"""
Trainingsrahmenprogramm — Rahmen‑Vorlage über mehrere Session‑Slots (CURR‑002 Stufe 2).
AuthZ wie Planungs‑Vorlagen: Admin sieht alle, sonst nur eigene Artefakte; Schreibzugriff mit Planungsrolle.
"""
from typing import Any, Dict, List, Optional

from fastapi import APIRouter, Depends, HTTPException

from auth import require_auth
from db import get_db, get_cursor, r2d

from routers.training_planning import (
    _assert_training_unit_permission,
    _can_access_group_for_create,
    _has_planning_role,
    _optional_positive_int,
    _training_unit_guard_row,
    _validate_variant_for_exercise,
)

router = APIRouter(prefix="/api", tags=["training_framework_programs"])

_VALID_PLAN_MODE = frozenset({"concrete", "library"})
_VALID_VISIBILITY = frozenset({"private", "club", "official"})


def _framework_access(cur, framework_id: int, profile_id: int, role: str) -> Dict[str, Any]:
    cur.execute("SELECT * FROM training_framework_programs WHERE id = %s", (framework_id,))
    r = cur.fetchone()
    if not r:
        raise HTTPException(status_code=404, detail="Trainingsrahmen nicht gefunden")
    row = r2d(r)
    if role in ("admin", "superadmin"):
        return row
    if row.get("created_by") != profile_id:
        raise HTTPException(status_code=403, detail="Keine Berechtigung für diesen Trainingsrahmen")
    return row


def _fetch_slot_exercises(cur, slot_id: int) -> List[Dict[str, Any]]:
    cur.execute(
        """
        SELECT t.id, t.slot_id, t.exercise_id, t.exercise_variant_id, t.order_index,
            e.title AS exercise_title,
            ev.variant_name AS exercise_variant_name
        FROM training_framework_slot_exercises t
        LEFT JOIN exercises e ON e.id = t.exercise_id
        LEFT JOIN exercise_variants ev ON ev.id = t.exercise_variant_id
        WHERE t.slot_id = %s
        ORDER BY t.order_index
        """,
        (slot_id,),
    )
    return [r2d(x) for x in cur.fetchall()]


def _hydrate_framework(cur, row: Dict[str, Any]) -> Dict[str, Any]:
    fid = row["id"]
    cur.execute(
        """
        SELECT id, framework_program_id, sort_order, title, notes
        FROM training_framework_goals
        WHERE framework_program_id = %s
        ORDER BY sort_order
        """,
        (fid,),
    )
    row["goals"] = [r2d(g) for g in cur.fetchall()]
    cur.execute(
        """
        SELECT id, framework_program_id, sort_order, title, notes, training_unit_id
        FROM training_framework_slots
        WHERE framework_program_id = %s
        ORDER BY sort_order
        """,
        (fid,),
    )
    slots = [r2d(s) for s in cur.fetchall()]
    for s in slots:
        s["exercises"] = _fetch_slot_exercises(cur, s["id"])
    row["slots"] = slots
    return row


def _assert_visibility(val: Optional[str]) -> Optional[str]:
    if val is None:
        return None
    if val not in _VALID_VISIBILITY:
        raise HTTPException(
            status_code=400,
            detail="visibility muss private, club oder official sein",
        )
    return val


def _assert_framework_invariants(plan_mode: str, group_id: Optional[int]) -> None:
    if plan_mode == "library" and group_id is not None:
        raise HTTPException(
            status_code=400,
            detail="plan_mode library erlaubt kein group_id",
        )


def _assert_slot_unit_constraints(
    cur,
    plan_mode: str,
    framework_group_id: Optional[int],
    training_unit_id: Optional[int],
    profile_id: int,
    role: str,
) -> None:
    if plan_mode == "library" and training_unit_id:
        raise HTTPException(
            status_code=400,
            detail="Im Bibliotheksmodus (library) keine Verknüpfung von Slots zu Trainingseinheiten",
        )
    if not training_unit_id:
        return
    uid = training_unit_id
    unit_row = _training_unit_guard_row(cur, uid)
    _assert_training_unit_permission(cur, unit_row, profile_id, role)
    if framework_group_id is not None and unit_row["group_id"] != framework_group_id:
        raise HTTPException(
            status_code=400,
            detail="training_unit_id muss zur group_id dieses Rahmens gehören",
        )


def _insert_goal_rows(cur, framework_id: int, goals_in: List[Any]) -> None:
    if not goals_in:
        raise HTTPException(status_code=400, detail="Mindestens ein Entwicklungsziel (goals) ist erforderlich")
    for gi, g in enumerate(goals_in):
        title_g = (g.get("title") or "").strip()
        if not title_g:
            raise HTTPException(status_code=400, detail="Jedes Ziel braucht ein nicht-leeres title")
        order_ix = g.get("sort_order")
        if order_ix is None:
            order_ix = gi
        cur.execute(
            """
            INSERT INTO training_framework_goals (
                framework_program_id, sort_order, title, notes
            ) VALUES (%s, %s, %s, %s)
            """,
            (framework_id, int(order_ix), title_g[:500], g.get("notes")),
        )


def _insert_slots_and_exercises(
    cur,
    framework_id: int,
    plan_mode: str,
    framework_group_id: Optional[int],
    slots_in: Optional[List[Any]],
    profile_id: int,
    role: str,
) -> None:
    if slots_in is None:
        return
    for si, slot in enumerate(slots_in):
        order_ix = slot.get("sort_order")
        if order_ix is None:
            order_ix = si
        title_s = slot.get("title")
        if title_s is not None:
            title_s = title_s.strip() or None
        unit_sid = _optional_positive_int(slot.get("training_unit_id"), "training_unit_id")
        _assert_slot_unit_constraints(cur, plan_mode, framework_group_id, unit_sid, profile_id, role)

        cur.execute(
            """
            INSERT INTO training_framework_slots (
                framework_program_id, sort_order, title, notes, training_unit_id
            ) VALUES (%s, %s, %s, %s, %s)
            RETURNING id
            """,
            (
                framework_id,
                int(order_ix),
                title_s,
                slot.get("notes"),
                unit_sid,
            ),
        )
        sid = cur.fetchone()["id"]
        ex_items = slot.get("exercises") or []
        for ej, raw in enumerate(ex_items):
            eid = raw.get("exercise_id")
            if not eid:
                continue
            eid = int(eid)
            vid = _optional_positive_int(raw.get("exercise_variant_id"), "exercise_variant_id")
            _validate_variant_for_exercise(cur, eid, vid)
            oidx = raw.get("order_index")
            if oidx is None:
                oidx = ej
            cur.execute(
                """
                INSERT INTO training_framework_slot_exercises (
                    slot_id, exercise_id, exercise_variant_id, order_index
                ) VALUES (%s, %s, %s, %s)
                """,
                (sid, eid, vid, int(oidx)),
            )


@router.get("/training-framework-programs")
def list_training_framework_programs(session=Depends(require_auth)):
    profile_id = session["profile_id"]
    role = session.get("role")
    with get_db() as conn:
        cur = get_cursor(conn)
        base_sel = """
            SELECT fp.*,
                (SELECT COUNT(*)::int FROM training_framework_goals g WHERE g.framework_program_id = fp.id)
                    AS goals_count,
                (SELECT COUNT(*)::int FROM training_framework_slots s WHERE s.framework_program_id = fp.id)
                    AS slots_count
            FROM training_framework_programs fp
        """
        if role in ("admin", "superadmin"):
            cur.execute(base_sel + " ORDER BY fp.updated_at DESC NULLS LAST, fp.title")
        else:
            cur.execute(
                base_sel + " WHERE fp.created_by = %s ORDER BY fp.updated_at DESC NULLS LAST, fp.title",
                (profile_id,),
            )
        return [r2d(r) for r in cur.fetchall()]


@router.get("/training-framework-programs/{framework_id}")
def get_training_framework_program(framework_id: int, session=Depends(require_auth)):
    profile_id = session["profile_id"]
    role = session.get("role")
    with get_db() as conn:
        cur = get_cursor(conn)
        row = _framework_access(cur, framework_id, profile_id, role)
        return _hydrate_framework(cur, row)


@router.post("/training-framework-programs")
def create_training_framework_program(data: dict, session=Depends(require_auth)):
    profile_id = session["profile_id"]
    role = session.get("role")
    if not _has_planning_role(role):
        raise HTTPException(status_code=403, detail="Nur Planungsberechtigte dürfen Rahmenprogramme anlegen")

    title = (data.get("title") or "").strip()
    if not title:
        raise HTTPException(status_code=400, detail="title ist Pflicht")

    plan_mode = (data.get("plan_mode") or "").strip().lower()
    if plan_mode not in _VALID_PLAN_MODE:
        raise HTTPException(status_code=400, detail="plan_mode muss concrete oder library sein")

    gid = None
    if data.get("group_id") not in (None, ""):
        gid = _optional_positive_int(data.get("group_id"), "group_id")
    _assert_framework_invariants(plan_mode, gid)

    vis = data.get("visibility") or "private"
    vis = _assert_visibility(vis)
    club_id = data.get("club_id")

    goals_in = data.get("goals")
    slots_in = data.get("slots")
    if not isinstance(goals_in, list) or not goals_in:
        raise HTTPException(status_code=400, detail="goals als Liste mit mindestens einem Eintrag ist Pflicht")

    with get_db() as conn:
        cur = get_cursor(conn)
        if gid is not None:
            _can_access_group_for_create(cur, gid, profile_id, role)

        cur.execute(
            """
            INSERT INTO training_framework_programs (
                title, description, plan_mode, group_id,
                planned_period_start, planned_period_end,
                visibility, club_id, created_by
            ) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s)
            RETURNING id
            """,
            (
                title[:200],
                data.get("description"),
                plan_mode,
                gid,
                data.get("planned_period_start"),
                data.get("planned_period_end"),
                vis,
                club_id,
                profile_id,
            ),
        )
        fid = cur.fetchone()["id"]
        _insert_goal_rows(cur, fid, goals_in)
        _insert_slots_and_exercises(cur, fid, plan_mode, gid, slots_in, profile_id, role)
        conn.commit()

    return get_training_framework_program(fid, session)


@router.put("/training-framework-programs/{framework_id}")
def update_training_framework_program(framework_id: int, data: dict, session=Depends(require_auth)):
    profile_id = session["profile_id"]
    role = session.get("role")
    if not _has_planning_role(role):
        raise HTTPException(status_code=403, detail="Keine Berechtigung")

    with get_db() as conn:
        cur = get_cursor(conn)
        existing = _framework_access(cur, framework_id, profile_id, role)

        plan_mode_new = existing["plan_mode"]
        if "plan_mode" in data:
            pm = (data.get("plan_mode") or "").strip().lower()
            if pm not in _VALID_PLAN_MODE:
                raise HTTPException(status_code=400, detail="plan_mode muss concrete oder library sein")
            plan_mode_new = pm

        group_id_eff = existing.get("group_id")
        if "group_id" in data:
            if data.get("group_id") in (None, ""):
                group_id_eff = None
            else:
                group_id_eff = _optional_positive_int(data.get("group_id"), "group_id")
        _assert_framework_invariants(plan_mode_new, group_id_eff)

        header_fields = []
        header_params: List[Any] = []
        if "title" in data:
            tit = (data.get("title") or "").strip()
            if not tit:
                raise HTTPException(status_code=400, detail="title ist Pflicht")
            header_fields.append("title = %s")
            header_params.append(tit[:200])
        if "description" in data:
            header_fields.append("description = %s")
            header_params.append(data.get("description"))
        if "plan_mode" in data:
            header_fields.append("plan_mode = %s")
            header_params.append(plan_mode_new)
        if "group_id" in data:
            header_fields.append("group_id = %s")
            header_params.append(group_id_eff)
        if "planned_period_start" in data:
            header_fields.append("planned_period_start = %s")
            header_params.append(data.get("planned_period_start"))
        if "planned_period_end" in data:
            header_fields.append("planned_period_end = %s")
            header_params.append(data.get("planned_period_end"))
        if "visibility" in data:
            v = _assert_visibility(data.get("visibility"))
            if v is None:
                raise HTTPException(status_code=400, detail="visibility fehlt")
            header_fields.append("visibility = %s")
            header_params.append(v)
        if "club_id" in data:
            header_fields.append("club_id = %s")
            header_params.append(data.get("club_id"))

        if group_id_eff is not None and (
            ("group_id" in data)
            or (plan_mode_new == "concrete" and plan_mode_new != existing.get("plan_mode"))
        ):
            _can_access_group_for_create(cur, group_id_eff, profile_id, role)

        if header_fields:
            header_fields.append("updated_at = NOW()")
            header_params.append(framework_id)
            cur.execute(
                f"""
                UPDATE training_framework_programs
                SET {", ".join(header_fields)}
                WHERE id = %s
                """,
                tuple(header_params),
            )

        if "goals" in data:
            goals_in = data["goals"]
            if not isinstance(goals_in, list) or not goals_in:
                raise HTTPException(status_code=400, detail="goals als Liste mit mindestens einem Eintrag ist Pflicht")
            cur.execute(
                "DELETE FROM training_framework_goals WHERE framework_program_id = %s",
                (framework_id,),
            )
            _insert_goal_rows(cur, framework_id, goals_in)

        if "slots" in data:
            cur.execute(
                "DELETE FROM training_framework_slots WHERE framework_program_id = %s",
                (framework_id,),
            )
            _insert_slots_and_exercises(
                cur,
                framework_id,
                plan_mode_new,
                group_id_eff,
                data.get("slots") or [],
                profile_id,
                role,
            )

        if plan_mode_new == "library":
            cur.execute(
                """
                UPDATE training_framework_slots SET training_unit_id = NULL
                WHERE framework_program_id = %s AND training_unit_id IS NOT NULL
                """,
                (framework_id,),
            )

        if "goals" in data or "slots" in data or header_fields:
            cur.execute(
                "UPDATE training_framework_programs SET updated_at = NOW() WHERE id = %s",
                (framework_id,),
            )

        conn.commit()

    return get_training_framework_program(framework_id, session)


@router.delete("/training-framework-programs/{framework_id}")
def delete_training_framework_program(framework_id: int, session=Depends(require_auth)):
    profile_id = session["profile_id"]
    role = session.get("role")
    with get_db() as conn:
        cur = get_cursor(conn)
        _framework_access(cur, framework_id, profile_id, role)
        cur.execute(
            "DELETE FROM training_framework_programs WHERE id = %s",
            (framework_id,),
        )
        conn.commit()
    return {"ok": True}