package notify

import (
	"io"
	"log"
	"strings"
	"testing"

	"gitea.dooplex.hu/admin/felhom-hub/internal/i18n"
	"gitea.dooplex.hu/admin/felhom-hub/internal/store"
)

// Localisation slice 3 (R-558) — the behaviour the bundle exists to produce.
//
// The goldens next door prove WHAT each mail says. These prove WHICH ONE a household gets, and that
// the operator's copy never moves.

// S3 — the box's own sentence.
//
// Roughly a third of the customer mails carry a sentence the BOX composed, naming a drive or an app
// or a number. The hub cannot translate one, so the box sends a second copy in the household's
// language. This is the test that the second copy is actually preferred — and that its absence
// leaves the mail exactly as it was, which is the state of every box in the fleet until the
// controller half ships.
func TestMessageCustomerPreferredForTheHousehold(t *testing.T) {
	const hunSentence = "A /mnt/adat lemez 91%-ig megtelt (12,4 GB szabad)."
	const engSentence = "The /mnt/adat disk is 91% full (12.4 GB free)."

	// disk_warning has NO bundle entry on purpose, so the box's sentence IS the mail.
	subject, body := FormatCustomerEmail("en", "c1", "disk_warning", "warning", hunSentence, engSentence, "")

	if !strings.Contains(body, engSentence) {
		t.Errorf("the English household's mail does not carry the English sentence:\n%s", body)
	}
	if strings.Contains(body, hunSentence) {
		t.Errorf("the English household's mail still carries the Hungarian sentence:\n%s", body)
	}
	if !strings.Contains(subject, engSentence) {
		t.Errorf("the subject is not the English sentence: %q", subject)
	}

	// The OPERATOR's mail is built from `message` and is untouched by any of this.
	opSubject, opBody := FormatOperatorEmail("c1", "disk_warning", "warning", hunSentence, "")
	if !strings.Contains(opBody, hunSentence) {
		t.Errorf("the operator's mail lost the Hungarian sentence:\n%s", opBody)
	}
	if strings.Contains(opBody, engSentence) || strings.Contains(opSubject, engSentence) {
		t.Error("the English sentence leaked into the operator's mail")
	}
}

// S3, the other half: an old controller sends no second sentence, and the mail must be byte-for-byte
// what it is today. Compared against the RENDER WITH NO NEW FIELD AT ALL, not against a retyped
// expectation — a retyped one would pass even if both sides changed together.
func TestMessageCustomerAbsentIsExactlyToday(t *testing.T) {
	const hunSentence = "A /mnt/adat lemez 91%-ig megtelt (12,4 GB szabad)."

	subject, body := FormatCustomerEmail(i18n.Default, "c1", "disk_warning", "warning", hunSentence, "", "")
	if !strings.Contains(body, hunSentence) || !strings.Contains(subject, hunSentence) {
		t.Fatalf("an absent message_customer lost the box's sentence:\n%s\n%s", subject, body)
	}

	// And a Hungarian household that DOES get a second sentence gets the Hungarian one, because the
	// box sends the same text twice. The point is that nothing about the hu path depends on it.
	s2, b2 := FormatCustomerEmail(i18n.Default, "c1", "disk_warning", "warning", hunSentence, hunSentence, "")
	if s2 != subject || b2 != body {
		t.Error("a Hungarian household's mail changed when the box sent the sentence twice")
	}
}

// The entry still WINS over the box's sentence, in both languages — the property that keeps the
// dynamic-message types (disk_warning and friends) working, stated from the other direction.
func TestEntryWinsAndTheBoxSentenceBecomesItsOwnLine(t *testing.T) {
	const hun = "A cel nincs beallitva."
	const eng = "The target is not set."

	_, body := FormatCustomerEmail("en", "c1", "backup_failed", "error", hun, eng, "")
	headline := i18n.Shared().Msg("en", "mail.event.backup_failed")
	if !strings.Contains(body, headline) {
		t.Errorf("the English entry is not the headline:\n%s", body)
	}
	if !strings.Contains(body, eng) {
		t.Errorf("the box's English sentence is not on its own line:\n%s", body)
	}
	if strings.Contains(body, hun) {
		t.Errorf("the Hungarian sentence reached an English household:\n%s", body)
	}
	// The line label is translated too — an English mail must not say "Üzenet".
	if strings.Contains(body, "Üzenet") {
		t.Errorf("the English mail carries the Hungarian field label:\n%s", body)
	}
}

// Every mail kind actually differs between the two languages. Without this, a key that silently fell
// back to Hungarian would pass every other test here: the mail sends, it just sends in the wrong
// language, which is the exact defect this slice exists to remove.
func TestEveryCustomerMailDiffersBetweenLanguages(t *testing.T) {
	for _, c := range customerMailCases("hu") {
		if strings.HasPrefix(c.name, "operator_") {
			continue // the operator's mails are English already and are not localised
		}
		name := c.name
		huSubject, huBody := c.render()
		var enSubject, enBody string
		for _, e := range customerMailCases("en") {
			if e.name == name {
				enSubject, enBody = e.render()
			}
		}
		if huBody == enBody {
			t.Errorf("%s renders identically in both languages — it is not localised", name)
		}
		if huSubject == enSubject && !strings.Contains(huSubject, "[Felhom] Információ") {
			t.Errorf("%s has the same subject in both languages: %q", name, huSubject)
		}
	}
}

// An unsupported or absent language renders Hungarian rather than a blank or a key.
func TestUnknownLanguageRendersHungarian(t *testing.T) {
	want, wantBody := FormatCustomerEmail("hu", "c1", "backup_completed", "info", "", "", "")
	for _, lang := range []string{"", "de", "en-GB", "  "} {
		got, gotBody := FormatCustomerEmail(lang, "c1", "backup_completed", "info", "", "", "")
		if got != want || gotBody != wantBody {
			t.Errorf("language %q did not fall back to Hungarian", lang)
		}
	}
}

// The TEST mail follows the household's language too.
//
// It is the one customer mail with its own text — it never goes through FormatCustomerEmail — and
// it is also the only one an operator can trigger on demand, so it is the one most likely to be
// used to CHECK whether the localisation works. It was still hardcoded Hungarian when the rest of
// this release was finished; pressing "send test" for an English household would have answered that
// question wrongly, in the most convincing possible way.
func TestTestMailFollowsTheHouseholdLanguage(t *testing.T) {
	for _, tc := range []struct{ lang, want, notWant string }{
		{"en", "Test notification", "Teszt"},
		{"hu", "Teszt értesítés", "Test notification"},
	} {
		st := newDispStore(t)
		if err := st.SaveCustomerConfig(&store.CustomerConfig{
			CustomerID: "c1", APIKey: "k", RetrievalPassword: "p", Language: tc.lang,
		}); err != nil {
			t.Fatal(err)
		}
		if err := st.SaveNotificationPrefs("c1", "fam@example.com", []string{"test"}, 6); err != nil {
			t.Fatal(err)
		}
		d := NewDispatcher(st, "test-key", "from@felhom.eu", "", false, log.New(io.Discard, "", 0))
		var subject, body string
		d.sendEmailFn = func(_, s, b string, _ map[string]string) error {
			subject, body = s, b
			return nil
		}
		d.ProcessEvent("c1", "test", "info", "", "{}", "hub")

		if !strings.Contains(subject, tc.want) {
			t.Errorf("%s test mail subject = %q, want it to contain %q", tc.lang, subject, tc.want)
		}
		if strings.Contains(subject, tc.notWant) || strings.Contains(body, tc.notWant) {
			t.Errorf("%s test mail carries the other language (%q):\n%s\n%s", tc.lang, tc.notWant, subject, body)
		}
		if body == "" {
			t.Fatalf("%s test mail has an empty body — the seam did not fire", tc.lang)
		}
	}
}