package main

// The dbus module's shape (novox/hq ADR 0215): it holds node-message-bus, owns the bus's packages,
// declares the bus running and never restarts or reloads it, and publishes only its curated events.

import (
	"encoding/json"
	"os"
	"reflect"
	"regexp"
	"sort"
	"strings"
	"testing"
)

type manifestShape struct {
	Module       string           `json:"module"`
	Capabilities []string         `json:"capabilities"`
	Claims       []map[string]any `json:"claims"`
	Emits        []string         `json:"emits"`
	Consumes     []string         `json:"consumes"`
	Tools        []string         `json:"tools"`
	Resources    []map[string]any `json:"resources"`
	Build        struct {
		Artifacts []map[string]any `json:"artifacts"`
	} `json:"build"`
}

func manifest(t *testing.T) (manifestShape, string) {
	t.Helper()
	raw, err := os.ReadFile("../../module.json")
	if err != nil {
		t.Fatal(err)
	}
	var m manifestShape
	if err := json.Unmarshal(raw, &m); err != nil {
		t.Fatal(err)
	}
	return m, string(raw)
}

func TestItHoldsTheMessageBusSeatWithOnlyWhatItNeeds(t *testing.T) {
	m, _ := manifest(t)
	if m.Module != "dbus" || len(m.Claims) != 1 || m.Claims[0]["name"] != "node-message-bus" || m.Claims[0]["scope"] != "node" {
		t.Fatalf("claims: %+v", m.Claims)
	}
	if _, serves := m.Claims[0]["serves"]; serves {
		t.Error("the seat receives nothing yet (ADR 0215 §4) and serves no verbs")
	}
	if !reflect.DeepEqual(m.Capabilities, []string{"package-manager", "service-manager"}) {
		t.Fatalf("capabilities: %v", m.Capabilities)
	}
}

func TestItOwnsTheBusImplementationsPackages(t *testing.T) {
	m, _ := manifest(t)
	var pkgs []string
	for _, r := range m.Resources {
		if r["type"] == "package" {
			pkgs = append(pkgs, r["package"].(string))
			if r["absent"] == true {
				t.Errorf("%v is declared absent", r["package"])
			}
		}
	}
	sort.Strings(pkgs)
	if !reflect.DeepEqual(pkgs, Packages) {
		t.Fatalf("packages %v, the check reads %v", pkgs, Packages)
	}
}

// TestTheBusIsNeverRestartedOrReloaded is ADR 0215 §2: the bus is declared running, with no trigger
// that would restart or reload it, and no boot state: dbus.service is an alias and dbus-broker.service
// is started at boot through dbus.socket, so enabling would write an alias link the machines do not
// have today.
func TestTheBusIsNeverRestartedOrReloaded(t *testing.T) {
	m, raw := manifest(t)
	if strings.Contains(raw, "restart-on") || strings.Contains(raw, "reload-on") {
		t.Fatal("the manifest carries a restart or reload trigger")
	}
	var services []map[string]any
	for _, r := range m.Resources {
		if r["type"] == "service" {
			services = append(services, r)
		}
	}
	if len(services) != 1 {
		t.Fatalf("services: %v", services)
	}
	s := services[0]
	if s["unit"] != SystemUnit || s["state"] != "running" {
		t.Fatalf("%v", s)
	}
	if _, ok := s["boot"]; ok {
		t.Fatal("a boot state on the bus would have the host enable it")
	}
	for k := range s {
		if k != "id" && k != "type" && k != "unit" && k != "state" {
			t.Errorf("the bus's service carries %q", k)
		}
	}
}

func TestItEmitsTheCuratedEventsAndConsumesNothing(t *testing.T) {
	m, _ := manifest(t)
	if !reflect.DeepEqual(m.Emits, Emits) {
		t.Fatalf("emits %v, the watcher publishes %v", m.Emits, Emits)
	}
	if len(m.Consumes) != 0 {
		t.Fatalf("consumes %v", m.Consumes)
	}
}

func TestToolsAreTheManifests(t *testing.T) {
	m, _ := manifest(t)
	served := map[string]bool{}
	for _, tool := range Tools(testMachine(t, nil), nil) {
		if served[tool.Name] {
			t.Errorf("%s is served twice", tool.Name)
		}
		served[tool.Name] = true
		if !strings.HasPrefix(tool.Name, "dbus_") {
			t.Errorf("%s is not named dbus_<verb>", tool.Name)
		}
	}
	for _, want := range m.Tools {
		if !served[want] {
			t.Errorf("the manifest lists %s and the bundle does not serve it", want)
		}
		delete(served, want)
	}
	for extra := range served {
		t.Errorf("the bundle serves %s, which the manifest does not list", extra)
	}
}

func TestTheBundleIsTheBuildersShape(t *testing.T) {
	m, _ := manifest(t)
	if len(m.Build.Artifacts) != 1 {
		t.Fatalf("%v", m.Build.Artifacts)
	}
	a := m.Build.Artifacts[0]
	for k, v := range map[string]string{"kind": "bundle", "language": "go", "system": "arch", "from": "cmd/dbus-tools", "binary": "dbus-tools"} {
		if a[k] != v {
			t.Errorf("%s is %v, want %s", k, a[k], v)
		}
	}
}

// TestNothingInstallationSpecific holds the manifest to the catalogue's rule: no node names, domains
// or home paths.
func TestNothingInstallationSpecific(t *testing.T) {
	_, raw := manifest(t)
	for _, re := range []*regexp.Regexp{regexp.MustCompile(`/home/`), regexp.MustCompile(`\.(be|internal|com)\b`)} {
		if loc := re.FindString(raw); loc != "" {
			t.Errorf("the manifest carries %q", loc)
		}
	}
}