package phrasebook

import (
	"io/fs"
	"os"
	"path/filepath"
	"regexp"
	"runtime"
	"sort"
	"strings"
	"testing"
	"testing/fstest"

	"git.golem15.com/golem15/summercms/backpack"
)

func TestPhase10Forms(t *testing.T) {
	cat := NewCatalog()
	if err := cat.Load("acme.demo", fstest.MapFS{
		"lang/en/lang.yaml": {Data: []byte(`plain: Hello :name
plural:
  one: ":count apple"
  other: ":count apples"
pipe: ":count apple|:count apples"
exact: "{0} No apples|[1,*] :count apples"
`)},
		"lang/pl/lang.yaml": {Data: []byte(`pipe: ":count jabłko|:count jabłka|:count jabłek|:count jabłka"
`)},
	}); err != nil {
		t.Fatal(err)
	}
	tr := NewTranslator(cat, Options{Locale: "en", Fallback: "en"})

	check := func(locale, key string, want map[string]string) {
		t.Helper()
		got, ok := tr.Forms(locale, key)
		if !ok {
			t.Fatalf("%s %s: not convertible", locale, key)
		}
		if len(got) != len(want) {
			t.Fatalf("%s %s = %v want %v", locale, key, got, want)
		}
		for cat, text := range want {
			if got[cat] != text {
				t.Fatalf("%s %s = %v want %v", locale, key, got, want)
			}
		}
	}
	check("en", "acme.demo::lang.plain", map[string]string{"other": "Hello :name"})
	check("en", "acme.demo::lang.plural", map[string]string{"one": ":count apple", "other": ":count apples"})
	check("en", "acme.demo::lang.pipe", map[string]string{"one": ":count apple", "other": ":count apples"})
	check("pl", "acme.demo::lang.pipe", map[string]string{"one": ":count jabłko", "few": ":count jabłka", "many": ":count jabłek", "other": ":count jabłka"})
	// pl falls back to en for a key it does not define.
	check("pl", "acme.demo::lang.plain", map[string]string{"other": "Hello :name"})

	if forms, ok := tr.Forms("en", "acme.demo::lang.exact"); ok {
		t.Fatalf("exact/range pipe converted to %v", forms)
	}
	if forms, ok := tr.Forms("en", "acme.demo::lang.missing"); ok {
		t.Fatalf("missing key converted to %v", forms)
	}

	got, ok := tr.Forms("en", "acme.demo::lang.plural")
	if !ok {
		t.Fatal("plural not convertible")
	}
	got["one"] = "mutated"
	if again, _ := tr.Forms("en", "acme.demo::lang.plural"); again["one"] != ":count apple" {
		t.Fatal("Forms returned the catalog's own map")
	}
}

type overridePlugin struct {
	id        string
	lang      fs.FS
	overrides fs.FS
}

func (p overridePlugin) ID() string             { return p.id }
func (p overridePlugin) LangFS() fs.FS          { return p.lang }
func (p overridePlugin) LangOverridesFS() fs.FS { return p.overrides }

func activateWith(t *testing.T, plugins ...overridePlugin) (*Translator, error) {
	t.Helper()
	app := backpack.New(nil)
	if err := Activate(app, plugins); err != nil {
		return nil, err
	}
	tr, ok := app.Lookup[*Translator]()
	if !ok || tr == nil {
		t.Fatal("translator was not published")
	}
	return tr, nil
}

func TestPhase10LangOverride(t *testing.T) {
	demo := fstest.MapFS{"lang/en/lang.yaml": {Data: []byte("title: Demo\n")}}
	tr, err := activateWith(t, overridePlugin{id: "acme.demo", lang: demo, overrides: fstest.MapFS{
		"lang/pl/backend/lang.yaml":   {Data: []byte("form:\n  save: Zachowaj\n  extra: Dodatkowy\n")},
		"lang/de/backend/lang.yaml":   {Data: []byte("form:\n  save: Speichern\n")},
		"lang/en/acme.demo/lang.yaml": {Data: []byte("title: Demo app\n")},
	}})
	if err != nil {
		t.Fatalf("activate: %v", err)
	}
	for _, tc := range []struct{ locale, key, want string }{
		{"pl", "backend::lang.form.save", "Zachowaj"},
		{"pl", "backend::lang.form.extra", "Dodatkowy"},
		{"pl", "backend::lang.form.cancel", "Anuluj"},
		{"de", "backend::lang.form.save", "Speichern"},
		{"en", "backend::lang.form.save", "Save"},
		{"en", "acme.demo::lang.title", "Demo app"},
	} {
		if got := tr.GetIn(tc.locale, tc.key, nil); got != tc.want {
			t.Fatalf("%s %s = %q want %q", tc.locale, tc.key, got, tc.want)
		}
	}
	if bundle := tr.Bundle("de", "backend::lang."); bundle["backend::lang.form.save"]["other"] != "Speichern" || bundle["backend::lang.form.cancel"]["other"] != "Cancel" {
		t.Fatalf("de bundle did not merge the fallback: save=%v cancel=%v", bundle["backend::lang.form.save"], bundle["backend::lang.form.cancel"])
	}

	for _, tc := range []struct {
		name      string
		overrides fstest.MapFS
		want      []string
	}{
		{"missing namespace segment", fstest.MapFS{"lang/pl/lang.yaml": {Data: []byte("a: b\n")}}, []string{"acme.demo", "malformed override path"}},
		{"not yaml", fstest.MapFS{"lang/pl/backend/lang.txt": {Data: []byte("a: b\n")}}, []string{"acme.demo", "malformed override path"}},
		{"too deep", fstest.MapFS{"lang/pl/backend/sub/lang.yaml": {Data: []byte("a: b\n")}}, []string{"acme.demo", "malformed override path"}},
		{"unknown namespace", fstest.MapFS{"lang/pl/acme.missing/lang.yaml": {Data: []byte("a: b\n")}}, []string{"acme.demo", "acme.missing"}},
		{"unconvertible backend key", fstest.MapFS{"lang/en/backend/lang.yaml": {Data: []byte("list:\n  results: \"{0} No results|[1,*] :count results\"\n")}}, []string{"backend::lang.list.results", "CLDR"}},
	} {
		t.Run(tc.name, func(t *testing.T) {
			_, err := activateWith(t, overridePlugin{id: "acme.demo", lang: demo, overrides: tc.overrides})
			if err == nil {
				t.Fatal("activation accepted a bad override")
			}
			for _, want := range tc.want {
				if !strings.Contains(err.Error(), want) {
					t.Fatalf("err=%v missing %q", err, want)
				}
			}
		})
	}
}

var spaKey = regexp.MustCompile(`backend::lang\.[A-Za-z0-9_.]*[A-Za-z0-9_]`)

// TestPhase10SPAKeysResolve walks the admin SPA sources and resolves every
// backend::lang key literal in pl and en, each without falling back to the
// other locale.
func TestPhase10SPAKeysResolve(t *testing.T) {
	_, file, _, ok := runtime.Caller(0)
	if !ok {
		t.Fatal("caller")
	}
	root := filepath.Join(filepath.Dir(file), "..", "admin", "src")
	keys := map[string]bool{}
	err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
		if err != nil {
			return err
		}
		if d.IsDir() || !(strings.HasSuffix(path, ".ts") || strings.HasSuffix(path, ".vue")) {
			return nil
		}
		raw, err := os.ReadFile(path)
		if err != nil {
			return err
		}
		for _, key := range spaKey.FindAllString(string(raw), -1) {
			keys[key] = true
		}
		return nil
	})
	if err != nil {
		t.Fatal(err)
	}
	if len(keys) < 10 {
		t.Fatalf("found only %d backend::lang keys under %s", len(keys), root)
	}
	sorted := make([]string, 0, len(keys))
	for key := range keys {
		sorted = append(sorted, key)
	}
	sort.Strings(sorted)
	cat := NewCatalog()
	if err := cat.Load("backend", backendLang()); err != nil {
		t.Fatal(err)
	}
	for _, locale := range []string{"pl", "en"} {
		tr := NewTranslator(cat, Options{Locale: locale, Fallback: locale})
		for _, key := range sorted {
			forms, ok := tr.Forms(locale, key)
			if !ok || forms["other"] == "" {
				t.Errorf("%s: %s does not resolve", locale, key)
			}
		}
	}
}