package kvm

import (
	"bytes"
	"io"
	"strings"
	"testing"

	"github.com/kdomanski/iso9660"
)

func readSeed(t *testing.T, iso []byte) (label string, files map[string]string) {
	t.Helper()
	img, err := iso9660.OpenImage(bytes.NewReader(iso))
	if err != nil {
		t.Fatalf("OpenImage() error = %v", err)
	}
	label, err = img.Label()
	if err != nil {
		t.Fatalf("Label() error = %v", err)
	}
	root, err := img.RootDir()
	if err != nil {
		t.Fatalf("RootDir() error = %v", err)
	}
	children, err := root.GetChildren()
	if err != nil {
		t.Fatalf("GetChildren() error = %v", err)
	}
	files = make(map[string]string, len(children))
	for _, c := range children {
		body, err := io.ReadAll(c.Reader())
		if err != nil {
			t.Fatalf("reading %s: %v", c.Name(), err)
		}
		files[c.Name()] = string(body)
	}
	return label, files
}

func TestBuildSeedISO_contents(t *testing.T) {
	t.Parallel()
	userData := "#cloud-config\npackages: [squid]\n"
	iso, err := buildSeedISO("proxy-abc123def456ghij", userData, defaultVendorData)
	if err != nil {
		t.Fatalf("buildSeedISO() error = %v", err)
	}
	label, files := readSeed(t, iso)
	if !strings.EqualFold(label, seedLabel) {
		t.Errorf("label = %q, want %q", label, seedLabel)
	}
	if len(files) != 3 {
		t.Errorf("files = %v, want exactly user-data, meta-data, vendor-data", files)
	}
	if files["user-data"] != userData {
		t.Errorf("user-data = %q, want verbatim cloud-init", files["user-data"])
	}
	if files["vendor-data"] != defaultVendorData {
		t.Errorf("vendor-data = %q", files["vendor-data"])
	}
	if got, want := files["meta-data"], "instance-id: proxy-abc123def456ghij\nlocal-hostname: proxy-abc123def456ghij\n"; got != want {
		t.Errorf("meta-data = %q, want %q", got, want)
	}
}

func TestBuildSeedISO_deterministic(t *testing.T) {
	t.Parallel()
	a, err := buildSeedISO("proxy-x", "#cloud-config\n", "")
	if err != nil {
		t.Fatalf("first buildSeedISO() error = %v", err)
	}
	b, err := buildSeedISO("proxy-x", "#cloud-config\n", "")
	if err != nil {
		t.Fatalf("second buildSeedISO() error = %v", err)
	}
	if !bytes.Equal(a, b) {
		t.Error("two builds for the same inputs differ; a re-created seed must be byte-identical")
	}
}

func TestBuildSeedISO_emptyUserData(t *testing.T) {
	t.Parallel()
	iso, err := buildSeedISO("proxy-x", "", defaultVendorData)
	if err != nil {
		t.Fatalf("buildSeedISO() error = %v", err)
	}
	_, files := readSeed(t, iso)
	if body, ok := files["user-data"]; !ok || body != "" {
		t.Errorf("user-data = %q (present=%v), want an empty file to still exist", body, ok)
	}
}