläge abrufen")

    cur.execute(
        """
        SELECT tu.*, tg.name AS group_name
        FROM training_units tu
        LEFT JOIN training_groups tg ON tg.id = tu.group_id
        WHERE tu.id = %s
        """,
        (body.unit_id,),
    )
    unit_row = cur.fetchone()
    if not unit_row:
        raise HTTPException(status_code=404, detail="Trainingseinheit nicht gefunden")
    unit = dict(unit_row)

    if unit.get("framework_slot_id"):
        if role not in ("admin", "superadmin"):
            cur.execute(
                """
                SELECT fp.created_by FROM training_framework_slots s
                JOIN training_framework_programs fp ON fp.id = s.framework_program_id
                WHERE s.id = %s
                """,
                (unit["framework_slot_id"],),
            )
            fr = cur.fetchone()
            cb = fr["created_by"] if fr else None
            if unit.get("created_by") != profile_id and cb != profile_id:
                raise HTTPException(status_code=403, detail="Keine Berechtigung")
    else:
        if not unit.get("group_id"):
            raise HTTPException(status_code=404, detail="Trainingseinheit nicht gefunden")
        _assert_training_unit_permission(cur, unit, profile_id, role)

    sections = _fetch_sections(cur, int(body.unit_id))
    planned_ids = _collect_planned_exercise_ids(sections)
    anchor_id = _resolve_anchor_from_plan(planned_ids, body.anchor_exercise_id)
    anchor_skills = _load_skill_ids_for_exercise(cur, anchor_id)
    progression_ids, progression_notes = _load_progression_successors(
        cur, body.progression_graph_id, anchor_id
    )
    group_recent = _load_group_recent_exercise_ids(cur, unit.get("group_id"), int(body.unit_id))

    titles = _load_exercise_titles(cur, [x for x in [anchor_id] if x])
    anchor_title = titles.get(anchor_id) if anchor_id else None

    return {
        "unit_id": int(body.unit_id),
        "unit": {
            "id": int(body.unit_id),
            "framework_slot_id": unit.get("framework_slot_id"),
            "origin_framework_slot_id": unit.get("origin_framework_slot_id"),
        },
        "unit_title": (unit.get("title") or unit.get("planned_focus") or "").strip() or None,
        "group_id": unit.get("group_id"),
        "group_name": (unit.get("group_name") or "").strip() or None,
        "section_order_index": body.section_order_index,
        "section_title": _section_title_for_index(sections, body.section_order_index),
        "planned_exercise_ids": planned_ids,
        "anchor_exercise_id": anchor_id,
        "anchor_title": anchor_title,
        "anchor_skill_ids": sorted(anchor_skills),
        "progression_graph_id": body.progression_graph_id,
        "progression_successor_ids": sorted(progression_ids),
        "progression_edge_notes": progression_notes,
        "group_recent_exercise_ids": sorted(group_recent),
    }


def build_client_planning_context_pack(
    cur,
    *,
    tenant: TenantContext,
    body: PlanningExerciseSuggestRequest,
) -> Dict[str, Any]:
    """Freie / Client-Kontext-Suche ohne persistierte training_units.id (Formular, Rahmen-Slot)."""
    role = tenant.global_role
    if not _has_planning_role(role):
        raise HTTPException(status_code=403, detail="Nur Trainer dürfen Planungs-Vorschläge abrufen")

    planned_ids: List[int] = []
    if body.planned_exercise_ids:
        seen: Set[int] = set()
        for raw in body.planned_exercise_ids:
            try:
                eid = int(raw)
            except (TypeError, ValueError):
                continue
            if eid < 1 or eid in seen:
                continue
            seen.add(eid)
            planned_ids.append(eid)

    anchor_id = _resolve_anchor_from_plan(planned_ids, body.anchor_exercise_id)
    anchor_skills = _load_skill_ids_for_exercise(cur, anchor_id)
    progression_ids, progression_notes = _load_progression_successors(
        cur, body.progression_graph_id, anchor_id
    )

    group_id = body.group_id
    group_name = None
    if group_id:
        cur.execute("SELECT name FROM training_groups WHERE id = %s", (int(group_id),))
        gr = cur.fetchone()
        if gr:
            group_name = (gr.get("name") or "").strip() or None

    group_recent = _load_group_recent_exercise_ids(cur, group_id, exclude_unit_id=None)
    titles = _load_exercise_titles(cur, [x for x in [anchor_id] if x])
    anchor_title = titles.get(anchor_id) if anchor_id else None

    return {
        "unit_id": None,
        "unit": {
            "id": None,
            "framework_slot_id": None,
            "origin_framework_slot_id": None,
        },
        "unit_title": None,
        "group_id": group_id,
        "group_name": group_name,
        "section_order_index": body.section_order_index,
        "section_title": None,
        "planned_exercise_ids": planned_ids,
        "anchor_exercise_id": anchor_id,
        "anchor_title": anchor_title,
        "anchor_skill_ids": sorted(anchor_skills),
        "progression_graph_id": body.progression_graph_id,
        "progression_successor_ids": sorted(progression_ids),
        "progression_edge_notes": progression_notes,
        "group_recent_exercise_ids": sorted(group_recent),
        "context_mode": "client_free",
    }


def suggest_planning_exercises(
    cur,
    *,
    tenant: TenantContext,
    body: PlanningExerciseSuggestRequest,
) -> Dict[str, Any]:
    if body.unit_id:
        pack = build_planning_exercise_context_pack(cur, tenant=tenant, body=body)
    else:
        pack = build_client_planning_context_pack(cur, tenant=tenant, body=body)
    pack = _apply_client_planned_override(cur, pack, body)
    query = _normalize_query(body.query)
    heuristic_intent = resolve_planning_exercise_intent(query, body.intent_hint)

    pipeline_context = {
        "unit_title": pack.get("unit_title"),
        "group_name": pack.get("group_name"),
        "section_title": pack.get("section_title"),
        "planned_count": len(pack.get("planned_exercise_ids") or []),
        "anchor_title": pack.get("anchor_title"),
        "anchor_exercise_id": pack.get("anchor_exercise_id"),
        "progression_graph_id": pack.get("progression_graph_id"),
    }
    target_profile, intent, scenario_kind, query_intent_summary = build_planning_target_with_query_pipeline(
        cur,
        unit=pack["unit"],
        planned_exercise_ids=pack["planned_exercise_ids"],
        anchor_exercise_id=pack.get("anchor_exercise_id"),
        query=query,
        heuristic_intent=heuristic_intent,
        include_llm_intent=body.include_llm_intent,
        context_summary=pipeline_context,
    )
    weights = _intent_weights(intent)
    target_profile_summary = target_profile.to_summary_dict(cur)
    query_intent_applied = bool(query_intent_summary.get("llm_applied"))

    profile_id = tenant.profile_id
    role = tenant.global_role
    vis_sql, vis_params = library_content_visibility_sql(
        alias="e",
        profile_id=profile_id,
        role=role,
        effective_club_id=tenant.effective_club_id,
    )

    hits, skills_by_ex, profile_preselect_applied = run_multistage_planning_retrieval(
        cur,
        vis_sql=vis_sql,
        vis_params=vis_params,
        query=query,
        exercise_kind_any=body.exercise_kind_any,
        target=target_profile,
        intent=intent,
        intent_weights=weights,
        pack=pack,
    )

    planned_set = set(pack["planned_exercise_ids"])

    llm_rank_applied = False
    retrieval_phase = compose_retrieval_phase(
        profile_preselect=profile_preselect_applied,
        query_intent=query_intent_applied,
        llm_rank=False,
    )
    run_llm_rank = should_run_llm_rank_pipeline(
        query,
        scenario_kind,
        include_llm_rank=body.include_llm_rank,
        query_intent_applied=query_intent_applied,
        hits=hits,
    )
    if run_llm_rank:
        pre_limit = max(int(body.limit), _LLM_RERANK_PRE_LIMIT)
        pool_hits = hits[:pre_limit]
        pool_hits, llm_rank_applied = try_llm_rerank_planning_hits(
            cur,
            hits=pool_hits,
            skills_by_ex=skills_by_ex,
            query=query,
            intent=intent,
            context_summary={
                "unit_title": pack.get("unit_title"),
                "group_name": pack.get("group_name"),
                "section_title": pack.get("section_title"),
                "planned_count": len(planned_set),
                "anchor_title": pack.get("anchor_title"),
                "intent": intent,
            },
            target_profile_summary=target_profile_summary,
            limit=int(body.limit),
        )
        if llm_rank_applied:
            retrieval_phase = compose_retrieval_phase(
                profile_preselect=profile_preselect_applied,
                query_intent=query_intent_applied,
                llm_rank=True,
            )
            tail = hits[pre_limit:]
            hits = pool_hits + tail
        else:
            hits = pool_hits[: int(body.limit)]
    else:
        hits = hits[: int(body.limit)]

    hits = hits[: int(body.limit)]

    context_summary = {
        "unit_title": pack.get("unit_title"),
        "group_name": pack.get("group_name"),
        "section_title": pack.get("section_title"),
        "planned_count": len(planned_set),
        "anchor_title": pack.get("anchor_title"),
        "anchor_exercise_id": pack.get("anchor_exercise_id"),
        "progression_graph_id": pack.get("progression_graph_id"),
        "context_mode": pack.get("context_mode") or ("unit" if pack.get("unit_id") else "client_free"),
    }

    return {
        "context_summary": context_summary,
        "target_profile_summary": target_profile_summary,
        "scenario_kind": scenario_kind,
        "query_intent_summary": query_intent_summary,
        "retrieval_phase": retrieval_phase,
        "profile_preselect_applied": profile_preselect_applied,
        "llm_rank_applied": llm_rank_applied,
        "llm_intent_applied": query_intent_applied,
        "intent_resolved": intent,
        "intent_heuristic": heuristic_intent,
        "query_normalized": query or None,
        "hits": hits,
    }