Feature/multi printer support (#12)

* Initial implementation of multi-printer support.

* Always show device dropdown and add bambu_diagnose for multi-printer troubleshooting.

* Add multi-AMS support: per-unit snapshot/usage tracking, grouped dashboard panels with real type labels, and dual-nozzle card UX fixes. Fixes a real-world AMS info-code parsing bug found by inspecting live H2C data.

* Add Vortek hotend rack tracking: per-SN registry with slot mapping confirmed against live MQTT capture, plus a fallback for non-inductive nozzles (e.g. H2C's fixed left nozzle) shown read-only without fabricated identity. New dashboard card hides entirely on printers with no Vortek/nozzle-info data at all.

tests/settings.py

@@ -0,0 +1,40 @@
+"""Minimal Django settings for running bambu_run's pytest suite (in-memory SQLite)."""
+
+SECRET_KEY = "test-secret-key"
+
+INSTALLED_APPS = [
+    "django.contrib.auth",
+    "django.contrib.contenttypes",
+    "django.contrib.sessions",
+    "bambu_run",
+]
+
+MIDDLEWARE = [
+    "django.contrib.sessions.middleware.SessionMiddleware",
+    "django.contrib.auth.middleware.AuthenticationMiddleware",
+]
+
+TEMPLATES = [
+    {
+        "BACKEND": "django.template.backends.django.DjangoTemplates",
+        "APP_DIRS": True,
+        "OPTIONS": {
+            "context_processors": [
+                "django.template.context_processors.request",
+                "django.contrib.auth.context_processors.auth",
+            ],
+        },
+    },
+]
+
+DATABASES = {
+    "default": {
+        "ENGINE": "django.db.backends.sqlite3",
+        "NAME": ":memory:",
+    }
+}
+
+USE_TZ = True
+DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"
+
+ROOT_URLCONF = "tests.urls"

tests/test_ams_type_from_info.py

@@ -0,0 +1,25 @@
+import pytest
+
+from bambu_run.models import ams_type_from_info
+
+
+@pytest.mark.parametrize(
+    "info_code,expected",
+    [
+        # Real-world 8-char info codes captured from a live H2C with
+        # AMS 2 Pro (unit 0), AMS (unit 1), AMS HT (unit 128).
+        ("10001003", "AMS 2 Pro"),
+        ("10001001", "AMS"),
+        ("11002104", "AMS HT"),
+        # Bare 4-digit codes (original assumption) still resolve.
+        ("1001", "AMS"),
+        ("1003", "AMS 2 Pro"),
+        ("2104", "AMS HT"),
+        # Unknown/missing codes resolve to empty string, not an error.
+        ("99999999", ""),
+        ("", ""),
+        (None, ""),
+    ],
+)
+def test_ams_type_from_info(info_code, expected):
+    assert ams_type_from_info(info_code) == expected

tests/test_diagnostics.py

@@ -0,0 +1,68 @@
+import pytest
+
+from bambu_run.diagnostics import redact_diagnostics, build_diagnostics_report
+
+
+def test_redacts_password_and_token_like_keys():
+    data = {"BAMBU_PASSWORD": "hunter2", "access_token": "abc123", "ok": "fine"}
+
+    redacted = redact_diagnostics(data)
+
+    assert redacted["BAMBU_PASSWORD"] == "***REDACTED***"
+    assert redacted["access_token"] == "***REDACTED***"
+    assert redacted["ok"] == "fine"
+
+
+def test_masks_known_identifier_keys_partially():
+    data = {"dev_id": "31B8BP592601478", "tray_uuid": "EE37828FA8844DE1AB12"}
+
+    redacted = redact_diagnostics(data)
+
+    assert redacted["dev_id"] == "31B8...1478"
+    assert redacted["tray_uuid"] == "EE37...AB12"
+
+
+def test_short_identifier_values_fully_masked():
+    data = {"dev_id": "short"}
+
+    redacted = redact_diagnostics(data)
+
+    assert redacted["dev_id"] == "***"
+
+
+def test_recurses_into_nested_structures():
+    data = {"devices": [{"dev_id": "31B8BP592601478", "name": "RNL-H2C"}]}
+
+    redacted = redact_diagnostics(data)
+
+    assert redacted["devices"][0]["dev_id"] == "31B8...1478"
+    assert redacted["devices"][0]["name"] == "RNL-H2C"
+
+
+def test_no_redact_passthrough_keeps_original_values():
+    data = {"dev_id": "31B8BP592601478", "BAMBU_PASSWORD": "hunter2"}
+
+    result = redact_diagnostics(data, redact=False)
+
+    assert result == data
+
+
+def test_build_diagnostics_report_structure():
+    devices = [{"dev_id": "SERIAL-A", "name": "Printer A", "dev_product_name": "H2C"}]
+    raw_payloads = {"SERIAL-A": {"device": {"extruder": {"info": []}}}}
+
+    report = build_diagnostics_report(devices, raw_payloads)
+
+    assert report["device_count"] == 1
+    assert "generated_at" in report
+    assert report["devices"][0]["device_info"]["dev_id"] == "SERIAL-A"
+    assert report["devices"][0]["raw_mqtt_payload"] == {"device": {"extruder": {"info": []}}}
+
+
+def test_build_diagnostics_report_handles_missing_payload():
+    devices = [{"dev_id": "SERIAL-A", "name": "Printer A"}]
+
+    report = build_diagnostics_report(devices, raw_payloads={})
+
+    assert report["devices"][0]["raw_mqtt_payload"] is None
+    assert report["devices"][0]["note"] == "No MQTT data received within the listen window."

tests/test_filament_context.py

@@ -0,0 +1,180 @@
+import pytest
+from decimal import Decimal
+from django.urls import reverse
+from django.utils import timezone
+
+from bambu_run.models import Printer, PrinterMetrics, FilamentSnapshot
+
+
+@pytest.fixture
+def logged_in_client(client, django_user_model):
+    user = django_user_model.objects.create_user(username="tester", password="pw")
+    client.force_login(user)
+    return client
+
+
+@pytest.mark.django_db
+def test_dashboard_filaments_carry_ams_unit_info(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    metric = PrinterMetrics.objects.create(device=printer, timestamp=timezone.now())
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=0, ams_type="AMS",
+        type="PLA", remain_percent=80,
+    )
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=128, ams_type="AMS HT",
+        type="PA-CF", remain_percent=50,
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    filaments = resp.context["stats"]["filaments"]
+    assert len(filaments) == 2
+    units = {(f["ams_unit_id"], f["ams_type"]) for f in filaments}
+    assert units == {(0, "AMS"), (128, "AMS HT")}
+
+    ams_units = resp.context["stats"]["ams_units"]
+    assert ams_units == [
+        {"ams_unit_id": 0, "ams_type": "AMS"},
+        {"ams_unit_id": 128, "ams_type": "AMS HT"},
+    ]
+
+
+@pytest.mark.django_db
+def test_filament_timeline_keeps_same_tray_id_units_separate(logged_in_client):
+    from bambu_run.views import PrinterDashboardView
+
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    metric = PrinterMetrics.objects.create(device=printer, timestamp=timezone.now())
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=0, ams_type="AMS",
+        type="PLA", sub_type="PLA Basic", color="FF0000", remain_percent=80,
+    )
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=128, ams_type="AMS HT",
+        type="PLA", sub_type="PLA Basic", color="FF0000", remain_percent=50,
+    )
+
+    view = PrinterDashboardView()
+    timeline = view._prepare_filament_timeline(PrinterMetrics.objects.filter(pk=metric.pk))
+
+    assert len(timeline) == 2
+
+
+@pytest.mark.django_db
+def test_dashboard_renders_unit_pills_and_badges_with_multiple_units(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    metric = PrinterMetrics.objects.create(device=printer, timestamp=timezone.now())
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=0, ams_type="AMS",
+        type="PLA", color="FF0000FF", remain_percent=80,
+    )
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=128, ams_type="AMS HT",
+        type="PA-CF", color="00FF00FF", remain_percent=50,
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    assert resp.status_code == 200
+    html = resp.content.decode()
+    assert "ams-filter-pills" in html
+    assert "ams-badge-ams" in html
+    assert "ams-badge-ams-ht" in html
+    assert 'data-ams-unit-id="0"' in html
+    assert 'data-ams-unit-id="128"' in html
+
+
+@pytest.mark.django_db
+def test_dashboard_groups_filaments_by_ams_unit(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    metric = PrinterMetrics.objects.create(
+        device=printer, timestamp=timezone.now(),
+        ams_units=[
+            {"unit_id": "0", "ams_type": "AMS 2 Pro", "humidity": 5, "temp": 22.5},
+            {"unit_id": "128", "ams_type": "AMS HT", "humidity": 8, "temp": 60.0},
+        ],
+    )
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=0, ams_type="AMS 2 Pro",
+        type="ABS", remain_percent=80,
+    )
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=1, ams_unit_id=0, ams_type="AMS 2 Pro",
+        type="ABS", remain_percent=60,
+    )
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=128, ams_type="AMS HT",
+        type="PA-CF", remain_percent=50,
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    groups = resp.context["stats"]["ams_groups"]
+    assert len(groups) == 2
+
+    ams2pro_group, ht_group = groups
+    assert ams2pro_group["unit_id"] == 0
+    assert ams2pro_group["label"] == "AMS 2 Pro (Unit 0)"
+    assert ams2pro_group["humidity"] == 5
+    assert ams2pro_group["temp"] == 22.5
+    assert len(ams2pro_group["filaments"]) == 2
+
+    assert ht_group["unit_id"] == 128
+    assert ht_group["label"] == "AMS HT (Unit 128)"
+    assert ht_group["humidity"] == 8
+    assert len(ht_group["filaments"]) == 1
+
+
+@pytest.mark.django_db
+def test_dashboard_renders_wide_and_compact_panels(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    metric = PrinterMetrics.objects.create(
+        device=printer, timestamp=timezone.now(),
+        ams_units=[
+            {"unit_id": "0", "ams_type": "AMS 2 Pro", "humidity": 5, "temp": 22.5},
+            {"unit_id": "128", "ams_type": "AMS HT", "humidity": 8, "temp": 60.0},
+        ],
+    )
+    for tray_id in range(4):
+        FilamentSnapshot.objects.create(
+            printer_metric=metric, tray_id=tray_id, ams_unit_id=0, ams_type="AMS 2 Pro",
+            type="ABS", remain_percent=80,
+        )
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=128, ams_type="AMS HT",
+        type="PA-CF", remain_percent=50,
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    html = resp.content.decode()
+    assert "ams-group--wide" in html
+    assert "ams-group--compact" in html
+    assert "AMS 2 Pro (Unit 0)" in html
+    assert "AMS HT (Unit 128)" in html
+
+
+@pytest.mark.django_db
+def test_dashboard_hides_unit_pills_with_single_unit(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    metric = PrinterMetrics.objects.create(device=printer, timestamp=timezone.now())
+    FilamentSnapshot.objects.create(
+        printer_metric=metric, tray_id=0, ams_unit_id=0, ams_type="AMS",
+        type="PLA", color="FF0000FF", remain_percent=80,
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    assert resp.status_code == 200
+    assert "ams-filter-pills" not in resp.content.decode()

tests/test_hotend_collection.py

@@ -0,0 +1,121 @@
+import pytest
+
+from bambu_run.management.commands.bambu_collector import Command, DeviceSession, resolve_printer_device
+from bambu_run.models import Hotend, HotendSnapshot, PrinterMetrics
+
+
+class FakeClient:
+    """Stub in place of BambuPrinter — returns canned snapshots, no real MQTT."""
+
+    def __init__(self, snapshots):
+        self._snapshots = snapshots
+        self._index = 0
+        self._client = None
+
+    def get_snapshot(self):
+        snap = self._snapshots[min(self._index, len(self._snapshots) - 1)]
+        self._index += 1
+        return snap
+
+
+def make_session(device_id, name, snapshots):
+    printer = resolve_printer_device(device_id, {"name": name, "dev_product_name": "H2C"})
+    return DeviceSession(device_id=device_id, client=FakeClient(snapshots), printer=printer)
+
+
+def hotends_snapshot(used_time=11472, wear=100.0):
+    return {
+        "gcode_state": "IDLE",
+        "hotends": [
+            {
+                "raw_id": 21, "serial_number": "20D06A5B2918952", "nozzle_type": "HS01",
+                "diameter": 0.4, "fila_id": "GFA01", "color": "FFFFFF",
+                "used_time_seconds": used_time, "wear_percent": wear, "stat": 0,
+                "is_toolhead": False, "is_empty": False, "slot_number": 6,
+            },
+            {
+                "raw_id": 1, "serial_number": "N/A", "nozzle_type": "HS01",
+                "diameter": 0.4, "fila_id": "", "color": None,
+                "used_time_seconds": 0, "wear_percent": 0.0, "stat": 0,
+                "is_toolhead": False, "is_empty": True, "slot_number": None,
+            },
+            {
+                "raw_id": 0, "serial_number": "20D06A5C0426280", "nozzle_type": "HS01",
+                "diameter": 0.4, "fila_id": "GFA00", "color": "FEC600",
+                "used_time_seconds": 93490, "wear_percent": 100.0, "stat": 0,
+                "is_toolhead": True, "is_empty": False, "slot_number": None,
+            },
+        ],
+    }
+
+
+@pytest.mark.django_db
+def test_first_poll_creates_one_hotend_per_non_empty_entry():
+    session = make_session("SERIAL-A", "Printer A", [hotends_snapshot()])
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session)
+
+    hotends = Hotend.objects.filter(printer=session.printer)
+    assert hotends.count() == 2  # empty bay (sn="N/A") skipped
+
+    rack = hotends.get(serial_number="20D06A5B2918952")
+    assert rack.raw_id == 21
+    assert rack.slot_number == 6
+    assert rack.is_toolhead is False
+    assert rack.used_time_seconds == 11472
+    assert rack.wear_percent == 100.0
+    assert rack.nozzle_type == "HS01"
+    assert rack.last_filament_profile_id == "GFA01"
+    assert rack.last_color == "FFFFFF"
+
+    toolhead = hotends.get(serial_number="20D06A5C0426280")
+    assert toolhead.is_toolhead is True
+    assert toolhead.slot_number is None
+
+
+@pytest.mark.django_db
+def test_first_poll_creates_one_snapshot_per_non_empty_hotend():
+    session = make_session("SERIAL-A", "Printer A", [hotends_snapshot()])
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session)
+
+    metric = PrinterMetrics.objects.get(device=session.printer)
+    assert HotendSnapshot.objects.filter(printer_metric=metric).count() == 2
+
+
+@pytest.mark.django_db
+def test_collector_persists_raw_nozzle_info_including_non_inductive_entries():
+    session = make_session("SERIAL-A", "Printer A", [hotends_snapshot()])
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session)
+
+    metric = PrinterMetrics.objects.get(device=session.printer)
+    assert len(metric.nozzle_info) == 3  # all entries, including the empty/non-inductive one
+    serials = {h["serial_number"] for h in metric.nozzle_info}
+    assert serials == {"20D06A5B2918952", "N/A", "20D06A5C0426280"}
+
+
+@pytest.mark.django_db
+def test_second_poll_updates_existing_hotend_instead_of_duplicating():
+    session = make_session(
+        "SERIAL-A", "Printer A",
+        [hotends_snapshot(used_time=11472, wear=100.0), hotends_snapshot(used_time=11500, wear=100.0)],
+    )
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session)
+    cmd._collect_printer_data(session)
+
+    hotends = Hotend.objects.filter(printer=session.printer, serial_number="20D06A5B2918952")
+    assert hotends.count() == 1
+    assert hotends.first().used_time_seconds == 11500
+
+    snapshots = HotendSnapshot.objects.filter(hotend=hotends.first())
+    assert snapshots.count() == 2

tests/test_hotend_dashboard.py

@@ -0,0 +1,128 @@
+import pytest
+from django.urls import reverse
+from django.utils import timezone
+
+from bambu_run.models import Printer, PrinterMetrics, Hotend
+
+
+@pytest.fixture
+def logged_in_client(client, django_user_model):
+    user = django_user_model.objects.create_user(username="tester", password="pw")
+    client.force_login(user)
+    return client
+
+
+@pytest.mark.django_db
+def test_dashboard_context_includes_hotends_toolhead_first(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    PrinterMetrics.objects.create(device=printer, timestamp=timezone.now())
+
+    Hotend.objects.create(
+        printer=printer, serial_number="RACK-SN", raw_id=16, slot_number=1,
+        is_toolhead=False, nozzle_type="HS01", used_time_seconds=3600, wear_percent=50,
+    )
+    Hotend.objects.create(
+        printer=printer, serial_number="TOOLHEAD-SN", raw_id=0, slot_number=None,
+        is_toolhead=True, nozzle_type="HS01", used_time_seconds=7200, wear_percent=80,
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    hotends = resp.context["stats"]["hotends"]
+    assert len(hotends) == 2
+    assert hotends[0].serial_number == "TOOLHEAD-SN"
+    assert hotends[1].serial_number == "RACK-SN"
+
+
+@pytest.mark.django_db
+def test_dashboard_context_includes_non_inductive_nozzle_positions(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    PrinterMetrics.objects.create(
+        device=printer, timestamp=timezone.now(),
+        nozzle_info=[
+            {
+                "raw_id": 1, "serial_number": "N/A", "nozzle_type": "HS01", "diameter": 0.4,
+                "fila_id": "", "color": None, "used_time_seconds": 0, "wear_percent": 0.0,
+                "stat": 0, "is_toolhead": False, "is_empty": True, "slot_number": None,
+            },
+        ],
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    positions = resp.context["stats"]["nozzle_positions"]
+    assert len(positions) == 1
+    assert positions[0]["nozzle_type"] == "HS01"
+
+
+@pytest.mark.django_db
+def test_dashboard_omits_nozzle_positions_with_no_readable_data(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    PrinterMetrics.objects.create(
+        device=printer, timestamp=timezone.now(),
+        nozzle_info=[
+            {
+                "raw_id": 1, "serial_number": "N/A", "nozzle_type": "", "diameter": 0,
+                "fila_id": "", "color": None, "used_time_seconds": 0, "wear_percent": 0.0,
+                "stat": 0, "is_toolhead": False, "is_empty": True, "slot_number": None,
+            },
+        ],
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    assert resp.context["stats"]["nozzle_positions"] == []
+    assert "<h5>Hotends</h5>" not in resp.content.decode()
+
+
+@pytest.mark.django_db
+def test_dashboard_renders_nozzle_position_without_serial_or_wear(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    PrinterMetrics.objects.create(
+        device=printer, timestamp=timezone.now(),
+        nozzle_info=[
+            {
+                "raw_id": 1, "serial_number": "N/A", "nozzle_type": "HS01", "diameter": 0.4,
+                "fila_id": "", "color": None, "used_time_seconds": 0, "wear_percent": 0.0,
+                "stat": 0, "is_toolhead": False, "is_empty": True, "slot_number": None,
+            },
+        ],
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    html = resp.content.decode()
+    assert "Hotends" in html
+    assert "HS01" in html
+    assert "SN: N/A" not in html
+    assert "SN N/A" not in html
+
+
+@pytest.mark.django_db
+def test_dashboard_renders_hotends_card(logged_in_client):
+    printer = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    PrinterMetrics.objects.create(device=printer, timestamp=timezone.now())
+
+    Hotend.objects.create(
+        printer=printer, serial_number="RACK-SN", raw_id=18, slot_number=3,
+        is_toolhead=False, nozzle_type="HS01", diameter=0.4,
+        used_time_seconds=3661, wear_percent=50, last_filament_profile_id="GFA01",
+        last_color="DE4343",
+    )
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer.pk})
+    )
+
+    html = resp.content.decode()
+    assert "Hotends" in html
+    assert "RACK-SN" in html
+    assert "Slot 3" in html

tests/test_hotend_parsing.py

@@ -0,0 +1,100 @@
+from bambu_run.mqtt_client import PrinterState
+
+
+def real_nozzle_payload():
+    """Real captured device.nozzle payload from a live H2C with a Vortek rack
+    (1x AMS, 1x AMS 2 Pro, 1x AMS HT physically connected — unrelated here).
+    SN/used-time cross-checked against the user's Bambu Studio Hotends Info table."""
+    return {
+        "exist": 3997699,
+        "src_id": 17,
+        "tar_id": 17,
+        "state": 0,
+        "info": [
+            {"id": 21, "sn": "20D06A5B2918952", "type": "HS01", "diameter": 0.4,
+             "fila_id": "GFA01", "color_m": "FFFFFFFF", "p_t": 11472, "wear": 128.0, "stat": 0, "tm": 350},
+            {"id": 1, "sn": "N/A", "type": "HS01", "diameter": 0.4,
+             "fila_id": "", "color_m": "00000000", "p_t": 0, "wear": 0.0, "stat": 0, "tm": 0},
+            {"id": 16, "sn": "20D06A5B2919219", "type": "HS01", "diameter": 0.4,
+             "fila_id": "GFA01", "color_m": "A3D8E1FF", "p_t": 105386, "wear": 128.0, "stat": 0, "tm": 350},
+            {"id": 20, "sn": "20D06A590610257", "type": "HS01", "diameter": 0.4,
+             "fila_id": "GFG01", "color_m": "00000000", "p_t": 81506, "wear": 128.0, "stat": 0, "tm": 350},
+            {"id": 18, "sn": "20D06A591506263", "type": "HS01", "diameter": 0.4,
+             "fila_id": "GFA01", "color_m": "DE4343FF", "p_t": 30962, "wear": 128.0, "stat": 0, "tm": 350},
+            {"id": 0, "sn": "20D06A5C0426280", "type": "HS01", "diameter": 0.4,
+             "fila_id": "GFA00", "color_m": "FEC600FF", "p_t": 93490, "wear": 128.0, "stat": 0, "tm": 350},
+            {"id": 19, "sn": "20D06A5C0207881", "type": "HS01", "diameter": 0.4,
+             "fila_id": "GFA01", "color_m": "DE4343FF", "p_t": 1430, "wear": 128.0, "stat": 0, "tm": 350},
+        ],
+    }
+
+
+def make_data(nozzle_payload):
+    return {"print": {"gcode_state": "IDLE", "device": {"nozzle": nozzle_payload}}}
+
+
+def test_snapshot_includes_one_hotend_per_nozzle_info_entry():
+    state = PrinterState.from_mqtt_data(make_data(real_nozzle_payload()))
+    snapshot = state.get_snapshot()
+
+    assert len(snapshot["hotends"]) == 7
+
+
+def test_hotend_fields_extracted_correctly():
+    state = PrinterState.from_mqtt_data(make_data(real_nozzle_payload()))
+    snapshot = state.get_snapshot()
+
+    by_sn = {h["serial_number"]: h for h in snapshot["hotends"]}
+    h = by_sn["20D06A5B2919219"]
+
+    assert h["raw_id"] == 16
+    assert h["nozzle_type"] == "HS01"
+    assert h["diameter"] == 0.4
+    assert h["fila_id"] == "GFA01"
+    assert h["color"] == "A3D8E1"  # alpha stripped
+    assert h["used_time_seconds"] == 105386
+    assert h["wear_percent"] == 100.0  # 128/128*100
+    assert h["is_empty"] is False
+
+
+def test_id_zero_is_toolhead_and_resolves_slot_number():
+    state = PrinterState.from_mqtt_data(make_data(real_nozzle_payload()))
+    snapshot = state.get_snapshot()
+
+    by_sn = {h["serial_number"]: h for h in snapshot["hotends"]}
+    toolhead = by_sn["20D06A5C0426280"]
+
+    assert toolhead["raw_id"] == 0
+    assert toolhead["is_toolhead"] is True
+    assert toolhead["slot_number"] is None  # true bay address hidden while id==0 sentinel
+
+
+def test_rack_bay_ids_resolve_to_slot_numbers_one_through_six():
+    state = PrinterState.from_mqtt_data(make_data(real_nozzle_payload()))
+    snapshot = state.get_snapshot()
+
+    by_sn = {h["serial_number"]: h for h in snapshot["hotends"]}
+
+    assert by_sn["20D06A5B2919219"]["slot_number"] == 1  # raw_id 16
+    assert by_sn["20D06A591506263"]["slot_number"] == 3  # raw_id 18
+    assert by_sn["20D06A5C0207881"]["slot_number"] == 4  # raw_id 19
+    assert by_sn["20D06A590610257"]["slot_number"] == 5  # raw_id 20
+    assert by_sn["20D06A5B2918952"]["slot_number"] == 6  # raw_id 21
+
+
+def test_empty_bay_with_na_serial_is_flagged_empty():
+    state = PrinterState.from_mqtt_data(make_data(real_nozzle_payload()))
+    snapshot = state.get_snapshot()
+
+    by_sn = {h["serial_number"]: h for h in snapshot["hotends"]}
+    empty = by_sn["N/A"]
+
+    assert empty["is_empty"] is True
+    assert empty["is_toolhead"] is False
+
+
+def test_snapshot_hotends_empty_list_when_no_nozzle_payload():
+    state = PrinterState.from_mqtt_data({"print": {"gcode_state": "IDLE"}})
+    snapshot = state.get_snapshot()
+
+    assert snapshot["hotends"] == []

tests/test_multi_ams_collection.py

@@ -0,0 +1,104 @@
+import pytest
+
+from bambu_run.management.commands.bambu_collector import Command, DeviceSession, resolve_printer_device
+from bambu_run.models import Filament, FilamentSnapshot, FilamentUsage, PrinterMetrics
+
+
+class FakeClient:
+    """Stub in place of BambuPrinter — returns canned snapshots, no real MQTT."""
+
+    def __init__(self, snapshots):
+        self._snapshots = snapshots
+        self._index = 0
+        self._client = None
+
+    def get_snapshot(self):
+        snap = self._snapshots[min(self._index, len(self._snapshots) - 1)]
+        self._index += 1
+        return snap
+
+
+def make_session(device_id, name, snapshots):
+    printer = resolve_printer_device(device_id, {"name": name, "dev_product_name": "H2C"})
+    return DeviceSession(device_id=device_id, client=FakeClient(snapshots), printer=printer)
+
+
+def two_unit_tray0_snapshot():
+    """Two AMS units (AMS unit_id=0, AMS HT unit_id=128) both report tray_id=0,
+    with different filament types loaded — these must not collide."""
+    return {
+        "gcode_state": "IDLE",
+        "ams_units": [
+            {"unit_id": "0", "ams_type": "AMS", "humidity": 30, "temp": 25.0},
+            {"unit_id": "128", "ams_type": "AMS HT", "humidity": 20, "temp": 60.0},
+        ],
+        "filaments": [
+            {
+                "tray_id": 0, "type": "PLA", "sub_type": "PLA Basic", "color": "FF0000FF",
+                "tray_uuid": "UUID-UNIT0-TRAY0",
+                "remain_percent": 80, "ams_unit_id": 0, "ams_type": "AMS",
+            },
+            {
+                "tray_id": 0, "type": "PA-CF", "sub_type": "PA6-CF", "color": "00FF00FF",
+                "tray_uuid": "UUID-UNIT128-TRAY0",
+                "remain_percent": 50, "ams_unit_id": 128, "ams_type": "AMS HT",
+            },
+        ],
+    }
+
+
+@pytest.mark.django_db
+def test_two_ams_units_with_same_tray_id_create_distinct_snapshots():
+    session = make_session("SERIAL-A", "Printer A", [two_unit_tray0_snapshot()])
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session)
+
+    metric = PrinterMetrics.objects.get(device=session.printer)
+    snapshots = FilamentSnapshot.objects.filter(printer_metric=metric).order_by("ams_unit_id")
+
+    assert snapshots.count() == 2
+
+    ams_snap, ht_snap = snapshots
+    assert ams_snap.tray_id == 0
+    assert ams_snap.ams_unit_id == 0
+    assert ams_snap.ams_type == "AMS"
+    assert ams_snap.type == "PLA"
+
+    assert ht_snap.tray_id == 0
+    assert ht_snap.ams_unit_id == 128
+    assert ht_snap.ams_type == "AMS HT"
+    assert ht_snap.type == "PA-CF"
+
+
+@pytest.mark.django_db
+def test_filament_usage_matches_correct_unit_when_tray_ids_collide():
+    start_snapshot = two_unit_tray0_snapshot()
+    start_snapshot.update({"gcode_state": "RUNNING", "subtask_name": "job_1", "print_percent": 1, "tray_now": "0"})
+
+    end_snapshot = two_unit_tray0_snapshot()
+    end_snapshot["filaments"][0]["remain_percent"] = 70  # AMS unit 0 consumed
+    end_snapshot["filaments"][1]["remain_percent"] = 50  # AMS HT unit 128 untouched
+    end_snapshot.update({"gcode_state": "FINISH", "subtask_name": "job_1", "print_percent": 100})
+
+    session = make_session("SERIAL-A", "Printer A", [start_snapshot, end_snapshot])
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session)
+    cmd._collect_printer_data(session)
+
+    usages = FilamentUsage.objects.filter(print_job__device=session.printer).order_by("ams_unit_id")
+    # Both units reported tray_id=0 with a tracked filament loaded throughout the
+    # job — usage is recorded per physical unit, not collapsed into one ambiguous row.
+    assert usages.count() == 2
+
+    ams_usage, ht_usage = usages
+    assert ams_usage.ams_unit_id == 0
+    assert ams_usage.starting_percent == 80
+    assert ams_usage.ending_percent == 70
+
+    assert ht_usage.ams_unit_id == 128
+    assert ht_usage.starting_percent == 50
+    assert ht_usage.ending_percent == 50

tests/test_multi_device_collection.py

@@ -0,0 +1,90 @@
+import pytest
+
+from bambu_run.management.commands.bambu_collector import (
+    Command,
+    DeviceSession,
+    resolve_printer_device,
+)
+from bambu_run.models import PrintJob, PrinterMetrics
+
+
+class FakeClient:
+    """Stub in place of BambuPrinter — returns canned snapshots, no real MQTT."""
+
+    def __init__(self, snapshots):
+        self._snapshots = snapshots
+        self._index = 0
+        self._client = None  # cloud BambuClient handle used by cloud task sync
+
+    def get_snapshot(self):
+        snap = self._snapshots[min(self._index, len(self._snapshots) - 1)]
+        self._index += 1
+        return snap
+
+
+def make_session(device_id, name, snapshots):
+    printer = resolve_printer_device(device_id, {"name": name, "dev_product_name": "H2C"})
+    return DeviceSession(device_id=device_id, client=FakeClient(snapshots), printer=printer)
+
+
+@pytest.mark.django_db
+def test_collects_metrics_against_the_correct_printer_per_session():
+    session_a = make_session("SERIAL-A", "Printer A", [{"nozzle_temp": 200, "gcode_state": "IDLE"}])
+    session_b = make_session("SERIAL-B", "Printer B", [{"nozzle_temp": 210, "gcode_state": "IDLE"}])
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session_a)
+    cmd._collect_printer_data(session_b)
+
+    metric_a = PrinterMetrics.objects.get(device=session_a.printer)
+    metric_b = PrinterMetrics.objects.get(device=session_b.printer)
+    assert metric_a.nozzle_temp == 200
+    assert metric_b.nozzle_temp == 210
+
+
+@pytest.mark.django_db
+def test_print_job_tracking_is_isolated_per_session():
+    session_a = make_session(
+        "SERIAL-A",
+        "Printer A",
+        [
+            {"gcode_state": "RUNNING", "subtask_name": "job_A", "print_percent": 10},
+            {"gcode_state": "FINISH", "subtask_name": "job_A", "print_percent": 100},
+        ],
+    )
+    session_b = make_session("SERIAL-B", "Printer B", [{"gcode_state": "IDLE"}])
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session_a)
+    cmd._collect_printer_data(session_b)
+    cmd._collect_printer_data(session_a)
+
+    assert PrintJob.objects.filter(device=session_a.printer).count() == 1
+    job = PrintJob.objects.get(device=session_a.printer)
+    assert job.final_status == "FINISH"
+    assert session_a.current_print_job is None
+
+    assert PrintJob.objects.filter(device=session_b.printer).count() == 0
+    assert session_b.current_print_job is None
+
+
+@pytest.mark.django_db
+def test_one_session_error_does_not_affect_another_session():
+    session_a = make_session("SERIAL-A", "Printer A", [{"nozzle_temp": 200, "gcode_state": "IDLE"}])
+    session_b = make_session("SERIAL-B", "Printer B", [{"nozzle_temp": 210, "gcode_state": "IDLE"}])
+
+    class ExplodingClient:
+        def get_snapshot(self):
+            raise RuntimeError("MQTT connection lost")
+
+    session_a.client = ExplodingClient()
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session_a)
+    cmd._collect_printer_data(session_b)
+
+    assert session_a.error_count == 1
+    assert PrinterMetrics.objects.filter(device=session_b.printer).exists()

tests/test_printer_routing.py

@@ -0,0 +1,78 @@
+import pytest
+from django.urls import reverse
+
+from bambu_run.models import Printer
+
+
+@pytest.fixture
+def logged_in_client(client, django_user_model):
+    user = django_user_model.objects.create_user(username="tester", password="pw")
+    client.force_login(user)
+    return client
+
+
+@pytest.mark.django_db
+def test_dashboard_with_no_printers_shows_error(logged_in_client):
+    resp = logged_in_client.get(reverse("bambu_run:printer_dashboard"))
+    assert resp.status_code == 200
+    assert "error" in resp.context
+
+
+@pytest.mark.django_db
+def test_dashboard_defaults_to_first_active_printer(logged_in_client):
+    printer = Printer.objects.create(name="Only Printer", model="H2C", is_active=True)
+
+    resp = logged_in_client.get(reverse("bambu_run:printer_dashboard"))
+
+    assert resp.context["printer_device"].pk == printer.pk
+    assert list(resp.context["all_printers"]) == [printer]
+    # Switcher shows even with a single printer, as a hint that multi-printer exists.
+    assert resp.context["show_printer_switcher"] is True
+
+
+@pytest.mark.django_db
+def test_dashboard_hides_switcher_with_zero_printers(logged_in_client):
+    resp = logged_in_client.get(reverse("bambu_run:printer_dashboard"))
+
+    assert resp.context["show_printer_switcher"] is False
+
+
+@pytest.mark.django_db
+def test_dashboard_pk_route_shows_requested_printer(logged_in_client):
+    Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    printer_b = Printer.objects.create(name="Printer B", model="X1C", is_active=True)
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": printer_b.pk})
+    )
+
+    assert resp.context["printer_device"].pk == printer_b.pk
+    assert resp.context["device_name"] == "Printer B"
+
+
+@pytest.mark.django_db
+def test_dashboard_unknown_pk_returns_404(logged_in_client):
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_dashboard", kwargs={"pk": 99999})
+    )
+    assert resp.status_code == 404
+
+
+@pytest.mark.django_db
+def test_api_pk_route_returns_only_requested_printer_data(logged_in_client):
+    from bambu_run.models import PrinterMetrics
+    from django.utils import timezone
+    from decimal import Decimal
+
+    printer_a = Printer.objects.create(name="Printer A", model="H2C", is_active=True)
+    printer_b = Printer.objects.create(name="Printer B", model="X1C", is_active=True)
+    PrinterMetrics.objects.create(device=printer_a, timestamp=timezone.now(), nozzle_temp=Decimal("200"))
+    PrinterMetrics.objects.create(device=printer_b, timestamp=timezone.now(), nozzle_temp=Decimal("210"))
+
+    resp = logged_in_client.get(
+        reverse("bambu_run:printer_api", kwargs={"pk": printer_b.pk})
+    )
+
+    assert resp.status_code == 200
+    data = resp.json()
+    assert data["nozzle_temp"] == [210.0]

tests/test_resolve_printer_device.py

@@ -0,0 +1,78 @@
+import pytest
+
+from bambu_run.management.commands.bambu_collector import resolve_printer_device
+from bambu_run.models import Printer
+
+
+@pytest.mark.django_db
+def test_creates_new_printer_keyed_by_serial():
+    printer = resolve_printer_device(
+        "0309DA123456", {"name": "RNL-H2C", "dev_product_name": "H2C"}
+    )
+
+    assert printer.serial_number == "0309DA123456"
+    assert printer.name == "RNL-H2C"
+    assert printer.model == "H2C"
+    assert printer.is_active is True
+
+
+@pytest.mark.django_db
+def test_second_call_with_same_serial_does_not_create_duplicate():
+    first = resolve_printer_device("SERIAL-A", {"name": "Printer A", "dev_product_name": "H2C"})
+    second = resolve_printer_device("SERIAL-A", {"name": "Printer A", "dev_product_name": "H2C"})
+
+    assert first.pk == second.pk
+    assert Printer.objects.filter(serial_number="SERIAL-A").count() == 1
+
+
+@pytest.mark.django_db
+def test_two_different_serials_create_two_printers():
+    a = resolve_printer_device("SERIAL-A", {"name": "Printer A", "dev_product_name": "H2C"})
+    b = resolve_printer_device("SERIAL-B", {"name": "Printer B", "dev_product_name": "X1C"})
+
+    assert a.pk != b.pk
+    assert Printer.objects.count() == 2
+
+
+@pytest.mark.django_db
+def test_backfills_single_legacy_printer_with_null_serial():
+    legacy = Printer.objects.create(
+        name="Bambu Lab Printer", model="Bambu Lab", manufacturer="Bambu Lab", is_active=True
+    )
+
+    resolved = resolve_printer_device("SERIAL-A", {"name": "RNL-H2C", "dev_product_name": "H2C"})
+
+    legacy.refresh_from_db()
+    assert resolved.pk == legacy.pk
+    assert legacy.serial_number == "SERIAL-A"
+    assert Printer.objects.count() == 1
+
+
+@pytest.mark.django_db
+def test_does_not_guess_when_multiple_legacy_printers_exist():
+    Printer.objects.create(name="Legacy 1", model="Bambu Lab")
+    Printer.objects.create(name="Legacy 2", model="Bambu Lab")
+
+    resolved = resolve_printer_device("SERIAL-A", {"name": "RNL-H2C", "dev_product_name": "H2C"})
+
+    assert resolved.serial_number == "SERIAL-A"
+    assert Printer.objects.count() == 3
+
+
+@pytest.mark.django_db
+def test_falls_back_to_generic_defaults_without_device_info():
+    printer = resolve_printer_device("SERIAL-A", None)
+
+    assert printer.serial_number == "SERIAL-A"
+    assert printer.name == "Bambu Lab Printer"
+    assert printer.model == "Bambu Lab"
+
+
+@pytest.mark.django_db
+def test_updates_name_and_model_on_existing_printer_when_changed():
+    resolve_printer_device("SERIAL-A", {"name": "Old Name", "dev_product_name": "H2C"})
+
+    updated = resolve_printer_device("SERIAL-A", {"name": "New Name", "dev_product_name": "H2C"})
+
+    assert updated.name == "New Name"
+    assert Printer.objects.filter(serial_number="SERIAL-A").count() == 1

tests/test_vortek_groundwork.py

@@ -0,0 +1,43 @@
+import pytest
+
+from bambu_run.mqtt_client import PrinterState
+from bambu_run.management.commands.bambu_collector import Command, DeviceSession, resolve_printer_device
+from bambu_run.models import PrinterMetrics
+
+
+def test_snapshot_includes_raw_device_payload_for_future_vortek_modeling():
+    raw_device = {
+        "extruder": {"info": [{"id": 0, "temp": 12058720}, {"id": 1, "temp": 11534560}]},
+        "nozzle": {"info": [{"id": 0, "diameter": 0.4}]},
+    }
+    data = {"print": {"device": raw_device, "gcode_state": "IDLE"}}
+
+    state = PrinterState.from_mqtt_data(data)
+    snapshot = state.get_snapshot()
+
+    assert snapshot["vortek_raw"] == raw_device
+
+
+def test_snapshot_vortek_raw_defaults_to_empty_dict_when_no_device_payload():
+    state = PrinterState.from_mqtt_data({"print": {"gcode_state": "IDLE"}})
+    snapshot = state.get_snapshot()
+
+    assert snapshot["vortek_raw"] == {}
+
+
+@pytest.mark.django_db
+def test_collector_persists_vortek_raw_onto_printer_metrics():
+    printer = resolve_printer_device("SERIAL-A", {"name": "H2C", "dev_product_name": "H2C"})
+
+    class FakeClient:
+        def get_snapshot(self):
+            return {"gcode_state": "IDLE", "vortek_raw": {"extruder": {"info": []}}}
+
+    session = DeviceSession(device_id="SERIAL-A", client=FakeClient(), printer=printer)
+
+    cmd = Command()
+    cmd.verbose = False
+    cmd._collect_printer_data(session)
+
+    metric = PrinterMetrics.objects.get(device=printer)
+    assert metric.vortek_raw == {"extruder": {"info": []}}

tests/urls.py

@@ -0,0 +1,5 @@
+from django.urls import include, path
+
+urlpatterns = [
+    path("", include("bambu_run.urls")),
+]