llmgw/internal/web/admin_serve_test.go

package web

import (
	"context"
	"errors"
	"fmt"
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"

	"gitea.mynodes.xyz/ilker/llmgw/internal/control/adminapi"
	"gitea.mynodes.xyz/ilker/llmgw/internal/control/catalog"
	"gitea.mynodes.xyz/ilker/llmgw/internal/control/modelsvc"
	"gitea.mynodes.xyz/ilker/llmgw/internal/gguf"
	"gitea.mynodes.xyz/ilker/llmgw/internal/mirror"
)

type fakeCatalog struct {
	added       []catalog.Model
	declared    string
	sources     map[string][]catalog.Model
	scaled      []string
	lastScale   catalog.Scaling
	err         error
	classes     []string
	owners      []string
	resources   []string
	adapterSets [][]catalog.Adapter
	// stops, starts and splits are the models stopped, started and counted
	// per profile, splitCPU the profile on CPUs last asked for.
	stops, starts []string
	splits        []map[string]int
	splitCPU      *modelsvc.CPUProfile
}

func (f *fakeCatalog) SetProfileReplicas(_ context.Context, name string, counts map[string]int, cpu *modelsvc.CPUProfile,
	_ string,
) (catalog.Model, error) {
	f.splits, f.splitCPU = append(f.splits, counts), cpu
	m := catalog.Model{Name: name}
	for p, n := range counts {
		m.Profiles = append(m.Profiles, catalog.Profile{Name: p, Replicas: n})
	}
	return m, f.err
}

func (f *fakeCatalog) Add(_ context.Context, m catalog.Model, _ string) error {
	if f.err != nil {
		return f.err
	}
	f.added = append(f.added, m)
	return nil
}
func (f *fakeCatalog) Declared(name string) bool { return name == f.declared }
func (f *fakeCatalog) Sources(context.Context) (map[string][]catalog.Model, error) {
	return f.sources, nil
}

func (f *fakeCatalog) SetAdapters(_ context.Context, name string, as []catalog.Adapter, _ string) (catalog.Model, error) {
	f.adapterSets = append(f.adapterSets, as)
	return catalog.Model{Name: name, Adapters: as}, f.err
}

func (f *fakeCatalog) SetClass(_ context.Context, name, class, _ string) (catalog.Model, error) {
	f.classes = append(f.classes, name+"="+class)
	return catalog.Model{Name: name, Class: class}, f.err
}

func (f *fakeCatalog) SetOwner(_ context.Context, name, owner, _ string) (catalog.Model, error) {
	f.owners = append(f.owners, name+"="+owner)
	return catalog.Model{Name: name, Owner: owner}, f.err
}

func (f *fakeCatalog) Resources(_ context.Context, name, _ string, mem, cores int, _ string) (catalog.Model, error) {
	f.resources = append(f.resources, fmt.Sprintf("%s=%d/%d", name, mem, cores))
	return catalog.Model{Name: name}, f.err
}

func (f *fakeCatalog) Scale(_ context.Context, name string, sc catalog.Scaling, _ string) (catalog.Model, error) {
	f.scaled = append(f.scaled, name)
	f.lastScale = sc
	return catalog.Model{Name: name, Scaling: sc}, f.err
}

// fleet reports a cluster with a given number of cards and engines.
type fakeFleet struct {
	gpus     int
	engines  []string
	memoryGB int
	// used is how many of the cards replicas hold.
	used int
}

func (f fakeFleet) Nodes() []adminapi.NodeView {
	return []adminapi.NodeView{
		{ID: "n1", GPUTotal: f.gpus, Engines: f.engines, MemoryGB: f.memoryGB},
	}
}
func (f fakeFleet) Models() []adminapi.ModelView           { return nil }
func (f fakeFleet) Replicas(string) []adminapi.ReplicaView { return nil }
func (f fakeFleet) Explain(string) adminapi.ExplainView    { return adminapi.ExplainView{} }
func (f fakeFleet) Summary() adminapi.Summary {
	if f.gpus == 0 {
		return adminapi.Summary{}
	}
	return adminapi.Summary{GPUs: []adminapi.ClassUse{{Class: "t4", Total: f.gpus, Used: f.used}}}
}

func held(model, version, file string) mirror.Status {
	return mirror.Status{Model: model, Version: version, File: file,
		State: mirror.Present, BytesDone: 10, BytesTotal: 10}
}

func servePage(t *testing.T, models []mirror.Status, cat CatalogAdmin, gpus int,
	engines ...string,
) *http.ServeMux {
	t.Helper()
	return mirrorPageDeps(t, MirrorDeps{
		Mirror: &fakeMirror{models: models}, Catalog: cat,
		Fleet: fakeFleet{gpus: gpus, engines: engines},
	}, true)
}

// reachableSource stands in for a mirror holding the file. The serve handler
// checks the source before the catalog sees it, the same as the CLI does, so a
// test that means to exercise the form has to offer something that answers.
func reachableSource(t *testing.T) string {
	t.Helper()
	srv := httptest.NewServer(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(http.StatusOK) }))
	t.Cleanup(srv.Close)
	return srv.URL + "/coder/v1/m.gguf"
}

func TestAGGUFCanBeServedStraightFromTheList(t *testing.T) {
	cat := &fakeCatalog{}
	body := mirrorGet(t, servePage(t, []mirror.Status{
		held("qwen2.5-coder-7b", "c03e6d35", "qwen-q4_k_m.gguf")}, cat, 0),
		"/admin/mirror?serve=qwen2.5-coder-7b:c03e6d35").Body.String()

	// The mirror already knows the name, the URL and what reads that kind of
	// file; leaving an operator to write YAML for it was the gap.
	if !strings.Contains(body, `name="engine" value="llamacpp"`) {
		t.Errorf("the engine should be inferred from the extension; got %s", body)
	}
	if !strings.Contains(body, "/qwen2.5-coder-7b/c03e6d35/qwen-q4_k_m.gguf") {
		t.Error("the source should be the mirror's own URL")
	}
}

func TestAShardedVersionIsServedAsTheWholeVersion(t *testing.T) {
	models := []mirror.Status{
		held("llama", "v1", "model-00001-of-00002.safetensors"),
		held("llama", "v1", "model-00002-of-00002.safetensors"),
	}
	body := mirrorGet(t, servePage(t, models, &fakeCatalog{}, 8, "vllm"),
		"/admin/mirror?serve=llama:v1").Body.String()

	// A catalogue entry names one source, and for a version of several files
	// that source is the version. Refusing it meant a sharded model could be
	// mirrored and never served — which is most of what is not a GGUF.
	if !strings.Contains(body, `value="http://mirror:8081/llama/v1/"`) {
		t.Errorf("the source should be the version directory; got %s", body)
	}
	if !strings.Contains(body, "The whole version, 2 files") {
		t.Error("the form should say it is fetching a set")
	}
	if !strings.Contains(body, `action="/admin/mirror/serve"`) {
		t.Error("it should be servable")
	}
}

func TestTheEngineForASetComesFromItsWeights(t *testing.T) {
	// A version is a mixture only when somebody has put a file there by hand.
	// config.json decides nothing; the safetensors do.
	models := []mirror.Status{
		held("llama", "v1", "config.json"),
		held("llama", "v1", "model-00001-of-00002.safetensors"),
	}
	body := mirrorGet(t, servePage(t, models, &fakeCatalog{}, 8, "vllm"),
		"/admin/mirror?serve=llama:v1").Body.String()

	if !strings.Contains(body, `name="engine" value="vllm"`) {
		t.Errorf("the weights should pick the engine; got %s", body)
	}
}

func TestSafetensorsOnACPUFleetWarnsBeforeAnybodyTries(t *testing.T) {
	body := mirrorGet(t, servePage(t, []mirror.Status{
		held("qwen", "v1", "model.safetensors")}, &fakeCatalog{}, 0, "llamacpp"),
		"/admin/mirror?serve=qwen:v1").Body.String()

	// Fifteen gigabytes arrived before anybody noticed the fleet had no card
	// and no vLLM to run them with. The page can say so.
	if !strings.Contains(body, "no node reports having vllm installed") {
		t.Errorf("expected the warning; got %s", body)
	}
	// And the way out, which on a fleet with no cards is a different build of
	// the same model rather than installing vLLM.
	if !strings.Contains(body, "GGUF build of the same model") {
		t.Error("a fleet with no GPU should be pointed at a GGUF")
	}
	// A warning, not a refusal: a card could be added tomorrow.
	if !strings.Contains(body, `action="/admin/mirror/serve"`) {
		t.Error("it should still be possible to add it")
	}
}

func TestSafetensorsOnAGPUFleetIsNotWarnedAbout(t *testing.T) {
	body := mirrorGet(t, servePage(t, []mirror.Status{
		held("qwen", "v1", "model.safetensors")}, &fakeCatalog{}, 8, "vllm"),
		"/admin/mirror?serve=qwen:v1").Body.String()

	if strings.Contains(body, "no node reports having") {
		t.Error("a fleet that runs vllm should not be warned about")
	}
	if !strings.Contains(body, `value="vllm"`) {
		t.Error("safetensors should propose vllm")
	}
}

func TestAModelDeclaredInConfigurationIsNotOfferedTwice(t *testing.T) {
	cat := &fakeCatalog{declared: "qwen"}
	body := mirrorGet(t, servePage(t, []mirror.Status{
		held("qwen", "v1", "m.gguf")}, cat, 0),
		"/admin/mirror?serve=qwen:v1").Body.String()

	if !strings.Contains(body, "declared in configuration") {
		t.Errorf("expected the refusal; got %s", body)
	}
}

func TestServingBuildsTheEntryFromTheForm(t *testing.T) {
	cat := &fakeCatalog{}
	source := reachableSource(t)
	mirrorPost(t, servePage(t, nil, cat, 0), "/admin/mirror/serve", url.Values{
		"csrf": {"tok"}, "name": {"coder"}, "aliases": {"c7b, coder-7b"},
		"source": {source}, "engine": {"llamacpp"},
		"replicas": {"3"}, "context_length": {"4096"}, "max_output": {"1024"},
		"ctx_size": {"16384"}, "profile": {"cpu-large"},
		"min_memory_gb": {"8"}, "selector_key": {"role"}, "selector_value": {"cpu-large"},
	})

	if len(cat.added) != 1 {
		t.Fatalf("expected one model added, got %d", len(cat.added))
	}
	m := cat.added[0]
	if m.Name != "coder" || len(m.Aliases) != 2 {
		t.Errorf("name and aliases did not arrive: %+v", m)
	}
	if m.Scaling.Min != 3 || m.Scaling.Max != 3 {
		t.Errorf("expected three replicas, got %+v", m.Scaling)
	}
	if len(m.Profiles) != 1 {
		t.Fatalf("expected one profile, got %+v", m.Profiles)
	}
	p := m.Profiles[0]
	if p.Engine != "llamacpp" || p.Name != "cpu-large" || p.MinMemoryGB != 8 {
		t.Errorf("the profile is wrong: %+v", p)
	}
	// The label is what keeps a large model off the small machines.
	if p.NodeSelector["role"] != "cpu-large" {
		t.Errorf("the node selector was lost: %+v", p.NodeSelector)
	}
	if strings.Join(p.Args, " ") != "--ctx-size 16384" {
		t.Errorf("the engine's context pool was lost: %v", p.Args)
	}
}

func TestRubbishInTheFormIsRefusedBeforeTheCatalog(t *testing.T) {
	cat := &fakeCatalog{}
	mirrorPost(t, servePage(t, nil, cat, 0), "/admin/mirror/serve", url.Values{
		"csrf": {"tok"}, "name": {"coder"}, "source": {"http://x/m.gguf"},
		"engine": {"llamacpp"}, "replicas": {"lots"}, "context_length": {"4096"},
	})
	if len(cat.added) != 0 {
		t.Error("nothing should have reached the catalog")
	}
}

func TestTheCatalogsOwnRefusalReachesTheOperator(t *testing.T) {
	cat := &fakeCatalog{err: errors.New("that name collides with an alias")}
	source := reachableSource(t)
	body := mirrorPost(t, servePage(t, nil, cat, 0), "/admin/mirror/serve", url.Values{
		"csrf": {"tok"}, "name": {"coder"}, "source": {source},
		"engine": {"llamacpp"}, "replicas": {"1"}, "context_length": {"4096"},
	}).Body.String()

	if !strings.Contains(body, "collides with an alias") {
		t.Errorf("the catalog's reason should be shown; got %s", body)
	}
}

func TestWithNoCatalogThereIsNoServeAction(t *testing.T) {
	body := mirrorGet(t, mirrorPageDeps(t, MirrorDeps{
		Mirror: &fakeMirror{models: []mirror.Status{held("qwen", "v1", "m.gguf")}},
	}, true), "/admin/mirror").Body.String()

	// Without a store a model added at runtime would not survive a restart, so
	// the action is absent rather than offered and then refused.
	if strings.Contains(body, "?serve=") {
		t.Error("serving should not be offered without somewhere to persist it")
	}
}

func TestAGPUNodeWithoutVLLMIsStillWarnedAbout(t *testing.T) {
	// The first version of this checked cards, which would have waved through
	// a fleet of eight-GPU nodes that had never had vLLM installed. Agents
	// report their engines now, so it is a fact.
	body := mirrorGet(t, servePage(t, []mirror.Status{
		held("qwen", "v1", "model.safetensors")}, &fakeCatalog{}, 8, "llamacpp"),
		"/admin/mirror?serve=qwen:v1").Body.String()

	if !strings.Contains(body, "no node reports having vllm installed") {
		t.Errorf("cards are not the question; the engine is. Got %s", body)
	}
}

func TestAFleetOfOlderAgentsIsNotToldEverythingIsUnservable(t *testing.T) {
	// An agent older than the engine probe reports nothing, which is not the
	// same as having no engines. Placement makes the same allowance, and the
	// two disagreeing would be worse than either.
	body := mirrorGet(t, servePage(t, []mirror.Status{
		held("qwen", "v1", "m.gguf")}, &fakeCatalog{}, 0),
		"/admin/mirror?serve=qwen:v1").Body.String()

	if strings.Contains(body, "no node reports having") {
		t.Error("silence from older agents must not read as a refusal")
	}
}

func sized(model, version, file string, gb float64) mirror.Status {
	n := int64(gb * (1 << 30))
	return mirror.Status{Model: model, Version: version, File: file,
		State: mirror.Present, BytesDone: n, BytesTotal: n}
}

func TestTheMemoryFieldIsFilledInFromTheWeights(t *testing.T) {
	// The real case: 4.68 GB of weights went onto a 7.9 GB node and left it
	// 3.5 GB for a KV pool, because the field was optional and blank. Blank
	// writes no constraint, and a CPU profile has no card to be short of.
	body := mirrorGet(t, servePage(t, []mirror.Status{
		sized("coder", "v1", "m.gguf", 4.68)}, &fakeCatalog{}, 0, "llamacpp"),
		"/admin/mirror?serve=coder:v1").Body.String()

	if !strings.Contains(body, `name="min_memory_gb" value="9"`) {
		t.Errorf("expected a figure derived from 4.68 GB of weights; got %s", body)
	}
}

func TestASmallModelDoesNotDemandALargeNode(t *testing.T) {
	// The estimate has to leave the small nodes usable, or every model ends up
	// pinned to the one big machine.
	body := mirrorGet(t, servePage(t, []mirror.Status{
		sized("small", "v1", "m.gguf", 1.12)}, &fakeCatalog{}, 0, "llamacpp"),
		"/admin/mirror?serve=small:v1").Body.String()

	if !strings.Contains(body, `name="min_memory_gb" value="3"`) {
		t.Errorf("a 1.12 GB model should fit a small node; got %s", body)
	}
}

func TestAModelTooBigForEveryNodeSaysSo(t *testing.T) {
	page := mirrorPageDeps(t, MirrorDeps{
		Mirror:  &fakeMirror{models: []mirror.Status{sized("huge", "v1", "m.gguf", 40)}},
		Catalog: &fakeCatalog{},
		Fleet:   fakeFleet{gpus: 0, engines: []string{"llamacpp"}, memoryGB: 31},
	}, true)
	body := mirrorGet(t, page, "/admin/mirror?serve=huge:v1").Body.String()

	// Better said here than discovered by a node being OOM-killed twenty
	// minutes into a load.
	if !strings.Contains(body, "largest node has 31 GB") {
		t.Errorf("expected the size warning; got %s", body)
	}
}

func TestAnEstimateIsNotMadeWhenTheSizeIsUnknown(t *testing.T) {
	// A version whose size nobody reported would otherwise be given a
	// requirement of two, which is a constraint that excludes nothing and
	// reads as though somebody measured it.
	body := mirrorGet(t, servePage(t, []mirror.Status{
		{Model: "m", Version: "v", File: "f.gguf", State: mirror.Present}},
		&fakeCatalog{}, 0, "llamacpp"), "/admin/mirror?serve=m:v").Body.String()

	if !strings.Contains(body, `name="min_memory_gb" value="0"`) {
		t.Errorf("an unknown size should leave no figure; got %s", body)
	}
}

func TestADescriptionReachesTheCatalog(t *testing.T) {
	cat := &fakeCatalog{}
	source := reachableSource(t)
	mirrorPost(t, servePage(t, nil, cat, 0), "/admin/mirror/serve", url.Values{
		"csrf": {"tok"}, "name": {"coder"}, "source": {source},
		"engine": {"llamacpp"}, "replicas": {"1"}, "context_length": {"4096"},
		"description": {"code completion and review; 7B, fits the large node"},
	})

	if len(cat.added) != 1 {
		t.Fatalf("expected one model, got %d", len(cat.added))
	}
	// The line a client sees in /v1/models, which for most of them is the only
	// view of what this gateway serves.
	if cat.added[0].Description != "code completion and review; 7B, fits the large node" {
		t.Errorf("the description was lost: %q", cat.added[0].Description)
	}
}

func TestAModelWithNoDescriptionIsStillAccepted(t *testing.T) {
	cat := &fakeCatalog{}
	source := reachableSource(t)
	mirrorPost(t, servePage(t, nil, cat, 0), "/admin/mirror/serve", url.Values{
		"csrf": {"tok"}, "name": {"coder"}, "source": {source},
		"engine": {"llamacpp"}, "replicas": {"1"}, "context_length": {"4096"},
	})
	if len(cat.added) != 1 || cat.added[0].Description != "" {
		t.Errorf("a description is optional: %+v", cat.added)
	}
}

func TestAnUnreachableSourceIsRefusedBeforeTheCatalog(t *testing.T) {
	// A port nothing is listening on: refused at once rather than after a
	// timeout, and the same shape of failure as a mirror that is down.
	srv := httptest.NewServer(http.HandlerFunc(
		func(http.ResponseWriter, *http.Request) {}))
	dead := srv.URL
	srv.Close()

	cat := &fakeCatalog{}
	body := mirrorPost(t, servePage(t, nil, cat, 0), "/admin/mirror/serve", url.Values{
		"csrf": {"tok"}, "name": {"coder"}, "source": {dead + "/m.gguf"},
		"engine": {"llamacpp"}, "replicas": {"1"}, "context_length": {"4096"},
	}).Body.String()

	if len(cat.added) != 0 {
		t.Error("a model whose weights are not there should not reach the catalog")
	}
	// The address, so the operator can see which one it could not reach; the
	// page used to accept this and leave the failure to a node, minutes later.
	if !strings.Contains(body, "cannot reach") {
		t.Errorf("the reason should name the source; got %s", body)
	}
}

func TestASourceTheMirrorNoLongerHoldsIsRefused(t *testing.T) {
	gone := httptest.NewServer(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) { http.Error(w, "gone", http.StatusNotFound) }))
	t.Cleanup(gone.Close)

	cat := &fakeCatalog{}
	body := mirrorPost(t, servePage(t, nil, cat, 0), "/admin/mirror/serve", url.Values{
		"csrf": {"tok"}, "name": {"coder"}, "source": {gone.URL + "/m.gguf"},
		"engine": {"llamacpp"}, "replicas": {"1"}, "context_length": {"4096"},
	}).Body.String()

	if len(cat.added) != 0 {
		t.Error("a file removed between the listing and the click should be caught")
	}
	if !strings.Contains(body, "404") {
		t.Errorf("the server's answer should be shown; got %s", body)
	}
}

func TestServingOnDemandLoadsWhenAskedFor(t *testing.T) {
	cat := &fakeCatalog{}
	mirrorPost(t, servePage(t, nil, cat, 0), "/admin/mirror/serve", url.Values{
		"csrf": {"tok"}, "name": {"big"}, "source": {reachableSource(t)}, "engine": {"llamacpp"},
		"replicas": {"1"}, "mode": {"ondemand"}, "context_length": {"4096"}, "profile": {"cpu"},
	})
	if len(cat.added) != 1 {
		t.Fatalf("expected one model added, got %d", len(cat.added))
	}
	if sc := cat.added[0].Scaling; sc.Min != 0 || sc.Max != 1 || sc.IdleTimeout == 0 {
		t.Errorf("on demand was added as %+v", sc)
	}
}

func TestAGGUFOnAFleetWithGPUsIsOfferedTheGPUFirst(t *testing.T) {
	gguf := []mirror.Status{held("coder", "v1", "coder-q4_k_m.gguf")}
	body := mirrorGet(t, servePage(t, gguf, &fakeCatalog{}, 4, "llamacpp"),
		"/admin/mirror?serve=coder:v1").Body.String()
	// Found in the field: no choice offered, a profile called "cpu", and a
	// model on the CPU of a GPU cluster at a tenth of the speed.
	if !strings.Contains(body, `<option value="gpu:t4" selected>GPU: t4, 4 of 4 free</option>`) {
		t.Errorf("the free GPU class should be offered and chosen; got %s", body)
	}
	if !strings.Contains(body, `<option value="cpu">CPU only`) {
		t.Error("the CPU should still be on offer, unselected")
	}
	if !strings.Contains(body, `name="cpu_ok"`) {
		t.Error("choosing the CPU with GPUs free needs saying so")
	}

	cpuOnly := mirrorGet(t, servePage(t, gguf, &fakeCatalog{}, 0, "llamacpp"),
		"/admin/mirror?serve=coder:v1").Body.String()
	if !strings.Contains(cpuOnly, `<option value="cpu" selected>CPU: this fleet has no GPU</option>`) ||
		strings.Contains(cpuOnly, `name="cpu_ok"`) {
		t.Errorf("a fleet without GPUs has only the CPU, and nothing to confirm; got %s", cpuOnly)
	}
}

func TestTheChosenPlacementDecidesWhereItRuns(t *testing.T) {
	form := func(engine, place, gpus string) url.Values {
		return url.Values{
			"name": {"m"}, "source": {"http://x/m"}, "engine": {engine}, "replicas": {"1"},
			"context_length": {"4096"}, "ctx_size": {"16384"}, "parallel": {"4"},
			"placement": {place}, "gpus": {gpus}, "min_memory_gb": {"8"},
		}
	}
	m, err := buildModel(english, form("llamacpp", "gpu:t4", "4").Get)
	if err != nil {
		t.Fatal(err)
	}
	p := m.Profiles[0]
	if p.GPUClass != "t4" || p.GPUsPerNode != 4 || p.TP > 1 || p.Name != "t4-x4" {
		t.Errorf("llama.cpp on four t4s: %+v", p)
	}
	if got := describeServe(english, m); got != "llama.cpp on 4 t4 GPUs of one node, 8 GB of host memory, "+
		"context pool 16384 over 4 parallel requests (4096 each)" {
		t.Errorf("summary %q", got)
	}
	if m, _ := buildModel(english, form("vllm", "gpu:t4", "2").Get); m.Profiles[0].TP != 2 || m.Profiles[0].GPUsPerNode != 0 {
		t.Errorf("vLLM's GPU count is tp: %+v", m.Profiles[0])
	}
	if m, _ := buildModel(english, form("llamacpp", "cpu", "1").Get); m.Profiles[0].GPUClass != "" || m.Profiles[0].Name != "cpu" {
		t.Errorf("the CPU: %+v", m.Profiles[0])
	}
	if _, err := buildModel(english, form("vllm", "cpu", "1").Get); err == nil {
		t.Error("vLLM on the CPU was accepted")
	}
}

func TestTheCPUWithGPUsFreeIsAChoiceMadeOnPurpose(t *testing.T) {
	values := func(extra ...string) url.Values {
		v := url.Values{
			"csrf": {"tok"}, "name": {"coder"}, "source": {reachableSource(t)}, "engine": {"llamacpp"},
			"replicas": {"1"}, "context_length": {"4096"}, "placement": {"cpu"}, "min_memory_gb": {"8"},
		}
		for i := 0; i+1 < len(extra); i += 2 {
			v.Set(extra[i], extra[i+1])
		}
		return v
	}
	cat := &fakeCatalog{}
	page := mirrorPageDeps(t, MirrorDeps{Mirror: &fakeMirror{}, Catalog: cat,
		Fleet: fakeFleet{gpus: 4, used: 1, engines: []string{"llamacpp"}}}, true)
	body := mirrorPost(t, page, "/admin/mirror/serve", values()).Body.String()
	if len(cat.added) != 0 || !strings.Contains(body, "3 GPUs free") {
		t.Fatalf("the CPU with three GPUs free went through unasked: %s", body)
	}
	mirrorPost(t, page, "/admin/mirror/serve", values("cpu_ok", "yes"))
	if len(cat.added) != 1 {
		t.Fatal("ticking the box should add it")
	}
	// Every card held: nothing to ask.
	cat = &fakeCatalog{}
	full := mirrorPageDeps(t, MirrorDeps{Mirror: &fakeMirror{}, Catalog: cat,
		Fleet: fakeFleet{gpus: 4, used: 4, engines: []string{"llamacpp"}}}, true)
	mirrorPost(t, full, "/admin/mirror/serve", values())
	if len(cat.added) != 1 {
		t.Error("with no GPU free the CPU is the only choice and should not be questioned")
	}
}

func (f *fakeCatalog) Stop(_ context.Context, name, _ string) (catalog.Model, error) {
	f.stops = append(f.stops, name)
	return catalog.Model{Name: name, Stopped: &catalog.Scaling{Min: 1, Max: 1}}, f.err
}

func (f *fakeCatalog) Start(_ context.Context, name, _ string) (catalog.Model, error) {
	f.starts = append(f.starts, name)
	return catalog.Model{Name: name, Scaling: catalog.Scaling{Min: 1, Max: 1}}, f.err
}

// A version of a family Strata runs, on a fleet with Strata, is served on it:
// one card, its family and size, the experts' memory, from the directory.
func TestAStrataFamilysVersionIsServedOnStrata(t *testing.T) {
	st := held("q38", "abc123", "Qwen3.8-Flash-Next-GSQ-RCO-IQ2_XS-00001-of-00002.gguf")
	st.Source = "https://huggingface.co/ISTA-DASLab/Qwen3.8-Flash-Next-GSQ-RCO-GGUF/resolve/abc/IQ2_XS/" + st.File
	files := []mirror.Status{st, held("q38", "abc123", "Qwen3.8-Flash-Next-GSQ-RCO-IQ2_XS-00002-of-00002.gguf")}
	f := planServe(english, st, files, "http://mirror:8081", fakeFleet{gpus: 1, engines: []string{"llamacpp", "strata"}, memoryGB: 251},
		nil, func(string) gguf.Verdict { return gguf.Verdict{Checked: true, Reason: "unknown architecture"} })
	if f.Engine != "strata" || f.StrataFamily != "qwen" || f.StrataSize != "IQ2_XS" || f.Refusal != "" ||
		f.MinMemoryGB != 52 || f.Context != 32768 || !strings.HasSuffix(f.Source, "/q38/abc123/") {
		t.Fatalf("%+v", f)
	}
	// Without Strata on any node, llama.cpp as before, and its refusal.
	if f := planServe(english, st, files, "http://mirror:8081", fakeFleet{gpus: 1, engines: []string{"llamacpp"}},
		nil, func(string) gguf.Verdict { return gguf.Verdict{Checked: true, Reason: "unknown architecture"} }); f.Engine != "llamacpp" || f.Refusal == "" {
		t.Errorf("%+v", f)
	}
	form := url.Values{"name": {"q38"}, "source": {f.Source}, "engine": {"strata"}, "replicas": {"1"},
		"context_length": {"32768"}, "placement": {"gpu:6000-24g"}, "min_memory_gb": {"52"},
		"strata_family": {"qwen"}, "strata_size": {"IQ2_XS"}}
	m, err := buildModel(english, form.Get)
	if err != nil {
		t.Fatal(err)
	}
	p := m.Profiles[0]
	if p.Engine != "strata" || p.GPUClass != "6000-24g" || p.GPUsPerNode != 1 || p.MinMemoryGB != 52 ||
		strings.Join(p.Args, " ") != "--family qwen --size IQ2_XS --context 32768 --vision no" {
		t.Errorf("%+v", p)
	}
	form.Set("strata_size", "IQ9")
	if _, err := buildModel(english, form.Get); err == nil {
		t.Error("an unknown size was taken")
	}
}

// speedFleet is two nodes with GPUs whose memory rates were measured: a
// large server and a small one, as on a fleet where every node has cards.
type speedFleet struct{ fakeFleet }

func (speedFleet) Nodes() []adminapi.NodeView {
	return []adminapi.NodeView{
		{ID: "big", State: "ready", MemoryGB: 512, CPUCount: 64, MemBandwidthGBs: 300, MemBandwidthCoreGBs: 10,
			Engines: []string{"llamacpp"}},
		{ID: "small", State: "ready", MemoryGB: 64, CPUCount: 8, MemBandwidthGBs: 40, MemBandwidthCoreGBs: 10,
			Engines: []string{"llamacpp"}},
	}
}

// The speed on the CPU follows the threads a replica is given: four of a
// large server read at four cores' rate, not the server's.
func TestTheCPUsSpeedFollowsTheCoresGiven(t *testing.T) {
	hosts := cpuHosts(speedFleet{}, 32)
	if len(hosts) != 2 {
		t.Fatalf("hosts %+v", hosts)
	}
	few, _ := bestCPUSpeed(hosts, 18e9, 4)
	half, node := bestCPUSpeed(hosts, 18e9, 0)
	if few > 2.5 || half < 8 || node != "big" {
		t.Errorf("four cores %.1f tok/s, half the big node's %.1f on %s", few, half, node)
	}
	if hosts := cpuHosts(speedFleet{}, 100); len(hosts) != 1 || hosts[0].ID != "big" {
		t.Errorf("a model of 100 GB fits the big node only: %+v", hosts)
	}
}

// Slow enough that a reply is minutes, the CPU is a choice made on purpose,
// GPUs free or not.
func TestAVerySlowModelOnTheCPUIsAChoiceMadeOnPurpose(t *testing.T) {
	big := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.Header().Set("Content-Length", "18000000000")
		w.WriteHeader(http.StatusOK)
	}))
	t.Cleanup(big.Close)
	values := func(extra ...string) url.Values {
		v := url.Values{
			"csrf": {"tok"}, "name": {"big-dense"}, "source": {big.URL + "/m/v1/m.gguf"}, "engine": {"llamacpp"},
			"replicas": {"1"}, "context_length": {"4096"}, "placement": {"cpu"}, "min_memory_gb": {"24"},
			"cpu_cores": {"4"},
		}
		for i := 0; i+1 < len(extra); i += 2 {
			v.Set(extra[i], extra[i+1])
		}
		return v
	}
	cat := &fakeCatalog{}
	page := mirrorPageDeps(t, MirrorDeps{Mirror: &fakeMirror{}, Catalog: cat, Fleet: speedFleet{}}, true)
	body := mirrorPost(t, page, "/admin/mirror/serve", values()).Body.String()
	if len(cat.added) != 0 || !strings.Contains(body, "tokens a second on the CPU") {
		t.Fatalf("an 18 GB model on four cores went through unasked: %s", body)
	}
	mirrorPost(t, page, "/admin/mirror/serve", values("cpu_ok", "yes"))
	if len(cat.added) != 1 {
		t.Fatal("ticking the box should add it")
	}
}

func TestTheServeFormStartsAtTheLongestContextThatFits(t *testing.T) {
	// An 8B's shape: 36 layers, 8 KV heads of 128, so 144 KiB a token.
	h := gguf.Header{BlockCount: 36, HeadCount: 32, HeadCountKV: 8, KeyLength: 128, ValueLength: 128,
		ContextLength: 40960}
	card := []placeChoice{{Value: "gpu:6000-24g", Selected: true}, {Value: "cpu"}}
	cpu := []placeChoice{{Value: "gpu:6000-24g"}, {Value: "cpu", Selected: true}}
	for _, c := range []struct {
		name          string
		weights       int64
		places        []placeChoice
		header        gguf.Header
		tokens, slots int
	}{
		// All it was trained for, and two slots of it in the room left.
		{"on a card with room", 5 << 30, card, h, 40960, 2},
		// The weights take most of the card: the most that fits, one slot.
		{"on a card nearly full", 18 << 30, card, h, 18432, 1},
		{"on the CPU of a 64 GB node", 5 << 30, cpu, h, 40960, 4},
		{"weights larger than the card", 30 << 30, card, h, 0, 0},
		{"a header that does not say", 5 << 30, card, gguf.Header{BlockCount: 36, HeadCountKV: 8, HeadCount: 32, KeyLength: 128}, 0, 0},
	} {
		tokens, slots := mostContext(c.header, c.weights, c.places, 1, fakeFleet{memoryGB: 64})
		if tokens != c.tokens || slots != c.slots {
			t.Errorf("%s: %d tokens × %d slots, want %d × %d", c.name, tokens, slots, c.tokens, c.slots)
		}
	}
}