package account

import (
	"strings"
	"testing"
	"unicode/utf8"
)

// TestTelegramSeed covers the pure mapping from Telegram launch fields to the
// create-time account seed: supported-language detection (bare and region-tagged),
// the first-name / username display-name precedence, and trimming.
func TestTelegramSeed(t *testing.T) {
	cases := map[string]struct {
		languageCode, username, firstName string
		wantLang, wantName                string
	}{
		"ru bare":           {"ru", "user", "Иван", "ru", "Иван"},
		"en region-tagged":  {"en-US", "user", "John", "en", "John"},
		"ru region-tagged":  {"ru-RU", "", "Пётр", "ru", "Пётр"},
		"unknown language":  {"fr", "frodo", "Frodo", "", "Frodo"},
		"empty language":    {"", "neo", "Neo", "", "Neo"},
		"first name wins":   {"en", "handle", "Real Name", "en", "Real Name"},
		"username fallback": {"en", "handle", "", "en", "handle"},
		"both empty":        {"en", "", "", "en", ""},
		"trimmed":           {" RU ", "  ", "  Anna  ", "ru", "Anna"},
	}
	for name, tc := range cases {
		t.Run(name, func(t *testing.T) {
			got := telegramSeed(tc.languageCode, tc.username, tc.firstName)
			if got.preferredLanguage != tc.wantLang {
				t.Errorf("preferredLanguage = %q, want %q", got.preferredLanguage, tc.wantLang)
			}
			if got.displayName != tc.wantName {
				t.Errorf("displayName = %q, want %q", got.displayName, tc.wantName)
			}
		})
	}
}

// TestTelegramSeedTruncatesLongName checks an over-long Telegram name is capped to
// maxDisplayName runes (counted in runes, not bytes).
func TestTelegramSeedTruncatesLongName(t *testing.T) {
	long := strings.Repeat("я", maxDisplayName+5)
	got := telegramSeed("ru", "", long)
	if n := utf8.RuneCountInString(got.displayName); n != maxDisplayName {
		t.Errorf("display name rune count = %d, want %d", n, maxDisplayName)
	}
}