package auth

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"gitea.parodia.dev/drwily/petal/internal/db"
)

// patchMe drives UpdateMeHandler as the given user would reach it: behind the
// middleware, which is the only thing that puts an id in the context.
func patchMe(t *testing.T, users *UserStore, id, body string) *httptest.ResponseRecorder {
	t.Helper()
	r := httptest.NewRequest(http.MethodPatch, "/me", strings.NewReader(body))
	r = r.WithContext(WithUser(r.Context(), id))
	w := httptest.NewRecorder()
	users.UpdateMeHandler()(w, r)
	return w
}

func TestSetPairLang(t *testing.T) {
	_, users, _ := newStores(t)

	if err := users.SetPairLang("bob", "pt-PT"); err != nil {
		t.Fatalf("set pt-PT: %v", err)
	}
	if u, _ := users.Get("bob"); u.PairLang != "pt-PT" {
		t.Fatalf("pair_lang = %q, want pt-PT", u.PairLang)
	}

	// Every pair with a langpack, not just the first one: this list and the
	// frontend's PACKS are two copies of the same fact, and the day they
	// disagree is the day she can pick a pair the app cannot render.
	if err := users.SetPairLang("bob", "fr"); err != nil {
		t.Fatalf("set fr: %v", err)
	}
	if u, _ := users.Get("bob"); u.PairLang != "fr" {
		t.Fatalf("pair_lang = %q, want fr", u.PairLang)
	}

	// And back — a writer who tries a pair and doesn't like it must be able to
	// return, which is the whole reason the picker exists.
	if err := users.SetPairLang("bob", "zh"); err != nil {
		t.Fatalf("set zh: %v", err)
	}
	if u, _ := users.Get("bob"); u.PairLang != "zh" {
		t.Fatalf("pair_lang = %q, want zh", u.PairLang)
	}
}

// A pair the frontend has no langpack for must not be storable. Accepting it
// would leave her looking at Chinese copy with no way back except a lucky guess.
func TestSetPairLangRejectsUnshippedPairs(t *testing.T) {
	_, users, _ := newStores(t)

	// "es" is the real case here — the pair whose pack has not been written yet.
	// "pt-BR" is the near-miss that matters most: a Brazilian code must not be
	// quietly served European copy and a European voice.
	for _, lang := range []string{"es", "pt-BR", "fr-CA", "klingon", "", "  "} {
		if err := users.SetPairLang("bob", lang); err == nil {
			t.Fatalf("stored unshipped pair %q", lang)
		}
	}
	if u, _ := users.Get("bob"); u.PairLang != "zh" {
		t.Fatalf("a refused write still moved pair_lang to %q", u.PairLang)
	}
}

func TestSetPairLangUnknownUser(t *testing.T) {
	_, users, _ := newStores(t)
	if err := users.SetPairLang("nobody", "pt-PT"); err == nil {
		t.Fatal("set a pair language on an account that does not exist")
	}
}

func TestUpdateMeHandler(t *testing.T) {
	_, users, _ := newStores(t)

	w := patchMe(t, users, "bob", `{"pair_lang":"pt-PT"}`)
	if w.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200 (%s)", w.Code, w.Body.String())
	}
	// The whole user comes back, so the client can re-read the pair from the
	// server instead of assuming its request took.
	var got db.User
	if err := json.Unmarshal(w.Body.Bytes(), &got); err != nil {
		t.Fatalf("decode: %v", err)
	}
	if got.ID != "bob" || got.PairLang != "pt-PT" {
		t.Fatalf("response = %+v, want bob on pt-PT", got)
	}
}

func TestUpdateMeHandlerRejects(t *testing.T) {
	_, users, _ := newStores(t)

	for name, body := range map[string]string{
		"unshipped pair": `{"pair_lang":"es"}`,
		"missing field":  `{}`,
		"not json":       `pt-PT`,
	} {
		if w := patchMe(t, users, "bob", body); w.Code != http.StatusBadRequest {
			t.Fatalf("%s: status = %d, want 400", name, w.Code)
		}
	}
	if u, _ := users.Get("bob"); u.PairLang != "zh" {
		t.Fatalf("a rejected request still moved pair_lang to %q", u.PairLang)
	}

	// A caller the middleware never resolved (or whose row is gone) is a lapsed
	// session, not a bad request — the client turns 401 into the sign-in overlay.
	if w := patchMe(t, users, "nobody", `{"pair_lang":"pt-PT"}`); w.Code != http.StatusUnauthorized {
		t.Fatalf("unknown user: status = %d, want 401", w.Code)
	}
}