package stickerlinks

import (
	"context"
	"errors"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"telesrv/internal/domain"
)

func TestHandlerServesStickerSetLandingPage(t *testing.T) {
	resolver := fakeResolver{
		"fresh_pack": {
			ID:        10,
			ShortName: "fresh_pack",
			Title:     "Fresh Pack",
			Count:     2,
			Kind:      domain.StickerSetKindStickers,
		},
	}
	rr := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/addstickers/fresh_pack", nil)

	NewHandler(resolver, "https://telesrv.net/").ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body=%s", rr.Code, rr.Body.String())
	}
	body := rr.Body.String()
	for _, want := range []string{
		"Fresh Pack",
		"https://telesrv.net/addstickers/fresh_pack",
		"telesrv://addstickers?set=fresh_pack",
		"tg://addstickers?set=fresh_pack",
		"Files are still fetched by the app through MTProto.",
	} {
		if !strings.Contains(body, want) {
			t.Fatalf("body missing %q:\n%s", want, body)
		}
	}
	if strings.Contains(body, `window.location.href = "tg://`) {
		t.Fatalf("landing page must not auto-open tg:// and steal official Telegram:\n%s", body)
	}
	if strings.Contains(body, "/upload/getFile") {
		t.Fatalf("landing page should not expose media download paths:\n%s", body)
	}
}

func TestHandlerServesEmojiLandingPage(t *testing.T) {
	resolver := fakeResolver{
		"emoji_pack": {
			ID:        11,
			ShortName: "emoji_pack",
			Title:     "Emoji Pack",
			Count:     1,
			Kind:      domain.StickerSetKindEmoji,
			Emojis:    true,
		},
	}
	rr := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/addemoji/emoji_pack", nil)

	NewHandler(resolver, "https://example.test/base").ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body=%s", rr.Code, rr.Body.String())
	}
	body := rr.Body.String()
	for _, want := range []string{
		"custom emoji set",
		"https://example.test/base/addemoji/emoji_pack",
		"telesrv://addemoji?set=emoji_pack",
		"tg://addemoji?set=emoji_pack",
	} {
		if !strings.Contains(body, want) {
			t.Fatalf("body missing %q:\n%s", want, body)
		}
	}
}

func TestHandlerRedirectsMismatchedKindToCanonicalURL(t *testing.T) {
	resolver := fakeResolver{
		"emoji_pack": {
			ID:        11,
			ShortName: "emoji_pack",
			Title:     "Emoji Pack",
			Kind:      domain.StickerSetKindEmoji,
			Emojis:    true,
		},
	}
	rr := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/addstickers/emoji_pack", nil)

	NewHandler(resolver, "https://telesrv.net").ServeHTTP(rr, req)

	if rr.Code != http.StatusPermanentRedirect {
		t.Fatalf("status = %d, want 308; body=%s", rr.Code, rr.Body.String())
	}
	if got, want := rr.Header().Get("Location"), "https://telesrv.net/addemoji/emoji_pack"; got != want {
		t.Fatalf("Location = %q, want %q", got, want)
	}
}

func TestHandlerNotFoundForMissingOrInvalidShortName(t *testing.T) {
	handler := NewHandler(fakeResolver{}, "https://telesrv.net")
	for _, path := range []string{
		"/addstickers/missing_pack",
		"/addstickers/bad-name",
		"/addemoji/%E4%B8%AD%E6%96%87",
	} {
		rr := httptest.NewRecorder()
		req := httptest.NewRequest(http.MethodGet, path, nil)
		handler.ServeHTTP(rr, req)
		if rr.Code != http.StatusNotFound {
			t.Fatalf("%s status = %d, want 404", path, rr.Code)
		}
	}
}

func TestHandlerLookupErrorIsInternalServerError(t *testing.T) {
	rr := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/addstickers/fresh_pack", nil)

	NewHandler(errorResolver{}, "https://telesrv.net").ServeHTTP(rr, req)

	if rr.Code != http.StatusInternalServerError {
		t.Fatalf("status = %d, want 500", rr.Code)
	}
}

type fakeResolver map[string]domain.StickerSet

func (f fakeResolver) ResolveStickerSet(_ context.Context, ref domain.StickerSetRef) (domain.StickerSet, []domain.Document, bool, error) {
	set, ok := f[ref.ShortName]
	if !ok {
		return domain.StickerSet{}, nil, false, nil
	}
	docs := make([]domain.Document, set.Count)
	return set, docs, true, nil
}

type errorResolver struct{}

func (errorResolver) ResolveStickerSet(context.Context, domain.StickerSetRef) (domain.StickerSet, []domain.Document, bool, error) {
	return domain.StickerSet{}, nil, false, errors.New("boom")
}