package main

import (
	"bytes"
	"encoding/base64"
	"errors"
	encrypt "fckeuspy-go/lib"
	"fmt"
	"image"
	"image/color"
	"image/png"
	"io"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/canvas"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/dialog"
	"fyne.io/fyne/v2/layout"
	"fyne.io/fyne/v2/storage"
	"fyne.io/fyne/v2/theme"
	"fyne.io/fyne/v2/widget"
)

// --- Core UI model ---
type uiParts struct {
	outKey, msg, peer, cipherOut, payload, plainOut *widget.Entry
	toastLabel                                      *widget.Label
	cipherQR, pubQR, crtQR, peerQR, payloadQR       *canvas.Image
	showQR, showPeerQR, showPayloadQR               bool
}

func buildEntries() *uiParts {
	p := &uiParts{
		outKey:     widget.NewMultiLineEntry(),
		msg:        widget.NewMultiLineEntry(),
		peer:       widget.NewMultiLineEntry(),
		cipherOut:  widget.NewMultiLineEntry(),
		payload:    widget.NewMultiLineEntry(),
		plainOut:   widget.NewMultiLineEntry(),
		toastLabel: widget.NewLabel(""),
		cipherQR:   canvas.NewImageFromImage(nil),
		pubQR:      canvas.NewImageFromImage(nil),
		crtQR:      canvas.NewImageFromImage(nil),
		peerQR:     canvas.NewImageFromImage(nil),
		payloadQR:  canvas.NewImageFromImage(nil),
		showQR:     true, showPeerQR: true, showPayloadQR: true,
	}
	p.cipherQR.SetMinSize(fyne.NewSize(220, 220))
	p.pubQR.SetMinSize(fyne.NewSize(200, 200))
	p.peerQR.SetMinSize(fyne.NewSize(200, 200))
	p.payloadQR.SetMinSize(fyne.NewSize(220, 220))
	p.toastLabel.Hide()
	return p
}

func (p *uiParts) showToast(s string) {
	fyne.Do(func() { p.toastLabel.SetText(s); p.toastLabel.Show() })
	time.AfterFunc(1500*time.Millisecond, func() {
		fyne.Do(func() {
			if p.toastLabel.Text == s {
				p.toastLabel.Hide()
			}
		})
	})
}

// Theme
type simpleTheme struct{}

func (simpleTheme) Color(n fyne.ThemeColorName, v fyne.ThemeVariant) color.Color {
	if n == theme.ColorNameBackground {
		return color.NRGBA{24, 27, 31, 255}
	}
	return theme.DefaultTheme().Color(n, v)
}
func (simpleTheme) Font(st fyne.TextStyle) fyne.Resource    { return theme.DefaultTheme().Font(st) }
func (simpleTheme) Icon(n fyne.ThemeIconName) fyne.Resource { return theme.DefaultTheme().Icon(n) }
func (simpleTheme) Size(n fyne.ThemeSizeName) float32       { return theme.DefaultTheme().Size(n) }

// Facade interface
type ServiceFacade interface {
	Encrypt(msg, peer string) (string, error)
	Decrypt(json string) (string, error)
	PublicPEM() string
	PublicCert() string
	ListContacts() ([]Contact, error)
	SaveContact(c Contact) error
	DeleteContact(id string) error
}

// Clipboard helpers
func copyClip(s string, parts *uiParts) {
	fyne.CurrentApp().Clipboard().SetContent(s)
	parts.showToast("Zkopírováno")
}

func copyImageToClipboard(img image.Image, parts *uiParts) {
	if img == nil {
		return
	}
	buf := &bytes.Buffer{}
	if err := png.Encode(buf, img); err != nil {
		parts.showToast("Chyba PNG")
		return
	}
	choose := func() *exec.Cmd {
		wayland := os.Getenv("WAYLAND_DISPLAY") != ""
		has := func(b string) bool { _, e := exec.LookPath(b); return e == nil }
		if wayland {
			if has("wl-copy") {
				return exec.Command("wl-copy", "--type", "image/png")
			}
			if has("xclip") {
				return exec.Command("xclip", "-selection", "clipboard", "-t", "image/png")
			}
		} else {
			if has("xclip") {
				return exec.Command("xclip", "-selection", "clipboard", "-t", "image/png")
			}
			if has("wl-copy") {
				return exec.Command("wl-copy", "--type", "image/png")
			}
		}
		return nil
	}()
	if choose == nil {
		parts.showToast("Chybí wl-copy/xclip")
		return
	}
	stdin, _ := choose.StdinPipe()
	if err := choose.Start(); err != nil {
		parts.showToast("Nelze spustit")
		return
	}
	_, _ = stdin.Write(buf.Bytes())
	_ = stdin.Close()
	if err := choose.Wait(); err != nil {
		parts.showToast("Selhalo")
		return
	}
	parts.showToast("QR obrázek ve schránce")
}

func readImageClipboard() (image.Image, error) {
	has := func(b string) bool { _, e := exec.LookPath(b); return e == nil }
	tryDecode := func(d []byte) (image.Image, bool) {
		if len(d) == 0 {
			return nil, false
		}
		if img, _, e := image.Decode(bytes.NewReader(d)); e == nil {
			return img, true
		}
		s := strings.TrimSpace(string(d))
		if strings.HasPrefix(s, "data:image") {
			if p := strings.Index(s, ","); p > 0 {
				s = s[p+1:]
			}
		}
		if raw, err := base64.StdEncoding.DecodeString(s); err == nil {
			if img, _, e2 := image.Decode(bytes.NewReader(raw)); e2 == nil {
				return img, true
			}
		}
		return nil, false
	}

	if os.Getenv("WAYLAND_DISPLAY") != "" && has("wl-paste") {
		if types, err := exec.Command("wl-paste", "--list-types").Output(); err == nil {
			log.Printf("[clip] wl types: %s", strings.TrimSpace(string(types)))
			pref := []string{"image/png", "image/jpeg", "image/jpg", "image/webp"}
			seen := map[string]bool{}
			for _, p := range pref {
				seen[p] = true
			}
			order := append([]string{}, pref...)
			for _, t := range strings.Split(string(types), "\n") {
				t = strings.TrimSpace(t)
				if t == "" || !strings.HasPrefix(t, "image/") {
					continue
				}
				if !seen[t] {
					order = append(order, t)
				}
			}
			for _, t := range order {
				if data, err := exec.Command("wl-paste", "--type", t).Output(); err == nil {
					log.Printf("[clip] got type %s size=%d", t, len(data))
					if img, ok := tryDecode(data); ok {
						// save debug
						_ = os.MkdirAll("qr_debug", 0o755)
						fn := filepath.Join("qr_debug", fmt.Sprintf("clip_raw_%d.png", time.Now().UnixNano()))
						if f, e := os.Create(fn); e == nil {
							_ = png.Encode(f, img)
							f.Close()
							log.Printf("[clip] saved %s", fn)
						}
						return img, nil
					}
				}
			}
		}
		if data, err := exec.Command("wl-paste").Output(); err == nil {
			log.Printf("[clip] generic wl-paste size=%d", len(data))
			if img, ok := tryDecode(data); ok {
				return img, nil
			}
		}
	}
	if has("xclip") {
		for _, m := range []string{"image/png", "image/jpeg", "image/jpg", "image/bmp"} {
			if data, err := exec.Command("xclip", "-selection", "clipboard", "-t", m, "-o").Output(); err == nil {
				log.Printf("[clip] xclip type %s size=%d", m, len(data))
				if img, ok := tryDecode(data); ok {
					return img, nil
				}
			}
		}
		if data, err := exec.Command("xclip", "-selection", "clipboard", "-o").Output(); err == nil {
			log.Printf("[clip] xclip raw size=%d", len(data))
			if img, ok := tryDecode(data); ok {
				return img, nil
			}
		}
	}
	return nil, errors.New("nenalezen žádný obrázek ve schránce")
}

// Identity tab
func buildIdentityTab(parts *uiParts, svc ServiceFacade, vaultPath string) fyne.CanvasObject {
	// Toolbar: choose what to encode into the QR to keep density manageable
	mode := "combined" // combined, cert, pub
	chooser := widget.NewSelect([]string{"Veřejný+Cert", "Jen Cert", "Jen Veřejný"}, func(string) {})
	chooser.Selected = "Veřejný+Cert"
	var update func()
	chooser.OnChanged = func(v string) {
		switch v {
		case "Jen Cert":
			mode = "cert"
		case "Jen Veřejný":
			mode = "pub"
		default:
			mode = "combined"
		}
		update()
	}
	deleteBtn := widget.NewButton("Smazat identitu", func() {
		pw := widget.NewPasswordEntry()
		form := widget.NewForm(widget.NewFormItem("Heslo", pw))
		warn := widget.NewLabel("Smazat vše?")
		d := dialog.NewCustomConfirm("Potvrdit smazání", "Smazat", "Zrušit", container.NewVBox(warn, form), func(ok bool) {
			if !ok {
				return
			}
			if _, err := encrypt.OpenEncryptedStore(vaultPath, pw.Text); err != nil {
				dialog.NewError(errors.New("neplatné heslo"), fyne.CurrentApp().Driver().AllWindows()[0]).Show()
				return
			}
			_ = os.Remove(vaultPath)
			fyne.CurrentApp().Quit()
		}, fyne.CurrentApp().Driver().AllWindows()[0])
		d.Resize(fyne.NewSize(420, 200))
		d.Show()
	})
	makeQR := func(data string, target *canvas.Image) {
		if data == "" {
			target.Image = nil
			target.Refresh()
			return
		}
		if b, err := GenerateQRPNG(data, 512); err == nil {
			if im, err2 := LoadPNG(b); err2 == nil {
				target.Image = im
				target.Refresh()
			}
		}
	}
	update = func() {
		if parts.showQR {
			var text string
			switch mode {
			case "cert":
				text = strings.TrimSpace(svc.PublicCert())
			case "pub":
				text = strings.TrimSpace(svc.PublicPEM())
			default:
				text = strings.TrimSpace(svc.PublicPEM() + "\n" + svc.PublicCert())
			}
			makeQR(text, parts.pubQR)
			// debug save for comparison
			if parts.pubQR.Image != nil {
				_ = os.MkdirAll("qr_debug", 0o755)
				if f, e := os.Create(filepath.Join("qr_debug", "identity_current.png")); e == nil {
					png.Encode(f, parts.pubQR.Image)
					f.Close()
				}
			}
		} else {
			parts.pubQR.Image = nil
			parts.pubQR.Refresh()
		}
	}
	update()
	box := container.NewVBox(container.NewHBox(widget.NewLabel("QR obsah:"), chooser, layout.NewSpacer(), widget.NewButtonWithIcon("Kopírovat jako obrázek", theme.ContentPasteIcon(), func() { copyImageToClipboard(parts.pubQR.Image, parts) })), parts.pubQR)
	return container.NewVScroll(container.NewVBox(container.NewHBox(widget.NewLabelWithStyle("Moje identita", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}), layout.NewSpacer()), box, deleteBtn))
}

// Decrypt tab
func buildDecryptTab(parts *uiParts, svc ServiceFacade) fyne.CanvasObject {
	parts.plainOut.Disable()
	parts.payload.Disable()
	parts.payload.SetPlaceHolder("Cyphertext se načte po vložení QR kódu…")
	parts.payload.OnChanged = nil
	parts.payloadQR.FillMode = canvas.ImageFillContain
	parts.payloadQR.SetMinSize(fyne.NewSize(260, 260))

	decrypt := func(text string) {
		trimmed := strings.TrimSpace(text)
		if trimmed == "" {
			parts.plainOut.SetText("")
			return
		}
		go func(j string) {
			res, err := svc.Decrypt(j)
			if err != nil {
				fyne.Do(func() {
					parts.plainOut.SetText("")
					parts.showToast("Chyba dešifrování")
				})
				return
			}
			fyne.Do(func() { parts.plainOut.SetText(res) })
		}(trimmed)
	}

	setPayload := func(cipher string, img image.Image) {
		parts.payload.SetText(cipher)
		parts.payloadQR.Image = img
		parts.payloadQR.Refresh()
		decrypt(cipher)
	}

	decodeFromImage := func(img image.Image) {
		if img == nil {
			parts.showToast("Žádný QR obrázek")
			return
		}
		txt, err := DecodeQR(img)
		if err != nil {
			bounds := img.Bounds()
			inv := image.NewRGBA(bounds)
			for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
				for x := bounds.Min.X; x < bounds.Max.X; x++ {
					r, g, b, a := img.At(x, y).RGBA()
					inv.Set(x, y, color.RGBA{uint8(255 - r/257), uint8(255 - g/257), uint8(255 - b/257), uint8(a / 257)})
				}
			}
			if txt2, err2 := DecodeQR(inv); err2 == nil {
				setPayload(txt2, img)
				parts.showToast("Načteno z invert QR")
				return
			}
			parts.showToast("QR nenalezen: " + err.Error())
			return
		}
		setPayload(txt, img)
		parts.showToast("Načteno z QR")
	}

	pasteQRBtn := widget.NewButtonWithIcon("Vložit ze schránky", theme.ContentPasteIcon(), func() {
		img, err := readImageClipboard()
		if err != nil {
			parts.showToast("Chyba schránky: " + err.Error())
			return
		}
		decodeFromImage(img)
	})

	openQRBtn := widget.NewButtonWithIcon("Otevřít obrázek", theme.FolderOpenIcon(), func() {
		win := fyne.CurrentApp().Driver().AllWindows()[0]
		fd := dialog.NewFileOpen(func(rc fyne.URIReadCloser, err error) {
			if err != nil || rc == nil {
				return
			}
			defer rc.Close()
			data, readErr := io.ReadAll(rc)
			if readErr != nil {
				parts.showToast("Chyba čtení souboru")
				return
			}
			img, _, decErr := image.Decode(bytes.NewReader(data))
			if decErr != nil {
				parts.showToast("Neplatný obrázek: " + decErr.Error())
				return
			}
			decodeFromImage(img)
		}, win)
		fd.SetFilter(storage.NewExtensionFileFilter([]string{".png", ".jpg", ".jpeg"}))
		fd.Show()
	})

	copyPayloadBtn := widget.NewButtonWithIcon("Kopírovat payload", theme.ContentCopyIcon(), func() {
		if parts.payload.Text == "" {
			return
		}
		copyClip(parts.payload.Text, parts)
	})

	clearBtn := widget.NewButtonWithIcon("Vymazat", theme.ContentClearIcon(), func() {
		parts.payload.SetText("")
		parts.payloadQR.Image = nil
		parts.payloadQR.Refresh()
		parts.plainOut.SetText("")
		parts.showToast("Vymazáno")
	})

	toolbar := container.NewHBox(pasteQRBtn, openQRBtn, copyPayloadBtn, clearBtn, layout.NewSpacer())

	return container.NewVBox(
		widget.NewLabelWithStyle("Dešifrování", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
		toolbar,
		container.NewHBox(parts.payloadQR, layout.NewSpacer()),
		widget.NewLabel("Payload"),
		parts.payload,
		widget.NewLabel("Výsledek"),
		parts.plainOut,
	)
}

// Per-contact encryption popup (QR-only output)
func openEncryptPopup(parts *uiParts, svc ServiceFacade, ct Contact) {
	msgEntry := widget.NewMultiLineEntry()
	msgEntry.SetMinRowsVisible(6)
	msgEntry.Wrapping = fyne.TextWrapWord
	status := widget.NewLabel("Zadej zprávu…")
	qrImg := canvas.NewImageFromImage(nil)
	qrImg.FillMode = canvas.ImageFillContain
	qrImg.SetMinSize(fyne.NewSize(300, 300))
	updateQR := func(text string) {
		if strings.TrimSpace(text) == "" {
			qrImg.Image = nil
			qrImg.Refresh()
			return
		}
		if b, err := GenerateQRPNG(text, 512); err == nil {
			if im, err2 := LoadPNG(b); err2 == nil {
				qrImg.Image = im
				qrImg.Refresh()
			}
		}
	}
	win := fyne.CurrentApp().Driver().AllWindows()[0]
	lastCipher := ""
	doEncrypt := func() {
		m := strings.TrimSpace(msgEntry.Text)
		fyne.Do(func() {
			if m == "" {
				status.SetText("Zpráva je prázdná")
				lastCipher = ""
				updateQR("")
				return
			}
			status.SetText("Šifruji…")
		})
		if m == "" {
			return
		}
		go func(txt string) {
			res, err := svc.Encrypt(txt, ct.Cert)
			if err != nil {
				fyne.Do(func() { status.SetText("Chyba: " + err.Error()) })
				return
			}
			fyne.Do(func() { lastCipher = res; updateQR(res); status.SetText("Hotovo") })
		}(m)
	}
	var tmr *time.Timer
	msgEntry.OnChanged = func(string) {
		if tmr != nil {
			tmr.Stop()
		}
		tmr = time.AfterFunc(300*time.Millisecond, doEncrypt)
	}
	copyPayloadBtn := widget.NewButton("Kopírovat payload", func() {
		if lastCipher != "" {
			copyClip(lastCipher, parts)
			status.SetText("Zkopírováno")
		}
	})
	copyQRBtn := widget.NewButton("Kopírovat QR", func() { copyImageToClipboard(qrImg.Image, parts) })
	saveQRBtn := widget.NewButton("Uložit QR", func() {
		if qrImg.Image == nil {
			return
		}
		img := qrImg.Image
		fd := dialog.NewFileSave(func(wc fyne.URIWriteCloser, err error) {
			if err != nil || wc == nil {
				return
			}
			defer wc.Close()
			_ = png.Encode(wc, img)
			status.SetText("QR uložen")
		}, win)
		fd.SetFileName("message_qr.png")
		fd.Show()
	})
	content := container.NewVBox(widget.NewLabel("Zpráva"), msgEntry, widget.NewSeparator(), container.NewHBox(widget.NewLabel("QR kód"), layout.NewSpacer(), copyPayloadBtn, copyQRBtn, saveQRBtn), qrImg, status)
	title := ct.Name
	if title == "" {
		title = "(bez názvu)"
	}
	if cn := extractCN(ct.Cert); cn != "" && !strings.Contains(title, cn) {
		title = fmt.Sprintf("%s (%s)", title, cn)
	}
	dlg := dialog.NewCustom(fmt.Sprintf("Poslat zprávu: %s", title), "Zavřít", content, win)
	dlg.Resize(fyne.NewSize(640, 520))
	dlg.Show()
}

// Contacts tab with QR-only popup
func buildContactsTab(parts *uiParts, svc ServiceFacade) fyne.CanvasObject {
	var all, filtered []Contact
	load := func() { items, _ := svc.ListContacts(); all = items; filtered = items }
	apply := func(q string) {
		if q == "" {
			filtered = all
			return
		}
		low := strings.ToLower(q)
		tmp := make([]Contact, 0, len(all))
		for _, c := range all {
			if strings.Contains(strings.ToLower(c.Name), low) || strings.Contains(strings.ToLower(c.Cert), low) {
				tmp = append(tmp, c)
			}
		}
		filtered = tmp
	}
	makeDefault := func() string {
		base := "Nový kontakt"
		exists := false
		maxN := 1
		for _, c := range all {
			if c.Name == base {
				exists = true
			}
			if strings.HasPrefix(c.Name, base+" ") {
				var n int
				if _, err := fmt.Sscanf(c.Name, "Nový kontakt %d", &n); err == nil && n >= maxN {
					maxN = n + 1
				}
			}
		}
		if !exists {
			return base
		}
		return fmt.Sprintf("%s %d", base, maxN)
	}
	search := widget.NewEntry()
	var list *widget.List
	openPopup := func(existing *Contact) {
		nameEntry := widget.NewEntry()
		if existing != nil {
			nameEntry.SetText(existing.Name)
		} else {
			nameEntry.SetText(makeDefault())
		}
		var certValue string
		if existing != nil {
			certValue = existing.Cert
		}
		manualEntry := widget.NewMultiLineEntry()
		manualEntry.SetMinRowsVisible(4)
		manualEntry.Wrapping = fyne.TextWrapWord
		manualEntry.SetPlaceHolder("Sem lze vložit text PEM pokud QR selže…")
		if certValue != "" {
			manualEntry.SetText(certValue)
		}
		qrImg := canvas.NewImageFromImage(nil)
		qrImg.FillMode = canvas.ImageFillContain
		qrImg.SetMinSize(fyne.NewSize(300, 300))
		updateQR := func() {
			if strings.TrimSpace(certValue) == "" {
				qrImg.Image = nil
				qrImg.Refresh()
				return
			}
			if b, err := GenerateQRPNG(certValue, 512); err == nil {
				if im, err2 := LoadPNG(b); err2 == nil {
					qrImg.Image = im
					qrImg.Refresh()
				}
			}
		}
		updateQR()
		// now that updateQR exists, bind manualEntry changes
		manualEntry.OnChanged = func(s string) {
			certValue = s
			updateQR()
		}
		pasteText := widget.NewToolbarAction(theme.ContentPasteIcon(), func() {
			clip := fyne.CurrentApp().Clipboard().Content()
			if strings.TrimSpace(clip) == "" {
				parts.showToast("Schránka prázdná")
				return
			}
			certValue = clip
			manualEntry.SetText(certValue)
			updateQR()
			parts.showToast("Vloženo")
		})
		pasteQR := widget.NewToolbarAction(theme.ComputerIcon(), func() {
			img, err := readImageClipboard()
			if err != nil {
				parts.showToast("Chyba čtení schránky: " + err.Error())
				return
			}
			if img == nil {
				parts.showToast("Žádný QR obrázek")
				return
			}

			txt, decErr := DecodeQR(img)
			if decErr != nil {
				bounds := img.Bounds()
				inv := image.NewRGBA(bounds)
				for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
					for x := bounds.Min.X; x < bounds.Max.X; x++ {
						r, g, b, a := img.At(x, y).RGBA()
						inv.Set(x, y, color.RGBA{uint8(255 - r/257), uint8(255 - g/257), uint8(255 - b/257), uint8(a / 257)})
					}
				}
				if txt2, err2 := DecodeQR(inv); err2 == nil {
					certValue = txt2
					manualEntry.SetText(certValue)
					updateQR()
					parts.showToast("Načteno z invert QR")
					return
				}
				debugDir := "qr_debug"
				_ = os.MkdirAll(debugDir, 0o755)
				fp := filepath.Join(debugDir, fmt.Sprintf("qr_clip_%d.png", time.Now().UnixNano()))
				if f, e := os.Create(fp); e == nil {
					_ = png.Encode(f, img)
					_ = f.Close()
					parts.showToast("QR nenalezen: " + decErr.Error() + " (" + fp + ")")
				} else {
					parts.showToast("QR nenalezen: " + decErr.Error())
				}
				return
			}
			certValue = txt
			manualEntry.SetText(certValue)
			updateQR()
			parts.showToast("Načteno z QR")
		})
		openImg := widget.NewToolbarAction(theme.FolderOpenIcon(), func() {
			win := fyne.CurrentApp().Driver().AllWindows()[0]
			fd := dialog.NewFileOpen(func(rc fyne.URIReadCloser, err error) {
				if err != nil || rc == nil {
					return
				}
				defer rc.Close()
				data, _ := io.ReadAll(rc)
				img, _, e2 := image.Decode(bytes.NewReader(data))
				if e2 != nil {
					parts.showToast("Neplatný obrázek: " + e2.Error())
					return
				}

				txt, e3 := DecodeQR(img)
				if e3 != nil {
					parts.showToast("QR nenalezeno: " + e3.Error())
					return
				}
				certValue = txt
				manualEntry.SetText(certValue)
				updateQR()
				parts.showToast("Načteno z QR")
			}, win)
			fd.SetFilter(storage.NewExtensionFileFilter([]string{".png", ".jpg", ".jpeg"}))
			fd.Show()
		})
		clearAct := widget.NewToolbarAction(theme.ContentClearIcon(), func() { certValue = ""; manualEntry.SetText(""); updateQR() })
		copyAct := widget.NewToolbarAction(theme.ContentCopyIcon(), func() {
			if certValue != "" {
				copyClip(certValue, parts)
			}
		})
		saveAct := widget.NewToolbarAction(theme.DocumentSaveIcon(), func() {
			if qrImg.Image == nil {
				return
			}
			win := fyne.CurrentApp().Driver().AllWindows()[0]
			img := qrImg.Image
			fd := dialog.NewFileSave(func(wc fyne.URIWriteCloser, err error) {
				if err != nil || wc == nil {
					return
				}
				defer wc.Close()
				_ = png.Encode(wc, img)
				parts.showToast("QR uložen")
			}, win)
			fd.SetFileName("contact_qr.png")
			fd.Show()
		})
		toolbar := widget.NewToolbar(pasteText, pasteQR, openImg, widget.NewToolbarSeparator(), copyAct, saveAct, clearAct)
		win := fyne.CurrentApp().Driver().AllWindows()[0]
		var popup dialog.Dialog
		save := func(useEncrypt bool) {
			name := strings.TrimSpace(nameEntry.Text)
			cert := strings.TrimSpace(certValue)
			if cert == "" {
				parts.showToast("Chybí cert")
				return
			}
			cn := extractCN(cert)
			ask := cn != "" && (name == "" || name == "Kontakt" || name == "Nový kontakt" || name != cn)
			proceed := func(final string) {
				if final == "" || final == "Kontakt" || final == "Nový kontakt" {
					final = makeDefault()
				}
				if existing == nil {
					_ = svc.SaveContact(Contact{Name: final, Cert: cert})
				} else {
					c := *existing
					c.Name = final
					c.Cert = cert
					_ = svc.SaveContact(c)
				}
				load()
				apply(strings.TrimSpace(search.Text))
				list.Refresh()
				parts.showToast("Uloženo")
				if useEncrypt {
					parts.peer.SetText(cert)
				}
				if popup != nil {
					popup.Hide()
				}
			}
			if ask {
				dialog.NewCustomConfirm("Common Name", "Použít", "Ponechat", widget.NewLabel(fmt.Sprintf("Common Name: %s\nPoužít jako název?", cn)), func(ok bool) {
					if ok {
						proceed(cn)
					} else {
						proceed(name)
					}
				}, win).Show()
				return
			}
			proceed(name)
		}
		delBtn := widget.NewButtonWithIcon("Smazat", theme.DeleteIcon(), func() {
			if existing == nil {
				popup.Hide()
				return
			}
			dialog.NewConfirm("Smazat", "Opravdu smazat?", func(ok bool) {
				if !ok {
					return
				}
				_ = svc.DeleteContact(existing.ID)
				load()
				apply(strings.TrimSpace(search.Text))
				list.Refresh()
				popup.Hide()
				parts.showToast("Smazáno")
			}, win).Show()
		})
		useBtn := widget.NewButton("Použít ve Šifrování", func() { save(true) })
		saveBtn := widget.NewButton("Uložit", func() { save(false) })
		row := container.NewHBox(saveBtn, useBtn, layout.NewSpacer(), delBtn)
		title := "Nový kontakt"
		if existing != nil {
			title = "Upravit kontakt"
		}
		// manual entry area below QR for fallback or direct edit
		popup = dialog.NewCustom(title, "Zavřít", container.NewVBox(
			widget.NewLabel("Název"), nameEntry,
			widget.NewLabel("Certifikát / Public key (QR)"), toolbar, qrImg,
			widget.NewLabel("Text PEM"), manualEntry,
			widget.NewSeparator(), row), win)
		popup.Resize(fyne.NewSize(640, 520))
		popup.Show()
	}
	list = widget.NewList(func() int { return len(filtered) }, func() fyne.CanvasObject {
		lbl := widget.NewLabel("")
		msg := widget.NewButton("Zpráva", nil)
		edit := widget.NewButton("Upravit", nil)
		msg.Importance = widget.LowImportance
		edit.Importance = widget.LowImportance
		return container.NewBorder(nil, nil, lbl, container.NewHBox(msg, edit))
	}, func(i widget.ListItemID, o fyne.CanvasObject) {
		if int(i) < 0 || int(i) >= len(filtered) {
			return
		}
		c := filtered[i]
		row := o.(*fyne.Container)
		lbl := row.Objects[0].(*widget.Label)
		btnBox := row.Objects[1].(*fyne.Container)
		msgBtn := btnBox.Objects[0].(*widget.Button)
		editBtn := btnBox.Objects[1].(*widget.Button)
		name := c.Name
		if name == "" {
			name = "(bez názvu)"
		}
		if cn := extractCN(c.Cert); cn != "" {
			lbl.SetText(fmt.Sprintf("%s (%s)", name, cn))
		} else {
			lbl.SetText(name)
		}
		msgBtn.OnTapped = func() { openEncryptPopup(parts, svc, c) }
		editBtn.OnTapped = func() {
			var ptr *Contact
			for i := range all {
				if all[i].ID == c.ID {
					ptr = &all[i]
					break
				}
			}
			openPopup(ptr)
		}
	})
	search.SetPlaceHolder("Hledat…")
	search.OnChanged = func(s string) { apply(s); list.Refresh() }
	addBtn := widget.NewButtonWithIcon("Přidat", theme.ContentAddIcon(), func() { openPopup(nil) })
	header := container.NewHBox(widget.NewLabelWithStyle("Kontakty", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}), layout.NewSpacer(), addBtn)
	load()
	list.Refresh()
	return container.NewBorder(header, nil, nil, nil, container.NewBorder(search, nil, nil, nil, list))
}

func buildTabbedUI(parts *uiParts, svc ServiceFacade, vaultPath string) fyne.CanvasObject {
	tabs := container.NewAppTabs(
		container.NewTabItem("Identita", buildIdentityTab(parts, svc, vaultPath)),
		container.NewTabItem("Kontakty", buildContactsTab(parts, svc)),
		container.NewTabItem("Dešifrování", buildDecryptTab(parts, svc)),
	)
	fyne.CurrentApp().Settings().SetTheme(simpleTheme{})
	return container.NewBorder(nil, parts.toastLabel, nil, nil, tabs)
}