package manifest_test

import (
	"os"
	"path/filepath"
	"strings"
	"testing"

	"git.vakhrushev.me/av/convy/internal/manifest"
)

func write(t *testing.T, dir, name, body string) string {
	t.Helper()
	path := filepath.Join(dir, name)
	if err := os.WriteFile(path, []byte(body), 0o644); err != nil {
		t.Fatal(err)
	}
	return path
}

// A manifest is data, and a command that changes it rewrites it whole. The
// second write of the same content has to come out the same, or every command
// would leave a diff of its own on top of the one it meant.
func TestSaveIsIdempotent(t *testing.T) {
	dir := t.TempDir()
	write(t, dir, manifest.Name, `[language]
version = 1
lang = "ru"

[topics.live]
time = "время"

[prefixes.live]
TIME = "conventions/time.md"
`)

	m, err := manifest.Load(dir)
	if err != nil {
		t.Fatal(err)
	}
	if err := m.Save(); err != nil {
		t.Fatal(err)
	}
	once, err := os.ReadFile(m.Path)
	if err != nil {
		t.Fatal(err)
	}

	again, err := manifest.Load(dir)
	if err != nil {
		t.Fatalf("the manifest the tool wrote does not load: %v\n%s", err, once)
	}
	if err := again.Save(); err != nil {
		t.Fatal(err)
	}
	twice, err := os.ReadFile(m.Path)
	if err != nil {
		t.Fatal(err)
	}
	if string(once) != string(twice) {
		t.Errorf("the second write differs from the first:\n%s\n---\n%s", once, twice)
	}
}

// A write goes out of the structs, so a key the tool does not know would be
// dropped. It refuses instead: that neither loses the key nor hides it.
func TestSaveRefusesWhileAKeyIsUnknown(t *testing.T) {
	dir := t.TempDir()
	write(t, dir, manifest.Name, `[language]
version = 1
descriptoin = "LANGUAGE.md"
`)

	m, err := manifest.Load(dir)
	if err != nil {
		t.Fatal(err)
	}
	before, _ := os.ReadFile(m.Path)

	err = m.Save()
	if err == nil {
		t.Fatal("the manifest was rewritten over a key the tool does not know")
	}
	if !strings.Contains(err.Error(), "descriptoin") {
		t.Errorf("the refusal does not name the key: %s", err)
	}
	after, _ := os.ReadFile(m.Path)
	if string(before) != string(after) {
		t.Errorf("the file was touched anyway:\n%s", after)
	}
}

// A name never leaves the manifest: it lives on in foreign repositories, and
// one handed out twice starts pointing at something else there.
func TestRetireMovesRatherThanDeletes(t *testing.T) {
	dir := t.TempDir()
	write(t, dir, manifest.Name, `[language]
version = 1

[topics.live]
time = "время"
logging = "логирование"
`)

	m, err := manifest.Load(dir)
	if err != nil {
		t.Fatal(err)
	}
	m.Topics.Retire("logging", "2026-07-28: свёрнута в errors")
	if err := m.Save(); err != nil {
		t.Fatal(err)
	}

	back, err := manifest.Load(dir)
	if err != nil {
		t.Fatal(err)
	}
	if back.TopicLive("logging") {
		t.Errorf("the topic stayed live")
	}
	if !back.TopicRetired("logging") {
		t.Errorf("the topic is neither live nor retired: the name is loose")
	}
	if !back.TopicLive("time") {
		t.Errorf("the other topic went with it")
	}
}

func TestProjectRoundTrip(t *testing.T) {
	dir := t.TempDir()
	p := &manifest.Project{
		Source: "../dev-conventions#v2",
		Components: map[string]manifest.Component{
			"backend": {Dir: `docs\conventions`, Lang: []string{"go"}, Topics: []string{"time"}},
			"web":     {Dir: "web/docs", Topics: []string{}},
		},
		Path: filepath.Join(dir, manifest.ProjectName),
		Root: dir,
	}
	if err := p.Save(); err != nil {
		t.Fatal(err)
	}

	back, err := manifest.LoadProject(dir)
	if err != nil {
		t.Fatalf("the manifest the tool wrote does not load: %v", err)
	}
	if back.Source != p.Source {
		t.Errorf("source came back as %q", back.Source)
	}
	// A backslash is the ordinary way a written value fails to read back.
	if got := back.Components["backend"].Dir; got != `docs\conventions` {
		t.Errorf("the directory came back as %q", got)
	}
	if len(back.Components["web"].Lang) != 0 {
		t.Errorf("an empty axis was written and read back as something")
	}

	back.Subscribe("web", "logging")
	back.Subscribe("web", "errors")
	if got := back.Components["web"].Topics; strings.Join(got, ",") != "errors,logging" {
		t.Errorf("the subscription is not kept in order: %v", got)
	}
	back.Unsubscribe("web", "errors")
	if got := back.Components["web"].Topics; strings.Join(got, ",") != "logging" {
		t.Errorf("unsubscribing left %v", got)
	}
}