bambuddy/backend/tests/unit/test_threemf_tools.py

"""Unit tests for 3MF parsing utilities (threemf_tools.py).

Tests G-code parsing, filament length-to-weight conversion,
and cumulative layer usage lookup.
"""

import io
import json
import math
import zipfile

from backend.app.utils.threemf_tools import (
    expand_to_project_slots,
    extract_bed_type_from_3mf,
    extract_embedded_presets_from_3mf,
    extract_filament_usage_from_3mf,
    extract_plate_extruder_set_from_3mf,
    extract_print_time_from_3mf,
    extract_project_filaments_from_3mf,
    extract_support_filament_slots_from_3mf,
    get_cumulative_usage_at_layer,
    mm_to_grams,
    parse_gcode_layer_filament_usage,
)


def create_mock_3mf(slice_info_content: str) -> io.BytesIO:
    """Create a mock 3MF file (ZIP) with slice_info.config content."""
    buffer = io.BytesIO()
    with zipfile.ZipFile(buffer, "w") as zf:
        zf.writestr("Metadata/slice_info.config", slice_info_content)
    buffer.seek(0)
    return buffer


class TestParseGcodeLayerFilamentUsage:
    """Tests for parse_gcode_layer_filament_usage()."""

    def test_single_filament_single_layer(self):
        """Single filament extruding on one layer."""
        gcode = """
M620 S0
G1 X10 Y10 E5.0
G1 X20 Y20 E3.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        assert result == {0: {0: 8.0}}

    def test_multi_layer_single_filament(self):
        """Single filament across multiple layers."""
        gcode = """
M620 S0
G1 X10 Y10 E10.0
M73 L1
G1 X20 Y20 E5.0
M73 L2
G1 X30 Y30 E7.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        assert result[0] == {0: 10.0}
        assert result[1] == {0: 15.0}
        assert result[2] == {0: 22.0}

    def test_multi_material(self):
        """Multiple filaments switching via M620."""
        gcode = """
M620 S0
G1 E10.0
M73 L1
M620 S1
G1 E5.0
M620 S0
G1 E3.0
M73 L2
G1 E2.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        # Layer 0: filament 0 = 10mm
        assert result[0] == {0: 10.0}
        # Layer 1: filament 0 = 13mm (10+3), filament 1 = 5mm
        assert result[1] == {0: 13.0, 1: 5.0}
        # Layer 2: filament 0 = 15mm (13+2)
        assert result[2] == {0: 15.0, 1: 5.0}

    def test_retractions_ignored(self):
        """Negative E values (retractions) should be ignored."""
        gcode = """
M620 S0
G1 E10.0
G1 E-2.0
G1 E5.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        assert result == {0: {0: 15.0}}

    def test_m620_s255_unloads(self):
        """M620 S255 means unload - extrusion after should be ignored."""
        gcode = """
M620 S0
G1 E10.0
M620 S255
G1 E5.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        assert result == {0: {0: 10.0}}

    def test_m620_with_suffix(self):
        """M620 S0A format (filament ID with suffix letter)."""
        gcode = """
M620 S0A
G1 E10.0
M620 S1A
G1 E5.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        assert result == {0: {0: 10.0, 1: 5.0}}

    def test_comments_ignored(self):
        """Comment lines and inline comments are ignored."""
        gcode = """
; This is a comment
M620 S0
G1 X10 E5.0 ; inline comment with E value
G1 E3.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        assert result == {0: {0: 8.0}}

    def test_empty_gcode(self):
        """Empty G-code returns empty dict."""
        assert parse_gcode_layer_filament_usage("") == {}
        assert parse_gcode_layer_filament_usage("\n\n\n") == {}

    def test_no_extrusion(self):
        """G-code with moves but no extrusion."""
        gcode = """
G1 X10 Y10
G1 X20 Y20
"""
        assert parse_gcode_layer_filament_usage(gcode) == {}

    def test_no_active_filament_extrusion_ignored(self):
        """Extrusion before any M620 is ignored (no active filament)."""
        gcode = """
G1 E10.0
M620 S0
G1 E5.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        assert result == {0: {0: 5.0}}

    def test_g0_g2_g3_extrusion(self):
        """G0, G2, G3 with E parameter are also tracked."""
        gcode = """
M620 S0
G0 E1.0
G1 E2.0
G2 E3.0
G3 E4.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        assert result == {0: {0: 10.0}}

    def test_cumulative_across_layers(self):
        """Values are cumulative, not per-layer."""
        gcode = """
M620 S0
G1 E100.0
M73 L1
G1 E100.0
M73 L2
G1 E100.0
"""
        result = parse_gcode_layer_filament_usage(gcode)
        assert result[0] == {0: 100.0}
        assert result[1] == {0: 200.0}
        assert result[2] == {0: 300.0}


class TestMmToGrams:
    """Tests for mm_to_grams()."""

    def test_default_pla_175(self):
        """Default PLA 1.75mm conversion."""
        # 1000mm of 1.75mm PLA at 1.24 g/cm³
        # Volume = π × (0.0875cm)² × 100cm = 2.405cm³
        # Weight = 2.405 × 1.24 = 2.982g
        result = mm_to_grams(1000.0)
        expected = math.pi * (0.0875**2) * 100 * 1.24
        assert abs(result - expected) < 0.001

    def test_zero_length(self):
        """Zero length returns zero weight."""
        assert mm_to_grams(0.0) == 0.0

    def test_custom_diameter(self):
        """Custom diameter (2.85mm) changes result."""
        result_175 = mm_to_grams(1000.0, diameter_mm=1.75)
        result_285 = mm_to_grams(1000.0, diameter_mm=2.85)
        # 2.85mm filament has more volume per mm
        assert result_285 > result_175
        ratio = (2.85 / 1.75) ** 2  # Volume scales with diameter²
        assert abs(result_285 / result_175 - ratio) < 0.001

    def test_custom_density(self):
        """Different density (ABS vs PLA)."""
        pla = mm_to_grams(1000.0, density_g_cm3=1.24)
        abs_ = mm_to_grams(1000.0, density_g_cm3=1.04)
        assert pla > abs_
        assert abs(pla / abs_ - 1.24 / 1.04) < 0.001

    def test_known_value(self):
        """Verify against a known calculation.

        1m (1000mm) of 1.75mm PLA at 1.24 g/cm³:
        r = 0.0875 cm, L = 100 cm
        V = π × 0.0875² × 100 = 2.4053 cm³
        m = 2.4053 × 1.24 = 2.9826 g
        """
        result = mm_to_grams(1000.0, 1.75, 1.24)
        assert abs(result - 2.9826) < 0.01


class TestGetCumulativeUsageAtLayer:
    """Tests for get_cumulative_usage_at_layer()."""

    def test_exact_layer_match(self):
        """Target layer exists exactly in the data."""
        data = {0: {0: 100.0}, 5: {0: 500.0}, 10: {0: 1000.0}}
        assert get_cumulative_usage_at_layer(data, 5) == {0: 500.0}

    def test_between_layers(self):
        """Target is between recorded layers - uses the closest lower one."""
        data = {0: {0: 100.0}, 5: {0: 500.0}, 10: {0: 1000.0}}
        # Layer 7 is between 5 and 10, should return layer 5's data
        assert get_cumulative_usage_at_layer(data, 7) == {0: 500.0}

    def test_beyond_last_layer(self):
        """Target is beyond the last recorded layer."""
        data = {0: {0: 100.0}, 5: {0: 500.0}}
        assert get_cumulative_usage_at_layer(data, 100) == {0: 500.0}

    def test_before_first_layer(self):
        """Target is before any recorded data."""
        data = {5: {0: 500.0}, 10: {0: 1000.0}}
        assert get_cumulative_usage_at_layer(data, 3) == {}

    def test_empty_data(self):
        """Empty layer_usage returns empty dict."""
        assert get_cumulative_usage_at_layer({}, 5) == {}

    def test_none_data(self):
        """None layer_usage returns empty dict."""
        assert get_cumulative_usage_at_layer(None, 5) == {}

    def test_multi_filament(self):
        """Multi-filament data at target layer."""
        data = {
            0: {0: 50.0},
            5: {0: 200.0, 1: 100.0},
            10: {0: 400.0, 1: 250.0, 2: 50.0},
        }
        result = get_cumulative_usage_at_layer(data, 8)
        assert result == {0: 200.0, 1: 100.0}

    def test_layer_zero(self):
        """Target layer 0."""
        data = {0: {0: 10.0}, 1: {0: 20.0}}
        assert get_cumulative_usage_at_layer(data, 0) == {0: 10.0}


class TestExtractFilamentUsageFrom3mf:
    """Tests for extract_filament_usage_from_3mf function."""

    def test_extract_single_filament(self, tmp_path):
        """Test extracting a single filament."""
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <filament id="1" used_g="50.5" type="PLA" color="#FF0000"/>
        </config>
        """
        mock_3mf = create_mock_3mf(xml_content)
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(mock_3mf.read())

        result = extract_filament_usage_from_3mf(file_path)

        assert len(result) == 1
        assert result[0]["slot_id"] == 1
        assert result[0]["used_g"] == 50.5
        assert result[0]["type"] == "PLA"
        assert result[0]["color"] == "#FF0000"

    def test_extract_multiple_filaments(self, tmp_path):
        """Test extracting multiple filaments."""
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <filament id="1" used_g="50.5" type="PLA" color="#FF0000"/>
            <filament id="2" used_g="30.2" type="PETG" color="#00FF00"/>
            <filament id="3" used_g="10.0" type="ABS" color="#0000FF"/>
        </config>
        """
        mock_3mf = create_mock_3mf(xml_content)
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(mock_3mf.read())

        result = extract_filament_usage_from_3mf(file_path)

        assert len(result) == 3
        assert result[0]["slot_id"] == 1
        assert result[1]["slot_id"] == 2
        assert result[2]["slot_id"] == 3

    def test_extract_filament_with_plate_id(self, tmp_path):
        """Test extracting filament for a specific plate."""
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <filament id="1" used_g="25.0" type="PLA" color="#FF0000"/>
            </plate>
            <plate>
                <metadata key="index" value="2"/>
                <filament id="1" used_g="75.0" type="PETG" color="#00FF00"/>
            </plate>
        </config>
        """
        mock_3mf = create_mock_3mf(xml_content)
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(mock_3mf.read())

        result = extract_filament_usage_from_3mf(file_path, plate_id=2)

        assert len(result) == 1
        assert result[0]["used_g"] == 75.0
        assert result[0]["type"] == "PETG"

    def test_missing_slice_info_returns_empty(self, tmp_path):
        """Test that missing slice_info.config returns empty list."""
        buffer = io.BytesIO()
        with zipfile.ZipFile(buffer, "w") as zf:
            zf.writestr("other_file.txt", "content")
        buffer.seek(0)

        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(buffer.read())

        result = extract_filament_usage_from_3mf(file_path)

        assert result == []

    def test_invalid_file_returns_empty(self, tmp_path):
        """Test that invalid file returns empty list."""
        file_path = tmp_path / "invalid.3mf"
        file_path.write_text("not a zip file")

        result = extract_filament_usage_from_3mf(file_path)

        assert result == []

    def test_nonexistent_file_returns_empty(self, tmp_path):
        """Test that nonexistent file returns empty list."""
        file_path = tmp_path / "nonexistent.3mf"

        result = extract_filament_usage_from_3mf(file_path)

        assert result == []

    def test_filament_without_id_is_skipped(self, tmp_path):
        """Test that filament without id is skipped."""
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <filament used_g="50.5" type="PLA" color="#FF0000"/>
            <filament id="2" used_g="30.0" type="PETG" color="#00FF00"/>
        </config>
        """
        mock_3mf = create_mock_3mf(xml_content)
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(mock_3mf.read())

        result = extract_filament_usage_from_3mf(file_path)

        assert len(result) == 1
        assert result[0]["slot_id"] == 2

    def test_invalid_used_g_is_skipped(self, tmp_path):
        """Test that filament with invalid used_g is skipped."""
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <filament id="1" used_g="invalid" type="PLA" color="#FF0000"/>
            <filament id="2" used_g="30.0" type="PETG" color="#00FF00"/>
        </config>
        """
        mock_3mf = create_mock_3mf(xml_content)
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(mock_3mf.read())

        result = extract_filament_usage_from_3mf(file_path)

        assert len(result) == 1
        assert result[0]["slot_id"] == 2

    def test_missing_optional_fields(self, tmp_path):
        """Test that missing type and color default to empty string."""
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <filament id="1" used_g="50.5"/>
        </config>
        """
        mock_3mf = create_mock_3mf(xml_content)
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(mock_3mf.read())

        result = extract_filament_usage_from_3mf(file_path)

        assert len(result) == 1
        assert result[0]["type"] == ""
        assert result[0]["color"] == ""


# ---------------------------------------------------------------------------
# Tests for extract_project_filaments_from_3mf — used by the slice modal as
# fallback when the sidecar can't run a preview slice.
# ---------------------------------------------------------------------------


def _make_3mf_with(files: dict[str, bytes | str]) -> zipfile.ZipFile:
    buf = io.BytesIO()
    with zipfile.ZipFile(buf, "w") as zf:
        for name, content in files.items():
            zf.writestr(name, content if isinstance(content, (bytes, str)) else str(content))
    buf.seek(0)
    return zipfile.ZipFile(buf, "r")


class TestExtractProjectFilamentsFrom3mf:
    """The helper backfills the slice modal when slice_info.config is empty
    (raw project files) and the sidecar is unreachable."""

    def test_returns_empty_when_project_settings_missing(self):
        with _make_3mf_with({"placeholder.txt": "hi"}) as zf:
            assert extract_project_filaments_from_3mf(zf) == []

    def test_happy_path_returns_one_entry_per_slot(self):
        proj = {
            "filament_type": ["PLA", "PETG"],
            "filament_colour": ["#000000", "#FFFFFF"],
        }
        with _make_3mf_with({"Metadata/project_settings.config": json.dumps(proj)}) as zf:
            out = extract_project_filaments_from_3mf(zf)
        assert [(f["slot_id"], f["type"], f["color"]) for f in out] == [
            (1, "PLA", "#000000"),
            (2, "PETG", "#FFFFFF"),
        ]

    def test_mismatched_array_lengths_use_max_with_blanks(self):
        proj = {
            "filament_type": ["PLA", "PETG", "ABS"],
            "filament_colour": ["#000000"],
        }
        with _make_3mf_with({"Metadata/project_settings.config": json.dumps(proj)}) as zf:
            out = extract_project_filaments_from_3mf(zf)
        assert len(out) == 3
        assert out[0]["color"] == "#000000"
        assert out[1]["color"] == ""
        assert out[2]["color"] == ""

    def test_corrupt_json_returns_empty_no_exception(self):
        with _make_3mf_with({"Metadata/project_settings.config": b"{not json"}) as zf:
            assert extract_project_filaments_from_3mf(zf) == []

    def test_root_is_list_returns_empty(self):
        # Defensive: spec says it's a dict, but a file shipping a top-level
        # list (or anything non-dict) shouldn't crash the modal.
        with _make_3mf_with({"Metadata/project_settings.config": json.dumps([])}) as zf:
            assert extract_project_filaments_from_3mf(zf) == []

    def test_empty_arrays_returns_empty(self):
        proj = {"filament_type": [], "filament_colour": []}
        with _make_3mf_with({"Metadata/project_settings.config": json.dumps(proj)}) as zf:
            assert extract_project_filaments_from_3mf(zf) == []


# ---------------------------------------------------------------------------
# Tests for expand_to_project_slots — #2712
# ---------------------------------------------------------------------------


class TestExpandToProjectSlots:
    """The slice modal's filament list is positional: index 0 is slot 1, all
    the way through to the ``filament_N.json`` parts handed to the slicer.

    A MakerWorld source that carries slice_info but paints with slot 4 alone
    used to yield a one-row list, so the user's single pick was bound to slot
    1 and slot 4 — the slot that actually prints — kept the source's embedded
    default. Picking PETG produced a PLA print.
    """

    PROJECT = json.dumps(
        {
            "filament_type": ["PLA", "PLA", "PLA", "PLA"],
            "filament_colour": ["#38CC0A", "#161616", "#898989", "#898989"],
        }
    )

    def test_a_single_used_slot_still_produces_a_full_positional_list(self):
        """The reported file: four project slots, only slot 4 printed."""
        used = [
            {
                "slot_id": 4,
                "type": "PLA",
                "color": "#898989",
                "used_grams": 105.9,
                "used_meters": 35.51,
                "tray_info_idx": "GFL99",
                "used_in_plate": True,
            }
        ]
        with _make_3mf_with({"Metadata/project_settings.config": self.PROJECT}) as zf:
            out = expand_to_project_slots(zf, used)

        assert [f["slot_id"] for f in out] == [1, 2, 3, 4]
        assert [f["used_in_plate"] for f in out] == [False, False, False, True]

    def test_the_used_row_keeps_its_usage_figures(self):
        """The modal shows the real weight and colour, and the print path
        downstream reads ``tray_info_idx`` — none of it may be flattened into
        a zeroed project row."""
        used = [
            {
                "slot_id": 4,
                "type": "PETG",
                "color": "#FF0000",
                "used_grams": 105.9,
                "used_meters": 35.51,
                "tray_info_idx": "GFL99",
                "used_in_plate": True,
            }
        ]
        with _make_3mf_with({"Metadata/project_settings.config": self.PROJECT}) as zf:
            out = expand_to_project_slots(zf, used)

        slot4 = out[3]
        assert slot4["used_grams"] == 105.9
        assert slot4["tray_info_idx"] == "GFL99"
        # Resolved from the slice, not the project's stale PLA/#898989.
        assert (slot4["type"], slot4["color"]) == ("PETG", "#FF0000")

    def test_padding_rows_carry_the_project_type_and_colour(self):
        """They drive the modal's pre-pick for the disabled rows."""
        used = [{"slot_id": 4, "type": "PLA", "color": "#898989", "used_grams": 1.0, "used_meters": 1.0}]
        with _make_3mf_with({"Metadata/project_settings.config": self.PROJECT}) as zf:
            out = expand_to_project_slots(zf, used)

        assert (out[0]["type"], out[0]["color"]) == ("PLA", "#38CC0A")
        assert out[0]["used_grams"] == 0

    def test_every_slot_used_is_a_shape_change_only(self):
        used = [
            {"slot_id": i, "type": "PLA", "color": "", "used_grams": 5.0, "used_meters": 1.0, "used_in_plate": True}
            for i in (1, 2, 3, 4)
        ]
        with _make_3mf_with({"Metadata/project_settings.config": self.PROJECT}) as zf:
            out = expand_to_project_slots(zf, used)

        assert len(out) == 4
        assert all(f["used_in_plate"] for f in out)
        assert all(f["used_grams"] == 5.0 for f in out)

    def test_a_used_slot_beyond_the_project_list_is_kept(self):
        """Dropping it would recreate the original bug on a file whose
        project settings and slice_info disagree — the one slot that prints
        would vanish from the list entirely."""
        used = [{"slot_id": 9, "type": "PLA", "color": "", "used_grams": 5.0, "used_meters": 1.0}]
        with _make_3mf_with({"Metadata/project_settings.config": self.PROJECT}) as zf:
            out = expand_to_project_slots(zf, used)

        assert [f["slot_id"] for f in out] == [1, 2, 3, 4, 9]
        assert out[-1]["used_in_plate"] is True

    def test_returns_the_input_unchanged_without_project_settings(self):
        """Nothing to widen against — a narrow list still prints correctly,
        an invented one might not."""
        used = [{"slot_id": 4, "type": "PLA", "color": "", "used_grams": 5.0, "used_meters": 1.0}]
        with _make_3mf_with({"placeholder.txt": "hi"}) as zf:
            assert expand_to_project_slots(zf, used) == used


# ---------------------------------------------------------------------------
# Tests for extract_plate_extruder_set_from_3mf — three sources unioned:
# object top-level extruder, per-part extruder, painted-face quadtree leaves.
# ---------------------------------------------------------------------------


def _model_settings(plate_id: int, objects: list[dict]) -> str:
    """Build a minimal model_settings.config XML for tests. Each object dict
    can have: id, extruder (top-level), parts (list of {extruder}).
    The plate references all object ids."""
    parts_xml = []
    for obj in objects:
        oid = obj["id"]
        ext = obj.get("extruder")
        parts = obj.get("parts", [])
        ext_meta = f'<metadata key="extruder" value="{ext}"/>' if ext is not None else ""
        part_blocks = "".join(
            f'<part id="{i}" subtype="normal_part"><metadata key="extruder" value="{p["extruder"]}"/></part>'
            for i, p in enumerate(parts)
            if p.get("extruder") is not None
        )
        parts_xml.append(f'<object id="{oid}"><metadata key="name" value="o{oid}"/>{ext_meta}{part_blocks}</object>')
    instances = "".join(
        f'<model_instance><metadata key="object_id" value="{o["id"]}"/></model_instance>' for o in objects
    )
    plate = f'<plate><metadata key="plater_id" value="{plate_id}"/>{instances}</plate>'
    return f'<?xml version="1.0"?><config>{"".join(parts_xml)}{plate}</config>'


class TestExtractPlateExtruderSetFrom3mf:
    def test_returns_empty_set_when_model_settings_missing(self):
        with _make_3mf_with({"placeholder.txt": "hi"}) as zf:
            assert extract_plate_extruder_set_from_3mf(zf, plate_id=1) == set()

    def test_object_top_level_extruder_only(self):
        xml = _model_settings(plate_id=1, objects=[{"id": "10", "extruder": 2}])
        with _make_3mf_with({"Metadata/model_settings.config": xml}) as zf:
            assert extract_plate_extruder_set_from_3mf(zf, plate_id=1) == {2}

    def test_per_part_extruder_unions_with_top_level(self):
        # Object's default is 1; one of its parts overrides to 3 (multi-color
        # via a sub-mesh). Union both — the slicer needs profiles for both.
        xml = _model_settings(
            plate_id=1,
            objects=[{"id": "10", "extruder": 1, "parts": [{"extruder": 3}]}],
        )
        with _make_3mf_with({"Metadata/model_settings.config": xml}) as zf:
            assert extract_plate_extruder_set_from_3mf(zf, plate_id=1) == {1, 3}

    def test_unknown_plate_id_returns_empty_set(self):
        xml = _model_settings(plate_id=1, objects=[{"id": "10", "extruder": 2}])
        with _make_3mf_with({"Metadata/model_settings.config": xml}) as zf:
            assert extract_plate_extruder_set_from_3mf(zf, plate_id=99) == set()

    def test_corrupt_xml_returns_empty_set_no_exception(self):
        with _make_3mf_with({"Metadata/model_settings.config": "<not valid xml"}) as zf:
            assert extract_plate_extruder_set_from_3mf(zf, plate_id=1) == set()

    def test_zero_extruder_value_ignored(self):
        # Bambu's 0 means "use object default" — not a real slot.
        xml = _model_settings(plate_id=1, objects=[{"id": "10", "extruder": 0}])
        with _make_3mf_with({"Metadata/model_settings.config": xml}) as zf:
            assert extract_plate_extruder_set_from_3mf(zf, plate_id=1) == set()

    def test_painted_face_above_threshold_kept(self):
        # 60/40 split: 60 triangles painted with extruder 1, 40 with ext 2.
        # Threshold is 5%; both above. The dominant ones are real colours.
        triangles = []
        for _ in range(60):
            triangles.append('<triangle v1="0" v2="1" v3="2" paint_color="1"/>')
        for _ in range(40):
            triangles.append('<triangle v1="0" v2="1" v3="2" paint_color="2"/>')
        per_obj = (
            '<?xml version="1.0"?>'
            '<model><resources><object id="100" type="model"><mesh>'
            "<triangles>" + "".join(triangles) + "</triangles>"
            "</mesh></object></resources><build/></model>"
        )
        ms = (
            '<?xml version="1.0"?><config>'
            '<object id="10"><metadata key="name" value="o"/></object>'
            '<plate><metadata key="plater_id" value="1"/>'
            '<model_instance><metadata key="object_id" value="10"/></model_instance>'
            "</plate></config>"
        )
        threed = (
            '<?xml version="1.0"?>'
            '<model xmlns="http://schemas.microsoft.com/3dmanufacturing/core/2015/02"'
            ' xmlns:p="http://schemas.microsoft.com/3dmanufacturing/production/2015/06">'
            "<resources>"
            '<object id="10" type="model"><components>'
            '<component p:path="/3D/Objects/o100.model" objectid="100"/>'
            "</components></object>"
            "</resources><build/></model>"
        )
        with _make_3mf_with(
            {
                "Metadata/model_settings.config": ms,
                "3D/3dmodel.model": threed,
                "3D/Objects/o100.model": per_obj,
            }
        ) as zf:
            result = extract_plate_extruder_set_from_3mf(zf, plate_id=1)
        # Both real colours kept (60/40 well above 5% threshold); the dropped
        # threshold case is the regression that motivates this test.
        assert result == {1, 2}

    def test_painted_face_below_threshold_dropped_as_noise(self):
        # 99 triangles at ext 1, 1 triangle at ext 9 (1% — below 5%
        # threshold). The 1% leaf is a single-leaf accident.
        triangles = []
        for _ in range(99):
            triangles.append('<triangle v1="0" v2="1" v3="2" paint_color="1"/>')
        triangles.append('<triangle v1="0" v2="1" v3="2" paint_color="9"/>')
        per_obj = (
            '<?xml version="1.0"?>'
            '<model><resources><object id="100" type="model"><mesh>'
            "<triangles>" + "".join(triangles) + "</triangles>"
            "</mesh></object></resources><build/></model>"
        )
        ms = (
            '<?xml version="1.0"?><config>'
            '<object id="10"><metadata key="name" value="o"/></object>'
            '<plate><metadata key="plater_id" value="1"/>'
            '<model_instance><metadata key="object_id" value="10"/></model_instance>'
            "</plate></config>"
        )
        threed = (
            '<?xml version="1.0"?>'
            '<model xmlns="http://schemas.microsoft.com/3dmanufacturing/core/2015/02"'
            ' xmlns:p="http://schemas.microsoft.com/3dmanufacturing/production/2015/06">'
            '<resources><object id="10" type="model"><components>'
            '<component p:path="/3D/Objects/o100.model" objectid="100"/>'
            "</components></object></resources><build/></model>"
        )
        with _make_3mf_with(
            {
                "Metadata/model_settings.config": ms,
                "3D/3dmodel.model": threed,
                "3D/Objects/o100.model": per_obj,
            }
        ) as zf:
            result = extract_plate_extruder_set_from_3mf(zf, plate_id=1)
        # Single-leaf accident at 1% filtered as noise; only the dominant
        # extruder survives.
        assert result == {1}

    def test_missing_per_object_model_file_silently_skipped(self):
        ms = (
            '<?xml version="1.0"?><config>'
            '<object id="10"><metadata key="extruder" value="2"/></object>'
            '<plate><metadata key="plater_id" value="1"/>'
            '<model_instance><metadata key="object_id" value="10"/></model_instance>'
            "</plate></config>"
        )
        threed = (
            '<?xml version="1.0"?>'
            '<model xmlns="http://schemas.microsoft.com/3dmanufacturing/core/2015/02"'
            ' xmlns:p="http://schemas.microsoft.com/3dmanufacturing/production/2015/06">'
            '<resources><object id="10" type="model"><components>'
            '<component p:path="/3D/Objects/missing.model" objectid="999"/>'
            "</components></object></resources><build/></model>"
        )
        with _make_3mf_with(
            {"Metadata/model_settings.config": ms, "3D/3dmodel.model": threed},
        ) as zf:
            # Top-level metadata still works; missing component model file
            # is silently skipped without crashing.
            assert extract_plate_extruder_set_from_3mf(zf, plate_id=1) == {2}


class TestExtractEmbeddedPresetsFrom3mf:
    """Printer / process preset names read from project_settings.config so the
    SliceModal can default its dropdowns to the file's own config (#1325)."""

    def test_extracts_printer_and_process(self):
        config = json.dumps(
            {
                "printer_settings_id": "Bambu Lab X1 Carbon 0.4 nozzle",
                "print_settings_id": "0.20mm Standard @BBL X1C",
                "filament_settings_id": ["Bambu PLA Basic @BBL X1C"],
            }
        )
        with _make_3mf_with({"Metadata/project_settings.config": config}) as zf:
            assert extract_embedded_presets_from_3mf(zf) == {
                "printer": "Bambu Lab X1 Carbon 0.4 nozzle",
                "process": "0.20mm Standard @BBL X1C",
            }

    def test_settings_id_as_list_takes_first(self):
        # Some exports write *_settings_id as a per-extruder list.
        config = json.dumps(
            {
                "printer_settings_id": ["Bambu Lab A1 0.4 nozzle"],
                "print_settings_id": ["0.16mm Optimal @BBL A1", "0.20mm @BBL A1"],
            }
        )
        with _make_3mf_with({"Metadata/project_settings.config": config}) as zf:
            result = extract_embedded_presets_from_3mf(zf)
            assert result["printer"] == "Bambu Lab A1 0.4 nozzle"
            assert result["process"] == "0.16mm Optimal @BBL A1"

    def test_missing_config_returns_none_values(self):
        with _make_3mf_with({"3D/3dmodel.model": "<model/>"}) as zf:
            assert extract_embedded_presets_from_3mf(zf) == {
                "printer": None,
                "process": None,
            }

    def test_malformed_json_returns_none_values(self):
        with _make_3mf_with({"Metadata/project_settings.config": "not json"}) as zf:
            assert extract_embedded_presets_from_3mf(zf) == {
                "printer": None,
                "process": None,
            }

    def test_blank_and_absent_keys_yield_none(self):
        config = json.dumps({"printer_settings_id": "  ", "other": "x"})
        with _make_3mf_with({"Metadata/project_settings.config": config}) as zf:
            assert extract_embedded_presets_from_3mf(zf) == {
                "printer": None,
                "process": None,
            }


class TestExtractBedTypeFrom3mf:
    """extract_bed_type_from_3mf reads per-plate `curr_bed_type` from
    slice_info.config so the queue / print modal can show the right plate
    even on multi-plate 3MFs where different plates target different beds
    (#1281). archive.bed_type is one-value-per-archive (first plate's
    curr_bed_type — see services/archive.py:235), so for accurate
    per-plate surfacing we have to re-read the 3MF."""

    def test_single_plate_returns_bed_type(self, tmp_path):
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="curr_bed_type" value="Textured PEI Plate"/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_bed_type_from_3mf(file_path) == "Textured PEI Plate"

    def test_multi_plate_returns_per_plate_value(self, tmp_path):
        # Reporter's case: a 3MF mixing PEI + Engineering across plates.
        # Looking up by plate_id must return THAT plate's value, not the
        # first plate's value the archive happens to cache.
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="curr_bed_type" value="Textured PEI Plate"/>
            </plate>
            <plate>
                <metadata key="index" value="2"/>
                <metadata key="curr_bed_type" value="Engineering Plate"/>
            </plate>
            <plate>
                <metadata key="index" value="3"/>
                <metadata key="curr_bed_type" value="Cool Plate"/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_bed_type_from_3mf(file_path, plate_id=1) == "Textured PEI Plate"
        assert extract_bed_type_from_3mf(file_path, plate_id=2) == "Engineering Plate"
        assert extract_bed_type_from_3mf(file_path, plate_id=3) == "Cool Plate"

    def test_no_plate_id_returns_first_plate(self, tmp_path):
        # The plate_id=None branch must match the archive-level capture
        # convention (first plate wins) so callers that don't care about
        # plate selection see the same value the archive table holds.
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="curr_bed_type" value="Cool Plate SuperTack"/>
            </plate>
            <plate>
                <metadata key="index" value="2"/>
                <metadata key="curr_bed_type" value="Engineering Plate"/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_bed_type_from_3mf(file_path) == "Cool Plate SuperTack"

    def test_unknown_plate_id_returns_none(self, tmp_path):
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="curr_bed_type" value="Textured PEI Plate"/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_bed_type_from_3mf(file_path, plate_id=99) is None

    def test_plate_without_bed_type_returns_none(self, tmp_path):
        # Older slicers may export a plate without curr_bed_type. The
        # helper must return None rather than falling through to another
        # plate's value (which would silently lie).
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
            </plate>
            <plate>
                <metadata key="index" value="2"/>
                <metadata key="curr_bed_type" value="Engineering Plate"/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_bed_type_from_3mf(file_path, plate_id=1) is None
        assert extract_bed_type_from_3mf(file_path, plate_id=2) == "Engineering Plate"

    def test_missing_slice_info_returns_none(self, tmp_path):
        buffer = io.BytesIO()
        with zipfile.ZipFile(buffer, "w") as zf:
            zf.writestr("other_file.txt", "content")
        buffer.seek(0)

        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(buffer.read())

        assert extract_bed_type_from_3mf(file_path) is None

    def test_invalid_file_returns_none(self, tmp_path):
        file_path = tmp_path / "invalid.3mf"
        file_path.write_text("not a zip file")

        assert extract_bed_type_from_3mf(file_path) is None

    def test_whitespace_trimmed(self, tmp_path):
        # 3MF values sometimes carry surrounding whitespace from manual
        # template tweaks; getBedTypeInfo() on the frontend is also
        # whitespace-tolerant, but the wire shape should be clean.
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="curr_bed_type" value="  Textured PEI Plate  "/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_bed_type_from_3mf(file_path) == "Textured PEI Plate"


class TestExtractPrintTimeFrom3mf:
    """Tests for extract_print_time_from_3mf — the per-plate `prediction` reader
    used by the completion notification path to scope the archive-level (summed)
    total down to the actually-printed plate (#1785)."""

    def test_returns_plate_prediction_when_plate_id_matches(self, tmp_path):
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="prediction" value="3600"/>
            </plate>
            <plate>
                <metadata key="index" value="2"/>
                <metadata key="prediction" value="7200"/>
            </plate>
            <plate>
                <metadata key="index" value="3"/>
                <metadata key="prediction" value="10800"/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_print_time_from_3mf(file_path, plate_id=2) == 7200

    def test_returns_first_plate_when_no_plate_id(self, tmp_path):
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="prediction" value="900"/>
            </plate>
            <plate>
                <metadata key="index" value="2"/>
                <metadata key="prediction" value="1800"/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_print_time_from_3mf(file_path) == 900

    def test_returns_none_when_plate_id_missing(self, tmp_path):
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="prediction" value="3600"/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_print_time_from_3mf(file_path, plate_id=5) is None

    def test_returns_none_when_prediction_unparseable(self, tmp_path):
        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="prediction" value="not-a-number"/>
            </plate>
        </config>
        """
        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(create_mock_3mf(xml_content).read())

        assert extract_print_time_from_3mf(file_path, plate_id=1) is None

    def test_returns_none_when_slice_info_missing(self, tmp_path):
        buffer = io.BytesIO()
        with zipfile.ZipFile(buffer, "w") as zf:
            zf.writestr("other_file.txt", "content")
        buffer.seek(0)

        file_path = tmp_path / "test.3mf"
        file_path.write_bytes(buffer.read())

        assert extract_print_time_from_3mf(file_path) is None
        assert extract_print_time_from_3mf(file_path, plate_id=1) is None

    def test_returns_none_when_file_invalid(self, tmp_path):
        file_path = tmp_path / "invalid.3mf"
        file_path.write_text("not a zip file")

        assert extract_print_time_from_3mf(file_path) is None
        assert extract_print_time_from_3mf(file_path, plate_id=1) is None

    def test_returns_none_when_file_missing(self, tmp_path):
        file_path = tmp_path / "nonexistent.3mf"

        assert extract_print_time_from_3mf(file_path) is None
        assert extract_print_time_from_3mf(file_path, plate_id=2) is None


# ---------------------------------------------------------------------------
# Tests for extract_support_filament_slots_from_3mf — #1881: a plate that uses
# PVA (or any material) exclusively for supports doesn't reference the support
# slot from object geometry, so without this helper substitute_unused_plate_
# filaments overwrites the user's support-material profile with slot 1's.
# ---------------------------------------------------------------------------


class TestExtractSupportFilamentSlotsFrom3mf:
    def test_pla_object_plus_pva_support_returns_support_slot(self):
        # The reporter's exact scenario (#1881): slot 1 = PLA (model),
        # slot 2 = PVA (support). enable_support on. Without this the
        # substitute logic replaces slot 2's PVA profile with PLA and
        # the printed supports come out in PLA.
        cfg = json.dumps(
            {
                "enable_support": "1",
                "support_filament": "2",
                "support_interface_filament": "2",
                "filament_type": ["PLA", "PVA"],
            }
        )
        with _make_3mf_with({"Metadata/project_settings.config": cfg}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == {2}

    def test_distinct_support_body_and_interface_slots(self):
        cfg = json.dumps(
            {
                "enable_support": "1",
                "support_filament": "2",
                "support_interface_filament": "3",
            }
        )
        with _make_3mf_with({"Metadata/project_settings.config": cfg}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == {2, 3}

    def test_supports_disabled_returns_empty(self):
        # enable_support off — supports won't be printed even if a slot is
        # configured. Don't force it into the "used" set; substitution
        # should still homogenise the loaded-filament array.
        cfg = json.dumps(
            {
                "enable_support": "0",
                "support_filament": "2",
                "support_interface_filament": "2",
            }
        )
        with _make_3mf_with({"Metadata/project_settings.config": cfg}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == set()

    def test_slot_zero_treated_as_same_as_model(self):
        # BambuStudio's `0` for support_filament means "same as model" —
        # no dedicated slot to preserve.
        cfg = json.dumps(
            {
                "enable_support": "1",
                "support_filament": "0",
                "support_interface_filament": "0",
            }
        )
        with _make_3mf_with({"Metadata/project_settings.config": cfg}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == set()

    def test_boolean_enable_support_accepted(self):
        # Some forks / older versions write a real JSON bool instead of "1"/"0".
        cfg = json.dumps({"enable_support": True, "support_filament": "2"})
        with _make_3mf_with({"Metadata/project_settings.config": cfg}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == {2}

    def test_integer_slot_value_accepted(self):
        cfg = json.dumps({"enable_support": "1", "support_filament": 3})
        with _make_3mf_with({"Metadata/project_settings.config": cfg}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == {3}

    def test_missing_project_settings_returns_empty(self):
        with _make_3mf_with({"placeholder.txt": "hi"}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == set()

    def test_malformed_json_returns_empty(self):
        with _make_3mf_with({"Metadata/project_settings.config": b"{not json"}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == set()

    def test_root_is_list_returns_empty(self):
        with _make_3mf_with({"Metadata/project_settings.config": json.dumps([])}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == set()

    def test_non_numeric_slot_value_skipped(self):
        cfg = json.dumps({"enable_support": "1", "support_filament": "not-a-number"})
        with _make_3mf_with({"Metadata/project_settings.config": cfg}) as zf:
            assert extract_support_filament_slots_from_3mf(zf) == set()


class TestExtractPlateMetadataFrom3mf:
    """The combined per-plate helper parses slice_info.config once and caches
    the result by file revision so queue polling doesn't re-open the same 3MF
    three times per row on every poll (#2573)."""

    _MULTI_PLATE = """<?xml version="1.0" encoding="UTF-8"?>
    <config>
        <plate>
            <metadata key="index" value="1"/>
            <metadata key="prediction" value="3600"/>
            <metadata key="curr_bed_type" value="Textured PEI Plate"/>
            <filament id="1" used_g="50.0" type="PLA" color="#FF0000"/>
        </plate>
        <plate>
            <metadata key="index" value="2"/>
            <metadata key="prediction" value="7200"/>
            <metadata key="curr_bed_type" value="Engineering Plate"/>
            <filament id="1" used_g="12.5" type="ABS" color="#00FF00"/>
            <filament id="2" used_g="7.5" type="ABS" color="#0000FF"/>
        </plate>
    </config>
    """

    def _write(self, tmp_path, xml, name="test.3mf"):
        from backend.app.utils.threemf_tools import clear_plate_metadata_cache

        clear_plate_metadata_cache()
        file_path = tmp_path / name
        file_path.write_bytes(create_mock_3mf(xml).read())
        return file_path

    def test_combines_all_three_fields_for_plate(self, tmp_path):
        from backend.app.utils.threemf_tools import extract_plate_metadata_from_3mf

        file_path = self._write(tmp_path, self._MULTI_PLATE)

        meta = extract_plate_metadata_from_3mf(file_path, plate_id=2)
        assert meta.print_time_seconds == 7200
        assert meta.bed_type == "Engineering Plate"
        assert meta.filament_used_grams == 20.0
        assert {f["slot_id"] for f in meta.filament_usage} == {1, 2}

    def test_plate_id_none_matches_legacy_behaviour(self, tmp_path):
        # Legacy None behaviour: time+bed from the first plate, but usage
        # collects EVERY filament in the file (not just plate 1).
        from backend.app.utils.threemf_tools import extract_plate_metadata_from_3mf

        file_path = self._write(tmp_path, self._MULTI_PLATE)

        meta = extract_plate_metadata_from_3mf(file_path, plate_id=None)
        assert meta.print_time_seconds == 3600
        assert meta.bed_type == "Textured PEI Plate"
        assert len(meta.filament_usage) == 3  # 1 from plate 1 + 2 from plate 2

    def test_second_call_hits_cache_without_reparsing(self, tmp_path):
        from unittest.mock import patch

        import backend.app.utils.threemf_tools as tools

        file_path = self._write(tmp_path, self._MULTI_PLATE)

        with patch.object(tools, "_parse_plate_metadata_uncached", wraps=tools._parse_plate_metadata_uncached) as spy:
            first = tools.extract_plate_metadata_from_3mf(file_path, plate_id=2)
            second = tools.extract_plate_metadata_from_3mf(file_path, plate_id=2)

        assert spy.call_count == 1  # parsed once, served from cache the second time
        assert first is second
        assert second.print_time_seconds == 7200

    def test_changed_file_reparses(self, tmp_path):
        from unittest.mock import patch

        import backend.app.utils.threemf_tools as tools

        file_path = self._write(tmp_path, self._MULTI_PLATE)

        with patch.object(tools, "_parse_plate_metadata_uncached", wraps=tools._parse_plate_metadata_uncached) as spy:
            tools.extract_plate_metadata_from_3mf(file_path, plate_id=1)
            # Replace the file with different content (and a different size, so the
            # revision key changes even if mtime resolution is coarse).
            new_xml = """<?xml version="1.0" encoding="UTF-8"?>
            <config>
                <plate>
                    <metadata key="index" value="1"/>
                    <metadata key="prediction" value="999"/>
                    <metadata key="curr_bed_type" value="Cool Plate"/>
                    <filament id="1" used_g="1.0" type="PLA" color="#FFFFFF"/>
                </plate>
            </config>
            """
            file_path.write_bytes(create_mock_3mf(new_xml).read())
            fresh = tools.extract_plate_metadata_from_3mf(file_path, plate_id=1)

        assert spy.call_count == 2  # revision changed -> re-parsed
        assert fresh.print_time_seconds == 999
        assert fresh.bed_type == "Cool Plate"

    def test_wrapper_returns_mutable_copy(self, tmp_path):
        # extract_filament_usage_from_3mf callers mutate the list; that must not
        # corrupt the shared cached PlateMetadata.
        from backend.app.utils.threemf_tools import (
            extract_filament_usage_from_3mf,
            extract_plate_metadata_from_3mf,
        )

        file_path = self._write(tmp_path, self._MULTI_PLATE)

        usage = extract_filament_usage_from_3mf(file_path, plate_id=2)
        usage.append({"slot_id": 99, "used_g": 0.0, "type": "", "color": ""})
        usage[0]["used_g"] = -1.0

        cached = extract_plate_metadata_from_3mf(file_path, plate_id=2)
        assert len(cached.filament_usage) == 2
        assert all(f["used_g"] > 0 for f in cached.filament_usage)

    def test_non_numeric_filament_id_is_skipped_not_raised(self, tmp_path):
        # A garbage filament id (or used_g) must be silently skipped, exactly as
        # the legacy helpers did — a raise here would 500 the queue listing that
        # calls this per row. Guards both the plate-specific and plate_id=None paths.
        from backend.app.utils.threemf_tools import (
            extract_filament_usage_from_3mf,
            extract_plate_metadata_from_3mf,
        )

        xml_content = """<?xml version="1.0" encoding="UTF-8"?>
        <config>
            <plate>
                <metadata key="index" value="1"/>
                <metadata key="prediction" value="3600"/>
                <filament id="abc" used_g="5.0" type="PLA" color="#FFFFFF"/>
                <filament id="1" used_g="10.0" type="PLA" color="#FF0000"/>
                <filament id="2" used_g="bad" type="PLA" color="#00FF00"/>
            </plate>
        </config>
        """
        file_path = self._write(tmp_path, xml_content)

        meta = extract_plate_metadata_from_3mf(file_path, plate_id=1)
        assert [f["slot_id"] for f in meta.filament_usage] == [1]
        assert meta.filament_used_grams == 10.0
        assert meta.print_time_seconds == 3600

        # plate_id=None path (collects all filaments in the file) must skip too.
        none_result = extract_filament_usage_from_3mf(file_path, plate_id=None)
        assert [f["slot_id"] for f in none_result] == [1]

    def test_missing_file_returns_empty_and_is_not_cached(self, tmp_path):
        from unittest.mock import patch

        import backend.app.utils.threemf_tools as tools

        tools.clear_plate_metadata_cache()
        missing = tmp_path / "nope.3mf"

        with patch.object(tools, "_parse_plate_metadata_uncached", wraps=tools._parse_plate_metadata_uncached) as spy:
            meta = tools.extract_plate_metadata_from_3mf(missing, plate_id=1)
            tools.extract_plate_metadata_from_3mf(missing, plate_id=1)

        assert meta.print_time_seconds is None
        assert meta.filament_usage == []
        # Missing file must not create a sticky cache entry (it may appear later).
        assert spy.call_count == 2