package userHandlerTotpSetup

import (
	"bytes"
	"encoding/base64"
	"fmt"
	"github.com/a-h/templ"
	"github.com/fossyy/filekeeper/app"
	"github.com/fossyy/filekeeper/view/client/user/totp"
	"image/png"
	"net/http"
	"time"

	"github.com/fossyy/filekeeper/types"
	"github.com/skip2/go-qrcode"
	"github.com/xlzd/gotp"
)

func generateQRCode(uri string) (string, error) {
	qr, err := qrcode.New(uri, qrcode.Medium)
	if err != nil {
		return "", fmt.Errorf("failed to generate QR code: %w", err)
	}

	var buffer bytes.Buffer
	if err := png.Encode(&buffer, qr.Image(256)); err != nil {
		return "", fmt.Errorf("failed to encode QR code to PNG: %w", err)
	}

	return base64.StdEncoding.EncodeToString(buffer.Bytes()), nil
}

func GET(w http.ResponseWriter, r *http.Request) {
	secret := gotp.RandomSecret(16)
	userSession := r.Context().Value("user").(types.User)
	totp := gotp.NewDefaultTOTP(secret)
	uri := totp.ProvisioningUri(userSession.Email, "filekeeper")
	base64Str, err := generateQRCode(uri)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		app.Server.Logger.Error(err.Error())
		return
	}

	var component templ.Component
	if r.Header.Get("hx-request") == "true" {
		component = userTotpSetupView.MainContent("Filekeeper - 2FA Setup Page", base64Str, secret, userSession, types.Message{
			Code:    3,
			Message: "",
		})
	} else {
		component = userTotpSetupView.Main("Filekeeper - 2FA Setup Page", base64Str, secret, userSession, types.Message{
			Code:    3,
			Message: "",
		})
	}
	if err := component.Render(r.Context(), w); err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		app.Server.Logger.Error(err.Error())
		return
	}
}

func POST(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseForm(); err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		app.Server.Logger.Error(err.Error())
		return
	}

	code := r.Form.Get("totp")
	secret := r.Form.Get("secret")
	totp := gotp.NewDefaultTOTP(secret)
	userSession := r.Context().Value("user").(types.User)
	uri := totp.ProvisioningUri(userSession.Email, "filekeeper")

	base64Str, err := generateQRCode(uri)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		app.Server.Logger.Error(err.Error())
		return
	}
	var component templ.Component
	if totp.Verify(code, time.Now().Unix()) {
		encryptedSecret, err := app.Server.Encryption.Encrypt(secret)
		if err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			app.Server.Logger.Error(err.Error())
			return
		}
		if err := app.Server.Database.InitializeTotp(userSession.Email, encryptedSecret); err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			app.Server.Logger.Error(err.Error())
			return
		}
		err = app.Server.Cache.RemoveUserCache(r.Context(), userSession.Email)
		if err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			app.Server.Logger.Error(err.Error())
			return
		}
		if r.Header.Get("hx-request") == "true" {
			component = userTotpSetupView.MainContent("Filekeeper - 2FA Setup Page", base64Str, secret, userSession, types.Message{
				Code:    1,
				Message: "Your TOTP setup is complete! Your account is now more secure.",
			})
		} else {
			component = userTotpSetupView.Main("Filekeeper - 2FA Setup Page", base64Str, secret, userSession, types.Message{
				Code:    1,
				Message: "Your TOTP setup is complete! Your account is now more secure.",
			})
		}

		if err := component.Render(r.Context(), w); err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			app.Server.Logger.Error(err.Error())
			return
		}
		return
	} else {
		if r.Header.Get("hx-request") == "true" {
			component = userTotpSetupView.MainContent("Filekeeper - 2FA Setup Page", base64Str, secret, userSession, types.Message{
				Code:    0,
				Message: "The code you entered is incorrect. Please double-check the code and try again.",
			})
		} else {
			component = userTotpSetupView.Main("Filekeeper - 2FA Setup Page", base64Str, secret, userSession, types.Message{
				Code:    0,
				Message: "The code you entered is incorrect. Please double-check the code and try again.",
			})
		}
		if err := component.Render(r.Context(), w); err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			app.Server.Logger.Error(err.Error())
			return
		}
		return
	}
}