package web

import (
	"net/http"
	"net/http/httptest"
	"net/url"
	"strings"
	"testing"
	"time"

	"golang.org/x/crypto/bcrypt"

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

// R-596 — THE ONE SCREEN THAT STOPPED AN ENGLISH-SPEAKING HOUSEHOLD.
//
// The 2026-09-20 drill (felhom.eu audits/DRILL-first-hour-en-0258-2026-09-20.md) walked a fresh box
// as an English speaker. Every page was English except this one: the claim page's CHROME was English
// and its ANSWERS were Hungarian, because each answer was a Hungarian literal composed in Go and
// handed to the renderer as page DATA. A person who mistypes the code from their e-mail is told
// „Hibás vagy lejárt kód" and cannot tell a typo from a dead code — on the single screen between
// them and their machine.
//
// The defect class is `composed-sentence-into-page-data` (R-573, R-590, R-596, R-598): a template
// parity fixture cannot see it, because the template renders `{{.Error}}` correctly in both
// languages; only the VALUE is wrong. So these tests drive the real handlers and read the HTML.

// claimPage POSTs form to /claim (or GETs it when form is nil) with the language cookie set to lang,
// and returns the HTML the browser receives. The full CSRF pair is set exactly as the page does.
func claimPage(t *testing.T, s *Server, lang string, form url.Values) string {
	t.Helper()
	tok := s.claimCSRFToken()
	var req *http.Request
	if form == nil {
		req = httptest.NewRequest(http.MethodGet, "/claim", nil)
	} else {
		form.Set(csrfFormField, tok)
		req = httptest.NewRequest(http.MethodPost, "/claim", strings.NewReader(form.Encode()))
		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	}
	req.AddCookie(&http.Cookie{Name: claimCSRFCookie, Value: tok})
	if lang != "" {
		req.AddCookie(&http.Cookie{Name: langCookieName, Value: lang})
	}
	rr := httptest.NewRecorder()
	if form == nil {
		s.handleClaimPage(rr, req, "", "")
	} else {
		s.handleClaimSubmit(rr, req)
	}
	return rr.Body.String()
}

// want is one answer in both languages: the Hungarian that must be byte-identical to what the box
// said before v0.259.0, and the English an English-speaking household must get instead.
type claimAnswer struct {
	what string
	form url.Values
	hu   string
	en   string
}

func claimAnswers() []claimAnswer {
	good := func(code, pw string) url.Values {
		return url.Values{"code": {code}, "new_password": {pw}, "confirm_password": {pw}}
	}
	return []claimAnswer{
		{
			what: "a wrong code — the drill's own screen",
			form: good("nem-ez-az", "correct-horse-battery"),
			hu:   "Hibás vagy lejárt kód",
			en:   "Wrong or expired code",
		},
		{
			what: "a password under the minimum",
			form: good("alma-korte-szilva", "short"),
			hu:   "A jelszónak legalább 12 karakter hosszúnak kell lennie",
			en:   "The password must be at least 12 characters long",
		},
		{
			what: "the two passwords disagree",
			form: url.Values{"code": {"alma-korte-szilva"}, "new_password": {"correct-horse-battery"}, "confirm_password": {"correct-horse-batteryX"}},
			hu:   "A két jelszó nem egyezik",
			en:   "The two passwords do not match",
		},
	}
}

// S1 — the claim page answers in the reader's language, and the Hungarian is unchanged.
func TestClaimAnswersFollowTheReadersLanguage(t *testing.T) {
	for _, c := range claimAnswers() {
		t.Run(c.what, func(t *testing.T) {
			s, _, _ := claimTestServer(t)
			if html := claimPage(t, s, "hu", c.form); !strings.Contains(html, c.hu) {
				t.Errorf("Hungarian answer CHANGED for %s.\n  want the page to contain: %q", c.what, c.hu)
			}

			s2, _, _ := claimTestServer(t)
			html := claimPage(t, s2, "en", c.form)
			if !strings.Contains(html, c.en) {
				t.Errorf("an English household is not told %q for %s — this is the screen the drill "+
					"stopped on", c.en, c.what)
			}
			// The decisive assertion: the Hungarian sentence must be GONE from the English page.
			// Asserting only that the English is present would pass a page carrying both.
			if strings.Contains(html, c.hu) {
				t.Errorf("the HUNGARIAN answer %q is still on the ENGLISH page for %s", c.hu, c.what)
			}
		})
	}
}

// The lockout answer needs five failures, so it gets its own case — and the counter is asserted
// separately from the text, because the lockout is language-blind by design (§8).
func TestClaimLockoutAnswersInEnglishAndCountsTheSame(t *testing.T) {
	const (
		hu = "Túl sok próbálkozás — próbáld újra 15 perc múlva."
		en = "Too many attempts — try again in 15 minutes."
	)
	for _, tc := range []struct{ lang, want, notWant string }{
		{"hu", hu, en},
		{"en", en, hu},
	} {
		s, _, _ := claimTestServer(t)
		var html string
		for i := 0; i < claimMaxAttempts; i++ {
			html = claimPage(t, s, tc.lang, url.Values{
				"code": {"nem-ez-az"}, "new_password": {"correct-horse-battery"},
				"confirm_password": {"correct-horse-battery"},
			})
		}
		if !strings.Contains(html, tc.want) {
			t.Errorf("[%s] the lockout answer is missing %q", tc.lang, tc.want)
		}
		if strings.Contains(html, tc.notWant) {
			t.Errorf("[%s] the lockout answer still carries the other language's text %q", tc.lang, tc.notWant)
		}
		// The LOCKOUT ITSELF, not its wording: exactly the same number of wrong codes locks the
		// page in either language. A guesser must not get a longer run by switching the cookie.
		//
		// (The first version of this assertion named 192.0.2.1 as "a source that never submitted"
		// and failed: httptest.NewRequest gives every request RemoteAddr 192.0.2.1:1234, so that IS
		// the submitting source. Kept as a different address, because the point stands — the
		// lockout must be per-source, not global-only.)
		if locked, _ := s.claimSourceLocked("198.51.100.7"); locked {
			t.Errorf("[%s] a source that never submitted is locked", tc.lang)
		}
		if locked, _ := s.claimSourceLocked("192.0.2.1"); !locked {
			t.Errorf("[%s] the submitting source is not locked after %d wrong codes", tc.lang, claimMaxAttempts)
		}
		if locked, _ := s.claimRateLocked(); !locked {
			t.Errorf("[%s] %d wrong codes did not trip the global lockout", tc.lang, claimMaxAttempts)
		}
	}
}

// An unclaimed box has no household session and may have no cookie either — the very first screen a
// stranger meets. Its language must come from `customer.language` in controller.yaml, which is what
// the operator set when creating the customer (slice 3 Part B).
//
// §3 of the closing task asked this to be CONFIRMED before any work: the chain is
// langFor → settings.GetLanguage → configLanguage ← main.go's SetConfigLanguage(cfg.Customer.Language).
// This test is the pin, so the chain cannot be broken without something failing.
func TestAnonymousClaimPageFollowsTheCustomerLanguageWithNoCookie(t *testing.T) {
	s, _, sett := claimTestServer(t)
	sett.SetConfigLanguage("en")

	if got := s.langFor(httptest.NewRequest(http.MethodGet, "/claim", nil)); got != "en" {
		t.Fatalf("a cookieless anonymous request resolved to %q, want \"en\" — the operator's "+
			"creation-time language never reaches the first screen a stranger sees", got)
	}
	html := claimPage(t, s, "", url.Values{
		"code": {"nem-ez-az"}, "new_password": {"correct-horse-battery"}, "confirm_password": {"correct-horse-battery"},
	})
	if !strings.Contains(html, "Wrong or expired code") {
		t.Error("an English customer with no cookie yet is answered in Hungarian on their first screen")
	}
}

// A code made of ENGLISH words must be accepted exactly as a Hungarian one (S3's box half). The box
// compares a bcrypt hash of whatever the hub minted, so this is a guard against anyone "helping" by
// validating the shape of a code.
func TestClaimAcceptsAnEnglishWordCode(t *testing.T) {
	s, _, sett := claimTestServer(t)
	sett.SetConfigLanguage("en")
	const englishCode = "abacus-abdomen-ratio-wreath"
	if err := setClaimCodeTo(t, sett, englishCode); err != nil {
		t.Fatal(err)
	}
	rr := httptest.NewRecorder()
	tok := s.claimCSRFToken()
	form := url.Values{"code": {englishCode}, "new_password": {"correct-horse-battery"},
		"confirm_password": {"correct-horse-battery"}, csrfFormField: {tok}}
	req := httptest.NewRequest(http.MethodPost, "/claim", strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	req.AddCookie(&http.Cookie{Name: claimCSRFCookie, Value: tok})
	s.handleClaimSubmit(rr, req)

	if rr.Code != http.StatusFound {
		t.Fatalf("an English-word code was not accepted: got %d, want 302\nbody: %s", rr.Code, rr.Body.String())
	}
	if !sett.GetClaimed() {
		t.Error("the box did not record itself as claimed after an English-word code")
	}
}

// Nothing in this package may answer the claim page with a literal again. The bundle is the only
// legal source, so every key the handlers name must exist in BOTH languages — an absent English key
// falls back to Hungarian silently, which is precisely the bug being closed.
func TestClaimMessageKeysExistInBothLanguages(t *testing.T) {
	b, err := i18n.Shared()
	if err != nil {
		t.Fatal(err)
	}
	keys := []string{
		"claim.msg.state_unreadable", "claim.msg.invalid_form", "claim.msg.too_many",
		"claim.msg.no_active_code", "claim.msg.bad_code", "claim.msg.password_too_short",
		"claim.msg.password_mismatch", "claim.msg.save_failed", "claim.msg.code_sent",
	}
	for _, k := range keys {
		hu, en := b.Msg("hu", k), b.Msg("en", k)
		if hu == k {
			t.Errorf("hu.json does not know %q", k)
		}
		if en == k {
			t.Errorf("en.json does not know %q", k)
		}
		if hu == en {
			t.Errorf("%q is the same string in both languages (%q) — an untranslated key", k, hu)
		}
	}
}

// setClaimCodeTo installs a specific plaintext code at a fresh generation (the hub's job in
// production). Extracted so the English-code test cannot accidentally test the fixture's code.
func setClaimCodeTo(t *testing.T, sett claimCodeSetter, code string) error {
	t.Helper()
	h, err := bcrypt.GenerateFromPassword([]byte(code), 10)
	if err != nil {
		return err
	}
	return sett.SetClaimCode(string(h), 9, time.Now().UTC().Format(time.RFC3339))
}

type claimCodeSetter interface {
	SetClaimCode(hash string, generation int, issuedAt string) error
}