package composer

import (
	"context"
	"encoding/json"
	"errors"
	"git.novox.be/novox/mesh-contracts/go/seats/meshmoduleassigner"
	"git.novox.be/novox/mesh-delivery/contracts/go/clients/meshcatalogclient"
	"git.novox.be/novox/mesh-delivery/contracts/go/seats/meshcatalog"
	"git.novox.be/novox/mesh-networking/modules/mesh-wireguard/go/overlay"
	"github.com/novox/mesh-host/internal/buckets/bucketstest"
	engcomp "github.com/novox/mesh-host/internal/compositions"
	"os"
	"reflect"
	"strings"
	"testing"

	"git.novox.be/novox/mesh-sdk/go/catalogue"
	"git.novox.be/novox/mesh-sdk/go/keys"
	"github.com/novox/mesh-host/internal/compose"
	"github.com/novox/mesh-host/internal/compose/frombus"
	"github.com/novox/mesh-host/internal/compose/frombus/frombustest"
)

const demo = `{"module": "demo", "version": "1", "claims": [{"name": "node-files"}]}`

// withInput is r with in as its input, as a caller puts it on the wire: the request's shape carries the input as JSON.
func withInput(t *testing.T, r Request, in compose.Input) Request {
	t.Helper()
	raw, err := json.Marshal(in)
	if err != nil {
		t.Fatal(err)
	}
	if err := json.Unmarshal(raw, &r.Input); err != nil {
		t.Fatal(err)
	}
	return r
}

// The seats a node's assigned modules claim are held there when the request says the holdings come from the claims.
func TestHoldingsComeFromTheClaims(t *testing.T) {
	m, err := catalogue.Decode([]byte(demo))
	if err != nil {
		t.Fatal(err)
	}
	got := HoldingsOf(map[string]catalogue.Manifest{"demo": m}, []compose.Node{{Name: "b", Assigned: []string{"demo"}}, {Name: "a", Assigned: []string{"demo"}}})
	if len(got) != 2 || got[0].Node != "a" || got[0].Claim != "node-files" || got[0].Scope != "node" {
		t.Fatalf("holdings = %+v", got)
	}
}

// A request the command cannot run is refused, never answered as a verdict: a case named twice, an unknown depth.
func TestARequestItCannotRunIsRefused(t *testing.T) {
	if _, err := Run(Request{V: Version, Cases: []Case{{Name: "a"}, {Name: "a"}}}); err == nil {
		t.Error("a case named twice runs")
	}
	if _, err := Run(Request{V: Version, Depth: "deep"}); err == nil {
		t.Error("an unknown depth runs")
	}
	// A case's own assignment (issue 1126) composes over a node the input holds, and is refused for one it does not.
	placed := withInput(t, Request{V: Version, Machines: []string{"a"}, Depth: DepthResolve,
		Cases: []Case{{Name: "trunk", Manifests: map[string]Manifest{"demo": {Raw: json.RawMessage(demo)}}},
			{Name: "change", Manifests: map[string]Manifest{"demo": {Raw: json.RawMessage(demo)}},
				Assignments: bucketstest.Raw(map[string]meshmoduleassigner.Assignments{"a": {V: 1, Node: "a", Modules: []meshmoduleassigner.PlacedModule{{Module: "ghost"}}}})}}},
		compose.Input{Nodes: []compose.Node{{Name: "a"}}})
	if v, err := Run(placed); err != nil || !v.Cases[0].Machines["a"].Composes || v.Cases[1].Machines["a"].Composes ||
		!strings.Contains(v.Cases[1].Machines["a"].Reason, "ghost") {
		t.Errorf("a case composes its own assignment: %+v, %v", v, err)
	}
	placed.Cases[1].Assignments = bucketstest.Raw(map[string]meshmoduleassigner.Assignments{"z": {V: 1, Node: "z"}})
	if _, err := Run(placed); err == nil || !strings.Contains(err.Error(), "holds no node for") {
		t.Errorf("a case placing a node the input lacks: %v", err)
	}
	// Issue 1126 (check of mesh-host #200): the module the mesh provides itself (the private network) comes from mesh-sdk,
	// a second source beside the indexer's manifests the cases carry, and the input carries no catalogue: a node it is
	// assigned to still composes, and what it provides is provided.
	wg := overlay.ProvidedModules()[0]
	provided := withInput(t, Request{V: Version, Machines: []string{"a"}, Depth: DepthResolve,
		Cases: []Case{{Name: "change", Manifests: map[string]Manifest{"demo": {Raw: json.RawMessage(demo)}}}}},
		compose.Input{Nodes: []compose.Node{{Name: "a", Assigned: []string{wg, "demo"}}}})
	if v, err := Run(provided); err != nil || !v.Cases[0].Machines["a"].Composes {
		t.Errorf("a node assigned the mesh's own module: %+v, %v", v, err)
	}
	// Issue 1126 (checks of mesh-host #200, fix-a-bug-met-twice): the sandbox composes one node from the same inputs as
	// the bus reader, through one path. A mesh whose restic is built (its files from an archive) and handed to the
	// provisioner composes n1 through frombus, and the request a node-engine answers for it (the input as the engine
	// sends it, the indexer's manifests in the case) declares the same paths for n1.
	t.Run("the sandbox composes a node as the bus reader does", func(t *testing.T) {
		b, err := frombustest.Provisioned()
		if err != nil {
			t.Fatal(err)
		}
		ctx, scope := context.Background(), frombus.Scope{Node: frombustest.Node}
		read, err := frombus.Input(ctx, b, frombus.Mesh{}, scope)
		if err != nil {
			t.Fatal(err)
		}
		d, problems, err := compose.Compose(read, frombustest.Node)
		if err != nil || len(problems) > 0 {
			t.Fatalf("the bus reader's input composes n1: %v %v", err, problems)
		}
		want := pathsOf(d)
		sent := SentInput(read, frombustest.Node)
		cases := Case{Name: "change", Manifests: map[string]Manifest{}}
		for name, m := range b.Module {
			cases.Manifests[name] = Manifest{Raw: b.Manifests[m.Manifest]}
		}
		r := withInput(t, Request{V: Version, Machines: []string{frombustest.Node}, Declarations: true, Cases: []Case{cases}}, sent)
		v, err := Run(r)
		if err != nil {
			t.Fatal(err)
		}
		got := v.Cases[0].Machines[frombustest.Node]
		if !got.Composes || !reflect.DeepEqual(got.Declared, want) {
			t.Errorf("the sandbox composed n1 %+v; the bus reader declared %+v", got, want)
		}
	})
	// Issue 774 (the check of the bus want, the third of a kind: the sandbox's input differs from what the bus reader
	// composes): a node like the bus node, its bus module folded in its own composition at a build of the old form and no
	// build published for the module's server artifact, composes in the sandbox as its node-engine composes it, from the
	// input that says how (compose.Input.ComposedHow); from an older engine's input, which does not, it is named not
	// judged, never failed and never passed in silence.
	t.Run("a module folded in the node's own composition", func(t *testing.T) {
		bus := `{"module": "bus", "version": "1", "claims": [{"name": "node-files"}], ` +
			`"resources": [{"id": "server", "type": "container", "name": "bus-server", "artifact": "server"}], ` +
			`"build": {"artifacts": [{"name": "server", "kind": "upstream", "from": "nats:2.11@sha256:` + strings.Repeat("a", 64) + `"}]}}`
		man, err := catalogue.Decode([]byte(bus))
		if err != nil {
			t.Fatal(err)
		}
		node := compose.Node{Name: "a", Assigned: []string{"bus"}, InOwn: map[string]bool{"bus": true},
			RunsOwn: &engcomp.Composed{Node: "a"}}
		in := compose.Input{Catalogue: map[string]catalogue.Manifest{"bus": man}, Nodes: []compose.Node{node}}
		request := func(in compose.Input) Request {
			return withInput(t, Request{V: Version, Machines: []string{"a"}, Depth: DepthCompose,
				Cases: []Case{{Name: "change", Manifests: map[string]Manifest{}}}}, in)
		}
		older, err := Run(request(in))
		if err != nil {
			t.Fatal(err)
		}
		if m := older.Cases[0].Machines["a"]; m.Composes || !strings.HasPrefix(m.NotJudged, NotJudged+"bus") || m.Reason != "" {
			t.Errorf("an older engine's input of a node with a folded module: %+v", m)
		}
		in.ComposedHow = &compose.ComposedHow{Node: "a", Builds: map[string]string{}}
		sent, err := Run(request(in))
		if err != nil {
			t.Fatal(err)
		}
		if m := sent.Cases[0].Machines["a"]; !m.Composes || m.Reason != "" {
			t.Errorf("the input that says how the node composes, its bus folded: %+v", m)
		}
		// A module the change refuses beside the folded one fails the node in its words, never passed with the rest
		// composed (review of the sandbox input); held already where the node-engine composed, it stays held as there.
		app, err := catalogue.Decode([]byte(`{"module": "app", "version": "1", ` +
			`"resources": [{"id": "env", "type": "file", "path": "/var/lib/app/env", "mode": "0600", "content": "N=${secret:repository}\n"}]}`))
		if err != nil {
			t.Fatal(err)
		}
		in.Catalogue["app"] = app
		in.Nodes[0].Assigned = []string{"bus", "app"}
		refused, err := Run(request(in))
		if err != nil {
			t.Fatal(err)
		}
		if m := refused.Cases[0].Machines["a"]; m.Composes || !strings.Contains(m.Reason, "app: ") || !strings.Contains(m.Reason, "repository") {
			t.Errorf("a module the change refuses on a node composed as its node-engine does: %+v", m)
		}
		// Held composing without the change, blamed for a refusal beyond the read (issue 1960's unset names): no refusal of
		// the change either (review round 1).
		in.ComposedHow.HeldBefore = map[string]string{"app": "its route names are unset"}
		before, err := Run(request(in))
		if err != nil {
			t.Fatal(err)
		}
		if m := before.Cases[0].Machines["a"]; !m.Composes {
			t.Errorf("a module the node holds composing without the change: %+v", m)
		}
		in.ComposedHow.HeldBefore = nil
		in.ComposedHow.Held = map[string]string{"app": "held on the node"}
		held, err := Run(request(in))
		if err != nil {
			t.Fatal(err)
		}
		if m := held.Cases[0].Machines["a"]; !m.Composes {
			t.Errorf("a module the node-engine holds too: %+v", m)
		}
	})
	// Issue 774 (the group check of feat/l3-final 278aa5f0ccbe): a tool runner its node-engine holds by its manifest's
	// verdict is sent as its stub, and the input says it holds it: the sandbox composes the node with it held, never refuses
	// it for its stub's missing bundle. An input from an engine before the mark is read by Refused alone, the same way. The
	// case gives the runner its refused verdict, as the checker does for a manifest the change does not bring.
	t.Run("a refused tool runner the engine sends as its stub", func(t *testing.T) {
		raw := `{"module": "runner", "version": "1", "tool-runner": true, ` +
			`"build": {"artifacts": [{"name": "runtime", "kind": "bundle", "language": "go", "from": "cmd/runner", "binary": "runner"}]}}`
		man, err := catalogue.Decode([]byte(raw))
		if err != nil {
			t.Fatal(err)
		}
		in := compose.Input{Catalogue: map[string]catalogue.Manifest{"runner": compose.Stub(man)},
			Refused: map[string]string{"runner": "the indexer's judge refused the manifest of runner"},
			Nodes:   []compose.Node{{Name: "a", Assigned: []string{"runner"}}}}
		wire, err := json.Marshal(in)
		if err != nil {
			t.Fatal(err)
		}
		var back compose.Input
		if err := json.Unmarshal(wire, &back); err != nil || !back.Catalogue["runner"].Stubbed || !strings.Contains(string(wire), `"Held"`) {
			t.Fatalf("the input's held mark across the wire: %s, %v", wire, err)
		}
		older := strings.Replace(string(wire), `"Held":{"Catalogue":["runner"]}`, `"Unsaid":null`, 1)
		for name, sent := range map[string]string{"with the mark": string(wire), "from an engine before it": older} {
			var r Request
			r = Request{V: Version, Machines: []string{"a"}, Depth: DepthCompose,
				Cases: []Case{{Name: "change", Manifests: map[string]Manifest{"runner": {Raw: json.RawMessage(raw)}},
					Verdicts: bucketstest.Raw(map[string]meshcatalog.VerdictsByDigestValue{"runner": {V: 1, Module: "runner",
						State: meshcatalogclient.VerdictRefused, Problems: []string{"p"}}})}}}
			if err := json.Unmarshal([]byte(sent), &r.Input); err != nil {
				t.Fatal(err)
			}
			v, err := Run(r)
			if err != nil {
				t.Fatal(err)
			}
			if m := v.Cases[0].Machines["a"]; !m.Composes || strings.Contains(m.Reason, "bundle") {
				t.Errorf("%s: the node with its tool runner held: %+v", name, m)
			}
			if read := v.Cases[0].Manifests["runner"]; read.Accepted || !strings.Contains(read.Refused, "the indexer's judge refused the manifest of runner") {
				t.Errorf("%s: the runner's read names not why its node-engine holds it: %+v", name, read)
			}
		}
	})
	// ADR 0578 §2, §3 (issue 1921): a module its node-engine holds by the running indexer's verdict gives way when the case,
	// judging the change's manifest itself, gives it an accepted verdict or none (the running checker drops the change's
	// own), and this composer reads its bytes whole. It is composed at the build the input carries for it (Input.Holds);
	// without one it is composed from the case's manifest and the node is not judged, naming it (never a silent pass), or,
	// where it cannot compose without its build (a tool runner's bundle), composed held as its node-engine holds it, named
	// so. Bytes that do not decode here, and a case's own refusal, stay held.
	t.Run("a held module the case judges itself", func(t *testing.T) {
		app := `{"module": "app", "version": "1", "resources": [{"id": "server", "type": "container", "name": "app-server", "artifact": "server"}], ` +
			`"build": {"artifacts": [{"name": "server", "kind": "upstream", "from": "nats:2.11@sha256:` + strings.Repeat("a", 64) + `"}]}}`
		// A module that names a build and composes from its manifest without it.
		plain := `{"module": "app", "version": "1", "resources": [{"id": "d", "type": "directory", "path": "/var/lib/app"}], ` +
			`"build": {"artifacts": [{"name": "server", "kind": "upstream", "from": "nats:2.11@sha256:` + strings.Repeat("a", 64) + `"}]}}`
		runner := `{"module": "app", "version": "1", "tool-runner": true, ` +
			`"build": {"artifacts": [{"name": "runtime", "kind": "bundle", "language": "go", "from": "cmd/runner", "binary": "runner"}]}}`
		built, err := catalogue.Decode([]byte(`{"module": "app", "version": "1", "resources": [{"id": "built", "type": "directory", "path": "/var/lib/app-built"}]}`))
		if err != nil {
			t.Fatal(err)
		}
		verdict := func(state string) map[string]json.RawMessage {
			return bucketstest.Raw(map[string]meshcatalog.VerdictsByDigestValue{"app": {V: 1, Module: "app", State: state, Problems: []string{"p"}}})
		}
		const why = "the indexer's judge refused the manifest of app"
		for _, row := range []struct {
			name     string
			raw      string
			verdicts map[string]json.RawMessage
			hold     *compose.Hold
			composes bool   // the machine composes, judged
			path     string // a path declared on it
			words    string // in NotJudged, else in the read's refusal
		}{
			{"an accepted verdict, its build carried", app, verdict(meshcatalogclient.VerdictAccepted),
				&compose.Hold{By: compose.HeldByVerdict, Build: "fp1", Built: &built}, true, "/var/lib/app-built", ""},
			{"no verdict, its build carried", app, nil, &compose.Hold{By: compose.HeldByVerdict, Build: "fp1", Built: &built}, true, "/var/lib/app-built", ""},
			{"an accepted verdict, its build awaited", plain, verdict(meshcatalogclient.VerdictAccepted), &compose.Hold{By: compose.HeldByVerdict, Build: "fp1"}, false, "",
				"composed from the change's manifest without its build: app is refused only by the running indexer (" + why + ") and accepted by the check's own validator, and its build fp1 is awaited"},
			{"no verdict, from an engine before holds", plain, nil, nil, false, "",
				"app is held by the running node-engine (" + why + ") and given no verdict by the check, so taken as accepted"},
			{"a container, its image awaited", app, nil, &compose.Hold{By: compose.HeldByVerdict}, false, "",
				"composed with it held as its node-engine holds it, since it does not compose without its build: app is refused only by the running indexer"},
			{"a tool runner, its bundle awaited", runner, nil, &compose.Hold{By: compose.HeldByVerdict}, false, "",
				"composed with it held as its node-engine holds it, since it does not compose without its build: app is refused only by the running indexer"},
			{"bytes that do not decode", `{"module": "app", "version": "1", "resources": "none"}`, nil, &compose.Hold{By: compose.HeldByVerdict, Built: &built}, true, "", "does not decode"},
			{"the case's own refusal", app, verdict(meshcatalogclient.VerdictRefused), &compose.Hold{By: compose.HeldByVerdict, Built: &built}, true, "", "refused the manifest of app"},
		} {
			man, _ := catalogue.Decode([]byte(app))
			in := compose.Input{Catalogue: map[string]catalogue.Manifest{"app": compose.Stub(man)}, Refused: map[string]string{"app": why},
				Nodes: []compose.Node{{Name: "a", Assigned: []string{"app"}}}}
			if row.hold != nil {
				in.Holds = map[string]compose.Hold{"app": *row.hold}
			}
			v, err := Run(withInput(t, Request{V: Version, Machines: []string{"a"}, Depth: DepthCompose, Declarations: true,
				Cases: []Case{{Name: "change", Manifests: map[string]Manifest{"app": {Raw: json.RawMessage(row.raw)}}, Verdicts: row.verdicts}}}, in))
			if err != nil {
				t.Fatal(err)
			}
			m, read := v.Cases[0].Machines["a"], v.Cases[0].Manifests["app"]
			declared := false
			for _, p := range m.Declared {
				declared = declared || p.Path == row.path
			}
			switch {
			case m.Composes != row.composes || (row.path != "" && !declared):
				t.Errorf("%s: machine %+v", row.name, m)
			case !row.composes && (m.NotJudged == "" || !strings.Contains(m.NotJudged, row.words)):
				t.Errorf("%s: not judged %q, want it naming %q", row.name, m.NotJudged, row.words)
			case row.composes && row.path == "" && (read.Accepted || !strings.Contains(read.Refused, row.words)):
				t.Errorf("%s: read %+v, want held naming %q", row.name, read, row.words)
			}
		}
	})
	v, err := Run(Request{V: Version, Cases: []Case{{Name: "only-read", Manifests: map[string]Manifest{"demo": {Raw: json.RawMessage(demo)}}}}})
	if err != nil || len(v.Cases) != 1 || !v.Cases[0].Manifests["demo"].Accepted || v.Cases[0].Machines != nil || v.SDK == "" {
		t.Fatalf("a request with no machines: %+v, %v", v, err)
	}
}

// The composer judges no manifest (novox/hq ADR 0578 §5): xterm's module.json from mesh-catalog at 835bf22b, whose
// config value falls back to "font-size", is read whatever list of predefined keys a request carries (a group touching
// xterm failed its composition on this, group check 18df81380db3); a module whose verdict in the input refuses it is
// held, composed as its stub, and named in the verdict's words.
func TestTheComposerTakesTheVerdictsOfItsInput(t *testing.T) {
	raw, err := os.ReadFile("testdata/catalogue-835bf22b-xterm.module.json")
	if err != nil {
		t.Fatal(err)
	}
	r := Request{V: Version, Predefined: catalogue.PredefinedList{"something-else": {Type: "string", Description: "x"}},
		Cases: []Case{{Name: "change", Manifests: map[string]Manifest{"xterm": {Raw: raw}}}}}
	v, err := Run(r)
	if err != nil {
		t.Fatal(err)
	}
	if got := v.Cases[0].Manifests["xterm"]; !got.Accepted {
		t.Fatalf("xterm: %+v, want accepted", got)
	}
	r.Cases[0].Verdicts = bucketstest.Raw(map[string]meshcatalog.VerdictsByDigestValue{"xterm": {V: 1, Module: "xterm", State: meshcatalogclient.VerdictRefused,
		Problems: []string{"falls back to a key not listed"}, Judge: "src2:j"}})
	shelf, err := parse(r.Cases[0].Manifests, map[string]ManifestRead{}, r.Cases[0].Verdicts)
	if err != nil || !shelf["xterm"].Stubbed {
		t.Fatalf("the refused module is not held as its stub: %+v %v", shelf["xterm"], err)
	}
	if v, err = Run(r); err != nil {
		t.Fatal(err)
	}
	if got := v.Cases[0].Manifests["xterm"]; got.Accepted ||
		!strings.Contains(got.Refused, "the indexer's judge (src2:j) refused the manifest of xterm: falls back to a key not listed") {
		t.Fatalf("xterm refused by its verdict: %+v, want refused in the verdict's words", got)
	}
	// The verdict as the trunk's checker hands it, version 0 and no judge (group try 1793952957648659842 failed on all
	// four nodes: "the verdict of f1-circuits is not one: ... the value is version 0"), holds the module too; a later
	// version is refused.
	r.Cases[0].Verdicts = map[string]json.RawMessage{"xterm": json.RawMessage(`{"v":0,"module":"xterm","state":"refused","problems":["falls back to a key not listed"],"judge":"","at":"0001-01-01T00:00:00Z"}`)}
	if v, err = Run(r); err != nil {
		t.Fatalf("a version-0 verdict of the trunk's checker: %v", err)
	}
	if got := v.Cases[0].Manifests["xterm"]; got.Accepted || !strings.Contains(got.Refused, "refused the manifest of xterm: falls back") {
		t.Fatalf("xterm refused by a version-0 verdict: %+v, want refused", got)
	}
	r.Cases[0].Verdicts["xterm"] = json.RawMessage(`{"v":2,"module":"xterm","state":"refused","problems":["p"]}`)
	if _, err = Run(r); !errors.Is(err, keys.ErrUnknownVersion) {
		t.Fatalf("a version-2 verdict: %v, want keys.ErrUnknownVersion", err)
	}
}