package i18n

import (
	"testing"
	"time"
)

func TestFormatDate(t *testing.T) {
	at := time.Date(2026, 9, 3, 10, 0, 0, 0, time.UTC)
	for _, c := range []struct{ lang, style, want string }{
		{"en", "long", "3 September 2026"}, {"en", "short", "3 Sep 2026"}, {"en", "iso", "2026-09-03"},
		{"el", "long", "3 Σεπτεμβρίου 2026"}, {"el", "short", "3 Σεπ 2026"}, {"el", "iso", "2026-09-03"},
		{"xx", "long", "3 September 2026"}, // unknown language reads as English
	} {
		if got := FormatDate(c.lang, c.style, at); got != c.want {
			t.Errorf("%s/%s: got %q, want %q", c.lang, c.style, got, c.want)
		}
	}
}

func TestMonth(t *testing.T) {
	if got := Month("en", time.May); got != "May" {
		t.Errorf("en: %q", got)
	}
	if got := Month("el", time.May); got != "Μάιος" {
		t.Errorf("el: %q", got)
	}
	for _, tbl := range monthTables {
		for i := 0; i < 12; i++ {
			if tbl.name[i] == "" || tbl.inDate[i] == "" || tbl.short[i] == "" {
				t.Errorf("month %d has an empty name", i+1)
			}
		}
	}
}

func TestTranslate(t *testing.T) {
	if T("el", "Save") != "Αποθήκευση" || T("en", "Save") != "Save" || T("el", "no such key") != "no such key" {
		t.Error("T")
	}
	if got := Tf("el", "Page %d of %d", 2, 5); got != "Σελίδα 2 από 5" {
		t.Errorf("Tf: %q", got)
	}
	for _, l := range Languages() {
		if !Valid(l.Code) {
			t.Errorf("%s not valid", l.Code)
		}
	}
	if Valid("") || Valid("fr") {
		t.Error("Valid accepts unknown codes")
	}
}

func TestMatch(t *testing.T) {
	for header, want := range map[string]string{
		"": "en", "fr": "en", "el": "el", "el-GR,el;q=0.9,en;q=0.8": "el", "en-US,en;q=0.9,el;q=0.8": "en",
		"fr-FR, EL;q=0.5": "el", "*": "en",
	} {
		if got := Match(header); got != want {
			t.Errorf("%q: got %q, want %q", header, got, want)
		}
	}
}