package main

import (
	"context"
	"encoding/json"
	"errors"
	"strings"
	"testing"
	"time"

	"github.com/novox/mesh-controller/internal/catalogue"
	"github.com/novox/mesh-controller/internal/identity"
	"github.com/novox/mesh-controller/internal/inventory"
	"github.com/novox/mesh-controller/internal/link"
)

// The grants step on a store (novox/hq issue 490): the machine holding the bus is sent its new user list,
// and nothing else — not the new build of a module it runs, not a module newly assigned there.
//
// The restic shape: anchor holds the bus and runs restic at c1, as does laptop; restic's c2 gives it a
// health tool. The grants step's send to anchor composes restic at c1, carries the user list that grants
// laptop's node-engine c2's tool, and records that anchor still runs c1. A module newly assigned to anchor
// makes the step fail, said, rather than install it unjudged.
func TestTheGrantsStepSendsTheUserListAndNothingElse(t *testing.T) {
	open := aMesh(t)
	ctx := t.Context()
	inv := open.inventory
	start := time.Now().Add(-time.Hour)
	build := func(module, commit string, at time.Time, manifest map[string]any) link.BuildResult {
		manifest["module"], manifest["version"] = module, "1"
		raw, _ := json.Marshal(manifest)
		return link.BuildResult{ID: link.NewBuildID(at), Repository: "novox/mesh-catalog", Path: "modules/" + module,
			On: "anchor", Module: module, Commit: commit, Manifest: raw,
			Source: &link.SourceOnSeat{Seat: "git", Repository: "novox/mesh-catalog"}}
	}
	for _, b := range []link.BuildResult{
		build("nats", "n1", start, natsFixture()),
		build("restic", "c1", start.Add(time.Second), resticFixture(false)),
		build("wallpaper", "w1", start.Add(2*time.Second), wallpaperFixture()),
	} {
		if _, _, err := takeIn(ctx, inv, asTheOperator(t, inv, b)); err != nil {
			t.Fatal(err)
		}
	}
	for _, a := range [][2]string{{"anchor", "nats"}, {"anchor", "restic"}, {"laptop", "restic"}} {
		if _, err := inv.Assign(ctx, a[0], a[1]); err != nil {
			t.Fatal(err)
		}
	}
	for _, n := range []string{"anchor", "laptop"} {
		if _, err := inv.MintBusPassword(ctx, inventory.BusUser{Username: "node." + n, Kind: inventory.BusNode, Node: n}); err != nil {
			t.Fatal(err)
		}
	}

	wasEpoch := epochForActs
	epochForActs = func(context.Context) (uint64, error) { return 7, nil }
	t.Cleanup(func() { epochForActs = wasEpoch })

	// A send to anchor composed as sendToEach composes it: numbered, planned, declared, stamped.
	compose := func(under context.Context) (catalogue.Resolution, sendable) {
		t.Helper()
		numbered, err := allot(under, inv, "anchor")
		if err != nil {
			t.Fatal(err)
		}
		plan, settings, err := planFor(under, open, "anchor")
		if err != nil {
			t.Fatal(err)
		}
		gens, err := generators(under, open)
		if err != nil {
			t.Fatal(err)
		}
		declared, err := declarationWith(under, open, "anchor", plan, settings, gens, Allocating)
		if err != nil {
			t.Fatal(err)
		}
		numbered.stamp(&declared)
		return plan, declared
	}
	record := func(declared sendable) {
		t.Helper()
		body, err := declared.Body()
		if err != nil {
			t.Fatal(err)
		}
		if _, err := recordSent(ctx, inv, "anchor", body, declared.Builds, declared.Epoch,
			sentRecordOf(ctx, declared)); err != nil {
			t.Fatal(err)
		}
	}
	// Kept for anchor alone. laptop is never recorded as sent, on purpose: composing anchor resolves laptop
	// too (who is on the private network), and a step that kept every machine's builds refused anchor's
	// composition for want of laptop's last send (repo-check of #230 at 0f853e93).
	kept := keepingEveryBuild(keepingRecorded(ctx), "anchor")

	// What anchor was last sent: everything at the builds of before the merge, as an ordinary send sends it.
	_, before := compose(keepingRecorded(ctx))
	record(before)
	plan, declared := compose(kept)
	if only, err := grantsOnlyIn(ctx, open, "anchor", plan, declared); err != nil || only != "" {
		t.Fatalf("with nothing changed, the step reads %q, %v", only, err)
	}

	// The merge: restic's c2 gives it a health tool.
	if _, _, err := takeIn(ctx, inv, build("restic", "c2", start.Add(time.Minute),
		resticFixture(true))); err != nil {
		t.Fatal(err)
	}

	// The step's send to anchor: restic as anchor runs it, c1, and the user list granting c2's tool.
	generation, err := inv.AssignmentGeneration(ctx)
	if err != nil {
		t.Fatal(err)
	}
	plan, declared = compose(kept)
	for _, m := range plan.Modules {
		if m.Module == "restic" && len(m.Tools) > 0 {
			t.Fatalf("the grants step composed restic's new build on anchor: tools %v", m.Tools)
		}
	}
	if declared.Builds["restic"] != "c1" {
		t.Fatalf("the step's send records it carries restic %q; want c1, which anchor runs", declared.Builds["restic"])
	}
	if !strings.Contains(declared.BusUsers, "mesh.mod.restic.tool.backup_health.laptop") {
		t.Errorf("the step's declaration does not grant laptop's node-engine restic's new tool:\n%s", declared.BusUsers)
	}
	// The generation it carries is the current one (novox/hq issue 234), and the step does not raise it.
	if declared.composedFrom != generation {
		t.Errorf("the step's send was composed from generation %d; the mesh is at %d", declared.composedFrom, generation)
	}
	// The guard, on the very declaration the send sends: only the user list differs from the last send.
	if only, err := grantsOnlyIn(ctx, open, "anchor", plan, declared); err != nil || only != "" {
		t.Fatalf("the step reads as changing more than the user list: %q, %v", only, err)
	}
	// And the gate's refusal still reads the step's send: it moves nothing there.
	if names, err := ungatedIn(kept, open, []string{"anchor"}, ""); err != nil || strings.Join(names, ",") != "anchor" {
		t.Fatalf("the step's send is refused as a move: %v, %v", names, err)
	}
	// Recorded as the send records it: anchor still runs restic c1, its gate still to come there.
	record(declared)
	if sent, _, err := inv.SentBuilds(ctx, "anchor"); err != nil || sent["restic"] != "c1" {
		t.Fatalf("after the step anchor reads as sent restic %q (%v); want c1", sent["restic"], err)
	}
	if after, err := inv.AssignmentGeneration(ctx); err != nil || after != generation {
		t.Fatalf("the step moved the assignment generation from %d to %d (%v)", generation, after, err)
	}

	// A module newly assigned to anchor: the step would install it, unjudged, so it is refused unsent.
	if _, err := inv.Assign(ctx, "anchor", "wallpaper"); err != nil {
		t.Fatal(err)
	}
	plan, declared = compose(kept)
	only, err := grantsOnlyIn(ctx, open, "anchor", plan, declared)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(only, "wallpaper newly assigned") || !strings.Contains(only, "+wallpaper") {
		t.Fatalf("a new assignment on the bus's machine reads %q; want the step refused, naming it", only)
	}
	// And the send itself refuses it, unsent: judged where it is composed, before the bus is dialled.
	identity.ForTest(t)
	if _, err := sendToEach(kept, open, []string{"anchor"}); !errors.Is(err, errNotGrantsOnly) ||
		!strings.Contains(err.Error(), "wallpaper") {
		t.Fatalf("the grants step's send of a new assignment was not refused by the send: %v", err)
	}
}

// fixtureImage is the image every fixture container of the grants step's tests runs.
var fixtureImage = "registry.invalid:5000/restic/backup@sha256:" + strings.Repeat("b", 64)

// resticFixture is restic's manifest in the shape of mesh-catalog #210: at c2 (withTool) its backup judged by
// its new tool `backup_health`, beside a check of another kind it does not run itself — a tool check alone
// is refused (ADR 0227 rule 8, ADR 0240 rule 2) — and at c1 neither.
func resticFixture(withTool bool) map[string]any {
	backup := map[string]any{"id": "backup", "type": "container", "name": "restic-backup", "image": fixtureImage}
	measure := map[string]any{"id": "measure", "type": "container", "name": "restic-measure", "image": fixtureImage}
	m := map[string]any{"resources": []any{backup, measure}}
	if withTool {
		backup["health"] = map[string]any{"kind": catalogue.HealthTool, "tool": "backup_health"}
		measure["health"] = map[string]any{"kind": "runtime"}
		m["tools"] = []string{"backup_health"}
	}
	return m
}

// natsFixture is the bus's module: it holds mesh-broker and is sent the user list.
func natsFixture() map[string]any {
	return map[string]any{"bus-users": "/var/lib/nats-module/conf/accounts.conf",
		"claims": []any{map[string]any{"name": catalogue.BrokerSeat, "scope": catalogue.ScopeMesh}}}
}

// wallpaperFixture is a module the bus's machine is newly assigned.
func wallpaperFixture() map[string]any {
	return map[string]any{"resources": []any{
		map[string]any{"id": "paper", "type": "container", "name": "wallpaper", "image": fixtureImage}}}
}