bambuddy/backend/app/api/routes/inventory.py

import json
import logging

import httpx
from fastapi import APIRouter, Depends, HTTPException
from fastapi.responses import StreamingResponse
from pydantic import BaseModel
from sqlalchemy import func, select
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import selectinload

from backend.app.core.auth import RequirePermissionIfAuthEnabled, require_auth_if_enabled
from backend.app.core.catalog_defaults import DEFAULT_COLOR_CATALOG, DEFAULT_SPOOL_CATALOG
from backend.app.core.database import get_db
from backend.app.core.permissions import Permission
from backend.app.core.websocket import ws_manager
from backend.app.models.ams_label import AmsLabel
from backend.app.models.color_catalog import ColorCatalogEntry
from backend.app.models.spool import Spool
from backend.app.models.spool_assignment import SpoolAssignment
from backend.app.models.spool_catalog import SpoolCatalogEntry
from backend.app.models.spool_k_profile import SpoolKProfile
from backend.app.models.user import User
from backend.app.schemas.spool import (
    SpoolAssignmentCreate,
    SpoolAssignmentResponse,
    SpoolBulkCreate,
    SpoolCreate,
    SpoolKProfileBase,
    SpoolKProfileResponse,
    SpoolResponse,
    SpoolUpdate,
)
from backend.app.schemas.spool_usage import SpoolUsageHistoryResponse
from backend.app.utils.filament_ids import filament_id_to_setting_id, normalize_slicer_filament
from backend.app.utils.tag_normalization import normalize_tag_uid, normalize_tray_uuid

logger = logging.getLogger(__name__)

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

# Material temperature defaults (nozzle min/max)
MATERIAL_TEMPS: dict[str, tuple[int, int]] = {
    "PLA": (190, 230),
    "PETG": (220, 260),
    "ABS": (240, 270),
    "ASA": (240, 270),
    "TPU": (200, 240),
    "PA": (260, 290),
    "PC": (250, 280),
    "PVA": (190, 210),
    "PLA-CF": (210, 240),
    "PETG-CF": (240, 270),
    "PA-CF": (270, 300),
}

# FilamentColors.xyz API
FILAMENT_COLORS_API = "https://filamentcolors.xyz/api"


# ── Spool Catalog Schemas ──────────────────────────────────────────────────


class CatalogEntryResponse(BaseModel):
    id: int
    name: str
    weight: int
    is_default: bool

    class Config:
        from_attributes = True


class CatalogEntryCreate(BaseModel):
    name: str
    weight: int


class CatalogEntryUpdate(BaseModel):
    name: str
    weight: int


class BulkDeleteIdsRequest(BaseModel):
    ids: list[int]


# ── Color Catalog Schemas ──────────────────────────────────────────────────


class ColorEntryResponse(BaseModel):
    id: int
    manufacturer: str
    color_name: str
    hex_color: str
    material: str | None
    is_default: bool

    class Config:
        from_attributes = True


class ColorEntryCreate(BaseModel):
    manufacturer: str
    color_name: str
    hex_color: str
    material: str | None = None


class ColorEntryUpdate(BaseModel):
    manufacturer: str
    color_name: str
    hex_color: str
    material: str | None = None


class ColorLookupResult(BaseModel):
    found: bool
    hex_color: str | None = None
    material: str | None = None


# ── Spool Catalog CRUD ─────────────────────────────────────────────────────


@router.get("/catalog", response_model=list[CatalogEntryResponse])
async def get_spool_catalog(
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_READ),
):
    """Get all spool catalog entries."""
    result = await db.execute(select(SpoolCatalogEntry).order_by(SpoolCatalogEntry.name))
    return list(result.scalars().all())


@router.post("/catalog", response_model=CatalogEntryResponse)
async def add_catalog_entry(
    entry: CatalogEntryCreate,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Add a new spool catalog entry."""
    row = SpoolCatalogEntry(name=entry.name, weight=entry.weight, is_default=False)
    db.add(row)
    await db.commit()
    await db.refresh(row)
    return row


@router.put("/catalog/{entry_id}", response_model=CatalogEntryResponse)
async def update_catalog_entry(
    entry_id: int,
    entry: CatalogEntryUpdate,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Update a spool catalog entry."""
    result = await db.execute(select(SpoolCatalogEntry).where(SpoolCatalogEntry.id == entry_id))
    row = result.scalar_one_or_none()
    if not row:
        raise HTTPException(404, "Entry not found")
    row.name = entry.name
    row.weight = entry.weight
    await db.commit()
    await db.refresh(row)
    return row


@router.delete("/catalog/{entry_id}")
async def delete_catalog_entry(
    entry_id: int,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Delete a spool catalog entry."""
    result = await db.execute(select(SpoolCatalogEntry).where(SpoolCatalogEntry.id == entry_id))
    row = result.scalar_one_or_none()
    if not row:
        raise HTTPException(404, "Entry not found")
    await db.delete(row)
    await db.commit()
    return {"status": "deleted"}


@router.post("/catalog/bulk-delete")
async def bulk_delete_catalog_entries(
    data: BulkDeleteIdsRequest,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Delete multiple spool catalog entries by ID."""
    if not data.ids:
        return {"deleted": 0}
    result = await db.execute(select(SpoolCatalogEntry).where(SpoolCatalogEntry.id.in_(data.ids)))
    rows = result.scalars().all()
    for row in rows:
        await db.delete(row)
    await db.commit()
    return {"deleted": len(rows)}


@router.post("/catalog/reset")
async def reset_spool_catalog(
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Reset spool catalog to defaults."""
    await db.execute(select(SpoolCatalogEntry))  # ensure table loaded
    # Delete all
    result = await db.execute(select(SpoolCatalogEntry))
    for row in result.scalars().all():
        await db.delete(row)
    # Re-seed defaults
    for name, weight in DEFAULT_SPOOL_CATALOG:
        db.add(SpoolCatalogEntry(name=name, weight=weight, is_default=True))
    await db.commit()
    return {"status": "reset"}


# ── Color Catalog CRUD ─────────────────────────────────────────────────────


@router.get("/colors", response_model=list[ColorEntryResponse])
async def get_color_catalog(
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_READ),
):
    """Get all color catalog entries."""
    result = await db.execute(
        select(ColorCatalogEntry).order_by(
            ColorCatalogEntry.manufacturer, ColorCatalogEntry.material, ColorCatalogEntry.color_name
        )
    )
    return list(result.scalars().all())


@router.get("/colors/map")
async def get_color_name_map(
    db: AsyncSession = Depends(get_db),
    _: User | None = Depends(require_auth_if_enabled),
):
    """Compact {hex: name} map for frontend color-name resolution.

    Not gated on INVENTORY_READ — every page that renders a spool color needs
    this, including read-only views available to users without inventory access.
    Normalized to lowercase 6-char hex without '#'. When multiple catalog entries
    share the same hex (different materials or manufacturers), Bambu Lab wins,
    then default entries, then the first encountered.
    """
    result = await db.execute(
        select(
            ColorCatalogEntry.hex_color,
            ColorCatalogEntry.color_name,
            ColorCatalogEntry.manufacturer,
            ColorCatalogEntry.is_default,
        )
    )
    mapping: dict[str, tuple[str, int]] = {}  # hex → (name, priority); higher priority wins
    for hex_color, color_name, manufacturer, is_default in result.all():
        if not hex_color or not color_name:
            continue
        key = hex_color.lstrip("#").lower()[:6]
        if len(key) != 6:
            continue
        priority = 0
        if manufacturer and manufacturer.strip().lower() == "bambu lab":
            priority += 2
        if is_default:
            priority += 1
        existing = mapping.get(key)
        if existing is None or priority > existing[1]:
            mapping[key] = (color_name, priority)
    return {"colors": {k: v[0] for k, v in mapping.items()}}


@router.post("/colors", response_model=ColorEntryResponse)
async def add_color_entry(
    entry: ColorEntryCreate,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Add a new color catalog entry."""
    row = ColorCatalogEntry(
        manufacturer=entry.manufacturer,
        color_name=entry.color_name,
        hex_color=entry.hex_color,
        material=entry.material,
        is_default=False,
    )
    db.add(row)
    await db.commit()
    await db.refresh(row)
    return row


@router.put("/colors/{entry_id}", response_model=ColorEntryResponse)
async def update_color_entry(
    entry_id: int,
    entry: ColorEntryUpdate,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Update a color catalog entry."""
    result = await db.execute(select(ColorCatalogEntry).where(ColorCatalogEntry.id == entry_id))
    row = result.scalar_one_or_none()
    if not row:
        raise HTTPException(404, "Entry not found")
    row.manufacturer = entry.manufacturer
    row.color_name = entry.color_name
    row.hex_color = entry.hex_color
    row.material = entry.material
    await db.commit()
    await db.refresh(row)
    return row


@router.delete("/colors/{entry_id}")
async def delete_color_entry(
    entry_id: int,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Delete a color catalog entry."""
    result = await db.execute(select(ColorCatalogEntry).where(ColorCatalogEntry.id == entry_id))
    row = result.scalar_one_or_none()
    if not row:
        raise HTTPException(404, "Entry not found")
    await db.delete(row)
    await db.commit()
    return {"status": "deleted"}


@router.post("/colors/bulk-delete")
async def bulk_delete_color_entries(
    data: BulkDeleteIdsRequest,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Delete multiple color catalog entries by ID."""
    if not data.ids:
        return {"deleted": 0}
    result = await db.execute(select(ColorCatalogEntry).where(ColorCatalogEntry.id.in_(data.ids)))
    rows = result.scalars().all()
    for row in rows:
        await db.delete(row)
    await db.commit()
    return {"deleted": len(rows)}


@router.post("/colors/reset")
async def reset_color_catalog(
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Reset color catalog to defaults."""
    result = await db.execute(select(ColorCatalogEntry))
    for row in result.scalars().all():
        await db.delete(row)
    for manufacturer, color_name, hex_color, material in DEFAULT_COLOR_CATALOG:
        db.add(
            ColorCatalogEntry(
                manufacturer=manufacturer,
                color_name=color_name,
                hex_color=hex_color,
                material=material,
                is_default=True,
            )
        )
    await db.commit()
    return {"status": "reset"}


@router.get("/colors/lookup", response_model=ColorLookupResult)
async def lookup_color(
    manufacturer: str,
    color_name: str,
    material: str | None = None,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_READ),
):
    """Look up a color by manufacturer and color name."""
    query = select(ColorCatalogEntry).where(
        ColorCatalogEntry.manufacturer == manufacturer,
        ColorCatalogEntry.color_name == color_name,
    )
    if material:
        query = query.where(ColorCatalogEntry.material == material)
    query = query.limit(1)
    result = await db.execute(query)
    row = result.scalar_one_or_none()
    if row:
        return ColorLookupResult(found=True, hex_color=row.hex_color, material=row.material)
    return ColorLookupResult(found=False)


@router.get("/colors/search", response_model=list[ColorEntryResponse])
async def search_colors(
    manufacturer: str | None = None,
    material: str | None = None,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_READ),
):
    """Search colors by manufacturer and/or material."""
    query = select(ColorCatalogEntry)
    if manufacturer:
        query = query.where(func.lower(ColorCatalogEntry.manufacturer).contains(manufacturer.lower()))
    if material:
        query = query.where(func.lower(ColorCatalogEntry.material).contains(material.lower()))
    query = query.order_by(ColorCatalogEntry.manufacturer, ColorCatalogEntry.color_name).limit(100)
    result = await db.execute(query)
    return list(result.scalars().all())


@router.post("/colors/sync")
async def sync_from_filamentcolors(
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Sync colors from FilamentColors.xyz API with progress streaming."""

    async def generate():
        from backend.app.core.database import async_session

        added = 0
        skipped = 0
        total_fetched = 0
        total_available = 0

        try:
            async with httpx.AsyncClient(timeout=120.0) as client:
                page = 1
                while True:
                    response = await client.get(
                        f"{FILAMENT_COLORS_API}/swatch/",
                        params={"page": page},
                    )
                    response.raise_for_status()
                    data = response.json()
                    total_available = data.get("count", total_available)
                    results = data.get("results", [])
                    if not results:
                        break

                    async with async_session() as db:
                        for swatch in results:
                            total_fetched += 1
                            manufacturer_data = swatch.get("manufacturer")
                            manufacturer_name = (
                                manufacturer_data.get("name", "") if isinstance(manufacturer_data, dict) else ""
                            )
                            filament_type_data = swatch.get("filament_type")
                            mat = filament_type_data.get("name", "") if isinstance(filament_type_data, dict) else None
                            color_name_val = swatch.get("color_name", "")
                            hex_color_val = swatch.get("hex_color", "")

                            if not manufacturer_name or not color_name_val or not hex_color_val:
                                skipped += 1
                                continue

                            if not hex_color_val.startswith("#"):
                                hex_color_val = f"#{hex_color_val}"

                            # Check if entry already exists
                            existing = await db.execute(
                                select(ColorCatalogEntry)
                                .where(
                                    ColorCatalogEntry.manufacturer == manufacturer_name,
                                    ColorCatalogEntry.color_name == color_name_val,
                                    ColorCatalogEntry.material == mat,
                                )
                                .limit(1)
                            )
                            if existing.scalar_one_or_none():
                                skipped += 1
                            else:
                                db.add(
                                    ColorCatalogEntry(
                                        manufacturer=manufacturer_name,
                                        color_name=color_name_val,
                                        hex_color=hex_color_val.upper(),
                                        material=mat,
                                        is_default=False,
                                    )
                                )
                                added += 1

                        await db.commit()

                    progress = {
                        "type": "progress",
                        "added": added,
                        "skipped": skipped,
                        "total_fetched": total_fetched,
                        "total_available": total_available,
                    }
                    yield f"data: {json.dumps(progress)}\n\n"

                    if not data.get("next") or total_fetched >= total_available:
                        break
                    page += 1

            result = {
                "type": "complete",
                "added": added,
                "skipped": skipped,
                "total_fetched": total_fetched,
                "total_available": total_available,
            }
            yield f"data: {json.dumps(result)}\n\n"

        except httpx.HTTPError as e:
            logger.error("HTTP error syncing from FilamentColors.xyz: %s", e)
            yield f"data: {json.dumps({'type': 'error', 'error': str(e)})}\n\n"
        except Exception as e:
            logger.error("Error syncing from FilamentColors.xyz: %s", e)
            yield f"data: {json.dumps({'type': 'error', 'error': 'Unexpected error during sync'})}\n\n"

    return StreamingResponse(generate(), media_type="text/event-stream")


# ── Spool CRUD ───────────────────────────────────────────────────────────────


@router.get("/spools", response_model=list[SpoolResponse])
async def list_spools(
    include_archived: bool = False,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_READ),
):
    """List all spools, excluding archived by default."""
    query = select(Spool).options(selectinload(Spool.k_profiles))
    if not include_archived:
        query = query.where(Spool.archived_at.is_(None))
    query = query.order_by(Spool.material, Spool.brand, Spool.color_name)
    result = await db.execute(query)
    return list(result.scalars().all())


@router.get("/spools/{spool_id}", response_model=SpoolResponse)
async def get_spool(
    spool_id: int,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_READ),
):
    """Get a single spool with k_profiles."""
    result = await db.execute(select(Spool).options(selectinload(Spool.k_profiles)).where(Spool.id == spool_id))
    spool = result.scalar_one_or_none()
    if not spool:
        raise HTTPException(404, "Spool not found")
    return spool


@router.post("/spools", response_model=SpoolResponse)
async def create_spool(
    spool_data: SpoolCreate,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Create a new spool."""
    spool = Spool(**spool_data.model_dump())
    db.add(spool)
    await db.commit()
    await db.refresh(spool)
    result = await db.execute(select(Spool).options(selectinload(Spool.k_profiles)).where(Spool.id == spool.id))
    await ws_manager.broadcast({"type": "inventory_changed"})
    return result.scalar_one()


@router.post("/spools/bulk", response_model=list[SpoolResponse])
async def bulk_create_spools(
    data: SpoolBulkCreate,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Create multiple identical spools."""
    spools = []
    for _ in range(data.quantity):
        spool = Spool(**data.spool.model_dump())
        db.add(spool)
        spools.append(spool)
    await db.commit()
    ids = [s.id for s in spools]
    result = await db.execute(select(Spool).options(selectinload(Spool.k_profiles)).where(Spool.id.in_(ids)))
    await ws_manager.broadcast({"type": "inventory_changed"})
    return list(result.scalars().all())


@router.patch("/spools/{spool_id}", response_model=SpoolResponse)
async def update_spool(
    spool_id: int,
    spool_data: SpoolUpdate,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Update a spool."""
    result = await db.execute(select(Spool).where(Spool.id == spool_id))
    spool = result.scalar_one_or_none()
    if not spool:
        raise HTTPException(404, "Spool not found")

    update_data = spool_data.model_dump(exclude_unset=True)
    # Auto-lock weight when user explicitly sets weight_used
    if "weight_used" in update_data and "weight_locked" not in update_data:
        update_data["weight_locked"] = True

    for field, value in update_data.items():
        setattr(spool, field, value)

    await db.commit()
    result = await db.execute(select(Spool).options(selectinload(Spool.k_profiles)).where(Spool.id == spool_id))
    await ws_manager.broadcast({"type": "inventory_changed"})
    return result.scalar_one()


@router.delete("/spools/{spool_id}")
async def delete_spool(
    spool_id: int,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Hard delete a spool."""
    result = await db.execute(select(Spool).where(Spool.id == spool_id))
    spool = result.scalar_one_or_none()
    if not spool:
        raise HTTPException(404, "Spool not found")

    await db.delete(spool)
    await db.commit()
    await ws_manager.broadcast({"type": "inventory_changed"})
    return {"status": "deleted"}


@router.post("/spools/{spool_id}/archive", response_model=SpoolResponse)
async def archive_spool(
    spool_id: int,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Soft-delete a spool by setting archived_at."""
    from datetime import datetime, timezone

    result = await db.execute(select(Spool).where(Spool.id == spool_id))
    spool = result.scalar_one_or_none()
    if not spool:
        raise HTTPException(404, "Spool not found")

    spool.archived_at = datetime.now(timezone.utc)
    await db.commit()
    result = await db.execute(select(Spool).options(selectinload(Spool.k_profiles)).where(Spool.id == spool_id))
    await ws_manager.broadcast({"type": "inventory_changed"})
    return result.scalar_one()


@router.post("/spools/{spool_id}/restore", response_model=SpoolResponse)
async def restore_spool(
    spool_id: int,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Restore an archived spool."""
    result = await db.execute(select(Spool).where(Spool.id == spool_id))
    spool = result.scalar_one_or_none()
    if not spool:
        raise HTTPException(404, "Spool not found")

    spool.archived_at = None
    await db.commit()
    result = await db.execute(select(Spool).options(selectinload(Spool.k_profiles)).where(Spool.id == spool_id))
    await ws_manager.broadcast({"type": "inventory_changed"})
    return result.scalar_one()


# ── K-Profiles ───────────────────────────────────────────────────────────────


@router.get("/spools/{spool_id}/k-profiles", response_model=list[SpoolKProfileResponse])
async def list_k_profiles(
    spool_id: int,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_READ),
):
    """List K-profiles for a spool."""
    result = await db.execute(select(SpoolKProfile).where(SpoolKProfile.spool_id == spool_id))
    return list(result.scalars().all())


@router.put("/spools/{spool_id}/k-profiles", response_model=list[SpoolKProfileResponse])
async def replace_k_profiles(
    spool_id: int,
    profiles: list[SpoolKProfileBase],
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Replace all K-profiles for a spool (batch save)."""
    # Verify spool exists
    result = await db.execute(select(Spool).where(Spool.id == spool_id))
    if not result.scalar_one_or_none():
        raise HTTPException(404, "Spool not found")

    # Delete existing
    existing = await db.execute(select(SpoolKProfile).where(SpoolKProfile.spool_id == spool_id))
    for old in existing.scalars().all():
        await db.delete(old)

    # Create new
    new_profiles = []
    for p in profiles:
        kp = SpoolKProfile(spool_id=spool_id, **p.model_dump())
        db.add(kp)
        new_profiles.append(kp)

    await db.commit()
    for kp in new_profiles:
        await db.refresh(kp)
    return new_profiles


# ── Spool Assignments ────────────────────────────────────────────────────────


@router.get("/assignments", response_model=list[SpoolAssignmentResponse])
async def list_assignments(
    printer_id: int | None = None,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_VIEW_ASSIGNMENTS),
):
    """List spool assignments, optionally filtered by printer."""
    from backend.app.services.printer_manager import printer_manager

    query = select(SpoolAssignment).options(
        selectinload(SpoolAssignment.spool).selectinload(Spool.k_profiles),
        selectinload(SpoolAssignment.printer),
    )
    if printer_id is not None:
        query = query.where(SpoolAssignment.printer_id == printer_id)
    result = await db.execute(query)
    assignments = list(result.scalars().all())

    # Build (printer_id, ams_id) -> ams_serial map from live printer states.
    # Fetch all statuses in one call rather than one get_status() call per printer.
    serial_map: dict[tuple[int, int], str] = {}
    seen_printer_ids: set[int] = {a.printer_id for a in assignments}
    all_statuses = printer_manager.get_all_statuses()
    for pid in seen_printer_ids:
        state = all_statuses.get(pid)
        if state and state.raw_data:
            for ams_unit in state.raw_data.get("ams", []):
                sn = str(ams_unit.get("sn") or ams_unit.get("serial_number") or "")
                if sn:
                    try:
                        serial_map[(pid, int(ams_unit.get("id", 0)))] = sn
                    except (ValueError, TypeError):
                        continue

    # Fetch all relevant AMS labels keyed by serial number
    all_serials = set(serial_map.values())
    # Also include synthetic fallback keys for assignments without a known serial
    synthetic_keys: dict[str, tuple[int, int]] = {}
    for a in assignments:
        if (a.printer_id, a.ams_id) not in serial_map:
            synthetic = f"p{a.printer_id}a{a.ams_id}"
            synthetic_keys[synthetic] = (a.printer_id, a.ams_id)
            all_serials.add(synthetic)

    label_by_serial: dict[str, str] = {}
    if all_serials:
        lbl_result = await db.execute(select(AmsLabel).where(AmsLabel.ams_serial_number.in_(all_serials)))
        for lbl in lbl_result.scalars().all():
            label_by_serial[lbl.ams_serial_number] = lbl.label

    # Build response objects, attaching ams_label where available
    responses: list[SpoolAssignmentResponse] = []
    for a in assignments:
        resp = SpoolAssignmentResponse.model_validate(a)
        sn = serial_map.get((a.printer_id, a.ams_id))
        if sn and sn in label_by_serial:
            resp.ams_label = label_by_serial[sn]
        elif not sn:
            synthetic = f"p{a.printer_id}a{a.ams_id}"
            resp.ams_label = label_by_serial.get(synthetic)
        responses.append(resp)

    return responses


@router.post("/assignments", response_model=SpoolAssignmentResponse)
async def assign_spool(
    data: SpoolAssignmentCreate,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Assign a spool to an AMS slot and auto-configure via MQTT."""
    from backend.app.services.printer_manager import printer_manager

    # 1. Validate spool exists and is not archived
    result = await db.execute(select(Spool).options(selectinload(Spool.k_profiles)).where(Spool.id == data.spool_id))
    spool = result.scalar_one_or_none()
    if not spool:
        raise HTTPException(404, "Spool not found")
    if spool.archived_at:
        raise HTTPException(400, "Cannot assign an archived spool")

    # 2. Get current AMS tray state for fingerprint + existing filament ID
    fingerprint_color = None
    fingerprint_type = None
    current_tray_info_idx = ""
    state = printer_manager.get_status(data.printer_id)
    if state and state.raw_data:
        if data.ams_id == 255:
            # External slot: look up tray from vt_tray by global ID
            vt_tray = state.raw_data.get("vt_tray") or []
            ext_id = data.tray_id + 254  # 0→254, 1→255
            for vt in vt_tray:
                if isinstance(vt, dict) and int(vt.get("id", 254)) == ext_id:
                    fingerprint_color = vt.get("tray_color", "")
                    fingerprint_type = vt.get("tray_type", "")
                    current_tray_info_idx = vt.get("tray_info_idx", "")
                    break
        else:
            ams_data = state.raw_data.get("ams", {})
            ams_list = (
                ams_data.get("ams", [])
                if isinstance(ams_data, dict)
                else ams_data
                if isinstance(ams_data, list)
                else []
            )
            tray = _find_tray_in_ams_data(
                ams_list,
                data.ams_id,
                data.tray_id,
            )
            if tray:
                fingerprint_color = tray.get("tray_color", "")
                fingerprint_type = tray.get("tray_type", "")
                current_tray_info_idx = tray.get("tray_info_idx", "")

    # 3. Upsert assignment (replace if same printer+ams+tray)
    existing = await db.execute(
        select(SpoolAssignment).where(
            SpoolAssignment.printer_id == data.printer_id,
            SpoolAssignment.ams_id == data.ams_id,
            SpoolAssignment.tray_id == data.tray_id,
        )
    )
    old = existing.scalar_one_or_none()
    if old:
        await db.delete(old)
        await db.flush()

    assignment = SpoolAssignment(
        spool_id=data.spool_id,
        printer_id=data.printer_id,
        ams_id=data.ams_id,
        tray_id=data.tray_id,
        fingerprint_color=fingerprint_color,
        fingerprint_type=fingerprint_type,
    )
    db.add(assignment)
    await db.commit()
    await db.refresh(assignment)

    # 4. Auto-configure AMS slot via MQTT
    configured = False
    try:
        client = printer_manager.get_client(data.printer_id)
        if client:
            # Build filament setting from spool data
            tray_type = spool.material
            tray_sub_brands = (
                f"{spool.brand} {spool.material} {spool.subtype}".strip()
                if spool.brand
                else f"{spool.material} {spool.subtype}"
                if spool.subtype
                else spool.material
            )
            tray_color = spool.rgba or "FFFFFFFF"

            _GENERIC_IDS = {
                "PLA": "GFL99",
                "PETG": "GFG99",
                "ABS": "GFB99",
                "ASA": "GFB98",
                "PC": "GFC99",
                "PA": "GFN99",
                "NYLON": "GFN99",
                "TPU": "GFU99",
                "PVA": "GFS99",
                "HIPS": "GFS98",
                "PLA-CF": "GFL98",
                "PETG-CF": "GFG98",
                "PA-CF": "GFN98",
                "PETG HF": "GFG96",
            }
            _GENERIC_ID_VALUES = set(_GENERIC_IDS.values())

            # Resolve tray_info_idx + setting_id for the MQTT command.
            # Three sources in priority order:
            #   1. Cloud profile (if cloud connected) — resolve filament_id
            #      from setting_id via cloud API
            #   2. Local profile — use generic filament ID for material
            #   3. Hard-coded fallback — generic Bambu filament IDs
            tray_info_idx = ""
            setting_id = ""
            sf = spool.slicer_filament or ""

            if sf:
                # Check if it's a cloud preset (GFS*, PFUS*, or GF* official)
                base_sf = sf.split("_")[0] if "_" in sf else sf
                if base_sf.startswith("GFS") or base_sf.startswith("PFUS"):
                    # Cloud setting_id — need to resolve real filament_id
                    # Use base_sf (version suffix stripped) for cloud API + MQTT
                    setting_id = base_sf
                    try:
                        from backend.app.services.bambu_cloud import get_cloud_service

                        cloud = get_cloud_service()
                        if cloud.is_authenticated:
                            detail = await cloud.get_setting_detail(base_sf)
                            if detail.get("filament_id"):
                                tray_info_idx = detail["filament_id"]
                                logger.info(
                                    "Spool assign: resolved filament_id=%r from cloud for setting_id=%r",
                                    tray_info_idx,
                                    sf,
                                )
                                # Use cloud preset name for tray_sub_brands if available
                                cloud_name = detail.get("name", "")
                                if cloud_name:
                                    tray_sub_brands = cloud_name.replace(r"@.*$", "").split("@")[0].strip()
                            elif detail.get("base_id"):
                                # Derive from base_id (e.g. "GFSL05" → "GFL05")
                                bid = detail["base_id"].split("_")[0]
                                if bid.startswith("GFS") and len(bid) >= 5:
                                    tray_info_idx = f"GF{bid[3:]}"
                                else:
                                    tray_info_idx = bid
                                logger.info(
                                    "Spool assign: derived filament_id=%r from base_id=%r",
                                    tray_info_idx,
                                    detail["base_id"],
                                )
                    except Exception as e:
                        logger.warning("Spool assign: cloud lookup failed for %r: %s", sf, e)

                    if not tray_info_idx:
                        # Cloud lookup failed — use normalize as fallback
                        tray_info_idx, setting_id = normalize_slicer_filament(sf)
                elif base_sf.startswith("GF"):
                    # Official Bambu filament_id (e.g. "GFL05")
                    tray_info_idx, setting_id = normalize_slicer_filament(sf)
                    logger.info("Spool assign: using official filament_id=%r", tray_info_idx)

                else:
                    # Could be a local preset ID or material type — try local DB
                    try:
                        local_id = int(sf)
                        from backend.app.models.local_preset import LocalPreset as LP

                        lp_result = await db.execute(select(LP).where(LP.id == local_id, LP.preset_type == "filament"))
                        lp = lp_result.scalar_one_or_none()
                        if lp:
                            mat = (spool.material or lp.filament_type or "").upper().strip()
                            tray_info_idx = (
                                _GENERIC_IDS.get(mat) or _GENERIC_IDS.get(mat.split("-")[0].split(" ")[0]) or ""
                            )
                            # Use local preset name for tray_sub_brands
                            if lp.name:
                                tray_sub_brands = lp.name.split("@")[0].strip()
                            logger.info(
                                "Spool assign: local preset %d, material=%r, tray_info_idx=%r",
                                local_id,
                                mat,
                                tray_info_idx,
                            )
                    except (ValueError, TypeError):
                        # Not a numeric ID — treat as material type string
                        tray_info_idx, setting_id = normalize_slicer_filament(sf)

            # Cross-check: the cloud API returns the base filament_id for
            # versioned setting_ids (e.g. GFSL99 → GFL99 for all PLA variants).
            # If the spool has a specific preset name (e.g. "Generic PLA Silk"),
            # reverse-lookup the correct filament_id from the built-in table.
            if tray_info_idx and spool.slicer_filament_name:
                from backend.app.api.routes.cloud import _BUILTIN_FILAMENT_NAMES

                expected_name = _BUILTIN_FILAMENT_NAMES.get(tray_info_idx, "")
                if expected_name and expected_name != spool.slicer_filament_name:
                    for fid, fname in _BUILTIN_FILAMENT_NAMES.items():
                        if fname == spool.slicer_filament_name:
                            logger.info(
                                "Spool assign: corrected filament_id %r→%r (name=%r)",
                                tray_info_idx,
                                fid,
                                spool.slicer_filament_name,
                            )
                            tray_info_idx = fid
                            setting_id = filament_id_to_setting_id(fid)
                            break

            if not tray_info_idx:
                # Fallback: reuse slot's existing tray_info_idx or generic ID
                if (
                    current_tray_info_idx
                    and current_tray_info_idx not in _GENERIC_ID_VALUES
                    and fingerprint_type
                    and fingerprint_type.upper() == tray_type.upper()
                ):
                    logger.info(
                        "Spool assign: reusing slot's existing tray_info_idx=%r (same material %r)",
                        current_tray_info_idx,
                        tray_type,
                    )
                    tray_info_idx = current_tray_info_idx
                elif tray_type:
                    material = tray_type.upper().strip()
                    generic = _GENERIC_IDS.get(material) or _GENERIC_IDS.get(material.split("-")[0].split(" ")[0]) or ""
                    if generic:
                        logger.info("Spool assign: falling back to generic %r for material %r", generic, tray_type)
                        tray_info_idx = generic

            # Temperature: use spool overrides if set, else material defaults
            temp_min, temp_max = MATERIAL_TEMPS.get(spool.material.upper(), (200, 240))
            if spool.nozzle_temp_min is not None:
                temp_min = spool.nozzle_temp_min
            if spool.nozzle_temp_max is not None:
                temp_max = spool.nozzle_temp_max

            # a. Set filament setting
            client.ams_set_filament_setting(
                ams_id=data.ams_id,
                tray_id=data.tray_id,
                tray_info_idx=tray_info_idx,
                tray_type=tray_type,
                tray_sub_brands=tray_sub_brands,
                tray_color=tray_color,
                nozzle_temp_min=temp_min,
                nozzle_temp_max=temp_max,
                setting_id=setting_id,
            )

            # b. Look up K-profile for this spool + printer + nozzle + extruder
            nozzle_diameter = "0.4"
            if state and state.nozzles:
                nd = state.nozzles[0].nozzle_diameter
                if nd:
                    nozzle_diameter = nd

            # Determine slot's extruder from ams_extruder_map
            slot_extruder = None
            if state and state.ams_extruder_map:
                if data.ams_id == 255:
                    # External slots: ext-L (tray 0) → extruder 1, ext-R (tray 1) → extruder 0
                    slot_extruder = 1 - data.tray_id  # 0→1, 1→0
                else:
                    slot_extruder = state.ams_extruder_map.get(str(data.ams_id))

            matching_kp = None
            for kp in spool.k_profiles:
                if kp.printer_id == data.printer_id and kp.nozzle_diameter == nozzle_diameter:
                    if slot_extruder is not None and kp.extruder is not None and kp.extruder != slot_extruder:
                        continue
                    matching_kp = kp
                    break

            if matching_kp and matching_kp.cali_idx is not None:
                client.extrusion_cali_sel(
                    ams_id=data.ams_id,
                    tray_id=data.tray_id,
                    cali_idx=matching_kp.cali_idx,
                    filament_id=tray_info_idx,
                    nozzle_diameter=nozzle_diameter,
                )

            configured = True
            logger.info(
                "Auto-configured AMS slot ams=%d tray=%d for spool %d on printer %d",
                data.ams_id,
                data.tray_id,
                spool.id,
                data.printer_id,
            )

            # Save slot preset mapping so the UI shows the correct preset name.
            # Use slicer_filament_name (authoritative) with fallback to tray_sub_brands.
            try:
                from backend.app.models.slot_preset import SlotPresetMapping

                preset_name = spool.slicer_filament_name or tray_sub_brands or tray_type
                preset_source = "cloud"
                if sf:
                    base_sf_mapping = sf.split("_")[0] if "_" in sf else sf
                    try:
                        local_id = int(base_sf_mapping)
                        preset_id_to_save = f"local_{local_id}"
                        preset_source = "local"
                    except (ValueError, TypeError):
                        # Cloud or builtin preset — convert filament_id to setting_id
                        preset_id_to_save = filament_id_to_setting_id(tray_info_idx) if tray_info_idx else setting_id
                else:
                    preset_id_to_save = filament_id_to_setting_id(tray_info_idx) if tray_info_idx else ""

                if preset_id_to_save:
                    existing_mapping = await db.execute(
                        select(SlotPresetMapping).where(
                            SlotPresetMapping.printer_id == data.printer_id,
                            SlotPresetMapping.ams_id == data.ams_id,
                            SlotPresetMapping.tray_id == data.tray_id,
                        )
                    )
                    mapping = existing_mapping.scalar_one_or_none()
                    if mapping:
                        mapping.preset_id = preset_id_to_save
                        mapping.preset_name = preset_name
                        mapping.preset_source = preset_source
                    else:
                        mapping = SlotPresetMapping(
                            printer_id=data.printer_id,
                            ams_id=data.ams_id,
                            tray_id=data.tray_id,
                            preset_id=preset_id_to_save,
                            preset_name=preset_name,
                            preset_source=preset_source,
                        )
                        db.add(mapping)
                    await db.commit()
                    logger.info(
                        "Saved slot preset mapping: preset_id=%r, preset_name=%r",
                        preset_id_to_save,
                        preset_name,
                    )
            except Exception as e:
                logger.warning("Failed to save slot preset mapping: %s", e)

    except Exception as e:
        logger.warning("MQTT auto-configure failed for spool %d: %s", spool.id, e)

    # Return assignment with spool data
    result = await db.execute(
        select(SpoolAssignment)
        .options(
            selectinload(SpoolAssignment.spool).selectinload(Spool.k_profiles),
            selectinload(SpoolAssignment.printer),
        )
        .where(SpoolAssignment.id == assignment.id)
    )
    resp = result.scalar_one()
    response = SpoolAssignmentResponse.model_validate(resp)
    response.configured = configured

    await ws_manager.broadcast(
        {
            "type": "spool_assignment_changed",
            "printer_id": data.printer_id,
            "ams_id": data.ams_id,
            "tray_id": data.tray_id,
        }
    )

    return response


@router.delete("/assignments/{printer_id}/{ams_id}/{tray_id}")
async def unassign_spool(
    printer_id: int,
    ams_id: int,
    tray_id: int,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Unassign a spool from an AMS slot."""
    result = await db.execute(
        select(SpoolAssignment).where(
            SpoolAssignment.printer_id == printer_id,
            SpoolAssignment.ams_id == ams_id,
            SpoolAssignment.tray_id == tray_id,
        )
    )
    assignment = result.scalar_one_or_none()
    if not assignment:
        raise HTTPException(404, "Assignment not found")

    await db.delete(assignment)
    await db.commit()

    await ws_manager.broadcast(
        {
            "type": "spool_assignment_changed",
            "printer_id": printer_id,
            "ams_id": ams_id,
            "tray_id": tray_id,
        }
    )

    return {"status": "deleted"}


# ── Tag Linking ───────────────────────────────────────────────────────────────


class LinkTagRequest(BaseModel):
    tag_uid: str | None = None
    tray_uuid: str | None = None
    tag_type: str | None = None
    data_origin: str | None = "nfc_link"


def _validate_tag_input(
    raw_value: str | None, normalized_value: str | None, field_name: str, exact_len: int | None = None
) -> None:
    if raw_value is None:
        return
    raw = str(raw_value).strip()
    if not raw:
        return
    if normalized_value is None:
        raise HTTPException(422, f"{field_name} must contain hexadecimal characters")
    if len(normalized_value) % 2 != 0:
        raise HTTPException(422, f"{field_name} must have an even number of hex characters")
    if exact_len is not None and len(normalized_value) != exact_len:
        raise HTTPException(422, f"{field_name} must be exactly {exact_len} hex characters")


@router.patch("/spools/{spool_id}/link-tag", response_model=SpoolResponse)
async def link_tag_to_spool(
    spool_id: int,
    data: LinkTagRequest,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Link an RFID tag_uid/tray_uuid to an existing spool."""
    result = await db.execute(select(Spool).options(selectinload(Spool.k_profiles)).where(Spool.id == spool_id))
    spool = result.scalar_one_or_none()
    if not spool:
        raise HTTPException(404, "Spool not found")
    if spool.archived_at:
        raise HTTPException(400, "Cannot link tag to archived spool")

    normalized_tag_uid = (normalize_tag_uid(data.tag_uid) or None) if data.tag_uid is not None else None
    normalized_tray_uuid = (normalize_tray_uuid(data.tray_uuid) or None) if data.tray_uuid is not None else None

    _validate_tag_input(data.tag_uid, normalized_tag_uid, "tag_uid")
    _validate_tag_input(data.tray_uuid, normalized_tray_uuid, "tray_uuid", exact_len=32)

    # Check for conflicts: tag already linked to another active spool
    if normalized_tag_uid:
        conflict = await db.execute(
            select(Spool).where(
                func.upper(Spool.tag_uid) == normalized_tag_uid,
                Spool.id != spool_id,
                Spool.archived_at.is_(None),
            )
        )
        if conflict.scalar_one_or_none():
            raise HTTPException(409, "Tag UID already linked to another active spool")
        # Auto-clear from archived spools (tag recycling)
        archived_with_tag = await db.execute(
            select(Spool).where(
                func.upper(Spool.tag_uid) == normalized_tag_uid,
                Spool.id != spool_id,
                Spool.archived_at.is_not(None),
            )
        )
        for old_spool in archived_with_tag.scalars().all():
            old_spool.tag_uid = None

    if normalized_tray_uuid:
        conflict = await db.execute(
            select(Spool).where(
                func.upper(Spool.tray_uuid) == normalized_tray_uuid,
                Spool.id != spool_id,
                Spool.archived_at.is_(None),
            )
        )
        if conflict.scalar_one_or_none():
            raise HTTPException(409, "Tray UUID already linked to another active spool")
        archived_with_uuid = await db.execute(
            select(Spool).where(
                func.upper(Spool.tray_uuid) == normalized_tray_uuid,
                Spool.id != spool_id,
                Spool.archived_at.is_not(None),
            )
        )
        for old_spool in archived_with_uuid.scalars().all():
            old_spool.tray_uuid = None

    if data.tag_uid is not None:
        spool.tag_uid = normalized_tag_uid
    if data.tray_uuid is not None:
        spool.tray_uuid = normalized_tray_uuid
    if data.tag_type is not None:
        spool.tag_type = data.tag_type
    if data.data_origin is not None:
        spool.data_origin = data.data_origin

    await db.commit()
    result = await db.execute(select(Spool).options(selectinload(Spool.k_profiles)).where(Spool.id == spool_id))
    return result.scalar_one()


# ── Usage History ─────────────────────────────────────────────────────────────


@router.get("/spools/{spool_id}/usage", response_model=list[SpoolUsageHistoryResponse])
async def get_spool_usage_history(
    spool_id: int,
    limit: int = 50,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_READ),
):
    """Get usage history for a specific spool."""
    from backend.app.models.spool_usage_history import SpoolUsageHistory

    # Verify spool exists
    spool_result = await db.execute(select(Spool).where(Spool.id == spool_id))
    if not spool_result.scalar_one_or_none():
        raise HTTPException(404, "Spool not found")

    result = await db.execute(
        select(SpoolUsageHistory)
        .where(SpoolUsageHistory.spool_id == spool_id)
        .order_by(SpoolUsageHistory.created_at.desc())
        .limit(limit)
    )
    return list(result.scalars().all())


@router.get("/usage", response_model=list[SpoolUsageHistoryResponse])
async def get_all_usage_history(
    limit: int = 100,
    printer_id: int | None = None,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_READ),
):
    """Get global usage history, optionally filtered by printer."""
    from backend.app.models.spool_usage_history import SpoolUsageHistory

    query = select(SpoolUsageHistory).order_by(SpoolUsageHistory.created_at.desc()).limit(limit)
    if printer_id is not None:
        query = query.where(SpoolUsageHistory.printer_id == printer_id)
    result = await db.execute(query)
    return list(result.scalars().all())


@router.delete("/spools/{spool_id}/usage")
async def clear_spool_usage_history(
    spool_id: int,
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Clear usage history for a spool."""
    from backend.app.models.spool_usage_history import SpoolUsageHistory

    result = await db.execute(select(SpoolUsageHistory).where(SpoolUsageHistory.spool_id == spool_id))
    for row in result.scalars().all():
        await db.delete(row)
    await db.commit()
    return {"status": "cleared"}


# ── AMS Weight Sync ──────────────────────────────────────────────────────────


@router.post("/sync-ams-weights")
async def sync_weights_from_ams(
    db: AsyncSession = Depends(get_db),
    _: User | None = RequirePermissionIfAuthEnabled(Permission.INVENTORY_UPDATE),
):
    """Force-sync spool weight_used from live AMS remain% data.

    Overwrites the database weight_used for every assigned spool using the
    current AMS remain% from connected printers.  This is a manual recovery
    tool — it bypasses the normal "only increase" guard.
    """
    from backend.app.services.printer_manager import printer_manager

    result = await db.execute(select(SpoolAssignment).options(selectinload(SpoolAssignment.spool)))
    assignments = list(result.scalars().all())
    logger.info("AMS weight sync: found %d assignments", len(assignments))

    synced = 0
    skipped = 0

    for assignment in assignments:
        spool = assignment.spool
        if not spool:
            logger.debug("AMS weight sync: assignment %d has no spool", assignment.id)
            skipped += 1
            continue

        if spool.weight_locked:
            logger.debug("AMS weight sync: spool %d is weight-locked, skipping", spool.id)
            skipped += 1
            continue

        state = printer_manager.get_status(assignment.printer_id)
        if not state or not state.raw_data:
            logger.info(
                "AMS weight sync: printer %d not connected, skipping spool %d",
                assignment.printer_id,
                spool.id,
            )
            skipped += 1
            continue

        ams_raw = state.raw_data.get("ams", [])
        if isinstance(ams_raw, dict):
            ams_raw = ams_raw.get("ams", [])
        tray = _find_tray_in_ams_data(ams_raw, assignment.ams_id, assignment.tray_id)
        if not tray:
            logger.info(
                "AMS weight sync: no tray data for spool %d (printer %d AMS%d-T%d)",
                spool.id,
                assignment.printer_id,
                assignment.ams_id,
                assignment.tray_id,
            )
            skipped += 1
            continue

        remain_raw = tray.get("remain")
        if remain_raw is None:
            logger.debug("AMS weight sync: no remain value for spool %d", spool.id)
            skipped += 1
            continue

        try:
            remain_val = int(remain_raw)
        except (TypeError, ValueError):
            skipped += 1
            continue

        if remain_val < 0 or remain_val > 100:
            logger.debug("AMS weight sync: invalid remain=%s for spool %d", remain_raw, spool.id)
            skipped += 1
            continue

        lw = spool.label_weight or 1000
        new_used = round(lw * (100 - remain_val) / 100.0, 1)
        old_used = spool.weight_used or 0

        if round(old_used, 1) != new_used:
            logger.info(
                "AMS weight sync: spool %d weight_used %s -> %s (remain=%d%%)",
                spool.id,
                old_used,
                new_used,
                remain_val,
            )
            spool.weight_used = new_used
            synced += 1
        else:
            skipped += 1

    await db.commit()
    return {"synced": synced, "skipped": skipped}


# ── Helpers ──────────────────────────────────────────────────────────────────


def _find_tray_in_ams_data(ams_data: list, ams_id: int, tray_id: int) -> dict | None:
    """Find a specific tray in the AMS data structure."""
    if not ams_data:
        return None
    for ams_unit in ams_data:
        if int(ams_unit.get("id", -1)) != ams_id:
            continue
        for tray in ams_unit.get("tray", []):
            if int(tray.get("id", -1)) == tray_id:
                return tray
    return None