package main

import (
	"crypto/rsa"
	encrypt "fckeuspy-go/lib"
	"html/template"
	"log"
	"net/http"
	"time"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/dialog"
	"fyne.io/fyne/v2/layout"
	"fyne.io/fyne/v2/widget"
)

var (
	priv    *rsa.PrivateKey
	pubPEM  []byte
	certPEM []byte // self-signed cert jen pro sdílení identity (volitelné)
	tmpl    *template.Template

	privPath = "identity_key.pem"
	pubPath  = "public.pem"
	certPath = "identity.crt"
)

type envelope struct {
	// Encrypted AES key, Nonce, Ciphertext (GCM)
	EK string `json:"ek"` // base64(RSA-OAEP(aesKey))
	N  string `json:"n"`  // base64(nonce 12B)
	CT string `json:"ct"` // base64(GCM(ciphertext||tag))
}

func main() {
	var (
		err error
		svc *encrypt.Service
	)

	storageDir, w := NewUI()

	// 2) inicializuj šifrovací službu
	svc, err = encrypt.NewService(storageDir)
	if err != nil {
		log.Fatal(err)
	}

	// Toast (stavový pruh)
	toast := widget.NewLabel("")
	toast.Hide()
	showToast := func(msg string) {
		toast.SetText(msg)
		toast.Show()
		time.AfterFunc(1200*time.Millisecond, func() { toast.SetText(""); toast.Hide() })
	}

	// Helpers
	copyToClipboard := func(s string) { w.Clipboard().SetContent(s); showToast("Zkopírováno") }
	/* setErr := func(e error) {
		if e != nil {
			dialog.ShowError(e, w)
		}
	}
	*/

	outKey := widget.NewMultiLineEntry()
	cipherOut := widget.NewMultiLineEntry()
	// cipherOut.SetReadOnly(true)
	plainOut := widget.NewMultiLineEntry()
	// plainOut.SetReadOnly(true)
	// toastLbl := widget.NewLabelWithData(toastB)

	// Widgets
	outKey = widget.NewMultiLineEntry()
	outKey.SetPlaceHolder("Veřejný klíč / certifikát…")
	msg := widget.NewMultiLineEntry()
	msg.SetPlaceHolder("Sem napiš zprávu…")
	peer := widget.NewMultiLineEntry()
	peer.SetPlaceHolder("-----BEGIN PUBLIC KEY----- … nebo CERTIFICATE …")
	cipherOut = widget.NewMultiLineEntry()
	cipherOut.SetPlaceHolder(`{"ek":"…","n":"…","ct":"…"}`)
	// cipherOut.SetReadOnly(true)
	payload := widget.NewMultiLineEntry()
	payload.SetPlaceHolder(`{"ek":"…","n":"…","ct":"…"}`)
	plainOut = widget.NewMultiLineEntry()
	plainOut.SetPlaceHolder("Dešifrovaná zpráva…")
	// plainOut.SetReadOnly(true)

	// Sekce: Můj veřejný klíč
	btnShowPub := widget.NewButton("Zobrazit public.pem", func() { outKey.SetText(svc.PublicPEM()) })
	btnShowCrt := widget.NewButton("Zobrazit identity.crt", func() { outKey.SetText(svc.PublicCert()) })
	btnCopyOut := widget.NewButton("Copy", func() { copyToClipboard(outKey.Text) })
	btnClearOut := widget.NewButton("Clear", func() { outKey.SetText("") })

	myKeyCard := container.NewVBox(
		widget.NewLabelWithStyle("Můj veřejný klíč", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
		container.New(layout.NewGridLayout(4), btnShowPub, btnShowCrt, btnCopyOut, btnClearOut),
		outKey,
	)

	// Sekce: Šifrovat
	btnEnc := widget.NewButton("Encrypt", func() {
		m := msg.Text
		p := peer.Text
		if m == "" {
			dialog.ShowInformation("Info", "Zpráva nesmí být prázdná.", w)
			return
		}
		if p == "" {
			dialog.ShowInformation("Info", "Vlož veřejný klíč (PEM) nebo certifikát (CERT).", w)
			return
		}
		go func() {
			res, err := svc.Encrypt(m, p)
			if err != nil {
				cipherOut.SetText("")
				toast.SetText("Chyba: " + err.Error())
				toast.Show()
				return
			}
			cipherOut.SetText(res)
			showToast("Zašifrováno")
		}()
	})
	btnCopyCipher := widget.NewButton("Copy", func() { copyToClipboard(cipherOut.Text) })

	encCard := container.NewVBox(
		widget.NewLabelWithStyle("Šifrovat pro cizí klíč", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
		widget.NewLabel("Zpráva"), msg,
		widget.NewLabel("Veřejný klíč příjemce (PEM nebo CERT)"), peer,
		container.New(layout.NewGridLayout(2), btnEnc, btnCopyCipher),
		cipherOut,
	)

	// Sekce: Dešifrovat
	btnDec := widget.NewButton("Decrypt", func() {
		pl := payload.Text
		if pl == "" {
			dialog.ShowInformation("Info", "Vlož JSON payload k dešifrování.", w)
			return
		}
		go func() {
			res, err := svc.Decrypt(pl)
			if err != nil {
				plainOut.SetText("")
				toast.SetText("Chyba: " + err.Error())
				toast.Show()
				return
			}
			plainOut.SetText(res)
			showToast("Dešifrováno")
		}()
	})
	btnCopyPlain := widget.NewButton("Copy", func() { copyToClipboard(plainOut.Text) })
	btnClearPayload := widget.NewButton("Clear payload", func() { payload.SetText("") })

	decCard := container.NewVBox(
		widget.NewLabelWithStyle("Dešifrovat", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
		widget.NewLabel("Payload (JSON envelope)"), payload,
		container.New(layout.NewGridLayout(3), btnDec, btnCopyPlain, btnClearPayload),
		plainOut,
	)

	left := container.NewVBox(myKeyCard, encCard)
	right := container.NewVBox(decCard)
	grid := container.New(layout.NewGridLayoutWithColumns(2), left, right)

	content := container.NewBorder(nil, toast, nil, nil, container.NewVScroll(grid))
	w.SetContent(content)
	w.ShowAndRun()
}

func RunWebApp() {
	var err error
	// 2) inicializuj šifrovací službu
	_, err = encrypt.NewService("")
	if err != nil {
		log.Fatal(err)
	}

	// 2) šablony
	tmpl = template.Must(template.ParseGlob("templates/*.html"))

	muxServer := NewServer()
	log.Fatal(http.ListenAndServe(":8080", muxServer))
}